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/* -*- Mode: C++; tab-width: 40; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "ScrollbarDrawingWin.h"
#include "mozilla/gfx/Helpers.h"
#include "mozilla/Maybe.h"
#include "mozilla/StaticPrefs_widget.h"
#include "nsLayoutUtils.h"
#include "Theme.h"
#include "nsNativeTheme.h"
namespace mozilla::widget {
LayoutDeviceIntSize ScrollbarDrawingWin::GetMinimumWidgetSize(
nsPresContext* aPresContext, StyleAppearance aAppearance,
nsIFrame* aFrame) {
MOZ_ASSERT(nsNativeTheme::IsWidgetScrollbarPart(aAppearance));
switch (aAppearance) {
case StyleAppearance::ScrollbarbuttonUp:
case StyleAppearance::ScrollbarbuttonDown:
case StyleAppearance::ScrollbarbuttonLeft:
case StyleAppearance::ScrollbarbuttonRight:
// For scrollbar-width:thin, we don't display the buttons.
if (IsScrollbarWidthThin(aFrame)) {
return LayoutDeviceIntSize{};
}
[[fallthrough]];
case StyleAppearance::ScrollbarVertical:
case StyleAppearance::ScrollbarHorizontal:
case StyleAppearance::ScrollbarthumbVertical:
case StyleAppearance::ScrollbarthumbHorizontal: {
// TODO: for short scrollbars it could be nice if the thumb could shrink
// under this size.
auto relevantSize = GetScrollbarSize(aPresContext, aFrame);
const bool isHorizontal =
aAppearance == StyleAppearance::ScrollbarHorizontal ||
aAppearance == StyleAppearance::ScrollbarthumbHorizontal ||
aAppearance == StyleAppearance::ScrollbarbuttonLeft ||
aAppearance == StyleAppearance::ScrollbarbuttonRight;
auto size = LayoutDeviceIntSize{relevantSize, relevantSize};
if (aAppearance == StyleAppearance::ScrollbarHorizontal ||
aAppearance == StyleAppearance::ScrollbarVertical) {
// Always reserve some space in the right direction. Historically we've
// reserved 2 times the size in the other axis (for the buttons).
// We do this even when painting thin scrollbars just for consistency,
// though there just one would probably do there.
if (isHorizontal) {
size.width *= 2;
} else {
size.height *= 2;
}
}
return size;
}
default:
return LayoutDeviceIntSize{};
}
}
// Returns the style for custom scrollbar if the scrollbar part frame should
// use the custom drawing path, nullptr otherwise.
const ComputedStyle* GetCustomScrollbarStyle(nsIFrame* aFrame) {
const ComputedStyle* style = nsLayoutUtils::StyleForScrollbar(aFrame);
if (style->StyleUI()->HasCustomScrollbars() ||
ScrollbarDrawing::IsScrollbarWidthThin(*style)) {
return style;
}
bool useDarkScrollbar = !StaticPrefs::widget_disable_dark_scrollbar() &&
nsNativeTheme::IsDarkBackgroundForScrollbar(aFrame);
if (useDarkScrollbar) {
return style;
}
return nullptr;
}
Maybe<nsITheme::Transparency> ScrollbarDrawingWin::GetScrollbarPartTransparency(
nsIFrame* aFrame, StyleAppearance aAppearance) {
if (nsNativeTheme::IsWidgetScrollbarPart(aAppearance)) {
if (const ComputedStyle* style = GetCustomScrollbarStyle(aFrame)) {
auto* ui = style->StyleUI();
if (ui->mScrollbarColor.IsAuto() ||
ui->mScrollbarColor.AsColors().track.MaybeTransparent()) {
return Some(nsITheme::eTransparent);
}
// These widgets may be thinner than the track, so we need to return
// transparent for them to make the track visible.
switch (aAppearance) {
case StyleAppearance::ScrollbarthumbHorizontal:
case StyleAppearance::ScrollbarthumbVertical:
case StyleAppearance::ScrollbarbuttonUp:
case StyleAppearance::ScrollbarbuttonDown:
case StyleAppearance::ScrollbarbuttonLeft:
case StyleAppearance::ScrollbarbuttonRight:
return Some(nsITheme::eTransparent);
default:
break;
}
}
if (aFrame->PresContext()->UseOverlayScrollbars()) {
return Some(nsITheme::eTransparent);
}
}
switch (aAppearance) {
case StyleAppearance::ScrollbarHorizontal:
case StyleAppearance::ScrollbarVertical:
case StyleAppearance::Scrollcorner:
// Knowing that scrollbars and statusbars are opaque improves
// performance, because we create layers for them. This better be
// true across all Windows themes! If it's not true, we should
// paint an opaque background for them to make it true!
// TODO(emilio): Unclear how much this optimization matters in practice
// now we're in a WR-only world.
return Some(nsITheme::eOpaque);
default:
break;
}
return Nothing();
}
template <typename PaintBackendData>
bool ScrollbarDrawingWin::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) {
sRGBColor thumbColor = ComputeScrollbarThumbColor(
aFrame, aStyle, aElementState, aDocumentState, aColors);
ThemeDrawing::FillRect(aPaintData, aRect, thumbColor);
return true;
}
bool ScrollbarDrawingWin::PaintScrollbarThumb(
DrawTarget& aDrawTarget, const LayoutDeviceRect& aRect,
ScrollbarKind aScrollbarKind, nsIFrame* aFrame, const ComputedStyle& aStyle,
const ElementState& aElementState, const DocumentState& aDocumentState,
const Colors& aColors, const DPIRatio& aDpiRatio) {
return DoPaintScrollbarThumb(aDrawTarget, aRect, aScrollbarKind, aFrame,
aStyle, aElementState, aDocumentState, aColors,
aDpiRatio);
}
bool ScrollbarDrawingWin::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) {
return DoPaintScrollbarThumb(aWrData, aRect, aScrollbarKind, aFrame, aStyle,
aElementState, aDocumentState, aColors,
aDpiRatio);
}
void ScrollbarDrawingWin::RecomputeScrollbarParams() {
uint32_t defaultSize = kDefaultWinScrollbarSize;
uint32_t overrideSize =
StaticPrefs::widget_non_native_theme_scrollbar_size_override();
if (overrideSize > 0) {
defaultSize = overrideSize;
}
ConfigureScrollbarSize(defaultSize);
if (StaticPrefs::widget_non_native_theme_win_scrollbar_use_system_size()) {
ConfigureScrollbarSize(LookAndFeel::GetInt(
LookAndFeel::IntID::SystemScrollbarSize, defaultSize));
}
}
} // namespace mozilla::widget