window.cpp

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/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */
 
#include "stdafx.h"
#include "company_func.h"
#include "gfx_func.h"
#include "console_func.h"
#include "console_gui.h"
#include "viewport_func.h"
#include "progress.h"
#include "blitter/factory.hpp"
#include "zoom_func.h"
#include "vehicle_base.h"
#include "depot_func.h"
#include "window_func.h"
#include "tilehighlight_func.h"
#include "network/network.h"
#include "querystring_gui.h"
#include "strings_func.h"
#include "settings_type.h"
#include "settings_func.h"
#include "ini_type.h"
#include "newgrf_debug.h"
#include "hotkeys.h"
#include "toolbar_gui.h"
#include "statusbar_gui.h"
#include "error.h"
#include "game/game.hpp"
#include "video/video_driver.hpp"
#include "framerate_type.h"
#include "network/network_func.h"
#include "news_func.h"
#include "sound_func.h"
#include "timer/timer.h"
#include "timer/timer_window.h"
 
#include "table/strings.h"
 
#include "safeguards.h"
 
enum ViewportAutoscrolling : uint8_t {
  VA_DISABLED,                  
  VA_MAIN_VIEWPORT_FULLSCREEN,  
  VA_MAIN_VIEWPORT,             
  VA_EVERY_VIEWPORT,            
};
enum ViewportAutoscrolling : uint8_t {…};
 
static Point _drag_delta; 
static Window *_mouseover_last_w = nullptr; 
static Window *_last_scroll_window = nullptr; 
 
WindowList _z_windows;
 
/* static */ std::vector<Window *> Window::closed_windows;
 
/* static */ void Window::DeleteClosedWindows()
{
  for (Window *w : Window::closed_windows) delete w;
  Window::closed_windows.clear();
 
  /* Remove dead entries from the window list */
  _z_windows.remove(nullptr);
}
/* static */ void Window::DeleteClosedWindows() {…}
 
bool _window_highlight_colour = false;
 
/*
 * Window that currently has focus. - The main purpose is to generate
 * #FocusLost events, not to give next window in z-order focus when a
 * window is closed.
 */
Window *_focused_window;
 
Point _cursorpos_drag_start;
 
int _scrollbar_start_pos;
int _scrollbar_size;
uint8_t _scroller_click_timeout = 0;
 
bool _scrolling_viewport;  
bool _mouse_hovering;      
 
SpecialMouseMode _special_mouse_mode; 
 
std::vector<WindowDesc*> *_window_descs = nullptr;
 
std::string _windows_file;
 
WindowDesc::WindowDesc(WindowPosition def_pos, std::string_view ini_key, int16_t def_width_trad, int16_t def_height_trad,
      WindowClass window_class, WindowClass parent_class, WindowDefaultFlags flags,
      const std::span<const NWidgetPart> nwid_parts, HotkeyList *hotkeys,
      const std::source_location location) :
  source_location(location),
  default_pos(def_pos),
  cls(window_class),
  parent_cls(parent_class),
  ini_key(ini_key),
  flags(flags),
  nwid_parts(nwid_parts),
  hotkeys(hotkeys),
  default_width_trad(def_width_trad),
  default_height_trad(def_height_trad)
{
  if (_window_descs == nullptr) _window_descs = new std::vector<WindowDesc*>();
  _window_descs->push_back(this);
}
WindowDesc::WindowDesc(WindowPosition def_pos, std::string_view ini_key, int16_t def_width_trad, int16_t def_height_trad, {…}
 
WindowDesc::~WindowDesc()
{
  _window_descs->erase(std::ranges::find(*_window_descs, this));
}
 
int16_t WindowDesc::GetDefaultWidth() const
{
  return this->pref_width != 0 ? this->pref_width : ScaleGUITrad(this->default_width_trad);
}
int16_t WindowDesc::GetDefaultWidth() const {…}
 
int16_t WindowDesc::GetDefaultHeight() const
{
  return this->pref_height != 0 ? this->pref_height : ScaleGUITrad(this->default_height_trad);
}
int16_t WindowDesc::GetDefaultHeight() const {…}
 
void WindowDesc::LoadFromConfig()
{
  IniFile ini;
  ini.LoadFromDisk(_windows_file, NO_DIRECTORY);
  for (WindowDesc *wd : *_window_descs) {
    if (wd->ini_key.empty()) continue;
    IniLoadWindowSettings(ini, wd->ini_key, wd);
  }
}
void WindowDesc::LoadFromConfig() {…}
 
static bool DescSorter(WindowDesc * const &a, WindowDesc * const &b)
{
  return a->ini_key < b->ini_key;
}
static bool DescSorter(WindowDesc * const &a, WindowDesc * const &b) {…}
 
void WindowDesc::SaveToConfig()
{
  /* Sort the stuff to get a nice ini file on first write */
  std::sort(_window_descs->begin(), _window_descs->end(), DescSorter);
 
  IniFile ini;
  ini.LoadFromDisk(_windows_file, NO_DIRECTORY);
  for (WindowDesc *wd : *_window_descs) {
    if (wd->ini_key.empty()) continue;
    IniSaveWindowSettings(ini, wd->ini_key, wd);
  }
  ini.SaveToDisk(_windows_file);
}
void WindowDesc::SaveToConfig() {…}
 
void Window::ApplyDefaults()
{
  if (this->nested_root != nullptr && this->nested_root->GetWidgetOfType(WWT_STICKYBOX) != nullptr) {
    if (this->window_desc.pref_sticky) this->flags.Set(WindowFlag::Sticky);
  } else {
    /* There is no stickybox; clear the preference in case someone tried to be funny */
    this->window_desc.pref_sticky = false;
  }
}
void Window::ApplyDefaults() {…}
 
int Window::GetRowFromWidget(int clickpos, WidgetID widget, int padding, int line_height) const
{
  const NWidgetBase *wid = this->GetWidget<NWidgetBase>(widget);
  if (line_height < 0) line_height = wid->resize_y;
  if (clickpos < wid->pos_y + padding) return INT_MAX;
  return (clickpos - wid->pos_y - padding) / line_height;
}
int Window::GetRowFromWidget(int clickpos, WidgetID widget, int padding, int line_height) const {…}
 
void Window::DisableAllWidgetHighlight()
{
  for (auto &pair : this->widget_lookup) {
    NWidgetBase *nwid = pair.second;
    if (nwid->IsHighlighted()) {
      nwid->SetHighlighted(TC_INVALID);
      nwid->SetDirty(this);
    }
  }
 
  this->flags.Reset(WindowFlag::Highlighted);
}
void Window::DisableAllWidgetHighlight() {…}
 
void Window::SetWidgetHighlight(WidgetID widget_index, TextColour highlighted_colour)
{
  NWidgetBase *nwid = this->GetWidget<NWidgetBase>(widget_index);
  if (nwid == nullptr) return;
 
  nwid->SetHighlighted(highlighted_colour);
  nwid->SetDirty(this);
 
  if (highlighted_colour != TC_INVALID) {
    /* If we set a highlight, the window has a highlight */
    this->flags.Set(WindowFlag::Highlighted);
  } else {
    /* If we disable a highlight, check all widgets if anyone still has a highlight */
    bool valid = false;
    for (const auto &pair : this->widget_lookup) {
      nwid = pair.second;
      if (!nwid->IsHighlighted()) continue;
 
      valid = true;
    }
    /* If nobody has a highlight, disable the flag on the window */
    if (!valid) this->flags.Reset(WindowFlag::Highlighted);
  }
}
void Window::SetWidgetHighlight(WidgetID widget_index, TextColour highlighted_colour) {…}
 
bool Window::IsWidgetHighlighted(WidgetID widget_index) const
{
  const NWidgetBase *nwid = this->GetWidget<NWidgetBase>(widget_index);
  if (nwid == nullptr) return false;
 
  return nwid->IsHighlighted();
}
bool Window::IsWidgetHighlighted(WidgetID widget_index) const {…}
 
void Window::OnDropdownClose(Point pt, WidgetID widget, int index, int click_result, bool instant_close)
{
  if (widget < 0) return;
 
  if (instant_close) {
    /* Send event for selected option if we're still
     * on the parent button of the dropdown (behaviour of the dropdowns in the main toolbar). */
    if (GetWidgetFromPos(this, pt.x, pt.y) == widget) {
      this->OnDropdownSelect(widget, index, click_result);
    }
  }
 
  /* Raise the dropdown button */
  NWidgetCore *nwi2 = this->GetWidget<NWidgetCore>(widget);
  if ((nwi2->type & WWT_MASK) == NWID_BUTTON_DROPDOWN) {
    nwi2->disp_flags.Reset(NWidgetDisplayFlag::DropdownActive);
  } else {
    this->RaiseWidget(widget);
  }
  this->SetWidgetDirty(widget);
}
void Window::OnDropdownClose(Point pt, WidgetID widget, int index, int click_result, bool instant_close) {…}
 
const Scrollbar *Window::GetScrollbar(WidgetID widnum) const
{
  return this->GetWidget<NWidgetScrollbar>(widnum);
}
const Scrollbar *Window::GetScrollbar(WidgetID widnum) const {…}
 
Scrollbar *Window::GetScrollbar(WidgetID widnum)
{
  return this->GetWidget<NWidgetScrollbar>(widnum);
}
Scrollbar *Window::GetScrollbar(WidgetID widnum) {…}
 
const QueryString *Window::GetQueryString(WidgetID widnum) const
{
  auto query = this->querystrings.find(widnum);
  return query != this->querystrings.end() ? query->second : nullptr;
}
const QueryString *Window::GetQueryString(WidgetID widnum) const {…}
 
QueryString *Window::GetQueryString(WidgetID widnum)
{
  auto query = this->querystrings.find(widnum);
  return query != this->querystrings.end() ? query->second : nullptr;
}
QueryString *Window::GetQueryString(WidgetID widnum) {…}
 
void Window::UpdateQueryStringSize()
{
  for (auto &qs : this->querystrings) {
    qs.second->text.UpdateSize();
  }
}
void Window::UpdateQueryStringSize() {…}
 
/* virtual */ const Textbuf *Window::GetFocusedTextbuf() const
{
  if (this->nested_focus != nullptr && this->nested_focus->type == WWT_EDITBOX) {
    return &this->GetQueryString(this->nested_focus->GetIndex())->text;
  }
 
  return nullptr;
}
/* virtual */ const Textbuf *Window::GetFocusedTextbuf() const {…}
 
/* virtual */ Point Window::GetCaretPosition() const
{
  if (this->nested_focus != nullptr && this->nested_focus->type == WWT_EDITBOX && !this->querystrings.empty()) {
    return this->GetQueryString(this->nested_focus->GetIndex())->GetCaretPosition(this, this->nested_focus->GetIndex());
  }
 
  Point pt = {0, 0};
  return pt;
}
/* virtual */ Point Window::GetCaretPosition() const {…}
 
/* virtual */ Rect Window::GetTextBoundingRect(size_t from, size_t to) const
{
  if (this->nested_focus != nullptr && this->nested_focus->type == WWT_EDITBOX) {
    return this->GetQueryString(this->nested_focus->GetIndex())->GetBoundingRect(this, this->nested_focus->GetIndex(), from, to);
  }
 
  Rect r = {0, 0, 0, 0};
  return r;
}
/* virtual */ Rect Window::GetTextBoundingRect(size_t from, size_t to) const {…}
 
/* virtual */ ptrdiff_t Window::GetTextCharacterAtPosition(const Point &pt) const
{
  if (this->nested_focus != nullptr && this->nested_focus->type == WWT_EDITBOX) {
    return this->GetQueryString(this->nested_focus->GetIndex())->GetCharAtPosition(this, this->nested_focus->GetIndex(), pt);
  }
 
  return -1;
}
/* virtual */ ptrdiff_t Window::GetTextCharacterAtPosition(const Point &pt) const {…}
 
void SetFocusedWindow(Window *w)
{
  if (_focused_window == w) return;
 
  /* Don't focus a tooltip */
  if (w != nullptr && w->window_class == WC_TOOLTIPS) return;
 
  /* Invalidate focused widget */
  if (_focused_window != nullptr) {
    if (_focused_window->nested_focus != nullptr) _focused_window->nested_focus->SetDirty(_focused_window);
  }
 
  /* Remember which window was previously focused */
  Window *old_focused = _focused_window;
  _focused_window = w;
 
  /* So we can inform it that it lost focus */
  if (old_focused != nullptr) old_focused->OnFocusLost(false);
  if (_focused_window != nullptr) _focused_window->OnFocus();
}
void SetFocusedWindow(Window *w) {…}
 
bool EditBoxInGlobalFocus()
{
  if (_focused_window == nullptr) return false;
 
  /* The console does not have an edit box so a special case is needed. */
  if (_focused_window->window_class == WC_CONSOLE) return true;
 
  return _focused_window->nested_focus != nullptr && _focused_window->nested_focus->type == WWT_EDITBOX;
}
bool EditBoxInGlobalFocus() {…}
 
bool FocusedWindowIsConsole()
{
  return _focused_window && _focused_window->window_class == WC_CONSOLE;
}
bool FocusedWindowIsConsole() {…}
 
void Window::UnfocusFocusedWidget()
{
  if (this->nested_focus != nullptr) {
    if (this->nested_focus->type == WWT_EDITBOX) VideoDriver::GetInstance()->EditBoxLostFocus();
 
    /* Repaint the widget that lost focus. A focused edit box may else leave the caret on the screen. */
    this->nested_focus->SetDirty(this);
    this->nested_focus = nullptr;
  }
}
void Window::UnfocusFocusedWidget() {…}
 
bool Window::SetFocusedWidget(WidgetID widget_index)
{
  NWidgetCore *widget = this->GetWidget<NWidgetCore>(widget_index);
  assert(widget != nullptr); /* Setting focus to a non-existing widget is a bad idea. */
 
  if (this->nested_focus != nullptr) {
    /* Do nothing if widget_index is already focused. */
    if (widget == this->nested_focus) return false;
 
    /* Repaint the widget that lost focus. A focused edit box may else leave the caret on the screen. */
    this->nested_focus->SetDirty(this);
    if (this->nested_focus->type == WWT_EDITBOX) VideoDriver::GetInstance()->EditBoxLostFocus();
  }
 
  this->nested_focus = widget;
  if (this->nested_focus->type == WWT_EDITBOX) VideoDriver::GetInstance()->EditBoxGainedFocus();
  return true;
}
bool Window::SetFocusedWidget(WidgetID widget_index) {…}
 
std::string Window::GetWidgetString([[maybe_unused]] WidgetID widget, StringID stringid) const
{
  if (stringid == STR_NULL) return {};
  return GetString(stringid);
}
std::string Window::GetWidgetString([[maybe_unused]] WidgetID widget, StringID stringid) const {…}
 
void Window::OnFocus()
{
  if (this->nested_focus != nullptr && this->nested_focus->type == WWT_EDITBOX) VideoDriver::GetInstance()->EditBoxGainedFocus();
}
void Window::OnFocus() {…}
 
void Window::OnFocusLost(bool)
{
  if (this->nested_focus != nullptr && this->nested_focus->type == WWT_EDITBOX) VideoDriver::GetInstance()->EditBoxLostFocus();
}
void Window::OnFocusLost(bool) {…}
 
void Window::RaiseButtons(bool autoraise)
{
  for (auto &pair : this->widget_lookup) {
    WidgetType type = pair.second->type;
    NWidgetCore *wid = dynamic_cast<NWidgetCore *>(pair.second);
    if (wid != nullptr && ((type & ~WWB_PUSHBUTTON) < WWT_LAST || type == NWID_PUSHBUTTON_DROPDOWN) &&
        (!autoraise || (type & WWB_PUSHBUTTON) || type == WWT_EDITBOX) && wid->IsLowered()) {
      wid->SetLowered(false);
      wid->SetDirty(this);
    }
  }
 
  /* Special widgets without widget index */
  {
    NWidgetCore *wid = this->nested_root != nullptr ? dynamic_cast<NWidgetCore *>(this->nested_root->GetWidgetOfType(WWT_DEFSIZEBOX)) : nullptr;
    if (wid != nullptr) {
      wid->SetLowered(false);
      wid->SetDirty(this);
    }
  }
}
void Window::RaiseButtons(bool autoraise) {…}
 
void Window::SetWidgetDirty(WidgetID widget_index) const
{
  /* Sometimes this function is called before the window is even fully initialized */
  auto it = this->widget_lookup.find(widget_index);
  if (it == std::end(this->widget_lookup)) return;
 
  it->second->SetDirty(this);
}
void Window::SetWidgetDirty(WidgetID widget_index) const {…}
 
EventState Window::OnHotkey(int hotkey)
{
  if (hotkey < 0) return ES_NOT_HANDLED;
 
  NWidgetCore *nw = this->GetWidget<NWidgetCore>(hotkey);
  if (nw == nullptr || nw->IsDisabled()) return ES_NOT_HANDLED;
 
  if (nw->type == WWT_EDITBOX) {
    if (this->IsShaded()) return ES_NOT_HANDLED;
 
    /* Focus editbox */
    this->SetFocusedWidget(hotkey);
    SetFocusedWindow(this);
  } else {
    /* Click button */
    this->OnClick(Point(), hotkey, 1);
  }
  return ES_HANDLED;
}
EventState Window::OnHotkey(int hotkey) {…}
 
void Window::HandleButtonClick(WidgetID widget)
{
  this->LowerWidget(widget);
  this->SetTimeout();
  this->SetWidgetDirty(widget);
  SndClickBeep();
}
void Window::HandleButtonClick(WidgetID widget) {…}
 
static void StartWindowDrag(Window *w);
static void StartWindowSizing(Window *w, bool to_left);
 
static void DispatchLeftClickEvent(Window *w, int x, int y, int click_count)
{
  NWidgetCore *nw = w->nested_root->GetWidgetFromPos(x, y);
  WidgetType widget_type = (nw != nullptr) ? nw->type : WWT_EMPTY;
 
  /* Allow dropdown close flag detection to work. */
  if (nw != nullptr) nw->disp_flags.Reset(NWidgetDisplayFlag::DropdownClosed);
 
  bool focused_widget_changed = false;
  /* If clicked on a window that previously did not have focus */
  if (_focused_window != w &&                 // We already have focus, right?
      !w->window_desc.flags.Test(WindowDefaultFlag::NoFocus) &&  // Don't lose focus to toolbars
      widget_type != WWT_CLOSEBOX) {          // Don't change focused window if 'X' (close button) was clicked
    focused_widget_changed = true;
    SetFocusedWindow(w);
  }
 
  if (nw == nullptr) return; // exit if clicked outside of widgets
 
  /* don't allow any interaction if the button has been disabled */
  if (nw->IsDisabled()) return;
 
  WidgetID widget_index = nw->GetIndex(); 
 
  /* Clicked on a widget that is not disabled.
   * So unless the clicked widget is the caption bar, change focus to this widget.
   * Exception: In the OSK we always want the editbox to stay focused. */
  if (widget_index >= 0 && widget_type != WWT_CAPTION && w->window_class != WC_OSK) {
    /* focused_widget_changed is 'now' only true if the window this widget
     * is in gained focus. In that case it must remain true, also if the
     * local widget focus did not change. As such it's the logical-or of
     * both changed states.
     *
     * If this is not preserved, then the OSK window would be opened when
     * a user has the edit box focused and then click on another window and
     * then back again on the edit box (to type some text).
     */
    focused_widget_changed |= w->SetFocusedWidget(widget_index);
  }
 
  /* Dropdown window of this widget was closed so don't process click this time. */
  if (nw->disp_flags.Test(NWidgetDisplayFlag::DropdownClosed)) return;
 
  if ((widget_type & ~WWB_PUSHBUTTON) < WWT_LAST && (widget_type & WWB_PUSHBUTTON)) w->HandleButtonClick(widget_index);
 
  Point pt = { x, y };
 
  switch (widget_type) {
    case NWID_VSCROLLBAR:
    case NWID_HSCROLLBAR:
      ScrollbarClickHandler(w, nw, x, y);
      break;
 
    case WWT_EDITBOX: {
      QueryString *query = w->GetQueryString(widget_index);
      if (query != nullptr) query->ClickEditBox(w, pt, widget_index, click_count, focused_widget_changed);
      break;
    }
 
    case WWT_CLOSEBOX: // 'X'
      w->Close();
      return;
 
    case WWT_CAPTION: // 'Title bar'
      StartWindowDrag(w);
      return;
 
    case WWT_RESIZEBOX:
      /* When the resize widget is on the left size of the window
       * we assume that that button is used to resize to the left. */
      StartWindowSizing(w, nw->pos_x < (w->width / 2));
      nw->SetDirty(w);
      return;
 
    case WWT_DEFSIZEBOX: {
      if (_ctrl_pressed) {
        if (click_count > 1) {
          w->window_desc.pref_width = 0;
          w->window_desc.pref_height = 0;
        } else {
          w->window_desc.pref_width = w->width;
          w->window_desc.pref_height = w->height;
        }
      } else {
        int16_t def_width = std::max<int16_t>(std::min<int16_t>(w->window_desc.GetDefaultWidth(), _screen.width), w->nested_root->smallest_x);
        int16_t def_height = std::max<int16_t>(std::min<int16_t>(w->window_desc.GetDefaultHeight(), _screen.height - 50), w->nested_root->smallest_y);
 
        int dx = (w->resize.step_width  == 0) ? 0 : def_width  - w->width;
        int dy = (w->resize.step_height == 0) ? 0 : def_height - w->height;
        /* dx and dy has to go by step.. calculate it.
         * The cast to int is necessary else dx/dy are implicitly casted to unsigned int, which won't work. */
        if (w->resize.step_width  > 1) dx -= dx % (int)w->resize.step_width;
        if (w->resize.step_height > 1) dy -= dy % (int)w->resize.step_height;
        ResizeWindow(w, dx, dy, false);
      }
 
      nw->SetLowered(true);
      nw->SetDirty(w);
      w->SetTimeout();
      break;
    }
 
    case WWT_DEBUGBOX:
      w->ShowNewGRFInspectWindow();
      break;
 
    case WWT_SHADEBOX:
      nw->SetDirty(w);
      w->SetShaded(!w->IsShaded());
      return;
 
    case WWT_STICKYBOX:
      w->flags.Flip(WindowFlag::Sticky);
      nw->SetDirty(w);
      if (_ctrl_pressed) w->window_desc.pref_sticky = w->flags.Test(WindowFlag::Sticky);
      return;
 
    default:
      break;
  }
 
  /* Widget has no index, so the window is not interested in it. */
  if (widget_index < 0) return;
 
  /* Check if the widget is highlighted; if so, disable highlight and dispatch an event to the GameScript */
  if (w->IsWidgetHighlighted(widget_index)) {
    w->SetWidgetHighlight(widget_index, TC_INVALID);
    Game::NewEvent(new ScriptEventWindowWidgetClick((ScriptWindow::WindowClass)w->window_class, w->window_number, widget_index));
  }
 
  w->OnClick(pt, widget_index, click_count);
}
static void DispatchLeftClickEvent(Window *w, int x, int y, int click_count) {…}
 
static void DispatchRightClickEvent(Window *w, int x, int y)
{
  NWidgetCore *wid = w->nested_root->GetWidgetFromPos(x, y);
  if (wid == nullptr) return;
 
  Point pt = { x, y };
 
  /* No widget to handle, or the window is not interested in it. */
  if (wid->GetIndex() >= 0) {
    if (w->OnRightClick(pt, wid->GetIndex())) return;
  }
 
  /* Right-click close is enabled and there is a closebox. */
  if (_settings_client.gui.right_click_wnd_close == RCC_YES && !w->window_desc.flags.Test(WindowDefaultFlag::NoClose)) {
    w->Close();
  } else if (_settings_client.gui.right_click_wnd_close == RCC_YES_EXCEPT_STICKY && !w->flags.Test(WindowFlag::Sticky) && !w->window_desc.flags.Test(WindowDefaultFlag::NoClose)) {
    /* Right-click close is enabled, but excluding sticky windows. */
    w->Close();
  } else if (_settings_client.gui.hover_delay_ms == 0 && !w->OnTooltip(pt, wid->GetIndex(), TCC_RIGHT_CLICK) && wid->GetToolTip() != STR_NULL) {
    GuiShowTooltips(w, GetEncodedString(wid->GetToolTip()), TCC_RIGHT_CLICK);
  }
}
static void DispatchRightClickEvent(Window *w, int x, int y) {…}
 
static void DispatchHoverEvent(Window *w, int x, int y)
{
  NWidgetCore *wid = w->nested_root->GetWidgetFromPos(x, y);
 
  /* No widget to handle */
  if (wid == nullptr) return;
 
  Point pt = { x, y };
 
  /* Show the tooltip if there is any */
  if (!w->OnTooltip(pt, wid->GetIndex(), TCC_HOVER) && wid->GetToolTip() != STR_NULL) {
    GuiShowTooltips(w, GetEncodedString(wid->GetToolTip()), TCC_HOVER);
    return;
  }
 
  /* Widget has no index, so the window is not interested in it. */
  if (wid->GetIndex() < 0) return;
 
  w->OnHover(pt, wid->GetIndex());
}
static void DispatchHoverEvent(Window *w, int x, int y) {…}
 
static void DispatchMouseWheelEvent(Window *w, NWidgetCore *nwid, int wheel)
{
  if (nwid == nullptr) return;
 
  /* Using wheel on caption/shade-box shades or unshades the window. */
  if (nwid->type == WWT_CAPTION || nwid->type == WWT_SHADEBOX) {
    w->SetShaded(wheel < 0);
    return;
  }
 
  /* Wheeling a vertical scrollbar. */
  if (nwid->type == NWID_VSCROLLBAR) {
    NWidgetScrollbar *sb = static_cast<NWidgetScrollbar *>(nwid);
    if (sb->GetCount() > sb->GetCapacity()) {
      if (sb->UpdatePosition(wheel)) {
        w->OnScrollbarScroll(nwid->GetIndex());
        w->SetDirty();
      }
    }
    return;
  }
 
  /* Scroll the widget attached to the scrollbar. */
  Scrollbar *sb = (nwid->GetScrollbarIndex() >= 0 ? w->GetScrollbar(nwid->GetScrollbarIndex()) : nullptr);
  if (sb != nullptr && sb->GetCount() > sb->GetCapacity()) {
    if (sb->UpdatePosition(wheel)) {
      w->OnScrollbarScroll(nwid->GetScrollbarIndex());
      w->SetDirty();
    }
  }
}
static void DispatchMouseWheelEvent(Window *w, NWidgetCore *nwid, int wheel) {…}
 
static bool MayBeShown(const Window *w)
{
  /* If we're not modal, everything is okay. */
  if (!HasModalProgress()) return true;
 
  switch (w->window_class) {
    case WC_MAIN_WINDOW:    
    case WC_MODAL_PROGRESS: 
    case WC_CONFIRM_POPUP_QUERY: 
      return true;
 
    default:
      return false;
  }
}
static bool MayBeShown(const Window *w) {…}
 
static void DrawOverlappedWindow(Window *w, int left, int top, int right, int bottom)
{
  Window::IteratorToFront it(w);
  ++it;
  for (; !it.IsEnd(); ++it) {
    const Window *v = *it;
    if (MayBeShown(v) &&
        right > v->left &&
        bottom > v->top &&
        left < v->left + v->width &&
        top < v->top + v->height) {
      /* v and rectangle intersect with each other */
      int x;
 
      if (left < (x = v->left)) {
        DrawOverlappedWindow(w, left, top, x, bottom);
        DrawOverlappedWindow(w, x, top, right, bottom);
        return;
      }
 
      if (right > (x = v->left + v->width)) {
        DrawOverlappedWindow(w, left, top, x, bottom);
        DrawOverlappedWindow(w, x, top, right, bottom);
        return;
      }
 
      if (top < (x = v->top)) {
        DrawOverlappedWindow(w, left, top, right, x);
        DrawOverlappedWindow(w, left, x, right, bottom);
        return;
      }
 
      if (bottom > (x = v->top + v->height)) {
        DrawOverlappedWindow(w, left, top, right, x);
        DrawOverlappedWindow(w, left, x, right, bottom);
        return;
      }
 
      return;
    }
  }
 
  /* Setup blitter, and dispatch a repaint event to window *wz */
  DrawPixelInfo *dp = _cur_dpi;
  dp->width = right - left;
  dp->height = bottom - top;
  dp->left = left - w->left;
  dp->top = top - w->top;
  dp->pitch = _screen.pitch;
  dp->dst_ptr = BlitterFactory::GetCurrentBlitter()->MoveTo(_screen.dst_ptr, left, top);
  dp->zoom = ZoomLevel::Min;
  w->OnPaint();
}
static void DrawOverlappedWindow(Window *w, int left, int top, int right, int bottom) {…}
 
void DrawOverlappedWindowForAll(int left, int top, int right, int bottom)
{
  DrawPixelInfo bk;
  AutoRestoreBackup dpi_backup(_cur_dpi, &bk);
 
  for (Window *w : Window::IterateFromBack()) {
    if (MayBeShown(w) &&
        right > w->left &&
        bottom > w->top &&
        left < w->left + w->width &&
        top < w->top + w->height) {
      /* Window w intersects with the rectangle => needs repaint */
      DrawOverlappedWindow(w, std::max(left, w->left), std::max(top, w->top), std::min(right, w->left + w->width), std::min(bottom, w->top + w->height));
    }
  }
}
void DrawOverlappedWindowForAll(int left, int top, int right, int bottom) {…}
 
void Window::SetDirty() const
{
  AddDirtyBlock(this->left, this->top, this->left + this->width, this->top + this->height);
}
void Window::SetDirty() const {…}
 
void Window::ReInit(int rx, int ry, bool reposition)
{
  this->SetDirty(); // Mark whole current window as dirty.
 
  /* Save current size. */
  int window_width  = this->width * _gui_scale / this->scale;
  int window_height = this->height * _gui_scale / this->scale;
  this->scale = _gui_scale;
 
  this->OnInit();
  /* Re-initialize window smallest size. */
  this->nested_root->SetupSmallestSize(this);
  this->nested_root->AssignSizePosition(ST_SMALLEST, 0, 0, this->nested_root->smallest_x, this->nested_root->smallest_y, _current_text_dir == TD_RTL);
  this->width  = this->nested_root->smallest_x;
  this->height = this->nested_root->smallest_y;
  this->resize.step_width  = this->nested_root->resize_x;
  this->resize.step_height = this->nested_root->resize_y;
 
  /* Resize as close to the original size + requested resize as possible. */
  window_width  = std::max(window_width  + rx, this->width);
  window_height = std::max(window_height + ry, this->height);
  int dx = (this->resize.step_width  == 0) ? 0 : window_width  - this->width;
  int dy = (this->resize.step_height == 0) ? 0 : window_height - this->height;
  /* dx and dy has to go by step.. calculate it.
   * The cast to int is necessary else dx/dy are implicitly casted to unsigned int, which won't work. */
  if (this->resize.step_width  > 1) dx -= dx % (int)this->resize.step_width;
  if (this->resize.step_height > 1) dy -= dy % (int)this->resize.step_height;
 
  if (reposition) {
    Point pt = this->OnInitialPosition(this->nested_root->smallest_x, this->nested_root->smallest_y, window_number);
    this->InitializePositionSize(pt.x, pt.y, this->nested_root->smallest_x, this->nested_root->smallest_y);
    this->FindWindowPlacementAndResize(this->window_desc.GetDefaultWidth(), this->window_desc.GetDefaultHeight(), false);
  }
 
  ResizeWindow(this, dx, dy, true, false);
  /* ResizeWindow() does this->SetDirty() already, no need to do it again here. */
}
void Window::ReInit(int rx, int ry, bool reposition) {…}
 
void Window::SetShaded(bool make_shaded)
{
  if (this->shade_select == nullptr) return;
 
  int desired = make_shaded ? SZSP_HORIZONTAL : 0;
  if (this->shade_select->shown_plane != desired) {
    if (make_shaded) {
      if (this->nested_focus != nullptr) this->UnfocusFocusedWidget();
      this->unshaded_size.width  = this->width;
      this->unshaded_size.height = this->height;
      this->shade_select->SetDisplayedPlane(desired);
      this->ReInit(0, -this->height);
    } else {
      this->shade_select->SetDisplayedPlane(desired);
      int dx = ((int)this->unshaded_size.width  > this->width)  ? (int)this->unshaded_size.width  - this->width  : 0;
      int dy = ((int)this->unshaded_size.height > this->height) ? (int)this->unshaded_size.height - this->height : 0;
      this->ReInit(dx, dy);
    }
  }
}
void Window::SetShaded(bool make_shaded) {…}
 
Window *Window::FindChildWindow(WindowClass wc) const
{
  for (Window *v : Window::Iterate()) {
    if ((wc == WC_INVALID || wc == v->window_class) && v->parent == this) return v;
  }
 
  return nullptr;
}
Window *Window::FindChildWindow(WindowClass wc) const {…}
 
Window *Window::FindChildWindowById(WindowClass wc, WindowNumber number) const
{
  for (Window *v : Window::Iterate()) {
    if (wc == v->window_class && number == v->window_number && v->parent == this) return v;
  }
 
  return nullptr;
}
Window *Window::FindChildWindowById(WindowClass wc, WindowNumber number) const {…}
 
void Window::CloseChildWindows(WindowClass wc) const
{
  Window *child = this->FindChildWindow(wc);
  while (child != nullptr) {
    child->Close();
    child = this->FindChildWindow(wc);
  }
}
void Window::CloseChildWindows(WindowClass wc) const {…}
 
 
void Window::CloseChildWindowById(WindowClass wc, WindowNumber number) const
{
  Window *child = this->FindChildWindowById(wc, number);
  while (child != nullptr) {
    child->Close();
    child = this->FindChildWindowById(wc, number);
  }
}
void Window::CloseChildWindowById(WindowClass wc, WindowNumber number) const {…}
 
void Window::Close([[maybe_unused]] int data)
{
  /* Don't close twice. */
  if (*this->z_position == nullptr) return;
 
  *this->z_position = nullptr;
 
  if (_thd.window_class == this->window_class &&
      _thd.window_number == this->window_number) {
    ResetObjectToPlace();
  }
 
  /* Prevent Mouseover() from resetting mouse-over coordinates on a non-existing window */
  if (_mouseover_last_w == this) _mouseover_last_w = nullptr;
 
  /* We can't scroll the window when it's closed. */
  if (_last_scroll_window == this) _last_scroll_window = nullptr;
 
  /* Make sure we don't try to access non-existing query strings. */
  this->querystrings.clear();
 
  /* Make sure we don't try to access this window as the focused window when it doesn't exist anymore. */
  if (_focused_window == this) {
    this->OnFocusLost(true);
    _focused_window = nullptr;
  }
 
  this->CloseChildWindows();
 
  this->SetDirty();
 
  Window::closed_windows.push_back(this);
}
void Window::Close([[maybe_unused]] int data) {…}
 
Window::~Window()
{
  /* Make sure the window is closed, deletion is allowed only in Window::DeleteClosedWindows(). */
  assert(*this->z_position == nullptr);
}
Window::~Window() {…}
 
Window *FindWindowById(WindowClass cls, WindowNumber number)
{
  for (Window *w : Window::Iterate()) {
    if (w->window_class == cls && w->window_number == number) return w;
  }
 
  return nullptr;
}
Window *FindWindowById(WindowClass cls, WindowNumber number) {…}
 
Window *FindWindowByClass(WindowClass cls)
{
  for (Window *w : Window::Iterate()) {
    if (w->window_class == cls) return w;
  }
 
  return nullptr;
}
Window *FindWindowByClass(WindowClass cls) {…}
 
Window *GetMainWindow()
{
  Window *w = FindWindowById(WC_MAIN_WINDOW, 0);
  assert(w != nullptr);
  return w;
}
Window *GetMainWindow() {…}
 
void CloseWindowById(WindowClass cls, WindowNumber number, bool force, int data)
{
  Window *w = FindWindowById(cls, number);
  if (w != nullptr && (force || !w->flags.Test(WindowFlag::Sticky))) {
    w->Close(data);
  }
}
void CloseWindowById(WindowClass cls, WindowNumber number, bool force, int data) {…}
 
void CloseWindowByClass(WindowClass cls, int data)
{
  /* Note: the container remains stable, even when deleting windows. */
  for (Window *w : Window::Iterate()) {
    if (w->window_class == cls) {
      w->Close(data);
    }
  }
}
void CloseWindowByClass(WindowClass cls, int data) {…}
 
void CloseCompanyWindows(CompanyID id)
{
  /* Note: the container remains stable, even when deleting windows. */
  for (Window *w : Window::Iterate()) {
    if (w->owner == id) {
      w->Close();
    }
  }
 
  /* Also delete the company specific windows that don't have a company-colour. */
  CloseWindowById(WC_BUY_COMPANY, id);
}
void CloseCompanyWindows(CompanyID id) {…}
 
void ChangeWindowOwner(Owner old_owner, Owner new_owner)
{
  for (Window *w : Window::Iterate()) {
    if (w->owner != old_owner) continue;
 
    switch (w->window_class) {
      case WC_COMPANY_COLOUR:
      case WC_FINANCES:
      case WC_STATION_LIST:
      case WC_TRAINS_LIST:
      case WC_ROADVEH_LIST:
      case WC_SHIPS_LIST:
      case WC_AIRCRAFT_LIST:
      case WC_BUY_COMPANY:
      case WC_COMPANY:
      case WC_COMPANY_INFRASTRUCTURE:
      case WC_VEHICLE_ORDERS: // Changing owner would also require changing WindowDesc, which is not possible; however keeping the old one crashes because of missing widgets etc.. See ShowOrdersWindow().
        continue;
 
      default:
        w->owner = new_owner;
        break;
    }
  }
}
void ChangeWindowOwner(Owner old_owner, Owner new_owner) {…}
 
static void BringWindowToFront(Window *w, bool dirty = true);
 
Window *BringWindowToFrontById(WindowClass cls, WindowNumber number)
{
  Window *w = FindWindowById(cls, number);
 
  if (w != nullptr) {
    if (w->IsShaded()) w->SetShaded(false); // Restore original window size if it was shaded.
 
    w->SetWhiteBorder();
    BringWindowToFront(w);
    w->SetDirty();
  }
 
  return w;
}
Window *BringWindowToFrontById(WindowClass cls, WindowNumber number) {…}
 
static inline bool IsVitalWindow(const Window *w)
{
  switch (w->window_class) {
    case WC_MAIN_TOOLBAR:
    case WC_STATUS_BAR:
    case WC_NEWS_WINDOW:
    case WC_SEND_NETWORK_MSG:
      return true;
 
    default:
      return false;
  }
}
 
static uint GetWindowZPriority(WindowClass wc)
{
  assert(wc != WC_INVALID);
 
  uint z_priority = 0;
 
  switch (wc) {
    case WC_TOOLTIPS:
      ++z_priority;
      [[fallthrough]];
 
    case WC_ERRMSG:
    case WC_CONFIRM_POPUP_QUERY:
      ++z_priority;
      [[fallthrough]];
 
    case WC_ENDSCREEN:
      ++z_priority;
      [[fallthrough]];
 
    case WC_HIGHSCORE:
      ++z_priority;
      [[fallthrough]];
 
    case WC_DROPDOWN_MENU:
      ++z_priority;
      [[fallthrough]];
 
    case WC_MAIN_TOOLBAR:
    case WC_STATUS_BAR:
      ++z_priority;
      [[fallthrough]];
 
    case WC_OSK:
      ++z_priority;
      [[fallthrough]];
 
    case WC_QUERY_STRING:
    case WC_SEND_NETWORK_MSG:
      ++z_priority;
      [[fallthrough]];
 
    case WC_NETWORK_ASK_RELAY:
    case WC_MODAL_PROGRESS:
    case WC_NETWORK_STATUS_WINDOW:
    case WC_SAVE_PRESET:
      ++z_priority;
      [[fallthrough]];
 
    case WC_GENERATE_LANDSCAPE:
    case WC_SAVELOAD:
    case WC_GAME_OPTIONS:
    case WC_CUSTOM_CURRENCY:
    case WC_NETWORK_WINDOW:
    case WC_GRF_PARAMETERS:
    case WC_SCRIPT_LIST:
    case WC_SCRIPT_SETTINGS:
    case WC_TEXTFILE:
      ++z_priority;
      [[fallthrough]];
 
    case WC_CONSOLE:
      ++z_priority;
      [[fallthrough]];
 
    case WC_NEWS_WINDOW:
      ++z_priority;
      [[fallthrough]];
 
    default:
      ++z_priority;
      [[fallthrough]];
 
    case WC_MAIN_WINDOW:
      return z_priority;
  }
}
static uint GetWindowZPriority(WindowClass wc) {…}
 
static void BringWindowToFront(Window *w, bool dirty)
{
  auto priority = GetWindowZPriority(w->window_class);
  WindowList::iterator dest = _z_windows.begin();
  while (dest != _z_windows.end() && (*dest == nullptr || GetWindowZPriority((*dest)->window_class) <= priority)) ++dest;
 
  if (dest != w->z_position) {
    _z_windows.splice(dest, _z_windows, w->z_position);
  }
 
  if (dirty) w->SetDirty();
}
static void BringWindowToFront(Window *w, bool dirty) {…}
 
void Window::InitializeData(WindowNumber window_number)
{
  /* Set up window properties; some of them are needed to set up smallest size below */
  this->window_class = this->window_desc.cls;
  this->SetWhiteBorder();
  if (this->window_desc.default_pos == WDP_CENTER) this->flags.Set(WindowFlag::Centred);
  this->owner = INVALID_OWNER;
  this->nested_focus = nullptr;
  this->window_number = window_number;
 
  this->OnInit();
  /* Initialize smallest size. */
  this->nested_root->SetupSmallestSize(this);
  /* Initialize to smallest size. */
  this->nested_root->AssignSizePosition(ST_SMALLEST, 0, 0, this->nested_root->smallest_x, this->nested_root->smallest_y, _current_text_dir == TD_RTL);
 
  /* Further set up window properties,
   * this->left, this->top, this->width, this->height, this->resize.width, and this->resize.height are initialized later. */
  this->resize.step_width  = this->nested_root->resize_x;
  this->resize.step_height = this->nested_root->resize_y;
 
  /* Give focus to the opened window unless a dropdown menu has focus or a text box of the focused window has focus
   * (so we don't interrupt typing) unless the new window has a text box. */
  bool dropdown_active = _focused_window != nullptr && _focused_window->window_class == WC_DROPDOWN_MENU;
  bool editbox_active = EditBoxInGlobalFocus() && this->nested_root->GetWidgetOfType(WWT_EDITBOX) == nullptr;
  if (!dropdown_active && !editbox_active) SetFocusedWindow(this);
 
  /* Insert the window into the correct location in the z-ordering. */
  BringWindowToFront(this, false);
}
void Window::InitializeData(WindowNumber window_number) {…}
 
void Window::InitializePositionSize(int x, int y, int sm_width, int sm_height)
{
  this->left = x;
  this->top = y;
  this->width = sm_width;
  this->height = sm_height;
}
void Window::InitializePositionSize(int x, int y, int sm_width, int sm_height) {…}
 
void Window::FindWindowPlacementAndResize(int def_width, int def_height, bool allow_resize)
{
  if (allow_resize) {
    def_width  = std::max(def_width,  this->width); // Don't allow default size to be smaller than smallest size
    def_height = std::max(def_height, this->height);
    /* Try to make windows smaller when our window is too small.
     * w->(width|height) is normally the same as min_(width|height),
     * but this way the GUIs can be made a little more dynamic;
     * one can use the same spec for multiple windows and those
     * can then determine the real minimum size of the window. */
    if (this->width != def_width || this->height != def_height) {
      /* Think about the overlapping toolbars when determining the minimum window size */
      int free_height = _screen.height;
      const Window *wt = FindWindowById(WC_STATUS_BAR, 0);
      if (wt != nullptr) free_height -= wt->height;
      wt = FindWindowById(WC_MAIN_TOOLBAR, 0);
      if (wt != nullptr) free_height -= wt->height;
 
      int enlarge_x = std::max(std::min(def_width  - this->width,  _screen.width - this->width),  0);
      int enlarge_y = std::max(std::min(def_height - this->height, free_height   - this->height), 0);
 
      /* X and Y has to go by step.. calculate it.
       * The cast to int is necessary else x/y are implicitly casted to
       * unsigned int, which won't work. */
      if (this->resize.step_width  > 1) enlarge_x -= enlarge_x % (int)this->resize.step_width;
      if (this->resize.step_height > 1) enlarge_y -= enlarge_y % (int)this->resize.step_height;
 
      ResizeWindow(this, enlarge_x, enlarge_y, true, false);
      /* ResizeWindow() calls this->OnResize(). */
    } else {
      /* Always call OnResize; that way the scrollbars and matrices get initialized. */
      this->OnResize();
    }
  }
 
  int nx = this->left;
  int ny = this->top;
 
  if (nx + this->width > _screen.width) nx -= (nx + this->width - _screen.width);
 
  const Window *wt = FindWindowById(WC_MAIN_TOOLBAR, 0);
  ny = std::max(ny, (wt == nullptr || this == wt || this->top == 0) ? 0 : wt->height);
  nx = std::max(nx, 0);
 
  if (this->viewport != nullptr) {
    this->viewport->left += nx - this->left;
    this->viewport->top  += ny - this->top;
  }
  this->left = nx;
  this->top = ny;
 
  this->SetDirty();
}
void Window::FindWindowPlacementAndResize(int def_width, int def_height, bool allow_resize) {…}
 
static bool IsGoodAutoPlace1(int left, int top, int width, int height, int toolbar_y, Point &pos)
{
  int right  = width + left;
  int bottom = height + top;
 
  if (left < 0 || top < toolbar_y || right > _screen.width || bottom > _screen.height) return false;
 
  /* Make sure it is not obscured by any window. */
  for (const Window *w : Window::Iterate()) {
    if (w->window_class == WC_MAIN_WINDOW) continue;
 
    if (right > w->left &&
        w->left + w->width > left &&
        bottom > w->top &&
        w->top + w->height > top) {
      return false;
    }
  }
 
  pos.x = left;
  pos.y = top;
  return true;
}
static bool IsGoodAutoPlace1(int left, int top, int width, int height, int toolbar_y, Point &pos) {…}
 
static bool IsGoodAutoPlace2(int left, int top, int width, int height, int toolbar_y, Point &pos)
{
  bool rtl = _current_text_dir == TD_RTL;
 
  /* Left part of the rectangle may be at most 1/4 off-screen,
   * right part of the rectangle may be at most 1/2 off-screen
   */
  if (rtl) {
    if (left < -(width >> 1) || left > _screen.width - (width >> 2)) return false;
  } else {
    if (left < -(width >> 2) || left > _screen.width - (width >> 1)) return false;
  }
 
  /* Bottom part of the rectangle may be at most 1/4 off-screen */
  if (top < toolbar_y || top > _screen.height - (height >> 2)) return false;
 
  /* Make sure it is not obscured by any window. */
  for (const Window *w : Window::Iterate()) {
    if (w->window_class == WC_MAIN_WINDOW) continue;
 
    if (left + width > w->left &&
        w->left + w->width > left &&
        top + height > w->top &&
        w->top + w->height > top) {
      return false;
    }
  }
 
  pos.x = left;
  pos.y = top;
  return true;
}
static bool IsGoodAutoPlace2(int left, int top, int width, int height, int toolbar_y, Point &pos) {…}
 
static Point GetAutoPlacePosition(int width, int height)
{
  Point pt;
 
  bool rtl = _current_text_dir == TD_RTL;
 
  /* First attempt, try top-left of the screen */
  const Window *main_toolbar = FindWindowByClass(WC_MAIN_TOOLBAR);
  const int toolbar_y =  main_toolbar != nullptr ? main_toolbar->height : 0;
  if (IsGoodAutoPlace1(rtl ? _screen.width - width : 0, toolbar_y, width, height, toolbar_y, pt)) return pt;
 
  /* Second attempt, try around all existing windows.
   * The new window must be entirely on-screen, and not overlap with an existing window.
   * Eight starting points are tried, two at each corner.
   */
  for (const Window *w : Window::Iterate()) {
    if (w->window_class == WC_MAIN_WINDOW) continue;
 
    if (IsGoodAutoPlace1(w->left + w->width,         w->top,                      width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace1(w->left            - width, w->top,                      width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace1(w->left,                    w->top + w->height,          width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace1(w->left,                    w->top             - height, width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace1(w->left + w->width,         w->top + w->height - height, width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace1(w->left            - width, w->top + w->height - height, width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace1(w->left + w->width - width, w->top + w->height,          width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace1(w->left + w->width - width, w->top             - height, width, height, toolbar_y, pt)) return pt;
  }
 
  /* Third attempt, try around all existing windows.
   * The new window may be partly off-screen, and must not overlap with an existing window.
   * Only four starting points are tried.
   */
  for (const Window *w : Window::Iterate()) {
    if (w->window_class == WC_MAIN_WINDOW) continue;
 
    if (IsGoodAutoPlace2(w->left + w->width, w->top,             width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace2(w->left    - width, w->top,             width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace2(w->left,            w->top + w->height, width, height, toolbar_y, pt)) return pt;
    if (IsGoodAutoPlace2(w->left,            w->top - height,    width, height, toolbar_y, pt)) return pt;
  }
 
  /* Fourth and final attempt, put window at diagonal starting from (0, toolbar_y), try multiples
   * of the closebox
   */
  int left = rtl ? _screen.width - width : 0, top = toolbar_y;
  int offset_x = rtl ? -(int)NWidgetLeaf::closebox_dimension.width : (int)NWidgetLeaf::closebox_dimension.width;
  int offset_y = std::max<int>(NWidgetLeaf::closebox_dimension.height, GetCharacterHeight(FS_NORMAL) + WidgetDimensions::scaled.captiontext.Vertical());
 
restart:
  for (const Window *w : Window::Iterate()) {
    if (w->left == left && w->top == top) {
      left += offset_x;
      top += offset_y;
      goto restart;
    }
  }
 
  pt.x = left;
  pt.y = top;
  return pt;
}
static Point GetAutoPlacePosition(int width, int height) {…}
 
Point GetToolbarAlignedWindowPosition(int window_width)
{
  const Window *w = FindWindowById(WC_MAIN_TOOLBAR, 0);
  assert(w != nullptr);
  Point pt = { _current_text_dir == TD_RTL ? w->left : (w->left + w->width) - window_width, w->top + w->height };
  return pt;
}
Point GetToolbarAlignedWindowPosition(int window_width) {…}
 
static Point LocalGetWindowPlacement(const WindowDesc &desc, int16_t sm_width, int16_t sm_height, int window_number)
{
  Point pt;
  const Window *w;
 
  int16_t default_width  = std::max(desc.GetDefaultWidth(),  sm_width);
  int16_t default_height = std::max(desc.GetDefaultHeight(), sm_height);
 
  if (desc.parent_cls != WC_NONE && (w = FindWindowById(desc.parent_cls, window_number)) != nullptr) {
    bool rtl = _current_text_dir == TD_RTL;
    if (desc.parent_cls == WC_BUILD_TOOLBAR || desc.parent_cls == WC_SCEN_LAND_GEN) {
      pt.x = w->left + (rtl ? w->width - default_width : 0);
      pt.y = w->top + w->height;
      return pt;
    } else {
      /* Position child window with offset of closebox, but make sure that either closebox or resizebox is visible
       *  - Y position: closebox of parent + closebox of child + statusbar
       *  - X position: closebox on left/right, resizebox on right/left (depending on ltr/rtl)
       */
      int indent_y = std::max<int>(NWidgetLeaf::closebox_dimension.height, GetCharacterHeight(FS_NORMAL) + WidgetDimensions::scaled.captiontext.Vertical());
      if (w->top + 3 * indent_y < _screen.height) {
        pt.y = w->top + indent_y;
        int indent_close = NWidgetLeaf::closebox_dimension.width;
        int indent_resize = NWidgetLeaf::resizebox_dimension.width;
        if (_current_text_dir == TD_RTL) {
          pt.x = std::max(w->left + w->width - default_width - indent_close, 0);
          if (pt.x + default_width >= indent_close && pt.x + indent_resize <= _screen.width) return pt;
        } else {
          pt.x = std::min(w->left + indent_close, _screen.width - default_width);
          if (pt.x + default_width >= indent_resize && pt.x + indent_close <= _screen.width) return pt;
        }
      }
    }
  }
 
  switch (desc.default_pos) {
    case WDP_ALIGN_TOOLBAR: // Align to the toolbar
      return GetToolbarAlignedWindowPosition(default_width);
 
    case WDP_AUTO: // Find a good automatic position for the window
      return GetAutoPlacePosition(default_width, default_height);
 
    case WDP_CENTER: // Centre the window horizontally
      pt.x = (_screen.width - default_width) / 2;
      pt.y = (_screen.height - default_height) / 2;
      break;
 
    case WDP_MANUAL:
      pt.x = 0;
      pt.y = 0;
      break;
 
    default:
      NOT_REACHED();
  }
 
  return pt;
}
static Point LocalGetWindowPlacement(const WindowDesc &desc, int16_t sm_width, int16_t sm_height, int window_number) {…}
 
/* virtual */ Point Window::OnInitialPosition([[maybe_unused]]int16_t sm_width, [[maybe_unused]]int16_t sm_height, [[maybe_unused]]int window_number)
{
  return LocalGetWindowPlacement(this->window_desc, sm_width, sm_height, window_number);
}
/* virtual */ Point Window::OnInitialPosition([[maybe_unused]]int16_t sm_width, [[maybe_unused]]int16_t sm_height, [[maybe_unused]]int window_number) {…}
 
void Window::CreateNestedTree()
{
  this->nested_root = MakeWindowNWidgetTree(this->window_desc.nwid_parts, &this->shade_select);
  this->nested_root->FillWidgetLookup(this->widget_lookup);
}
void Window::CreateNestedTree() {…}
 
void Window::FinishInitNested(WindowNumber window_number)
{
  this->InitializeData(window_number);
  this->ApplyDefaults();
  Point pt = this->OnInitialPosition(this->nested_root->smallest_x, this->nested_root->smallest_y, window_number);
  this->InitializePositionSize(pt.x, pt.y, this->nested_root->smallest_x, this->nested_root->smallest_y);
  this->FindWindowPlacementAndResize(this->window_desc.GetDefaultWidth(), this->window_desc.GetDefaultHeight(), true);
}
void Window::FinishInitNested(WindowNumber window_number) {…}
 
void Window::InitNested(WindowNumber window_number)
{
  this->CreateNestedTree();
  this->FinishInitNested(window_number);
}
void Window::InitNested(WindowNumber window_number) {…}
 
Window::Window(WindowDesc &desc) : window_desc(desc), scale(_gui_scale), mouse_capture_widget(-1)
{
  this->z_position = _z_windows.insert(_z_windows.end(), this);
}
Window::Window(WindowDesc &desc) : window_desc(desc), scale(_gui_scale), mouse_capture_widget(-1) {…}
 
Window *FindWindowFromPt(int x, int y)
{
  for (Window *w : Window::IterateFromFront()) {
    if (MayBeShown(w) && IsInsideBS(x, w->left, w->width) && IsInsideBS(y, w->top, w->height)) {
      return w;
    }
  }
 
  return nullptr;
}
Window *FindWindowFromPt(int x, int y) {…}
 
void InitWindowSystem()
{
  IConsoleClose();
 
  _focused_window = nullptr;
  _mouseover_last_w = nullptr;
  _last_scroll_window = nullptr;
  _scrolling_viewport = false;
  _mouse_hovering = false;
 
  SetupWidgetDimensions();
  NWidgetLeaf::InvalidateDimensionCache(); // Reset cached sizes of several widgets.
  NWidgetScrollbar::InvalidateDimensionCache();
 
  InitDepotWindowBlockSizes();
 
  ShowFirstError();
}
void InitWindowSystem() {…}
 
void UnInitWindowSystem()
{
  UnshowCriticalError();
 
  for (Window *w : Window::Iterate()) w->Close();
 
  Window::DeleteClosedWindows();
 
  assert(_z_windows.empty());
}
void UnInitWindowSystem() {…}
 
void ResetWindowSystem()
{
  UnInitWindowSystem();
  InitWindowSystem();
  _thd.Reset();
}
void ResetWindowSystem() {…}
 
static void DecreaseWindowCounters()
{
  if (_scroller_click_timeout != 0) _scroller_click_timeout--;
 
  for (Window *w : Window::Iterate()) {
    if (_scroller_click_timeout == 0) {
      /* Unclick scrollbar buttons if they are pressed. */
      for (auto &pair : w->widget_lookup) {
        NWidgetBase *nwid = pair.second;
        if (nwid->type == NWID_HSCROLLBAR || nwid->type == NWID_VSCROLLBAR) {
          NWidgetScrollbar *sb = static_cast<NWidgetScrollbar*>(nwid);
          if (sb->disp_flags.Any({NWidgetDisplayFlag::ScrollbarUp, NWidgetDisplayFlag::ScrollbarDown})) {
            sb->disp_flags.Reset({NWidgetDisplayFlag::ScrollbarUp, NWidgetDisplayFlag::ScrollbarDown});
            w->mouse_capture_widget = -1;
            sb->SetDirty(w);
          }
        }
      }
    }
 
    /* Handle editboxes */
    for (auto &pair : w->querystrings) {
      pair.second->HandleEditBox(w, pair.first);
    }
 
    w->OnMouseLoop();
  }
 
  for (Window *w : Window::Iterate()) {
    if (w->flags.Test(WindowFlag::Timeout) && --w->timeout_timer == 0) {
      w->flags.Reset(WindowFlag::Timeout);
 
      w->OnTimeout();
      w->RaiseButtons(true);
    }
  }
}
 
static void HandlePlacePresize()
{
  if (_special_mouse_mode != WSM_PRESIZE) return;
 
  Window *w = _thd.GetCallbackWnd();
  if (w == nullptr) return;
 
  Point pt = GetTileBelowCursor();
  if (pt.x == -1) {
    _thd.selend.x = -1;
    return;
  }
 
  w->OnPlacePresize(pt, TileVirtXY(pt.x, pt.y));
}
 
static EventState HandleMouseDragDrop()
{
  if (_special_mouse_mode != WSM_DRAGDROP) return ES_NOT_HANDLED;
 
  if (_left_button_down && _cursor.delta.x == 0 && _cursor.delta.y == 0) return ES_HANDLED; // Dragging, but the mouse did not move.
 
  Window *w = _thd.GetCallbackWnd();
  if (w != nullptr) {
    /* Send an event in client coordinates. */
    Point pt;
    pt.x = _cursor.pos.x - w->left;
    pt.y = _cursor.pos.y - w->top;
    if (_left_button_down) {
      w->OnMouseDrag(pt, GetWidgetFromPos(w, pt.x, pt.y));
    } else {
      w->OnDragDrop(pt, GetWidgetFromPos(w, pt.x, pt.y));
    }
  }
 
  if (!_left_button_down) ResetObjectToPlace(); // Button released, finished dragging.
  return ES_HANDLED;
}
static EventState HandleMouseDragDrop() {…}
 
static void HandleMouseOver()
{
  Window *w = FindWindowFromPt(_cursor.pos.x, _cursor.pos.y);
 
  /* We changed window, put an OnMouseOver event to the last window */
  if (_mouseover_last_w != nullptr && _mouseover_last_w != w) {
    /* Reset mouse-over coordinates of previous window */
    Point pt = { -1, -1 };
    _mouseover_last_w->OnMouseOver(pt, 0);
  }
 
  /* _mouseover_last_w will get reset when the window is deleted, see DeleteWindow() */
  _mouseover_last_w = w;
 
  if (w != nullptr) {
    /* send an event in client coordinates. */
    Point pt = { _cursor.pos.x - w->left, _cursor.pos.y - w->top };
    const NWidgetCore *widget = w->nested_root->GetWidgetFromPos(pt.x, pt.y);
    if (widget != nullptr) w->OnMouseOver(pt, widget->GetIndex());
  }
}
static void HandleMouseOver() {…}
 
enum PreventHideDirection : uint8_t {
  PHD_UP,   
  PHD_DOWN, 
};
enum PreventHideDirection : uint8_t {…};
 
static void PreventHiding(int *nx, int *ny, const Rect &rect, const Window *v, int px, PreventHideDirection dir)
{
  if (v == nullptr) return;
 
  const int min_visible = rect.Height();
 
  int v_bottom = v->top + v->height - 1;
  int v_right = v->left + v->width - 1;
  int safe_y = (dir == PHD_UP) ? (v->top - min_visible - rect.top) : (v_bottom + min_visible - rect.bottom); // Compute safe vertical position.
 
  if (*ny + rect.top <= v->top - min_visible) return; // Above v is enough space
  if (*ny + rect.bottom >= v_bottom + min_visible) return; // Below v is enough space
 
  /* Vertically, the rectangle is hidden behind v. */
  if (*nx + rect.left + min_visible < v->left) { // At left of v.
    if (v->left < min_visible) *ny = safe_y; // But enough room, force it to a safe position.
    return;
  }
  if (*nx + rect.right - min_visible > v_right) { // At right of v.
    if (v_right > _screen.width - min_visible) *ny = safe_y; // Not enough room, force it to a safe position.
    return;
  }
 
  /* Horizontally also hidden, force movement to a safe area. */
  if (px + rect.left < v->left && v->left >= min_visible) { // Coming from the left, and enough room there.
    *nx = v->left - min_visible - rect.left;
  } else if (px + rect.right > v_right && v_right <= _screen.width - min_visible) { // Coming from the right, and enough room there.
    *nx = v_right + min_visible - rect.right;
  } else {
    *ny = safe_y;
  }
}
static void PreventHiding(int *nx, int *ny, const Rect &rect, const Window *v, int px, PreventHideDirection dir) {…}
 
static void EnsureVisibleCaption(Window *w, int nx, int ny)
{
  /* Search for the title bar rectangle. */
  const NWidgetBase *caption = w->nested_root->GetWidgetOfType(WWT_CAPTION);
  if (caption != nullptr) {
    const Rect caption_rect = caption->GetCurrentRect();
 
    const int min_visible = caption_rect.Height();
 
    /* Make sure the window doesn't leave the screen */
    nx = Clamp(nx, min_visible - caption_rect.right, _screen.width - min_visible - caption_rect.left);
    ny = Clamp(ny, 0, _screen.height - min_visible);
 
    /* Make sure the title bar isn't hidden behind the main tool bar or the status bar. */
    PreventHiding(&nx, &ny, caption_rect, FindWindowById(WC_MAIN_TOOLBAR, 0), w->left, PHD_DOWN);
    PreventHiding(&nx, &ny, caption_rect, FindWindowById(WC_STATUS_BAR,   0), w->left, PHD_UP);
  }
 
  if (w->viewport != nullptr) {
    w->viewport->left += nx - w->left;
    w->viewport->top  += ny - w->top;
  }
 
  w->left = nx;
  w->top  = ny;
}
static void EnsureVisibleCaption(Window *w, int nx, int ny) {…}
 
void ResizeWindow(Window *w, int delta_x, int delta_y, bool clamp_to_screen, bool schedule_resize)
{
  if (delta_x != 0 || delta_y != 0) {
    if (clamp_to_screen) {
      /* Determine the new right/bottom position. If that is outside of the bounds of
       * the resolution clamp it in such a manner that it stays within the bounds. */
      int new_right  = w->left + w->width  + delta_x;
      int new_bottom = w->top  + w->height + delta_y;
      if (new_right  >= (int)_screen.width)  delta_x -= Ceil(new_right  - _screen.width,  std::max(1U, w->nested_root->resize_x));
      if (new_bottom >= (int)_screen.height) delta_y -= Ceil(new_bottom - _screen.height, std::max(1U, w->nested_root->resize_y));
    }
 
    w->SetDirty();
 
    uint new_xinc = std::max(0, (w->nested_root->resize_x == 0) ? 0 : (int)(w->nested_root->current_x - w->nested_root->smallest_x) + delta_x);
    uint new_yinc = std::max(0, (w->nested_root->resize_y == 0) ? 0 : (int)(w->nested_root->current_y - w->nested_root->smallest_y) + delta_y);
    assert(w->nested_root->resize_x == 0 || new_xinc % w->nested_root->resize_x == 0);
    assert(w->nested_root->resize_y == 0 || new_yinc % w->nested_root->resize_y == 0);
 
    w->nested_root->AssignSizePosition(ST_RESIZE, 0, 0, w->nested_root->smallest_x + new_xinc, w->nested_root->smallest_y + new_yinc, _current_text_dir == TD_RTL);
    w->width  = w->nested_root->current_x;
    w->height = w->nested_root->current_y;
  }
 
  EnsureVisibleCaption(w, w->left, w->top);
 
  /* Schedule OnResize to make sure everything is initialised correctly if it needs to be. */
  if (schedule_resize) {
    w->ScheduleResize();
  } else {
    w->OnResize();
  }
  w->SetDirty();
}
void ResizeWindow(Window *w, int delta_x, int delta_y, bool clamp_to_screen, bool schedule_resize) {…}
 
int GetMainViewTop()
{
  Window *w = FindWindowById(WC_MAIN_TOOLBAR, 0);
  return (w == nullptr) ? 0 : w->top + w->height;
}
int GetMainViewTop() {…}
 
int GetMainViewBottom()
{
  Window *w = FindWindowById(WC_STATUS_BAR, 0);
  return (w == nullptr) ? _screen.height : w->top;
}
int GetMainViewBottom() {…}
 
static bool _dragging_window; 
 
static EventState HandleWindowDragging()
{
  /* Get out immediately if no window is being dragged at all. */
  if (!_dragging_window) return ES_NOT_HANDLED;
 
  /* If button still down, but cursor hasn't moved, there is nothing to do. */
  if (_left_button_down && _cursor.delta.x == 0 && _cursor.delta.y == 0) return ES_HANDLED;
 
  /* Otherwise find the window... */
  for (Window *w : Window::Iterate()) {
    if (w->flags.Test(WindowFlag::Dragging)) {
      /* Stop the dragging if the left mouse button was released */
      if (!_left_button_down) {
        w->flags.Reset(WindowFlag::Dragging);
        break;
      }
 
      w->SetDirty();
 
      int x = _cursor.pos.x + _drag_delta.x;
      int y = _cursor.pos.y + _drag_delta.y;
      int nx = x;
      int ny = y;
 
      if (_settings_client.gui.window_snap_radius != 0) {
        int hsnap = _settings_client.gui.window_snap_radius;
        int vsnap = _settings_client.gui.window_snap_radius;
        int delta;
 
        for (const Window *v : Window::Iterate()) {
          if (v == w) continue; // Don't snap at yourself
 
          if (y + w->height > v->top && y < v->top + v->height) {
            /* Your left border <-> other right border */
            delta = abs(v->left + v->width - x);
            if (delta <= hsnap) {
              nx = v->left + v->width;
              hsnap = delta;
            }
 
            /* Your right border <-> other left border */
            delta = abs(v->left - x - w->width);
            if (delta <= hsnap) {
              nx = v->left - w->width;
              hsnap = delta;
            }
          }
 
          if (w->top + w->height >= v->top && w->top <= v->top + v->height) {
            /* Your left border <-> other left border */
            delta = abs(v->left - x);
            if (delta <= hsnap) {
              nx = v->left;
              hsnap = delta;
            }
 
            /* Your right border <-> other right border */
            delta = abs(v->left + v->width - x - w->width);
            if (delta <= hsnap) {
              nx = v->left + v->width - w->width;
              hsnap = delta;
            }
          }
 
          if (x + w->width > v->left && x < v->left + v->width) {
            /* Your top border <-> other bottom border */
            delta = abs(v->top + v->height - y);
            if (delta <= vsnap) {
              ny = v->top + v->height;
              vsnap = delta;
            }
 
            /* Your bottom border <-> other top border */
            delta = abs(v->top - y - w->height);
            if (delta <= vsnap) {
              ny = v->top - w->height;
              vsnap = delta;
            }
          }
 
          if (w->left + w->width >= v->left && w->left <= v->left + v->width) {
            /* Your top border <-> other top border */
            delta = abs(v->top - y);
            if (delta <= vsnap) {
              ny = v->top;
              vsnap = delta;
            }
 
            /* Your bottom border <-> other bottom border */
            delta = abs(v->top + v->height - y - w->height);
            if (delta <= vsnap) {
              ny = v->top + v->height - w->height;
              vsnap = delta;
            }
          }
        }
      }
 
      EnsureVisibleCaption(w, nx, ny);
 
      w->SetDirty();
      return ES_HANDLED;
    } else if (w->flags.Test(WindowFlag::SizingLeft) || w->flags.Test(WindowFlag::SizingRight)) {
      /* Stop the sizing if the left mouse button was released */
      if (!_left_button_down) {
        w->flags.Reset(WindowFlag::SizingLeft);
        w->flags.Reset(WindowFlag::SizingRight);
        w->SetDirty();
        break;
      }
 
      /* Compute difference in pixels between cursor position and reference point in the window.
       * If resizing the left edge of the window, moving to the left makes the window bigger not smaller.
       */
      int x, y = _cursor.pos.y - _drag_delta.y;
      if (w->flags.Test(WindowFlag::SizingLeft)) {
        x = _drag_delta.x - _cursor.pos.x;
      } else {
        x = _cursor.pos.x - _drag_delta.x;
      }
 
      /* resize.step_width and/or resize.step_height may be 0, which means no resize is possible. */
      if (w->resize.step_width  == 0) x = 0;
      if (w->resize.step_height == 0) y = 0;
 
      /* Check the resize button won't go past the bottom of the screen */
      if (w->top + w->height + y > _screen.height) {
        y = _screen.height - w->height - w->top;
      }
 
      /* X and Y has to go by step.. calculate it.
       * The cast to int is necessary else x/y are implicitly casted to
       * unsigned int, which won't work. */
      if (w->resize.step_width  > 1) x -= x % (int)w->resize.step_width;
      if (w->resize.step_height > 1) y -= y % (int)w->resize.step_height;
 
      /* Check that we don't go below the minimum set size */
      if ((int)w->width + x < (int)w->nested_root->smallest_x) {
        x = w->nested_root->smallest_x - w->width;
      }
      if ((int)w->height + y < (int)w->nested_root->smallest_y) {
        y = w->nested_root->smallest_y - w->height;
      }
 
      /* Window already on size */
      if (x == 0 && y == 0) return ES_HANDLED;
 
      /* Now find the new cursor pos.. this is NOT _cursor, because we move in steps. */
      _drag_delta.y += y;
      if (w->flags.Test(WindowFlag::SizingLeft) && x != 0) {
        _drag_delta.x -= x; // x > 0 -> window gets longer -> left-edge moves to left -> subtract x to get new position.
        w->SetDirty();
        w->left -= x;  // If dragging left edge, move left window edge in opposite direction by the same amount.
        /* ResizeWindow() below ensures marking new position as dirty. */
      } else {
        _drag_delta.x += x;
      }
 
      /* ResizeWindow sets both pre- and after-size to dirty for redrawal */
      ResizeWindow(w, x, y);
      return ES_HANDLED;
    }
  }
 
  _dragging_window = false;
  return ES_HANDLED;
}
static EventState HandleWindowDragging() {…}
 
static void StartWindowDrag(Window *w)
{
  w->flags.Set(WindowFlag::Dragging);
  w->flags.Reset(WindowFlag::Centred);
  _dragging_window = true;
 
  _drag_delta.x = w->left - _cursor.pos.x;
  _drag_delta.y = w->top  - _cursor.pos.y;
 
  BringWindowToFront(w);
}
static void StartWindowDrag(Window *w) {…}
 
static void StartWindowSizing(Window *w, bool to_left)
{
  w->flags.Set(to_left ? WindowFlag::SizingLeft : WindowFlag::SizingRight);
  w->flags.Reset(WindowFlag::Centred);
  _dragging_window = true;
 
  _drag_delta.x = _cursor.pos.x;
  _drag_delta.y = _cursor.pos.y;
 
  BringWindowToFront(w);
}
static void StartWindowSizing(Window *w, bool to_left) {…}
 
static void HandleScrollbarScrolling(Window *w)
{
  int i;
  NWidgetScrollbar *sb = w->GetWidget<NWidgetScrollbar>(w->mouse_capture_widget);
  bool rtl = false;
 
  if (sb->type == NWID_HSCROLLBAR) {
    i = _cursor.pos.x - _cursorpos_drag_start.x;
    rtl = _current_text_dir == TD_RTL;
  } else {
    i = _cursor.pos.y - _cursorpos_drag_start.y;
  }
 
  if (sb->disp_flags.Any({NWidgetDisplayFlag::ScrollbarUp, NWidgetDisplayFlag::ScrollbarDown})) {
    if (_scroller_click_timeout == 1) {
      _scroller_click_timeout = 3;
      if (sb->UpdatePosition(rtl == sb->disp_flags.Test(NWidgetDisplayFlag::ScrollbarUp) ? 1 : -1)) {
        w->OnScrollbarScroll(w->mouse_capture_widget);
        w->SetDirty();
      }
    }
    return;
  }
 
  /* Find the item we want to move to. SetPosition will make sure it's inside bounds. */
  int range = sb->GetCount() - sb->GetCapacity();
  if (range <= 0) return;
 
  int pos = RoundDivSU((i + _scrollbar_start_pos) * range, std::max(1, _scrollbar_size));
  if (rtl) pos = range - pos;
  if (sb->SetPosition(pos)) {
    w->OnScrollbarScroll(w->mouse_capture_widget);
    w->SetDirty();
  }
}
static void HandleScrollbarScrolling(Window *w) {…}
 
static EventState HandleActiveWidget()
{
  for (Window *w : Window::Iterate()) {
    if (w->mouse_capture_widget >= 0) {
      /* Abort if no button is clicked any more. */
      if (!_left_button_down) {
        w->SetWidgetDirty(w->mouse_capture_widget);
        w->mouse_capture_widget = -1;
        return ES_HANDLED;
      }
 
      /* Handle scrollbar internally, or dispatch click event */
      WidgetType type = w->GetWidget<NWidgetBase>(w->mouse_capture_widget)->type;
      if (type == NWID_VSCROLLBAR || type == NWID_HSCROLLBAR) {
        HandleScrollbarScrolling(w);
      } else {
        /* If cursor hasn't moved, there is nothing to do. */
        if (_cursor.delta.x == 0 && _cursor.delta.y == 0) return ES_HANDLED;
 
        Point pt = { _cursor.pos.x - w->left, _cursor.pos.y - w->top };
        w->OnClick(pt, w->mouse_capture_widget, 0);
      }
      return ES_HANDLED;
    }
  }
 
  return ES_NOT_HANDLED;
}
static EventState HandleActiveWidget() {…}
 
static EventState HandleViewportScroll()
{
  bool scrollwheel_scrolling = _settings_client.gui.scrollwheel_scrolling == SWS_SCROLL_MAP && _cursor.wheel_moved;
 
  if (!_scrolling_viewport) return ES_NOT_HANDLED;
 
  /* When we don't have a last scroll window we are starting to scroll.
   * When the last scroll window and this are not the same we went
   * outside of the window and should not left-mouse scroll anymore. */
  if (_last_scroll_window == nullptr) _last_scroll_window = FindWindowFromPt(_cursor.pos.x, _cursor.pos.y);
 
  if (_last_scroll_window == nullptr || !((_settings_client.gui.scroll_mode != VSM_MAP_LMB && _right_button_down) || scrollwheel_scrolling || (_settings_client.gui.scroll_mode == VSM_MAP_LMB && _left_button_down))) {
    _cursor.fix_at = false;
    _scrolling_viewport = false;
    _last_scroll_window = nullptr;
    return ES_NOT_HANDLED;
  }
 
  if (_last_scroll_window == GetMainWindow() && _last_scroll_window->viewport->follow_vehicle != VehicleID::Invalid()) {
    /* If the main window is following a vehicle, then first let go of it! */
    const Vehicle *veh = Vehicle::Get(_last_scroll_window->viewport->follow_vehicle);
    ScrollMainWindowTo(veh->x_pos, veh->y_pos, veh->z_pos, true); // This also resets follow_vehicle
    return ES_NOT_HANDLED;
  }
 
  Point delta;
  if (scrollwheel_scrolling) {
    /* We are using scrollwheels for scrolling */
    /* Use the integer part for movement */
    delta.x = static_cast<int>(_cursor.h_wheel);
    delta.y = static_cast<int>(_cursor.v_wheel);
    /* Keep the fractional part so that subtle movement is accumulated */
    float temp;
    _cursor.v_wheel = std::modf(_cursor.v_wheel, &temp);
    _cursor.h_wheel = std::modf(_cursor.h_wheel, &temp);
  } else {
    if (_settings_client.gui.scroll_mode != VSM_VIEWPORT_RMB_FIXED) {
      delta.x = -_cursor.delta.x;
      delta.y = -_cursor.delta.y;
    } else {
      delta.x = _cursor.delta.x;
      delta.y = _cursor.delta.y;
    }
  }
 
  /* Create a scroll-event and send it to the window */
  if (delta.x != 0 || delta.y != 0) _last_scroll_window->OnScroll(delta);
 
  _cursor.delta.x = 0;
  _cursor.delta.y = 0;
  _cursor.wheel_moved = false;
  return ES_HANDLED;
}
static EventState HandleViewportScroll() {…}
 
static bool MaybeBringWindowToFront(Window *w)
{
  bool bring_to_front = false;
 
  if (w->window_class == WC_MAIN_WINDOW ||
      IsVitalWindow(w) ||
      w->window_class == WC_TOOLTIPS ||
      w->window_class == WC_DROPDOWN_MENU) {
    return true;
  }
 
  /* Use unshaded window size rather than current size for shaded windows. */
  int w_width  = w->width;
  int w_height = w->height;
  if (w->IsShaded()) {
    w_width  = w->unshaded_size.width;
    w_height = w->unshaded_size.height;
  }
 
  Window::IteratorToFront it(w);
  ++it;
  for (; !it.IsEnd(); ++it) {
    Window *u = *it;
    /* A modal child will prevent the activation of the parent window */
    if (u->parent == w && u->window_desc.flags.Test(WindowDefaultFlag::Modal)) {
      u->SetWhiteBorder();
      u->SetDirty();
      return false;
    }
 
    if (u->window_class == WC_MAIN_WINDOW ||
        IsVitalWindow(u) ||
        u->window_class == WC_TOOLTIPS ||
        u->window_class == WC_DROPDOWN_MENU) {
      continue;
    }
 
    /* Window sizes don't interfere, leave z-order alone */
    if (w->left + w_width <= u->left ||
        u->left + u->width <= w->left ||
        w->top  + w_height <= u->top ||
        u->top + u->height <= w->top) {
      continue;
    }
 
    bring_to_front = true;
  }
 
  if (bring_to_front) BringWindowToFront(w);
  return true;
}
static bool MaybeBringWindowToFront(Window *w) {…}
 
EventState Window::HandleEditBoxKey(WidgetID wid, char32_t key, uint16_t keycode)
{
  QueryString *query = this->GetQueryString(wid);
  if (query == nullptr) return ES_NOT_HANDLED;
 
  int action = QueryString::ACTION_NOTHING;
 
  switch (query->text.HandleKeyPress(key, keycode)) {
    case HKPR_EDITING:
      this->SetWidgetDirty(wid);
      this->OnEditboxChanged(wid);
      break;
 
    case HKPR_CURSOR:
      this->SetWidgetDirty(wid);
      /* For the OSK also invalidate the parent window */
      if (this->window_class == WC_OSK) this->InvalidateData();
      break;
 
    case HKPR_CONFIRM:
      if (this->window_class == WC_OSK) {
        this->OnClick(Point(), WID_OSK_OK, 1);
      } else if (query->ok_button >= 0) {
        this->OnClick(Point(), query->ok_button, 1);
      } else {
        action = query->ok_button;
      }
      break;
 
    case HKPR_CANCEL:
      if (this->window_class == WC_OSK) {
        this->OnClick(Point(), WID_OSK_CANCEL, 1);
      } else if (query->cancel_button >= 0) {
        this->OnClick(Point(), query->cancel_button, 1);
      } else {
        action = query->cancel_button;
      }
      break;
 
    case HKPR_NOT_HANDLED:
      return ES_NOT_HANDLED;
 
    default: break;
  }
 
  switch (action) {
    case QueryString::ACTION_DESELECT:
      this->UnfocusFocusedWidget();
      break;
 
    case QueryString::ACTION_CLEAR:
      if (query->text.GetText().empty()) {
        /* If already empty, unfocus instead */
        this->UnfocusFocusedWidget();
      } else {
        query->text.DeleteAll();
        this->SetWidgetDirty(wid);
        this->OnEditboxChanged(wid);
      }
      break;
 
    default:
      break;
  }
 
  return ES_HANDLED;
}
EventState Window::HandleEditBoxKey(WidgetID wid, char32_t key, uint16_t keycode) {…}
 
void HandleToolbarHotkey(int hotkey)
{
  assert(HasModalProgress() || IsLocalCompany());
 
  Window *w = FindWindowById(WC_MAIN_TOOLBAR, 0);
  if (w != nullptr) {
    if (w->window_desc.hotkeys != nullptr) {
      if (hotkey >= 0 && w->OnHotkey(hotkey) == ES_HANDLED) return;
    }
  }
}
void HandleToolbarHotkey(int hotkey) {…}
 
void HandleKeypress(uint keycode, char32_t key)
{
  /* World generation is multithreaded and messes with companies.
   * But there is no company related window open anyway, so _current_company is not used. */
  assert(HasModalProgress() || IsLocalCompany());
 
  /*
   * The Unicode standard defines an area called the private use area. Code points in this
   * area are reserved for private use and thus not portable between systems. For instance,
   * Apple defines code points for the arrow keys in this area, but these are only printable
   * on a system running OS X. We don't want these keys to show up in text fields and such,
   * and thus we have to clear the unicode character when we encounter such a key.
   */
  if (key >= 0xE000 && key <= 0xF8FF) key = 0;
 
  /*
   * If both key and keycode is zero, we don't bother to process the event.
   */
  if (key == 0 && keycode == 0) return;
 
  /* Check if the focused window has a focused editbox */
  if (EditBoxInGlobalFocus()) {
    /* All input will in this case go to the focused editbox */
    if (_focused_window->window_class == WC_CONSOLE) {
      if (_focused_window->OnKeyPress(key, keycode) == ES_HANDLED) return;
    } else {
      if (_focused_window->HandleEditBoxKey(_focused_window->nested_focus->GetIndex(), key, keycode) == ES_HANDLED) return;
    }
  }
 
  /* Call the event, start with the uppermost window, but ignore the toolbar. */
  for (Window *w : Window::IterateFromFront()) {
    if (w->window_class == WC_MAIN_TOOLBAR) continue;
    if (w->window_desc.hotkeys != nullptr) {
      int hotkey = w->window_desc.hotkeys->CheckMatch(keycode);
      if (hotkey >= 0 && w->OnHotkey(hotkey) == ES_HANDLED) return;
    }
    if (w->OnKeyPress(key, keycode) == ES_HANDLED) return;
  }
 
  Window *w = FindWindowById(WC_MAIN_TOOLBAR, 0);
  /* When there is no toolbar w is null, check for that */
  if (w != nullptr) {
    if (w->window_desc.hotkeys != nullptr) {
      int hotkey = w->window_desc.hotkeys->CheckMatch(keycode);
      if (hotkey >= 0 && w->OnHotkey(hotkey) == ES_HANDLED) return;
    }
    if (w->OnKeyPress(key, keycode) == ES_HANDLED) return;
  }
 
  HandleGlobalHotkeys(key, keycode);
}
void HandleKeypress(uint keycode, char32_t key) {…}
 
void HandleCtrlChanged()
{
  /* Call the event, start with the uppermost window. */
  for (Window *w : Window::IterateFromFront()) {
    if (w->OnCTRLStateChange() == ES_HANDLED) return;
  }
}
void HandleCtrlChanged() {…}
 
/* virtual */ void Window::InsertTextString(WidgetID wid, std::string_view str, bool marked, std::optional<size_t> caret, std::optional<size_t> insert_location, std::optional<size_t> replacement_end)
{
  QueryString *query = this->GetQueryString(wid);
  if (query == nullptr) return;
 
  if (query->text.InsertString(str, marked, caret, insert_location, replacement_end) || marked) {
    this->SetWidgetDirty(wid);
    this->OnEditboxChanged(wid);
  }
}
/* virtual */ void Window::InsertTextString(WidgetID wid, std::string_view str, bool marked, std::optional<size_t> caret, std::optional<size_t> insert_location, std::optional<size_t> replacement_end) {…}
 
void HandleTextInput(std::string_view str, bool marked, std::optional<size_t> caret, std::optional<size_t> insert_location, std::optional<size_t> replacement_end)
{
  if (!EditBoxInGlobalFocus()) return;
 
  _focused_window->InsertTextString(_focused_window->window_class == WC_CONSOLE ? 0 : _focused_window->nested_focus->GetIndex(), str, marked, caret, insert_location, replacement_end);
}
void HandleTextInput(std::string_view str, bool marked, std::optional<size_t> caret, std::optional<size_t> insert_location, std::optional<size_t> replacement_end) {…}
 
static void HandleAutoscroll()
{
  if (_game_mode == GM_MENU || HasModalProgress()) return;
  if (_settings_client.gui.auto_scrolling == VA_DISABLED) return;
  if (_settings_client.gui.auto_scrolling == VA_MAIN_VIEWPORT_FULLSCREEN && !_fullscreen) return;
 
  int x = _cursor.pos.x;
  int y = _cursor.pos.y;
  Window *w = FindWindowFromPt(x, y);
  if (w == nullptr || w->flags.Test(WindowFlag::DisableVpScroll)) return;
  if (_settings_client.gui.auto_scrolling != VA_EVERY_VIEWPORT && w->window_class != WC_MAIN_WINDOW) return;
 
  Viewport *vp = IsPtInWindowViewport(w, x, y);
  if (vp == nullptr) return;
 
  x -= vp->left;
  y -= vp->top;
 
  /* here allows scrolling in both x and y axis */
  /* If we succeed at scrolling in any direction, stop following a vehicle. */
  static const int SCROLLSPEED = 3;
  if (x - 15 < 0) {
    w->viewport->CancelFollow(*w);
    w->viewport->dest_scrollpos_x += ScaleByZoom((x - 15) * SCROLLSPEED, vp->zoom);
  } else if (15 - (vp->width - x) > 0) {
    w->viewport->CancelFollow(*w);
    w->viewport->dest_scrollpos_x += ScaleByZoom((15 - (vp->width - x)) * SCROLLSPEED, vp->zoom);
  }
  if (y - 15 < 0) {
    w->viewport->CancelFollow(*w);
    w->viewport->dest_scrollpos_y += ScaleByZoom((y - 15) * SCROLLSPEED, vp->zoom);
  } else if (15 - (vp->height - y) > 0) {
    w->viewport->CancelFollow(*w);
    w->viewport->dest_scrollpos_y += ScaleByZoom((15 - (vp->height - y)) * SCROLLSPEED, vp->zoom);
  }
}
static void HandleAutoscroll() {…}
 
enum MouseClick : uint8_t {
  MC_NONE = 0,
  MC_LEFT,
  MC_RIGHT,
  MC_DOUBLE_LEFT,
  MC_HOVER,
};
 
static constexpr int MAX_OFFSET_DOUBLE_CLICK = 5; 
static constexpr int MAX_OFFSET_HOVER = 5; 
 
extern EventState VpHandlePlaceSizingDrag();
 
const std::chrono::milliseconds TIME_BETWEEN_DOUBLE_CLICK(500); 
 
static void ScrollMainViewport(int x, int y)
{
  if (_game_mode != GM_MENU && _game_mode != GM_BOOTSTRAP) {
    Window *w = GetMainWindow();
    w->viewport->dest_scrollpos_x += ScaleByZoom(x, w->viewport->zoom);
    w->viewport->dest_scrollpos_y += ScaleByZoom(y, w->viewport->zoom);
  }
}
 
static const int8_t scrollamt[16][2] = {
  { 0,  0}, 
  {-2,  0}, 
  { 0, -2}, 
  {-2, -1}, 
  { 2,  0}, 
  { 0,  0}, 
  { 2, -1}, 
  { 0, -2}, 
  { 0,  2}, 
  {-2,  1}, 
  { 0,  0}, 
  {-2,  0}, 
  { 2,  1}, 
  { 0,  2}, 
  { 2,  0}, 
  { 0,  0}, 
};
static const int8_t scrollamt[16][2] = {…};
 
static void HandleKeyScrolling()
{
  /*
   * Check that any of the dirkeys is pressed and that the focused window
   * doesn't have an edit-box as focused widget.
   */
  if (_dirkeys && !EditBoxInGlobalFocus()) {
    int factor = _shift_pressed ? 50 : 10;
 
    if (_game_mode != GM_MENU && _game_mode != GM_BOOTSTRAP) {
      /* Key scrolling stops following a vehicle. */
      Window *main_window = GetMainWindow();
      main_window->viewport->CancelFollow(*main_window);
    }
 
    ScrollMainViewport(scrollamt[_dirkeys][0] * factor, scrollamt[_dirkeys][1] * factor);
  }
}
 
static void MouseLoop(MouseClick click, int mousewheel)
{
  /* World generation is multithreaded and messes with companies.
   * But there is no company related window open anyway, so _current_company is not used. */
  assert(HasModalProgress() || IsLocalCompany());
 
  HandlePlacePresize();
  UpdateTileSelection();
 
  if (VpHandlePlaceSizingDrag()  == ES_HANDLED) return;
  if (HandleMouseDragDrop()      == ES_HANDLED) return;
  if (HandleWindowDragging()     == ES_HANDLED) return;
  if (HandleActiveWidget()       == ES_HANDLED) return;
  if (HandleViewportScroll()     == ES_HANDLED) return;
 
  HandleMouseOver();
 
  bool scrollwheel_scrolling = _settings_client.gui.scrollwheel_scrolling == SWS_SCROLL_MAP && _cursor.wheel_moved;
  if (click == MC_NONE && mousewheel == 0 && !scrollwheel_scrolling) return;
 
  int x = _cursor.pos.x;
  int y = _cursor.pos.y;
  Window *w = FindWindowFromPt(x, y);
  if (w == nullptr) return;
 
  if (click != MC_HOVER && !MaybeBringWindowToFront(w)) return;
  Viewport *vp = IsPtInWindowViewport(w, x, y);
 
  /* Don't allow any action in a viewport if either in menu or when having a modal progress window */
  if (vp != nullptr && (_game_mode == GM_MENU || HasModalProgress())) return;
 
  if (mousewheel != 0) {
    /* Send mousewheel event to window, unless we're scrolling a viewport or the map */
    if (!scrollwheel_scrolling || (vp == nullptr && w->window_class != WC_SMALLMAP)) {
      if (NWidgetCore *nwid = w->nested_root->GetWidgetFromPos(x - w->left, y - w->top); nwid != nullptr) {
        w->OnMouseWheel(mousewheel, nwid->GetIndex());
      }
    }
 
    /* Dispatch a MouseWheelEvent for widgets if it is not a viewport */
    if (vp == nullptr) DispatchMouseWheelEvent(w, w->nested_root->GetWidgetFromPos(x - w->left, y - w->top), mousewheel);
  }
 
  if (vp != nullptr) {
    if (scrollwheel_scrolling && !w->flags.Test(WindowFlag::DisableVpScroll)) {
      _scrolling_viewport = true;
      _cursor.fix_at = true;
      return;
    }
 
    switch (click) {
      case MC_DOUBLE_LEFT:
      case MC_LEFT:
        if (HandleViewportClicked(*vp, x, y)) return;
        if (!w->flags.Test(WindowFlag::DisableVpScroll) &&
            _settings_client.gui.scroll_mode == VSM_MAP_LMB) {
          _scrolling_viewport = true;
          _cursor.fix_at = false;
          return;
        }
        break;
 
      case MC_RIGHT:
        if (!w->flags.Test(WindowFlag::DisableVpScroll) &&
            _settings_client.gui.scroll_mode != VSM_MAP_LMB) {
          _scrolling_viewport = true;
          _cursor.fix_at = (_settings_client.gui.scroll_mode == VSM_VIEWPORT_RMB_FIXED ||
              _settings_client.gui.scroll_mode == VSM_MAP_RMB_FIXED);
          DispatchRightClickEvent(w, x - w->left, y - w->top);
          return;
        }
        break;
 
      default:
        break;
    }
  }
 
  switch (click) {
    case MC_LEFT:
    case MC_DOUBLE_LEFT:
      DispatchLeftClickEvent(w, x - w->left, y - w->top, click == MC_DOUBLE_LEFT ? 2 : 1);
      return;
 
    default:
      if (!scrollwheel_scrolling || w == nullptr || w->window_class != WC_SMALLMAP) break;
      /* We try to use the scrollwheel to scroll since we didn't touch any of the buttons.
       * Simulate a right button click so we can get started. */
      [[fallthrough]];
 
    case MC_RIGHT:
      DispatchRightClickEvent(w, x - w->left, y - w->top);
      return;
 
    case MC_HOVER:
      DispatchHoverEvent(w, x - w->left, y - w->top);
      break;
  }
 
  /* We're not doing anything with 2D scrolling, so reset the value.  */
  _cursor.h_wheel = 0.0f;
  _cursor.v_wheel = 0.0f;
  _cursor.wheel_moved = false;
}
 
void HandleMouseEvents()
{
  /* World generation is multithreaded and messes with companies.
   * But there is no company related window open anyway, so _current_company is not used. */
  assert(HasModalProgress() || IsLocalCompany());
 
  static std::chrono::steady_clock::time_point double_click_time = {};
  static Point double_click_pos = {0, 0};
 
  /* Mouse event? */
  MouseClick click = MC_NONE;
  if (_left_button_down && !_left_button_clicked) {
    click = MC_LEFT;
    if (std::chrono::steady_clock::now() <= double_click_time + TIME_BETWEEN_DOUBLE_CLICK &&
        double_click_pos.x != 0 && abs(_cursor.pos.x - double_click_pos.x) < MAX_OFFSET_DOUBLE_CLICK  &&
        double_click_pos.y != 0 && abs(_cursor.pos.y - double_click_pos.y) < MAX_OFFSET_DOUBLE_CLICK) {
      click = MC_DOUBLE_LEFT;
    }
    double_click_time = std::chrono::steady_clock::now();
    double_click_pos = _cursor.pos;
    _left_button_clicked = true;
  } else if (_right_button_clicked) {
    _right_button_clicked = false;
    click = MC_RIGHT;
  }
 
  int mousewheel = 0;
  if (_cursor.wheel) {
    mousewheel = _cursor.wheel;
    _cursor.wheel = 0;
  }
 
  static std::chrono::steady_clock::time_point hover_time = {};
  static Point hover_pos = {0, 0};
 
  if (_settings_client.gui.hover_delay_ms > 0) {
    if (!_cursor.in_window || click != MC_NONE || mousewheel != 0 || _left_button_down || _right_button_down ||
        hover_pos.x == 0 || abs(_cursor.pos.x - hover_pos.x) >= MAX_OFFSET_HOVER  ||
        hover_pos.y == 0 || abs(_cursor.pos.y - hover_pos.y) >= MAX_OFFSET_HOVER) {
      hover_pos = _cursor.pos;
      hover_time = std::chrono::steady_clock::now();
      _mouse_hovering = false;
    } else if (!_mouse_hovering) {
      if (std::chrono::steady_clock::now() > hover_time + std::chrono::milliseconds(_settings_client.gui.hover_delay_ms)) {
        click = MC_HOVER;
        _mouse_hovering = true;
        hover_time = std::chrono::steady_clock::now();
      }
    }
  }
 
  if (click == MC_LEFT && _newgrf_debug_sprite_picker.mode == SPM_WAIT_CLICK) {
    /* Mark whole screen dirty, and wait for the next realtime tick, when drawing is finished. */
    Blitter *blitter = BlitterFactory::GetCurrentBlitter();
    _newgrf_debug_sprite_picker.clicked_pixel = blitter->MoveTo(_screen.dst_ptr, _cursor.pos.x, _cursor.pos.y);
    _newgrf_debug_sprite_picker.sprites.clear();
    _newgrf_debug_sprite_picker.mode = SPM_REDRAW;
    MarkWholeScreenDirty();
  } else {
    MouseLoop(click, mousewheel);
  }
 
  /* We have moved the mouse the required distance,
   * no need to move it at any later time. */
  _cursor.delta.x = 0;
  _cursor.delta.y = 0;
}
void HandleMouseEvents() {…}
 
static void CheckSoftLimit()
{
  if (_settings_client.gui.window_soft_limit == 0) return;
 
  for (;;) {
    uint deletable_count = 0;
    Window *last_deletable = nullptr;
    for (Window *w : Window::IterateFromFront()) {
      if (w->window_class == WC_MAIN_WINDOW || IsVitalWindow(w) || w->flags.Test(WindowFlag::Sticky)) continue;
 
      last_deletable = w;
      deletable_count++;
    }
 
    /* We've not reached the soft limit yet. */
    if (deletable_count <= _settings_client.gui.window_soft_limit) break;
 
    assert(last_deletable != nullptr);
    last_deletable->Close();
  }
}
static void CheckSoftLimit() {…}
 
void InputLoop()
{
  /* World generation is multithreaded and messes with companies.
   * But there is no company related window open anyway, so _current_company is not used. */
  assert(HasModalProgress() || IsLocalCompany());
 
  CheckSoftLimit();
 
  /* Process scheduled window deletion. */
  Window::DeleteClosedWindows();
 
  /* HandleMouseEvents was already called for this tick */
  HandleMouseEvents();
}
void InputLoop() {…}
 
static std::chrono::time_point<std::chrono::steady_clock> _realtime_tick_start;
 
bool CanContinueRealtimeTick()
{
  auto now = std::chrono::steady_clock::now();
  return std::chrono::duration_cast<std::chrono::milliseconds>(now - _realtime_tick_start).count() < (MILLISECONDS_PER_TICK * 3 / 4);
}
 
void CallWindowRealtimeTickEvent(uint delta_ms)
{
  _realtime_tick_start = std::chrono::steady_clock::now();
  for (Window *w : Window::Iterate()) {
    w->OnRealtimeTick(delta_ms);
  }
}
void CallWindowRealtimeTickEvent(uint delta_ms) {…}
 
static const IntervalTimer<TimerWindow> window_interval(std::chrono::milliseconds(30), [](auto) {
  extern int _caret_timer;
  _caret_timer += 3;
  CursorTick();
 
  HandleKeyScrolling();
  HandleAutoscroll();
  DecreaseWindowCounters();
});
 
static const IntervalTimer<TimerWindow> highlight_interval(TIMER_BLINK_INTERVAL, [](auto) {
  _window_highlight_colour = !_window_highlight_colour;
});
 
static const IntervalTimer<TimerWindow> white_border_interval(std::chrono::milliseconds(30), [](auto) {
  if (_network_dedicated) return;
 
  for (Window *w : Window::Iterate()) {
    if (w->flags.Test(WindowFlag::WhiteBorder) && --w->white_border_timer == 0) {
      w->flags.Reset(WindowFlag::WhiteBorder);
      w->SetDirty();
    }
  }
});
 
void UpdateWindows()
{
  static auto last_time = std::chrono::steady_clock::now();
  auto now = std::chrono::steady_clock::now();
  auto delta_ms = std::chrono::duration_cast<std::chrono::milliseconds>(now - last_time);
 
  if (delta_ms.count() == 0) return;
 
  last_time = now;
 
  PerformanceMeasurer framerate(PFE_DRAWING);
  PerformanceAccumulator::Reset(PFE_DRAWWORLD);
 
  ProcessPendingPerformanceMeasurements();
 
  TimerManager<TimerWindow>::Elapsed(delta_ms);
  CallWindowRealtimeTickEvent(delta_ms.count());
 
  /* Process invalidations before anything else. */
  for (Window *w : Window::Iterate()) {
    w->ProcessScheduledResize();
    w->ProcessScheduledInvalidations();
    w->ProcessHighlightedInvalidations();
  }
 
  /* Skip the actual drawing on dedicated servers without screen.
   * But still empty the invalidation queues above. */
  if (_network_dedicated) return;
 
  DrawDirtyBlocks();
 
  for (Window *w : Window::Iterate()) {
    /* Update viewport only if window is not shaded. */
    if (w->viewport != nullptr && !w->IsShaded()) UpdateViewportPosition(w, delta_ms.count());
  }
  NetworkDrawChatMessage();
  /* Redraw mouse cursor in case it was hidden */
  DrawMouseCursor();
 
  if (_newgrf_debug_sprite_picker.mode == SPM_REDRAW) {
    /* We are done with the last draw-frame, so we know what sprites we
     * clicked on. Reset the picker mode and invalidate the window. */
    _newgrf_debug_sprite_picker.mode = SPM_NONE;
    InvalidateWindowData(WC_SPRITE_ALIGNER, 0, 1);
  }
}
void UpdateWindows() {…}
 
void SetWindowDirty(WindowClass cls, WindowNumber number)
{
  for (const Window *w : Window::Iterate()) {
    if (w->window_class == cls && w->window_number == number) w->SetDirty();
  }
}
void SetWindowDirty(WindowClass cls, WindowNumber number) {…}
 
void SetWindowWidgetDirty(WindowClass cls, WindowNumber number, WidgetID widget_index)
{
  for (const Window *w : Window::Iterate()) {
    if (w->window_class == cls && w->window_number == number) {
      w->SetWidgetDirty(widget_index);
    }
  }
}
void SetWindowWidgetDirty(WindowClass cls, WindowNumber number, WidgetID widget_index) {…}
 
void SetWindowClassesDirty(WindowClass cls)
{
  for (const Window *w : Window::Iterate()) {
    if (w->window_class == cls) w->SetDirty();
  }
}
void SetWindowClassesDirty(WindowClass cls) {…}
 
void Window::ScheduleResize()
{
  this->scheduled_resize = true;
}
void Window::ScheduleResize() {…}
 
void Window::ProcessScheduledResize()
{
  /* Sometimes OnResize() resizes the window again, in which case we can reprocess immediately. */
  while (this->scheduled_resize) {
    this->scheduled_resize = false;
    this->OnResize();
  }
}
void Window::ProcessScheduledResize() {…}
 
void Window::InvalidateData(int data, bool gui_scope)
{
  this->SetDirty();
  if (!gui_scope) {
    /* Schedule GUI-scope invalidation for next redraw. */
    this->scheduled_invalidation_data.push_back(data);
  }
  this->OnInvalidateData(data, gui_scope);
}
void Window::InvalidateData(int data, bool gui_scope) {…}
 
void Window::ProcessScheduledInvalidations()
{
  for (int data : this->scheduled_invalidation_data) {
    if (this->window_class == WC_INVALID) break;
    this->OnInvalidateData(data, true);
  }
  this->scheduled_invalidation_data.clear();
}
void Window::ProcessScheduledInvalidations() {…}
 
void Window::ProcessHighlightedInvalidations()
{
  if (!this->flags.Test(WindowFlag::Highlighted)) return;
 
  for (const auto &pair : this->widget_lookup) {
    if (pair.second->IsHighlighted()) pair.second->SetDirty(this);
  }
}
void Window::ProcessHighlightedInvalidations() {…}
 
void InvalidateWindowData(WindowClass cls, WindowNumber number, int data, bool gui_scope)
{
  for (Window *w : Window::Iterate()) {
    if (w->window_class == cls && w->window_number == number) {
      w->InvalidateData(data, gui_scope);
    }
  }
}
void InvalidateWindowData(WindowClass cls, WindowNumber number, int data, bool gui_scope) {…}
 
void InvalidateWindowClassesData(WindowClass cls, int data, bool gui_scope)
{
  for (Window *w : Window::Iterate()) {
    if (w->window_class == cls) {
      w->InvalidateData(data, gui_scope);
    }
  }
}
void InvalidateWindowClassesData(WindowClass cls, int data, bool gui_scope) {…}
 
void CallWindowGameTickEvent()
{
  for (Window *w : Window::Iterate()) {
    w->OnGameTick();
  }
}
void CallWindowGameTickEvent() {…}
 
void CloseNonVitalWindows()
{
  /* Note: the container remains stable, even when deleting windows. */
  for (Window *w : Window::Iterate()) {
    if (!w->window_desc.flags.Test(WindowDefaultFlag::NoClose) &&
        !w->flags.Test(WindowFlag::Sticky)) { // do not delete windows which are 'pinned'
 
      w->Close();
    }
  }
}
void CloseNonVitalWindows() {…}
 
void CloseAllNonVitalWindows()
{
  /* Note: the container remains stable, even when closing windows. */
  for (Window *w : Window::Iterate()) {
    if (!w->window_desc.flags.Test(WindowDefaultFlag::NoClose)) {
      w->Close();
    }
  }
}
void CloseAllNonVitalWindows() {…}
 
void DeleteAllMessages()
{
  InitNewsItemStructs();
  InvalidateWindowData(WC_STATUS_BAR, 0, SBI_NEWS_DELETED); // invalidate the statusbar
  InvalidateWindowData(WC_MESSAGE_HISTORY, 0); // invalidate the message history
  CloseWindowById(WC_NEWS_WINDOW, 0); // close newspaper or general message window if shown
}
void DeleteAllMessages() {…}
 
void CloseConstructionWindows()
{
  /* Note: the container remains stable, even when deleting windows. */
  for (Window *w : Window::Iterate()) {
    if (w->window_desc.flags.Test(WindowDefaultFlag::Construction)) {
      w->Close();
    }
  }
 
  for (const Window *w : Window::Iterate()) w->SetDirty();
}
void CloseConstructionWindows() {…}
 
void HideVitalWindows()
{
  CloseWindowById(WC_MAIN_TOOLBAR, 0);
  CloseWindowById(WC_STATUS_BAR, 0);
}
void HideVitalWindows() {…}
 
void ReInitWindow(Window *w, bool zoom_changed)
{
  if (w == nullptr) return;
  if (zoom_changed) {
    w->nested_root->AdjustPaddingForZoom();
    w->UpdateQueryStringSize();
  }
  w->ReInit();
}
 
void ReInitAllWindows(bool zoom_changed)
{
  SetupWidgetDimensions();
  NWidgetLeaf::InvalidateDimensionCache(); // Reset cached sizes of several widgets.
  NWidgetScrollbar::InvalidateDimensionCache();
 
  InitDepotWindowBlockSizes();
 
  /* When _gui_zoom has changed, we need to resize toolbar and statusbar first,
   * so EnsureVisibleCaption uses the updated size information. */
  ReInitWindow(FindWindowById(WC_MAIN_TOOLBAR, 0), zoom_changed);
  ReInitWindow(FindWindowById(WC_STATUS_BAR, 0), zoom_changed);
  for (Window *w : Window::Iterate()) {
    if (w->window_class == WC_MAIN_TOOLBAR || w->window_class == WC_STATUS_BAR) continue;
    ReInitWindow(w, zoom_changed);
  }
 
  if (_networking) NetworkUndrawChatMessage();
  NetworkReInitChatBoxSize();
 
  /* Make sure essential parts of all windows are visible */
  RelocateAllWindows(_screen.width, _screen.height);
  MarkWholeScreenDirty();
}
void ReInitAllWindows(bool zoom_changed) {…}
 
static int PositionWindow(Window *w, WindowClass clss, int setting)
{
  if (w == nullptr || w->window_class != clss) {
    w = FindWindowById(clss, 0);
  }
  if (w == nullptr) return 0;
 
  int old_left = w->left;
  switch (setting) {
    case 1:  w->left = (_screen.width - w->width) / 2; break;
    case 2:  w->left = _screen.width - w->width; break;
    default: w->left = 0; break;
  }
  if (w->viewport != nullptr) w->viewport->left += w->left - old_left;
  AddDirtyBlock(0, w->top, _screen.width, w->top + w->height); // invalidate the whole row
  return w->left;
}
static int PositionWindow(Window *w, WindowClass clss, int setting) {…}
 
int PositionMainToolbar(Window *w)
{
  Debug(misc, 5, "Repositioning Main Toolbar...");
  return PositionWindow(w, WC_MAIN_TOOLBAR, _settings_client.gui.toolbar_pos);
}
int PositionMainToolbar(Window *w) {…}
 
int PositionStatusbar(Window *w)
{
  Debug(misc, 5, "Repositioning statusbar...");
  return PositionWindow(w, WC_STATUS_BAR, _settings_client.gui.statusbar_pos);
}
int PositionStatusbar(Window *w) {…}
 
int PositionNewsMessage(Window *w)
{
  Debug(misc, 5, "Repositioning news message...");
  return PositionWindow(w, WC_NEWS_WINDOW, _settings_client.gui.statusbar_pos);
}
int PositionNewsMessage(Window *w) {…}
 
int PositionNetworkChatWindow(Window *w)
{
  Debug(misc, 5, "Repositioning network chat window...");
  return PositionWindow(w, WC_SEND_NETWORK_MSG, _settings_client.gui.statusbar_pos);
}
int PositionNetworkChatWindow(Window *w) {…}
 
 
void ChangeVehicleViewports(VehicleID from_index, VehicleID to_index)
{
  for (const Window *w : Window::Iterate()) {
    if (w->viewport != nullptr && w->viewport->follow_vehicle == from_index) {
      w->viewport->follow_vehicle = to_index;
      w->SetDirty();
    }
  }
}
void ChangeVehicleViewports(VehicleID from_index, VehicleID to_index) {…}
 
 
void RelocateAllWindows(int neww, int newh)
{
  CloseWindowByClass(WC_DROPDOWN_MENU);
 
  /* Reposition toolbar then status bar before other all windows. */
  if (Window *wt = FindWindowById(WC_MAIN_TOOLBAR, 0); wt != nullptr) {
    ResizeWindow(wt, std::min<uint>(neww, _toolbar_width) - wt->width, 0, false);
    wt->left = PositionMainToolbar(wt);
  }
 
  if (Window *ws = FindWindowById(WC_STATUS_BAR, 0); ws != nullptr) {
    ResizeWindow(ws, std::min<uint>(neww, _toolbar_width) - ws->width, 0, false);
    ws->top = newh - ws->height;
    ws->left = PositionStatusbar(ws);
  }
 
  for (Window *w : Window::Iterate()) {
    int left, top;
    /* XXX - this probably needs something more sane. For example specifying
     * in a 'backup'-desc that the window should always be centered. */
    switch (w->window_class) {
      case WC_MAIN_WINDOW:
      case WC_BOOTSTRAP:
      case WC_HIGHSCORE:
      case WC_ENDSCREEN:
        ResizeWindow(w, neww, newh);
        continue;
 
      case WC_MAIN_TOOLBAR:
      case WC_STATUS_BAR:
        continue;
 
      case WC_NEWS_WINDOW:
        top = newh - w->height;
        left = PositionNewsMessage(w);
        break;
 
      case WC_SEND_NETWORK_MSG:
        ResizeWindow(w, std::min<uint>(neww, _toolbar_width) - w->width, 0, false);
 
        top = newh - w->height - FindWindowById(WC_STATUS_BAR, 0)->height;
        left = PositionNetworkChatWindow(w);
        break;
 
      case WC_CONSOLE:
        IConsoleResize(w);
        continue;
 
      default: {
        if (w->flags.Test(WindowFlag::Centred)) {
          top = (newh - w->height) >> 1;
          left = (neww - w->width) >> 1;
          break;
        }
 
        left = w->left;
        if (left + (w->width >> 1) >= neww) left = neww - w->width;
        if (left < 0) left = 0;
 
        top = w->top;
        if (top + (w->height >> 1) >= newh) top = newh - w->height;
        break;
      }
    }
 
    EnsureVisibleCaption(w, left, top);
  }
}
void RelocateAllWindows(int neww, int newh) {…}
 
void PickerWindowBase::Close([[maybe_unused]] int data)
{
  ResetObjectToPlace();
  this->Window::Close();
}
void PickerWindowBase::Close([[maybe_unused]] int data) {…}