dropdown.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 "../window_gui.h"
#include "../string_func.h"
#include "../strings_func.h"
#include "../window_func.h"
#include "../guitimer_func.h"
#include "../zoom_func.h"
#include "dropdown_type.h"
 
#include "dropdown_widget.h"
 
#include "../safeguards.h"
 
 
void DropDownListItem::Draw(const Rect &r, bool sel, Colours bg_colour) const
{
  int c1 = _colour_gradient[bg_colour][3];
  int c2 = _colour_gradient[bg_colour][7];
 
  int mid = CenterBounds(r.top, r.bottom, 0);
  GfxFillRect(r.left, mid - WidgetDimensions::scaled.bevel.bottom, r.right, mid - 1, c1);
  GfxFillRect(r.left, mid, r.right, mid + WidgetDimensions::scaled.bevel.top - 1, c2);
}
 
uint DropDownListStringItem::Width() const
{
  char buffer[512];
  GetString(buffer, this->String(), lastof(buffer));
  return GetStringBoundingBox(buffer).width + WidgetDimensions::scaled.dropdowntext.Horizontal();
}
 
void DropDownListStringItem::Draw(const Rect &r, bool sel, Colours bg_colour) const
{
  Rect ir = r.Shrink(WidgetDimensions::scaled.dropdowntext);
  DrawString(ir.left, ir.right, r.top, this->String(), sel ? TC_WHITE : TC_BLACK);
}
 
/* static */ bool DropDownListStringItem::NatSortFunc(std::unique_ptr<const DropDownListItem> const &first, std::unique_ptr<const DropDownListItem> const &second)
{
  char buffer1[512], buffer2[512];
  GetString(buffer1, static_cast<const DropDownListStringItem*>(first.get())->String(), lastof(buffer1));
  GetString(buffer2, static_cast<const DropDownListStringItem*>(second.get())->String(), lastof(buffer2));
  return strnatcmp(buffer1, buffer2) < 0;
}
 
StringID DropDownListParamStringItem::String() const
{
  for (uint i = 0; i < lengthof(this->decode_params); i++) SetDParam(i, this->decode_params[i]);
  return this->string;
}
 
StringID DropDownListCharStringItem::String() const
{
  SetDParamStr(0, this->raw_string);
  return this->string;
}
 
DropDownListIconItem::DropDownListIconItem(SpriteID sprite, PaletteID pal, StringID string, int result, bool masked) : DropDownListParamStringItem(string, result, masked), sprite(sprite), pal(pal)
{
  this->dim = GetSpriteSize(sprite);
  this->sprite_y = dim.height;
}
 
uint DropDownListIconItem::Height(uint width) const
{
  return std::max(this->dim.height, (uint)FONT_HEIGHT_NORMAL);
}
 
uint DropDownListIconItem::Width() const
{
  return DropDownListParamStringItem::Width() + this->dim.width + WidgetDimensions::scaled.hsep_wide;
}
 
void DropDownListIconItem::Draw(const Rect &r, bool sel, Colours bg_colour) const
{
  bool rtl = _current_text_dir == TD_RTL;
  Rect ir = r.Shrink(WidgetDimensions::scaled.dropdowntext);
  Rect tr = ir.Indent(this->dim.width + WidgetDimensions::scaled.hsep_normal, rtl);
  DrawSprite(this->sprite, this->pal, ir.WithWidth(this->dim.width, rtl).left, CenterBounds(r.top, r.bottom, this->sprite_y));
  DrawString(tr.left, tr.right, CenterBounds(r.top, r.bottom, FONT_HEIGHT_NORMAL), this->String(), sel ? TC_WHITE : TC_BLACK);
}
 
void DropDownListIconItem::SetDimension(Dimension d)
{
  this->dim = d;
}
 
static const NWidgetPart _nested_dropdown_menu_widgets[] = {
  NWidget(NWID_HORIZONTAL),
    NWidget(WWT_PANEL, COLOUR_END, WID_DM_ITEMS), SetMinimalSize(1, 1), SetScrollbar(WID_DM_SCROLL), EndContainer(),
    NWidget(NWID_SELECTION, INVALID_COLOUR, WID_DM_SHOW_SCROLL),
      NWidget(NWID_VSCROLLBAR, COLOUR_END, WID_DM_SCROLL),
    EndContainer(),
  EndContainer(),
};
 
static WindowDesc _dropdown_desc(
  WDP_MANUAL, nullptr, 0, 0,
  WC_DROPDOWN_MENU, WC_NONE,
  WDF_NO_FOCUS,
  _nested_dropdown_menu_widgets, lengthof(_nested_dropdown_menu_widgets)
);
 
struct DropdownWindow : Window {
  int parent_button;            
  const DropDownList list;      
  int selected_index;           
  byte click_delay;             
  bool drag_mode;
  bool instant_close;           
  int scrolling;                
  GUITimer scrolling_timer;     
  Point position;               
  Scrollbar *vscroll;
 
  DropdownWindow(Window *parent, DropDownList &&list, int selected, int button, bool instant_close, const Point &position, const Dimension &size, Colours wi_colour, bool scroll)
      : Window(&_dropdown_desc), list(std::move(list))
  {
    assert(this->list.size() > 0);
 
    this->position = position;
 
    this->CreateNestedTree();
 
    this->vscroll = this->GetScrollbar(WID_DM_SCROLL);
 
    uint items_width = size.width - (scroll ? NWidgetScrollbar::GetVerticalDimension().width : 0);
    NWidgetCore *nwi = this->GetWidget<NWidgetCore>(WID_DM_ITEMS);
    nwi->SetMinimalSizeAbsolute(items_width, size.height + WidgetDimensions::scaled.fullbevel.Vertical() * 2);
    nwi->colour = wi_colour;
 
    nwi = this->GetWidget<NWidgetCore>(WID_DM_SCROLL);
    nwi->colour = wi_colour;
 
    this->GetWidget<NWidgetStacked>(WID_DM_SHOW_SCROLL)->SetDisplayedPlane(scroll ? 0 : SZSP_NONE);
 
    this->FinishInitNested(0);
    CLRBITS(this->flags, WF_WHITE_BORDER);
 
    /* Total length of list */
    int list_height = 0;
    for (const auto &item : this->list) {
      list_height += item->Height(items_width);
    }
 
    /* Capacity is the average number of items visible */
    this->vscroll->SetCapacity(size.height * (uint16)this->list.size() / list_height);
    this->vscroll->SetCount((uint16)this->list.size());
 
    this->parent           = parent;
    this->parent_button    = button;
    this->selected_index   = selected;
    this->click_delay      = 0;
    this->drag_mode        = true;
    this->instant_close    = instant_close;
    this->scrolling_timer  = GUITimer(MILLISECONDS_PER_TICK);
  }
 
  void Close() override
  {
    /* Finish closing the dropdown, so it doesn't affect new window placement.
     * Also mark it dirty in case the callback deals with the screen. (e.g. screenshots). */
    this->Window::Close();
 
    Point pt = _cursor.pos;
    pt.x -= this->parent->left;
    pt.y -= this->parent->top;
    this->parent->OnDropdownClose(pt, this->parent_button, this->selected_index, this->instant_close);
 
    /* Set flag on parent widget to indicate that we have just closed. */
    NWidgetCore *nwc = this->parent->GetWidget<NWidgetCore>(this->parent_button);
    if (nwc != nullptr) SetBit(nwc->disp_flags, NDB_DROPDOWN_CLOSED);
  }
 
  void OnFocusLost(bool closing) override
  {
    if (!closing) {
      this->instant_close = false;
      this->Close();
    }
  }
 
  Point OnInitialPosition(int16 sm_width, int16 sm_height, int window_number) override
  {
    return this->position;
  }
 
  bool GetDropDownItem(int &value)
  {
    if (GetWidgetFromPos(this, _cursor.pos.x - this->left, _cursor.pos.y - this->top) < 0) return false;
 
    const Rect &r = this->GetWidget<NWidgetBase>(WID_DM_ITEMS)->GetCurrentRect().Shrink(WidgetDimensions::scaled.fullbevel);
    int y     = _cursor.pos.y - this->top - r.top - WidgetDimensions::scaled.fullbevel.top;
    int width = r.Width();
    int pos   = this->vscroll->GetPosition();
 
    for (const auto &item : this->list) {
      /* Skip items that are scrolled up */
      if (--pos >= 0) continue;
 
      int item_height = item->Height(width);
 
      if (y < item_height) {
        if (item->masked || !item->Selectable()) return false;
        value = item->result;
        return true;
      }
 
      y -= item_height;
    }
 
    return false;
  }
 
  void DrawWidget(const Rect &r, int widget) const override
  {
    if (widget != WID_DM_ITEMS) return;
 
    Colours colour = this->GetWidget<NWidgetCore>(widget)->colour;
 
    Rect ir = r.Shrink(WidgetDimensions::scaled.fullbevel).Shrink(RectPadding::zero, WidgetDimensions::scaled.fullbevel);
    int y = ir.top;
    int pos = this->vscroll->GetPosition();
    for (const auto &item : this->list) {
      int item_height = item->Height(ir.Width());
 
      /* Skip items that are scrolled up */
      if (--pos >= 0) continue;
 
      if (y + item_height - 1 <= ir.bottom) {
        bool selected = (this->selected_index == item->result);
        if (selected) GfxFillRect(ir.left, y, ir.right, y + item_height - 1, PC_BLACK);
 
        item->Draw({ir.left, y, ir.right, y + item_height - 1}, selected, colour);
 
        if (item->masked) {
          GfxFillRect(ir.left, y, ir.right, y + item_height - 1, _colour_gradient[colour][5], FILLRECT_CHECKER);
        }
      }
      y += item_height;
    }
  }
 
  void OnClick(Point pt, int widget, int click_count) override
  {
    if (widget != WID_DM_ITEMS) return;
    int item;
    if (this->GetDropDownItem(item)) {
      this->click_delay = 4;
      this->selected_index = item;
      this->SetDirty();
    }
  }
 
  void OnRealtimeTick(uint delta_ms) override
  {
    if (!this->scrolling_timer.Elapsed(delta_ms)) return;
    this->scrolling_timer.SetInterval(MILLISECONDS_PER_TICK);
 
    if (this->scrolling != 0) {
      int pos = this->vscroll->GetPosition();
 
      this->vscroll->UpdatePosition(this->scrolling);
      this->scrolling = 0;
 
      if (pos != this->vscroll->GetPosition()) {
        this->SetDirty();
      }
    }
  }
 
  void OnMouseLoop() override
  {
    if (this->click_delay != 0 && --this->click_delay == 0) {
      /* Close the dropdown, so it doesn't affect new window placement.
       * Also mark it dirty in case the callback deals with the screen. (e.g. screenshots). */
      this->Close();
      this->parent->OnDropdownSelect(this->parent_button, this->selected_index);
      return;
    }
 
    if (this->drag_mode) {
      int item;
 
      if (!_left_button_clicked) {
        this->drag_mode = false;
        if (!this->GetDropDownItem(item)) {
          if (this->instant_close) this->Close();
          return;
        }
        this->click_delay = 2;
      } else {
        if (_cursor.pos.y <= this->top + 2) {
          /* Cursor is above the list, set scroll up */
          this->scrolling = -1;
          return;
        } else if (_cursor.pos.y >= this->top + this->height - 2) {
          /* Cursor is below list, set scroll down */
          this->scrolling = 1;
          return;
        }
 
        if (!this->GetDropDownItem(item)) return;
      }
 
      if (this->selected_index != item) {
        this->selected_index = item;
        this->SetDirty();
      }
    }
  }
};
 
void ShowDropDownListAt(Window *w, DropDownList &&list, int selected, int button, Rect wi_rect, Colours wi_colour, bool auto_width, bool instant_close)
{
  CloseWindowByClass(WC_DROPDOWN_MENU);
 
  /* The preferred position is just below the dropdown calling widget */
  int top = w->top + wi_rect.bottom + 1;
 
  /* The preferred width equals the calling widget */
  uint width = wi_rect.Width();
 
  /* Longest item in the list, if auto_width is enabled */
  uint max_item_width = 0;
 
  /* Total height of list */
  uint height = 0;
 
  for (const auto &item : list) {
    height += item->Height(width);
    if (auto_width) max_item_width = std::max(max_item_width, item->Width());
  }
 
  if (auto_width) max_item_width += WidgetDimensions::scaled.fullbevel.Horizontal();
 
  /* Scrollbar needed? */
  bool scroll = false;
 
  /* Is it better to place the dropdown above the widget? */
  bool above = false;
 
  /* Available height below (or above, if the dropdown is placed above the widget). */
  uint available_height = std::max(GetMainViewBottom() - top - (int)WidgetDimensions::scaled.fullbevel.Vertical() * 2, 0);
 
  /* If the dropdown doesn't fully fit below the widget... */
  if (height > available_height) {
 
    uint available_height_above = std::max(w->top + wi_rect.top - GetMainViewTop() - (int)WidgetDimensions::scaled.fullbevel.Vertical() * 2, 0);
 
    /* Put the dropdown above if there is more available space. */
    if (available_height_above > available_height) {
      above = true;
      available_height = available_height_above;
    }
 
    /* If the dropdown doesn't fully fit, we need a dropdown. */
    if (height > available_height) {
      scroll = true;
      uint avg_height = height / (uint)list.size();
 
      /* Fit the list; create at least one row, even if there is no height available. */
      uint rows = std::max<uint>(available_height / avg_height, 1);
      height = rows * avg_height;
 
      /* Add space for the scrollbar. */
      max_item_width += NWidgetScrollbar::GetVerticalDimension().width;
    }
 
    /* Set the top position if needed. */
    if (above) {
      top = w->top + wi_rect.top - height - WidgetDimensions::scaled.fullbevel.Vertical() * 2;
    }
  }
 
  if (auto_width) width = std::max(width, max_item_width);
 
  Point dw_pos = { w->left + (_current_text_dir == TD_RTL ? wi_rect.right + 1 - (int)width : wi_rect.left), top};
  Dimension dw_size = {width, height};
  DropdownWindow *dropdown = new DropdownWindow(w, std::move(list), selected, button, instant_close, dw_pos, dw_size, wi_colour, scroll);
 
  /* The dropdown starts scrolling downwards when opening it towards
   * the top and holding down the mouse button. It can be fooled by
   * opening the dropdown scrolled to the very bottom.  */
  if (above && scroll) dropdown->vscroll->UpdatePosition(INT_MAX);
}
 
void ShowDropDownList(Window *w, DropDownList &&list, int selected, int button, uint width, bool auto_width, bool instant_close)
{
  /* Our parent's button widget is used to determine where to place the drop
   * down list window. */
  NWidgetCore *nwi = w->GetWidget<NWidgetCore>(button);
  Rect wi_rect      = nwi->GetCurrentRect();
  Colours wi_colour = nwi->colour;
 
  if ((nwi->type & WWT_MASK) == NWID_BUTTON_DROPDOWN) {
    nwi->disp_flags |= ND_DROPDOWN_ACTIVE;
  } else {
    w->LowerWidget(button);
  }
  w->SetWidgetDirty(button);
 
  if (width != 0) {
    if (_current_text_dir == TD_RTL) {
      wi_rect.left = wi_rect.right + 1 - ScaleGUITrad(width);
    } else {
      wi_rect.right = wi_rect.left + ScaleGUITrad(width) - 1;
    }
  }
 
  ShowDropDownListAt(w, std::move(list), selected, button, wi_rect, wi_colour, auto_width, instant_close);
}
 
void ShowDropDownMenu(Window *w, const StringID *strings, int selected, int button, uint32 disabled_mask, uint32 hidden_mask, uint width)
{
  DropDownList list;
 
  for (uint i = 0; strings[i] != INVALID_STRING_ID; i++) {
    if (!HasBit(hidden_mask, i)) {
      list.emplace_back(new DropDownListStringItem(strings[i], i, HasBit(disabled_mask, i)));
    }
  }
 
  if (!list.empty()) ShowDropDownList(w, std::move(list), selected, button, width);
}