gecko-dev/gfx/layers/FrameMetrics.cpp

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6.6 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 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
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "FrameMetrics.h"
#include "gfxUtils.h"
#include "nsStyleConsts.h"
#include "nsStyleStruct.h"
#include "mozilla/WritingModes.h"
#include "mozilla/gfx/Types.h"
namespace mozilla {
namespace layers {
const ScrollableLayerGuid::ViewID ScrollableLayerGuid::NULL_SCROLL_ID = 0;
void FrameMetrics::RecalculateLayoutViewportOffset() {
if (!mIsRootContent) {
return;
}
KeepLayoutViewportEnclosingVisualViewport(GetVisualViewport(),
mScrollableRect, mLayoutViewport);
}
/* static */
void FrameMetrics::KeepLayoutViewportEnclosingVisualViewport(
const CSSRect& aVisualViewport, const CSSRect& aScrollableRect,
CSSRect& aLayoutViewport) {
// If the visual viewport is contained within the layout viewport, we don't
// need to make any adjustments, so we can exit early.
//
// Additionally, if the composition bounds changes (due to an orientation
// change, window resize, etc.), it may take a few frames for aLayoutViewport
// to update and during that time, the visual viewport may be larger than the
// layout viewport. In such situations, we take an early exit if the visual
// viewport contains the layout viewport.
if (aLayoutViewport.Contains(aVisualViewport) ||
aVisualViewport.Contains(aLayoutViewport)) {
return;
}
// If visual viewport size is greater than the layout viewport, move the
// layout viewport such that it remains inside the visual viewport. Otherwise,
// move the layout viewport such that the visual viewport is contained
// inside the layout viewport.
if ((aLayoutViewport.Width() < aVisualViewport.Width() &&
!FuzzyEqualsMultiplicative(aLayoutViewport.Width(),
aVisualViewport.Width())) ||
(aLayoutViewport.Height() < aVisualViewport.Height() &&
!FuzzyEqualsMultiplicative(aLayoutViewport.Height(),
aVisualViewport.Height()))) {
if (aLayoutViewport.X() < aVisualViewport.X()) {
// layout viewport moves right
aLayoutViewport.MoveToX(aVisualViewport.X());
} else if (aVisualViewport.XMost() < aLayoutViewport.XMost()) {
// layout viewport moves left
aLayoutViewport.MoveByX(aVisualViewport.XMost() -
aLayoutViewport.XMost());
}
if (aLayoutViewport.Y() < aVisualViewport.Y()) {
// layout viewport moves down
aLayoutViewport.MoveToY(aVisualViewport.Y());
} else if (aVisualViewport.YMost() < aLayoutViewport.YMost()) {
// layout viewport moves up
aLayoutViewport.MoveByY(aVisualViewport.YMost() -
aLayoutViewport.YMost());
}
} else {
if (aVisualViewport.X() < aLayoutViewport.X()) {
aLayoutViewport.MoveToX(aVisualViewport.X());
} else if (aLayoutViewport.XMost() < aVisualViewport.XMost()) {
aLayoutViewport.MoveByX(aVisualViewport.XMost() -
aLayoutViewport.XMost());
}
if (aVisualViewport.Y() < aLayoutViewport.Y()) {
aLayoutViewport.MoveToY(aVisualViewport.Y());
} else if (aLayoutViewport.YMost() < aVisualViewport.YMost()) {
aLayoutViewport.MoveByY(aVisualViewport.YMost() -
aLayoutViewport.YMost());
}
}
// Regardless of any adjustment above, the layout viewport is not allowed
// to go outside the scrollable rect.
aLayoutViewport = aLayoutViewport.MoveInsideAndClamp(aScrollableRect);
}
ScrollSnapInfo::ScrollSnapInfo()
: mScrollSnapStrictnessX(StyleScrollSnapStrictness::None),
mScrollSnapStrictnessY(StyleScrollSnapStrictness::None) {}
bool ScrollSnapInfo::HasScrollSnapping() const {
return mScrollSnapStrictnessY != StyleScrollSnapStrictness::None ||
mScrollSnapStrictnessX != StyleScrollSnapStrictness::None;
}
bool ScrollSnapInfo::HasSnapPositions() const {
return (!mSnapPositionX.IsEmpty() &&
mScrollSnapStrictnessX != StyleScrollSnapStrictness::None) ||
(!mSnapPositionY.IsEmpty() &&
mScrollSnapStrictnessY != StyleScrollSnapStrictness::None);
}
void ScrollSnapInfo::InitializeScrollSnapStrictness(
WritingMode aWritingMode, const nsStyleDisplay* aDisplay) {
if (aDisplay->mScrollSnapType.strictness == StyleScrollSnapStrictness::None) {
return;
}
mScrollSnapStrictnessX = StyleScrollSnapStrictness::None;
mScrollSnapStrictnessY = StyleScrollSnapStrictness::None;
switch (aDisplay->mScrollSnapType.axis) {
case StyleScrollSnapAxis::X:
mScrollSnapStrictnessX = aDisplay->mScrollSnapType.strictness;
break;
case StyleScrollSnapAxis::Y:
mScrollSnapStrictnessY = aDisplay->mScrollSnapType.strictness;
break;
case StyleScrollSnapAxis::Block:
if (aWritingMode.IsVertical()) {
mScrollSnapStrictnessX = aDisplay->mScrollSnapType.strictness;
} else {
mScrollSnapStrictnessY = aDisplay->mScrollSnapType.strictness;
}
break;
case StyleScrollSnapAxis::Inline:
if (aWritingMode.IsVertical()) {
mScrollSnapStrictnessY = aDisplay->mScrollSnapType.strictness;
} else {
mScrollSnapStrictnessX = aDisplay->mScrollSnapType.strictness;
}
break;
case StyleScrollSnapAxis::Both:
mScrollSnapStrictnessX = aDisplay->mScrollSnapType.strictness;
mScrollSnapStrictnessY = aDisplay->mScrollSnapType.strictness;
break;
}
}
static OverscrollBehavior ToOverscrollBehavior(
StyleOverscrollBehavior aBehavior) {
switch (aBehavior) {
case StyleOverscrollBehavior::Auto:
return OverscrollBehavior::Auto;
case StyleOverscrollBehavior::Contain:
return OverscrollBehavior::Contain;
case StyleOverscrollBehavior::None:
return OverscrollBehavior::None;
}
MOZ_ASSERT_UNREACHABLE("Invalid overscroll behavior");
return OverscrollBehavior::Auto;
}
OverscrollBehaviorInfo OverscrollBehaviorInfo::FromStyleConstants(
StyleOverscrollBehavior aBehaviorX, StyleOverscrollBehavior aBehaviorY) {
OverscrollBehaviorInfo result;
result.mBehaviorX = ToOverscrollBehavior(aBehaviorX);
result.mBehaviorY = ToOverscrollBehavior(aBehaviorY);
return result;
}
void ScrollMetadata::SetBackgroundColor(
const gfx::sRGBColor& aBackgroundColor) {
mBackgroundColor = gfx::ToDeviceColor(aBackgroundColor);
}
StaticAutoPtr<const ScrollMetadata> ScrollMetadata::sNullMetadata;
} // namespace layers
} // namespace mozilla