Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: C++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 2; -*- */
/* vim: set sw=2 ts=8 et tw=80 : */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "ScrollbarDrawingCocoa.h"
#include "mozilla/RelativeLuminanceUtils.h"
#include "nsAlgorithm.h"
#include "nsIFrame.h"
#include "nsLayoutUtils.h"
#include "nsNativeTheme.h"
using namespace mozilla::gfx;
namespace mozilla::widget {
using ScrollbarKind = ScrollbarDrawing::ScrollbarKind;
struct ColoredRect {
LayoutDeviceRect mRect;
nscolor mColor = 0;
};
// The caller can draw this rectangle with rounded corners as appropriate.
struct ThumbRect {
LayoutDeviceRect mRect;
nscolor mFillColor = 0;
nscolor mStrokeColor = 0;
float mStrokeWidth = 0.0f;
float mStrokeOutset = 0.0f;
};
using ScrollbarTrackRects = Array<ColoredRect, 4>;
using ScrollCornerRects = Array<ColoredRect, 7>;
struct ScrollbarParams {
bool isOverlay = false;
bool isRolledOver = false;
bool isSmall = false;
bool isHorizontal = false;
bool isRtl = false;
bool isDark = false;
bool isCustom = false;
// Two colors only used when custom is true.
nscolor trackColor = NS_RGBA(0, 0, 0, 0);
nscolor faceColor = NS_RGBA(0, 0, 0, 0);
};
static ScrollbarParams ComputeScrollbarParams(nsIFrame* aFrame,
const ComputedStyle& aStyle,
const ThemeColors& aColors,
ScrollbarKind aScrollbarKind) {
ScrollbarParams params;
params.isOverlay = aFrame->PresContext()->UseOverlayScrollbars();
params.isRolledOver = ScrollbarDrawing::IsParentScrollbarRolledOver(aFrame);
params.isSmall =
aStyle.StyleUIReset()->ScrollbarWidth() == StyleScrollbarWidth::Thin;
params.isRtl = aScrollbarKind == ScrollbarKind::VerticalLeft;
params.isHorizontal = aScrollbarKind == ScrollbarKind::Horizontal;
params.isDark = aColors.IsDark();
const nsStyleUI* ui = aStyle.StyleUI();
if (ui->HasCustomScrollbars()) {
const auto& colors = ui->mScrollbarColor.AsColors();
params.isCustom = true;
params.trackColor = colors.track.CalcColor(aStyle);
params.faceColor = colors.thumb.CalcColor(aStyle);
}
return params;
}
LayoutDeviceIntSize ScrollbarDrawingCocoa::GetMinimumWidgetSize(
nsPresContext* aPresContext, StyleAppearance aAppearance,
nsIFrame* aFrame) {
MOZ_ASSERT(nsNativeTheme::IsWidgetScrollbarPart(aAppearance));
auto minSize = [&]() -> CSSIntSize {
switch (aAppearance) {
case StyleAppearance::ScrollbarthumbHorizontal:
return {26, 0};
case StyleAppearance::ScrollbarthumbVertical:
return {0, 26};
case StyleAppearance::ScrollbarVertical:
case StyleAppearance::ScrollbarHorizontal: {
ComputedStyle* style = nsLayoutUtils::StyleForScrollbar(aFrame);
auto scrollbarWidth = style->StyleUIReset()->ScrollbarWidth();
auto size = GetCSSScrollbarSize(
scrollbarWidth, Overlay(aPresContext->UseOverlayScrollbars()));
return {size, size};
}
case StyleAppearance::ScrollbarbuttonUp:
case StyleAppearance::ScrollbarbuttonDown:
return {15, 16};
case StyleAppearance::ScrollbarbuttonLeft:
case StyleAppearance::ScrollbarbuttonRight:
return {16, 15};
default:
return {};
}
}();
auto dpi = GetDPIRatioForScrollbarPart(aPresContext);
return LayoutDeviceIntSize::Round(CSSSize(minSize) * dpi);
}
static ThumbRect GetThumbRect(const LayoutDeviceRect& aRect,
const ScrollbarParams& aParams, float aScale) {
// Compute the thumb thickness. This varies based on aParams.isSmall,
// aParams.isOverlay and aParams.isRolledOver.
// non-overlay: 6 / 8, overlay non-hovered: 5 / 7, overlay hovered: 7 / 11
// Note that this is drawn inside the rect of a size as specified by
// ConfigureScrollbarSize().
float thickness = aParams.isSmall ? 6.0f : 8.0f;
if (aParams.isOverlay) {
thickness -= 1.0f;
if (aParams.isRolledOver) {
thickness = aParams.isSmall ? 7.0f : 11.0f;
}
}
thickness *= aScale;
// Compute the thumb rect.
const float outerSpacing =
((aParams.isOverlay || aParams.isSmall) ? 1.0f : 2.0f) * aScale;
LayoutDeviceRect thumbRect = aRect;
thumbRect.Deflate(1.0f * aScale);
if (aParams.isHorizontal) {
float bottomEdge = thumbRect.YMost() - outerSpacing;
thumbRect.SetBoxY(bottomEdge - thickness, bottomEdge);
} else {
if (aParams.isRtl) {
float leftEdge = thumbRect.X() + outerSpacing;
thumbRect.SetBoxX(leftEdge, leftEdge + thickness);
} else {
float rightEdge = thumbRect.XMost() - outerSpacing;
thumbRect.SetBoxX(rightEdge - thickness, rightEdge);
}
}
// Compute the thumb fill color.
nscolor faceColor;
if (aParams.isCustom) {
faceColor = aParams.faceColor;
} else {
if (aParams.isOverlay) {
faceColor =
aParams.isDark ? NS_RGBA(255, 255, 255, 128) : NS_RGBA(0, 0, 0, 128);
} else if (aParams.isDark) {
faceColor = aParams.isRolledOver ? NS_RGBA(158, 158, 158, 255)
: NS_RGBA(117, 117, 117, 255);
} else {
faceColor = aParams.isRolledOver ? NS_RGBA(125, 125, 125, 255)
: NS_RGBA(194, 194, 194, 255);
}
}
nscolor strokeColor = 0;
float strokeOutset = 0.0f;
float strokeWidth = 0.0f;
// Overlay scrollbars have an additional stroke around the fill.
if (aParams.isOverlay) {
// For the default alpha of 128 we want to end up with 48 in the outline.
constexpr float kAlphaScaling = 48.0f / 128.0f;
const uint8_t strokeAlpha =
uint8_t(clamped(NS_GET_A(faceColor) * kAlphaScaling, 0.0f, 48.0f));
if (strokeAlpha) {
strokeOutset = (aParams.isDark ? 0.3f : 0.5f) * aScale;
strokeWidth = (aParams.isDark ? 0.6f : 0.8f) * aScale;
strokeColor = aParams.isDark ? NS_RGBA(0, 0, 0, strokeAlpha)
: NS_RGBA(255, 255, 255, strokeAlpha);
}
}
return {thumbRect, faceColor, strokeColor, strokeWidth, strokeOutset};
}
struct ScrollbarTrackDecorationColors {
nscolor mInnerColor = 0;
nscolor mShadowColor = 0;
nscolor mOuterColor = 0;
};
static ScrollbarTrackDecorationColors ComputeScrollbarTrackDecorationColors(
nscolor aTrackColor) {
ScrollbarTrackDecorationColors result;
float luminance = RelativeLuminanceUtils::Compute(aTrackColor);
if (luminance >= 0.5f) {
result.mInnerColor =
RelativeLuminanceUtils::Adjust(aTrackColor, luminance * 0.836f);
result.mShadowColor =
RelativeLuminanceUtils::Adjust(aTrackColor, luminance * 0.982f);
result.mOuterColor =
RelativeLuminanceUtils::Adjust(aTrackColor, luminance * 0.886f);
} else {
result.mInnerColor =
RelativeLuminanceUtils::Adjust(aTrackColor, luminance * 1.196f);
result.mShadowColor =
RelativeLuminanceUtils::Adjust(aTrackColor, luminance * 1.018f);
result.mOuterColor =
RelativeLuminanceUtils::Adjust(aTrackColor, luminance * 1.129f);
}
return result;
}
static bool GetScrollbarTrackRects(const LayoutDeviceRect& aRect,
const ScrollbarParams& aParams, float aScale,
ScrollbarTrackRects& aRects) {
nscolor trackColor;
if (aParams.isCustom) {
trackColor = aParams.trackColor;
} else {
if (aParams.isOverlay) {
trackColor = aParams.isDark ? NS_RGBA(201, 201, 201, 38)
: NS_RGBA(250, 250, 250, 191);
} else {
trackColor = aParams.isDark ? NS_RGBA(46, 46, 46, 255)
: NS_RGBA(250, 250, 250, 255);
}
}
float thickness = aParams.isHorizontal ? aRect.height : aRect.width;
// The scrollbar track is drawn as multiple non-overlapping segments, which
// make up lines of different widths and with slightly different shading.
ScrollbarTrackDecorationColors colors =
ComputeScrollbarTrackDecorationColors(trackColor);
struct {
nscolor color;
float thickness;
} segments[] = {
{colors.mInnerColor, 1.0f * aScale},
{colors.mShadowColor, 1.0f * aScale},
{trackColor, thickness - 3.0f * aScale},
{colors.mOuterColor, 1.0f * aScale},
};
// Iterate over the segments "from inside to outside" and fill each segment.
// For horizontal scrollbars, iterate top to bottom.
// For vertical scrollbars, iterate left to right or right to left based on
// aParams.isRtl.
auto current = aRects.begin();
float accumulatedThickness = 0.0f;
for (const auto& segment : segments) {
LayoutDeviceRect segmentRect = aRect;
float startThickness = accumulatedThickness;
float endThickness = startThickness + segment.thickness;
if (aParams.isHorizontal) {
segmentRect.SetBoxY(aRect.Y() + startThickness, aRect.Y() + endThickness);
} else {
if (aParams.isRtl) {
segmentRect.SetBoxX(aRect.XMost() - endThickness,
aRect.XMost() - startThickness);
} else {
segmentRect.SetBoxX(aRect.X() + startThickness,
aRect.X() + endThickness);
}
}
accumulatedThickness = endThickness;
*current++ = {segmentRect, segment.color};
}
return true;
}
static bool GetScrollCornerRects(const LayoutDeviceRect& aRect,
const ScrollbarParams& aParams, float aScale,
ScrollCornerRects& aRects) {
if (aParams.isOverlay && !aParams.isRolledOver) {
// Non-hovered overlay scrollbars don't have a corner. Draw nothing.
return false;
}
// Draw the following scroll corner.
//
// Output: Rectangles:
// +---+---+----------+---+ +---+---+----------+---+
// | I | S | T ... T | O | | I | S | T ... T | O |
// +---+ | | | +---+---+ | |
// | S S | T ... T | | | S S | T ... T | . |
// +-------+ | . | +-------+----------+ . |
// | T ... T | . | | T ... T | . |
// | . . | . | | . . | |
// | T ... T | | | T ... T | O |
// +------------------+ | +------------------+---+
// | O ... O | | O ... O |
// +----------------------+ +----------------------+
float width = aRect.width;
float height = aRect.height;
nscolor trackColor;
if (aParams.isCustom) {
trackColor = aParams.trackColor;
} else {
trackColor =
aParams.isDark ? NS_RGBA(46, 46, 46, 255) : NS_RGBA(250, 250, 250, 255);
}
ScrollbarTrackDecorationColors colors =
ComputeScrollbarTrackDecorationColors(trackColor);
struct {
nscolor color;
LayoutDeviceRect relativeRect;
} pieces[] = {
{colors.mInnerColor, {0.0f, 0.0f, 1.0f * aScale, 1.0f * aScale}},
{colors.mShadowColor,
{1.0f * aScale, 0.0f, 1.0f * aScale, 1.0f * aScale}},
{colors.mShadowColor,
{0.0f, 1.0f * aScale, 2.0f * aScale, 1.0f * aScale}},
{trackColor, {2.0f * aScale, 0.0f, width - 3.0f * aScale, 2.0f * aScale}},
{trackColor,
{0.0f, 2.0f * aScale, width - 1.0f * aScale, height - 3.0f * aScale}},
{colors.mOuterColor,
{width - 1.0f * aScale, 0.0f, 1.0f * aScale, height - 1.0f * aScale}},
{colors.mOuterColor,
{0.0f, height - 1.0f * aScale, width, 1.0f * aScale}},
};
auto current = aRects.begin();
for (const auto& piece : pieces) {
LayoutDeviceRect pieceRect = piece.relativeRect + aRect.TopLeft();
if (aParams.isRtl) {
pieceRect.x = aRect.XMost() - piece.relativeRect.XMost();
}
*current++ = {pieceRect, piece.color};
}
return true;
}
template <typename PaintBackendData>
void ScrollbarDrawingCocoa::DoPaintScrollbarThumb(
PaintBackendData& aPaintData, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const ElementState& aElementState, const DocumentState& aDocumentState,
const Colors& aColors, const DPIRatio& aDpiRatio) {
ScrollbarParams params =
ComputeScrollbarParams(aFrame, aStyle, aColors, aScrollbarKind);
auto thumb = GetThumbRect(aRect, params, aDpiRatio.scale);
LayoutDeviceCoord radius =
(params.isHorizontal ? thumb.mRect.Height() : thumb.mRect.Width()) / 2.0f;
ThemeDrawing::PaintRoundedRectWithRadius(
aPaintData, thumb.mRect, thumb.mRect,
sRGBColor::FromABGR(thumb.mFillColor), sRGBColor::White(0.0f), 0.0f,
radius / aDpiRatio, aDpiRatio);
if (!thumb.mStrokeColor) {
return;
}
// Paint the stroke if needed.
auto strokeRect = thumb.mRect;
strokeRect.Inflate(thumb.mStrokeOutset + thumb.mStrokeWidth);
radius =
(params.isHorizontal ? strokeRect.Height() : strokeRect.Width()) / 2.0f;
ThemeDrawing::PaintRoundedRectWithRadius(
aPaintData, strokeRect, sRGBColor::White(0.0f),
sRGBColor::FromABGR(thumb.mStrokeColor), thumb.mStrokeWidth,
radius / aDpiRatio, aDpiRatio);
}
bool ScrollbarDrawingCocoa::PaintScrollbarThumb(
DrawTarget& aDt, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const ElementState& aElementState, const DocumentState& aDocumentState,
const Colors& aColors, const DPIRatio& aDpiRatio) {
DoPaintScrollbarThumb(aDt, aRect, aScrollbarKind, aFrame, aStyle,
aElementState, aDocumentState, aColors, aDpiRatio);
return true;
}
bool ScrollbarDrawingCocoa::PaintScrollbarThumb(
WebRenderBackendData& aWrData, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const ElementState& aElementState, const DocumentState& aDocumentState,
const Colors& aColors, const DPIRatio& aDpiRatio) {
DoPaintScrollbarThumb(aWrData, aRect, aScrollbarKind, aFrame, aStyle,
aElementState, aDocumentState, aColors, aDpiRatio);
return true;
}
template <typename PaintBackendData>
void ScrollbarDrawingCocoa::DoPaintScrollbar(
PaintBackendData& aPaintData, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const ElementState& aElementState, const DocumentState& aDocumentState,
const Colors& aColors, const DPIRatio& aDpiRatio) {
ScrollbarParams params =
ComputeScrollbarParams(aFrame, aStyle, aColors, aScrollbarKind);
if (params.isOverlay && !params.isRolledOver) {
// Non-hovered overlay scrollbars don't have a track. Draw nothing.
return;
}
// Paint our track.
const auto color =
ComputeScrollbarTrackColor(aFrame, aStyle, aDocumentState, aColors);
ThemeDrawing::FillRect(aPaintData, aRect, color);
// Paint our decorations.
ScrollbarTrackRects rects;
GetScrollbarTrackRects(aRect, params, aDpiRatio.scale, rects);
for (const auto& rect : rects) {
ThemeDrawing::FillRect(aPaintData, rect.mRect,
sRGBColor::FromABGR(rect.mColor));
}
}
bool ScrollbarDrawingCocoa::PaintScrollbar(
DrawTarget& aDrawTarget, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const ElementState& aElementState, const DocumentState& aDocumentState,
const Colors& aColors, const DPIRatio& aDpiRatio) {
DoPaintScrollbar(aDrawTarget, aRect, aScrollbarKind, aFrame, aStyle,
aElementState, aDocumentState, aColors, aDpiRatio);
return true;
}
bool ScrollbarDrawingCocoa::PaintScrollbar(
WebRenderBackendData& aWrData, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const ElementState& aElementState, const DocumentState& aDocumentState,
const Colors& aColors, const DPIRatio& aDpiRatio) {
DoPaintScrollbar(aWrData, aRect, aScrollbarKind, aFrame, aStyle,
aElementState, aDocumentState, aColors, aDpiRatio);
return true;
}
template <typename PaintBackendData>
void ScrollbarDrawingCocoa::DoPaintScrollCorner(
PaintBackendData& aPaintData, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const DocumentState& aDocumentState, const Colors& aColors,
const DPIRatio& aDpiRatio) {
ScrollbarParams params =
ComputeScrollbarParams(aFrame, aStyle, aColors, aScrollbarKind);
ScrollCornerRects rects;
if (GetScrollCornerRects(aRect, params, aDpiRatio.scale, rects)) {
for (const auto& rect : rects) {
ThemeDrawing::FillRect(aPaintData, rect.mRect,
sRGBColor::FromABGR(rect.mColor));
}
}
}
bool ScrollbarDrawingCocoa::PaintScrollCorner(
DrawTarget& aDt, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const DocumentState& aDocumentState, const Colors& aColors,
const DPIRatio& aDpiRatio) {
DoPaintScrollCorner(aDt, aRect, aScrollbarKind, aFrame, aStyle,
aDocumentState, aColors, aDpiRatio);
return true;
}
bool ScrollbarDrawingCocoa::PaintScrollCorner(
WebRenderBackendData& aWrData, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const DocumentState& aDocumentState, const Colors& aColors,
const DPIRatio& aDpiRatio) {
DoPaintScrollCorner(aWrData, aRect, aScrollbarKind, aFrame, aStyle,
aDocumentState, aColors, aDpiRatio);
return true;
}
void ScrollbarDrawingCocoa::RecomputeScrollbarParams() {
// FIXME(emilio): This doesn't respect the
// StaticPrefs::widget_non_native_theme_scrollbar_size_override() pref;
ConfigureScrollbarSize(15); // Just in case, for future-proofing
ConfigureScrollbarSize(StyleScrollbarWidth::Auto, Overlay::No, 15);
ConfigureScrollbarSize(StyleScrollbarWidth::Thin, Overlay::No, 11);
ConfigureScrollbarSize(StyleScrollbarWidth::Auto, Overlay::Yes, 16);
ConfigureScrollbarSize(StyleScrollbarWidth::Thin, Overlay::Yes, 12);
}
} // namespace mozilla::widget