Source code
Revision control
Copy as Markdown
Other Tools
/* -*- 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
#include "FrameMetrics.h"
#include <ostream>
#include "gfxUtils.h"
#include "nsStyleConsts.h"
#include "mozilla/gfx/Types.h"
namespace mozilla {
namespace layers {
const ScrollableLayerGuid::ViewID ScrollableLayerGuid::NULL_SCROLL_ID = 0;
std::ostream& operator<<(std::ostream& aStream, const FrameMetrics& aMetrics) {
aStream << "{ [cb=" << aMetrics.GetCompositionBounds()
<< "] [sr=" << aMetrics.GetScrollableRect()
<< "] [s=" << aMetrics.GetVisualScrollOffset();
if (aMetrics.GetVisualScrollUpdateType() != FrameMetrics::eNone) {
aStream << "] [vd=" << aMetrics.GetVisualDestination();
}
if (aMetrics.IsScrollInfoLayer()) {
aStream << "] [scrollinfo";
}
aStream << "] [dp=" << aMetrics.GetDisplayPort()
<< "] [rcs=" << aMetrics.GetBoundingCompositionSize()
<< "] [v=" << aMetrics.GetLayoutViewport()
<< nsPrintfCString("] [z=(ld=%.3f r=%.3f",
aMetrics.GetDevPixelsPerCSSPixel().scale,
aMetrics.GetPresShellResolution())
.get()
<< " cr=" << aMetrics.GetCumulativeResolution()
<< " z=" << aMetrics.GetZoom()
<< " t=" << aMetrics.GetTransformToAncestorScale() << " )] [u=("
<< (int)aMetrics.GetVisualScrollUpdateType() << " "
<< aMetrics.GetScrollGeneration()
<< ")] scrollId=" << aMetrics.GetScrollId();
if (aMetrics.IsRootContent()) {
aStream << " [rcd]";
}
aStream << " }";
return aStream;
}
void FrameMetrics::RecalculateLayoutViewportOffset() {
// For subframes, the visual and layout viewports coincide, so just
// keep the layout viewport offset in sync with the visual one.
if (!mIsRootContent) {
mLayoutViewport.MoveTo(GetVisualScrollOffset());
return;
}
// For the root, the two viewports can diverge, but the layout
// viewport needs to keep enclosing the visual viewport.
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);
}
/* static */
CSSRect FrameMetrics::CalculateScrollRange(
const CSSRect& aScrollableRect, const ParentLayerRect& aCompositionBounds,
const CSSToParentLayerScale& aZoom) {
CSSSize scrollPortSize =
CalculateCompositedSizeInCssPixels(aCompositionBounds, aZoom);
CSSRect scrollRange = aScrollableRect;
scrollRange.SetWidth(
std::max(scrollRange.Width() - scrollPortSize.width, 0.0f));
scrollRange.SetHeight(
std::max(scrollRange.Height() - scrollPortSize.height, 0.0f));
return scrollRange;
}
/* static */
CSSSize FrameMetrics::CalculateCompositedSizeInCssPixels(
const ParentLayerRect& aCompositionBounds,
const CSSToParentLayerScale& aZoom) {
if (aZoom == CSSToParentLayerScale(0)) {
return CSSSize(); // avoid division by zero
}
return aCompositionBounds.Size() / aZoom;
}
bool FrameMetrics::ApplyScrollUpdateFrom(const ScrollPositionUpdate& aUpdate) {
// In applying a main-thread scroll update, try to preserve the relative
// offset between the visual and layout viewports.
CSSPoint relativeOffset = GetVisualScrollOffset() - GetLayoutScrollOffset();
MOZ_ASSERT(IsRootContent() || relativeOffset == CSSPoint());
// We need to set the two offsets together, otherwise a subsequent
// RecalculateLayoutViewportOffset() could see divergent layout and
// visual offsets.
bool offsetChanged = SetLayoutScrollOffset(aUpdate.GetDestination());
offsetChanged |=
ClampAndSetVisualScrollOffset(aUpdate.GetDestination() + relativeOffset);
return offsetChanged;
}
CSSPoint FrameMetrics::ApplyRelativeScrollUpdateFrom(
const ScrollPositionUpdate& aUpdate) {
MOZ_ASSERT(aUpdate.GetType() == ScrollUpdateType::Relative);
CSSPoint origin = GetVisualScrollOffset();
CSSPoint delta = (aUpdate.GetDestination() - aUpdate.GetSource());
SetVisualScrollOffset(origin + delta);
return GetVisualScrollOffset() - origin;
}
CSSPoint FrameMetrics::ApplyPureRelativeScrollUpdateFrom(
const ScrollPositionUpdate& aUpdate) {
MOZ_ASSERT(aUpdate.GetType() == ScrollUpdateType::PureRelative);
CSSPoint origin = GetVisualScrollOffset();
ClampAndSetVisualScrollOffset(origin + aUpdate.GetDelta());
return GetVisualScrollOffset() - origin;
}
void FrameMetrics::UpdatePendingScrollInfo(const ScrollPositionUpdate& aInfo) {
// We only get this "pending scroll info" for paint-skip transactions,
// but PureRelative position updates always trigger a full paint, so
// we should never enter this code with a PureRelative update type. For
// the other types, the destination field on the ScrollPositionUpdate will
// tell us the final layout scroll position on the main thread.
MOZ_ASSERT(aInfo.GetType() != ScrollUpdateType::PureRelative);
// In applying a main-thread scroll update, try to preserve the relative
// offset between the visual and layout viewports.
CSSPoint relativeOffset = GetVisualScrollOffset() - GetLayoutScrollOffset();
MOZ_ASSERT(IsRootContent() || relativeOffset == CSSPoint());
SetLayoutScrollOffset(aInfo.GetDestination());
ClampAndSetVisualScrollOffset(aInfo.GetDestination() + relativeOffset);
mScrollGeneration = aInfo.GetGeneration();
}
std::ostream& operator<<(std::ostream& aStream,
const OverscrollBehavior& aBehavior) {
switch (aBehavior) {
case OverscrollBehavior::Auto: {
aStream << "auto";
break;
}
case OverscrollBehavior::Contain: {
aStream << "contain";
break;
}
case OverscrollBehavior::None: {
aStream << "none";
break;
}
}
return aStream;
}
OverscrollBehaviorInfo::OverscrollBehaviorInfo()
: mBehaviorX(OverscrollBehavior::Auto),
mBehaviorY(OverscrollBehavior::Auto) {}
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;
}
bool OverscrollBehaviorInfo::operator==(
const OverscrollBehaviorInfo& aOther) const {
return mBehaviorX == aOther.mBehaviorX && mBehaviorY == aOther.mBehaviorY;
}
std::ostream& operator<<(std::ostream& aStream,
const OverscrollBehaviorInfo& aInfo) {
if (aInfo.mBehaviorX == aInfo.mBehaviorY) {
aStream << aInfo.mBehaviorX;
} else {
aStream << "{ x=" << aInfo.mBehaviorX << ", y=" << aInfo.mBehaviorY << " }";
}
return aStream;
}
std::ostream& operator<<(std::ostream& aStream,
const ScrollMetadata& aMetadata) {
aStream << "{ [description=" << aMetadata.GetContentDescription()
<< "] [metrics=" << aMetadata.GetMetrics();
if (aMetadata.GetScrollParentId() != ScrollableLayerGuid::NULL_SCROLL_ID) {
aStream << "] [scrollParent=" << aMetadata.GetScrollParentId();
}
if (aMetadata.GetHasScrollgrab()) {
aStream << "] [scrollgrab";
}
aStream << "] [overscroll=" << aMetadata.GetOverscrollBehavior() << "] ["
<< aMetadata.GetScrollUpdates().Length() << " scrollupdates"
<< "] }";
return aStream;
}
StaticAutoPtr<const ScrollMetadata> ScrollMetadata::sNullMetadata;
} // namespace layers
} // namespace mozilla