widget/ScrollbarDrawing.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_widget_ScrollbarDrawing_h
   8 #define mozilla_widget_ScrollbarDrawing_h
   9
  10 #include "mozilla/dom/RustTypes.h"
  11 #include "mozilla/gfx/2D.h"
  12 #include "nsColor.h"
  13 #include "nsITheme.h"
  14 #include "ThemeColors.h"
  15 #include "ThemeDrawing.h"
  16 #include "Units.h"
  17
  18 namespace mozilla::widget {
  19
  20 class ScrollbarDrawing {
  21  protected:
  22   using DPIRatio = mozilla::CSSToLayoutDeviceScale;
  23   using ElementState = dom::ElementState;
  24   using DocumentState = dom::DocumentState;
  25   using DrawTarget = mozilla::gfx::DrawTarget;
  26   using sRGBColor = mozilla::gfx::sRGBColor;
  27   using Colors = ThemeColors;
  28   using Overlay = nsITheme::Overlay;
  29   using WebRenderBackendData = mozilla::widget::WebRenderBackendData;
  30
  31   enum class Kind : uint8_t {
  32     Android,
  33     Cocoa,
  34     Gtk,
  35     Win10,
  36     Win11,
  37   };
  38
  39   explicit ScrollbarDrawing(Kind aKind) : mKind(aKind) {}
  40
  41  public:
  42   virtual ~ScrollbarDrawing() = default;
  43
  44   enum class ScrollbarKind : uint8_t {
  45     Horizontal,
  46     VerticalLeft,
  47     VerticalRight,
  48   };
  49
  50   DPIRatio GetDPIRatioForScrollbarPart(const nsPresContext*);
  51
  52   static nsIFrame* GetParentScrollbarFrame(nsIFrame* aFrame);
  53   static bool IsParentScrollbarRolledOver(nsIFrame* aFrame);
  54   static bool IsParentScrollbarHoveredOrActive(nsIFrame* aFrame);
  55
  56   static bool IsScrollbarWidthThin(const ComputedStyle& aStyle);
  57   static bool IsScrollbarWidthThin(nsIFrame* aFrame);
  58
  59   CSSIntCoord GetCSSScrollbarSize(StyleScrollbarWidth, Overlay) const;
  60   LayoutDeviceIntCoord GetScrollbarSize(const nsPresContext*,
  61                                         StyleScrollbarWidth, Overlay);
  62   LayoutDeviceIntCoord GetScrollbarSize(const nsPresContext*, nsIFrame*);
  63
  64   virtual LayoutDeviceIntSize GetMinimumWidgetSize(nsPresContext*,
  65                                                    StyleAppearance aAppearance,
  66                                                    nsIFrame* aFrame) = 0;
  67   virtual Maybe<nsITheme::Transparency> GetScrollbarPartTransparency(
  68       nsIFrame* aFrame, StyleAppearance aAppearance) {
  69     return Nothing();
  70   }
  71
  72   bool IsScrollbarTrackOpaque(nsIFrame*);
  73   virtual sRGBColor ComputeScrollbarTrackColor(nsIFrame*, const ComputedStyle&,
  74                                                const DocumentState&,
  75                                                const Colors&);
  76   virtual sRGBColor ComputeScrollbarThumbColor(nsIFrame*, const ComputedStyle&,
  77                                                const ElementState&,
  78                                                const DocumentState&,
  79                                                const Colors&);
  80
  81   nscolor GetScrollbarButtonColor(nscolor aTrackColor, ElementState);
  82   Maybe<nscolor> GetScrollbarArrowColor(nscolor aButtonColor);
  83
  84   // Returned colors are button, arrow.
  85   virtual std::pair<sRGBColor, sRGBColor> ComputeScrollbarButtonColors(
  86       nsIFrame*, StyleAppearance, const ComputedStyle&, const ElementState&,
  87       const DocumentState&, const Colors&);
  88
  89   virtual bool PaintScrollbarButton(DrawTarget&, StyleAppearance,
  90                                     const LayoutDeviceRect&, ScrollbarKind,
  91                                     nsIFrame*, const ComputedStyle&,
  92                                     const ElementState&, const DocumentState&,
  93                                     const Colors&, const DPIRatio&);
  94
  95   virtual bool PaintScrollbarThumb(DrawTarget&, const LayoutDeviceRect&,
  96                                    ScrollbarKind, nsIFrame*,
  97                                    const ComputedStyle&, const ElementState&,
  98                                    const DocumentState&, const Colors&,
  99                                    const DPIRatio&) = 0;
 100   virtual bool PaintScrollbarThumb(WebRenderBackendData&,
 101                                    const LayoutDeviceRect&, ScrollbarKind,
 102                                    nsIFrame*, const ComputedStyle&,
 103                                    const ElementState&, const DocumentState&,
 104                                    const Colors&, const DPIRatio&) = 0;
 105
 106   template <typename PaintBackendData>
 107   bool DoPaintDefaultScrollbar(PaintBackendData&, const LayoutDeviceRect&,
 108                                ScrollbarKind, nsIFrame*, const ComputedStyle&,
 109                                const ElementState&, const DocumentState&,
 110                                const Colors&, const DPIRatio&);
 111   bool PaintScrollbar(DrawTarget&, const LayoutDeviceRect&, ScrollbarKind,
 112                       nsIFrame*, const ComputedStyle&, const ElementState&,
 113                       const DocumentState&, const Colors&, const DPIRatio&);
 114   bool PaintScrollbar(WebRenderBackendData&, const LayoutDeviceRect&,
 115                       ScrollbarKind, nsIFrame*, const ComputedStyle&,
 116                       const ElementState&, const DocumentState&, const Colors&,
 117                       const DPIRatio&);
 118
 119   virtual bool PaintScrollbarTrack(DrawTarget&, const LayoutDeviceRect&,
 120                                    ScrollbarKind, nsIFrame*,
 121                                    const ComputedStyle&, const DocumentState&,
 122                                    const Colors&, const DPIRatio&) {
 123     // Draw nothing by default. Subclasses can override this.
 124     return true;
 125   }
 126   virtual bool PaintScrollbarTrack(WebRenderBackendData&,
 127                                    const LayoutDeviceRect&, ScrollbarKind,
 128                                    nsIFrame*, const ComputedStyle&,
 129                                    const DocumentState&, const Colors&,
 130                                    const DPIRatio&) {
 131     // Draw nothing by default. Subclasses can override this.
 132     return true;
 133   }
 134
 135   template <typename PaintBackendData>
 136   bool DoPaintDefaultScrollCorner(PaintBackendData&, const LayoutDeviceRect&,
 137                                   ScrollbarKind, nsIFrame*,
 138                                   const ComputedStyle&, const DocumentState&,
 139                                   const Colors&, const DPIRatio&);
 140   virtual bool PaintScrollCorner(DrawTarget&, const LayoutDeviceRect&,
 141                                  ScrollbarKind, nsIFrame*, const ComputedStyle&,
 142                                  const DocumentState&, const Colors&,
 143                                  const DPIRatio&);
 144   virtual bool PaintScrollCorner(WebRenderBackendData&, const LayoutDeviceRect&,
 145                                  ScrollbarKind, nsIFrame*, const ComputedStyle&,
 146                                  const DocumentState&, const Colors&,
 147                                  const DPIRatio&);
 148
 149   virtual void RecomputeScrollbarParams() = 0;
 150
 151   virtual bool ShouldDrawScrollbarButtons() { return true; }
 152
 153  private:
 154   // The scrollbar sizes for all our scrollbars. Indices are overlay or not,
 155   // then thin or not. Should be configured via ConfigureScrollbarSize.
 156   CSSIntCoord mScrollbarSize[2][2]{};
 157
 158  protected:
 159   // For some kind of style differences a full virtual method is overkill, so we
 160   // store the kind here so we can branch on it if necessary.
 161   Kind mKind;
 162
 163   // Configures the scrollbar sizes based on a single size.
 164   void ConfigureScrollbarSize(CSSIntCoord);
 165
 166   // Configures a particular scrollbar size.
 167   void ConfigureScrollbarSize(StyleScrollbarWidth, Overlay, CSSIntCoord);
 168 };
 169
 170 }  // namespace mozilla::widget
 171
 172 #endif