widget/ScrollbarDrawingGTK.cpp

   1 /* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "ScrollbarDrawingGTK.h"
   7
   8 #include "mozilla/gfx/Helpers.h"
   9 #include "mozilla/StaticPrefs_widget.h"
  10 #include "nsLayoutUtils.h"
  11 #include "nsNativeTheme.h"
  12
  13 using namespace mozilla;
  14 using namespace mozilla::gfx;
  15 using namespace mozilla::widget;
  16
  17 LayoutDeviceIntSize ScrollbarDrawingGTK::GetMinimumWidgetSize(
  18     nsPresContext* aPresContext, StyleAppearance aAppearance,
  19     nsIFrame* aFrame) {
  20   MOZ_ASSERT(nsNativeTheme::IsWidgetScrollbarPart(aAppearance));
  21   auto sizes = GetScrollbarSizes(aPresContext, aFrame);
  22   MOZ_ASSERT(sizes.mHorizontal == sizes.mVertical);
  23   LayoutDeviceIntSize size{sizes.mHorizontal, sizes.mVertical};
  24   if (aAppearance == StyleAppearance::ScrollbarHorizontal ||
  25       aAppearance == StyleAppearance::ScrollbarVertical ||
  26       aAppearance == StyleAppearance::ScrollbarthumbHorizontal ||
  27       aAppearance == StyleAppearance::ScrollbarthumbVertical) {
  28     CSSCoord thumbSize(
  29         StaticPrefs::widget_non_native_theme_gtk_scrollbar_thumb_cross_size());
  30     const bool isVertical =
  31         aAppearance == StyleAppearance::ScrollbarVertical ||
  32         aAppearance == StyleAppearance::ScrollbarthumbVertical;
  33     auto dpi = GetDPIRatioForScrollbarPart(aPresContext);
  34     if (isVertical) {
  35       size.height = thumbSize * dpi;
  36     } else {
  37       size.width = thumbSize * dpi;
  38     }
  39   }
  40   return size;
  41 }
  42
  43 Maybe<nsITheme::Transparency> ScrollbarDrawingGTK::GetScrollbarPartTransparency(
  44     nsIFrame* aFrame, StyleAppearance aAppearance) {
  45   if (!aFrame->PresContext()->UseOverlayScrollbars() &&
  46       (aAppearance == StyleAppearance::ScrollbarVertical ||
  47        aAppearance == StyleAppearance::ScrollbarHorizontal) &&
  48       IsScrollbarTrackOpaque(aFrame)) {
  49     return Some(nsITheme::eOpaque);
  50   }
  51
  52   return Nothing();
  53 }
  54
  55 template <typename PaintBackendData>
  56 bool ScrollbarDrawingGTK::DoPaintScrollbarThumb(
  57     PaintBackendData& aPaintData, const LayoutDeviceRect& aRect,
  58     ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
  59     const ElementState& aElementState, const DocumentState& aDocumentState,
  60     const Colors& aColors, const DPIRatio& aDpiRatio) {
  61   sRGBColor thumbColor = ComputeScrollbarThumbColor(
  62       aFrame, aStyle, aElementState, aDocumentState, aColors);
  63
  64   LayoutDeviceRect thumbRect(aRect);
  65
  66   const bool horizontal = aScrollbarKind == ScrollbarKind::Horizontal;
  67   if (aFrame->PresContext()->UseOverlayScrollbars() &&
  68       !ScrollbarDrawing::IsParentScrollbarHoveredOrActive(aFrame)) {
  69     if (horizontal) {
  70       thumbRect.height *= 0.5;
  71       thumbRect.y += thumbRect.height;
  72     } else {
  73       thumbRect.width *= 0.5;
  74       if (aScrollbarKind == ScrollbarKind::VerticalRight) {
  75         thumbRect.x += thumbRect.width;
  76       }
  77     }
  78   }
  79
  80   {
  81     float factor = std::max(
  82         0.0f,
  83         1.0f - StaticPrefs::widget_non_native_theme_gtk_scrollbar_thumb_size());
  84     thumbRect.Deflate((horizontal ? thumbRect.height : thumbRect.width) *
  85                       factor);
  86   }
  87
  88   LayoutDeviceCoord radius =
  89       StaticPrefs::widget_non_native_theme_gtk_scrollbar_round_thumb()
  90           ? (horizontal ? thumbRect.height : thumbRect.width) / 2.0f
  91           : 0.0f;
  92
  93   ThemeDrawing::PaintRoundedRectWithRadius(aPaintData, thumbRect, thumbColor,
  94                                            sRGBColor(), 0, radius / aDpiRatio,
  95                                            aDpiRatio);
  96   return true;
  97 }
  98
  99 bool ScrollbarDrawingGTK::PaintScrollbarThumb(
 100     DrawTarget& aDrawTarget, const LayoutDeviceRect& aRect,
 101     ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
 102     const ElementState& aElementState, const DocumentState& aDocumentState,
 103     const Colors& aColors, const DPIRatio& aDpiRatio) {
 104   return DoPaintScrollbarThumb(aDrawTarget, aRect, aScrollbarKind, aFrame,
 105                                aStyle, aElementState, aDocumentState, aColors,
 106                                aDpiRatio);
 107 }
 108
 109 bool ScrollbarDrawingGTK::PaintScrollbarThumb(
 110     WebRenderBackendData& aWrData, const LayoutDeviceRect& aRect,
 111     ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
 112     const ElementState& aElementState, const DocumentState& aDocumentState,
 113     const Colors& aColors, const DPIRatio& aDpiRatio) {
 114   return DoPaintScrollbarThumb(aWrData, aRect, aScrollbarKind, aFrame, aStyle,
 115                                aElementState, aDocumentState, aColors,
 116                                aDpiRatio);
 117 }
 118
 119 bool ScrollbarDrawingGTK::ShouldDrawScrollbarButtons() {
 120   if (StaticPrefs::widget_non_native_theme_enabled()) {
 121     return StaticPrefs::widget_non_native_theme_gtk_scrollbar_allow_buttons();
 122   }
 123   return true;
 124 }
 125
 126 void ScrollbarDrawingGTK::RecomputeScrollbarParams() {
 127   uint32_t defaultSize = 12;
 128   uint32_t overrideSize =
 129       StaticPrefs::widget_non_native_theme_scrollbar_size_override();
 130   if (overrideSize > 0) {
 131     defaultSize = overrideSize;
 132   }
 133   mHorizontalScrollbarHeight = mVerticalScrollbarWidth = defaultSize;
 134 }