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 "WheelHandlingHelper.h"
#include <utility> // for std::swap
#include "mozilla/EventDispatcher.h"
#include "mozilla/EventStateManager.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/Preferences.h"
#include "mozilla/PresShell.h"
#include "mozilla/StaticPrefs_mousewheel.h"
#include "mozilla/StaticPrefs_test.h"
#include "mozilla/TextControlElement.h"
#include "mozilla/dom/WheelEventBinding.h"
#include "nsCOMPtr.h"
#include "nsContentUtils.h"
#include "nsIContent.h"
#include "nsIContentInlines.h"
#include "mozilla/dom/Document.h"
#include "DocumentInlines.h" // for Document and HTMLBodyElement
#include "nsIScrollableFrame.h"
#include "nsITimer.h"
#include "nsPresContext.h"
#include "prtime.h"
#include "Units.h"
#include "ScrollAnimationPhysics.h"
namespace mozilla {
/******************************************************************/
/* mozilla::DeltaValues */
/******************************************************************/
DeltaValues::DeltaValues(WidgetWheelEvent* aEvent)
: deltaX(aEvent->mDeltaX), deltaY(aEvent->mDeltaY) {}
/******************************************************************/
/* mozilla::WheelHandlingUtils */
/******************************************************************/
/* static */
bool WheelHandlingUtils::CanScrollInRange(nscoord aMin, nscoord aValue,
nscoord aMax, double aDirection) {
return aDirection > 0.0 ? aValue < static_cast<double>(aMax)
: static_cast<double>(aMin) < aValue;
}
/* static */
bool WheelHandlingUtils::CanScrollOn(nsIFrame* aFrame, double aDirectionX,
double aDirectionY) {
nsIScrollableFrame* scrollableFrame = do_QueryFrame(aFrame);
if (!scrollableFrame) {
return false;
}
return CanScrollOn(scrollableFrame, aDirectionX, aDirectionY);
}
/* static */
bool WheelHandlingUtils::CanScrollOn(nsIScrollableFrame* aScrollFrame,
double aDirectionX, double aDirectionY) {
MOZ_ASSERT(aScrollFrame);
NS_ASSERTION(aDirectionX || aDirectionY,
"One of the delta values must be non-zero at least");
nsPoint scrollPt = aScrollFrame->GetVisualViewportOffset();
nsRect scrollRange = aScrollFrame->GetScrollRangeForUserInputEvents();
layers::ScrollDirections directions =
aScrollFrame->GetAvailableScrollingDirectionsForUserInputEvents();
return ((aDirectionX != 0.0) &&
(directions.contains(layers::ScrollDirection::eHorizontal)) &&
CanScrollInRange(scrollRange.x, scrollPt.x, scrollRange.XMost(),
aDirectionX)) ||
((aDirectionY != 0.0) &&
(directions.contains(layers::ScrollDirection::eVertical)) &&
CanScrollInRange(scrollRange.y, scrollPt.y, scrollRange.YMost(),
aDirectionY));
}
/*static*/ Maybe<layers::ScrollDirection>
WheelHandlingUtils::GetDisregardedWheelScrollDirection(const nsIFrame* aFrame) {
nsIContent* content = aFrame->GetContent();
if (!content) {
return Nothing();
}
TextControlElement* textControlElement = TextControlElement::FromNodeOrNull(
content->IsInNativeAnonymousSubtree()
? content->GetClosestNativeAnonymousSubtreeRootParentOrHost()
: content);
if (!textControlElement || !textControlElement->IsSingleLineTextControl()) {
return Nothing();
}
// Disregard scroll in the block-flow direction by mouse wheel on a
// single-line text control. For instance, in tranditional Chinese writing
// system, a single-line text control cannot be scrolled horizontally with
// mouse wheel even if they overflow at the right and left edges; Whereas in
// latin-based writing system, a single-line text control cannot be scrolled
// vertically with mouse wheel even if they overflow at the top and bottom
// edges
return Some(aFrame->GetWritingMode().IsVertical()
? layers::ScrollDirection::eHorizontal
: layers::ScrollDirection::eVertical);
}
/******************************************************************/
/* mozilla::WheelTransaction */
/******************************************************************/
AutoWeakFrame WheelTransaction::sScrollTargetFrame(nullptr);
AutoWeakFrame WheelTransaction::sEventTargetFrame(nullptr);
bool WheelTransaction::sHandledByApz(false);
uint32_t WheelTransaction::sTime = 0;
uint32_t WheelTransaction::sMouseMoved = 0;
nsITimer* WheelTransaction::sTimer = nullptr;
int32_t WheelTransaction::sScrollSeriesCounter = 0;
bool WheelTransaction::sOwnScrollbars = false;
/* static */
bool WheelTransaction::OutOfTime(uint32_t aBaseTime, uint32_t aThreshold) {
uint32_t now = PR_IntervalToMilliseconds(PR_IntervalNow());
return (now - aBaseTime > aThreshold);
}
/* static */
void WheelTransaction::OwnScrollbars(bool aOwn) { sOwnScrollbars = aOwn; }
/* static */
void WheelTransaction::BeginTransaction(nsIFrame* aScrollTargetFrame,
nsIFrame* aEventTargetFrame,
const WidgetWheelEvent* aEvent) {
NS_ASSERTION(!sScrollTargetFrame && !sEventTargetFrame,
"previous transaction is not finished!");
MOZ_ASSERT(aEvent->mMessage == eWheel,
"Transaction must be started with a wheel event");
ScrollbarsForWheel::OwnWheelTransaction(false);
sScrollTargetFrame = aScrollTargetFrame;
// Only set the static event target if wheel event groups are enabled.
if (StaticPrefs::dom_event_wheel_event_groups_enabled()) {
// Set a static event target for the wheel transaction. This will be used
// to override the event target frame when computing the event target from
// input coordinates. When this preference is not set or there is no stored
// event target for the current wheel transaction, the event target will
// not be overridden by the current wheel transaction, but will be computed
// from the input coordinates.
sEventTargetFrame = aEventTargetFrame;
// If the wheel events will be handled by APZ, set a flag here. We can use
// this later to determine if we need to scroll snap at the end of the
// wheel operation.
sHandledByApz = aEvent->mFlags.mHandledByAPZ;
}
sScrollSeriesCounter = 0;
if (!UpdateTransaction(aEvent)) {
NS_ERROR("BeginTransaction is called even cannot scroll the frame");
EndTransaction();
}
}
/* static */
bool WheelTransaction::UpdateTransaction(const WidgetWheelEvent* aEvent) {
nsIFrame* scrollToFrame = GetScrollTargetFrame();
nsIScrollableFrame* scrollableFrame = scrollToFrame->GetScrollTargetFrame();
if (scrollableFrame) {
scrollToFrame = do_QueryFrame(scrollableFrame);
}
if (!WheelHandlingUtils::CanScrollOn(scrollToFrame, aEvent->mDeltaX,
aEvent->mDeltaY)) {
OnFailToScrollTarget();
// We should not modify the transaction state when the view will not be
// scrolled actually.
return false;
}
SetTimeout();
if (sScrollSeriesCounter != 0 &&
OutOfTime(sTime, StaticPrefs::mousewheel_scroll_series_timeout())) {
sScrollSeriesCounter = 0;
}
sScrollSeriesCounter++;
// We should use current time instead of WidgetEvent.time.
// 1. Some events doesn't have the correct creation time.
// 2. If the computer runs slowly by other processes eating the CPU resource,
// the event creation time doesn't keep real time.
sTime = PR_IntervalToMilliseconds(PR_IntervalNow());
sMouseMoved = 0;
return true;
}
/* static */
void WheelTransaction::MayEndTransaction() {
if (!sOwnScrollbars && ScrollbarsForWheel::IsActive()) {
ScrollbarsForWheel::OwnWheelTransaction(true);
} else {
EndTransaction();
}
}
/* static */
void WheelTransaction::EndTransaction() {
if (sTimer) {
sTimer->Cancel();
}
sScrollTargetFrame = nullptr;
sEventTargetFrame = nullptr;
sScrollSeriesCounter = 0;
sHandledByApz = false;
if (sOwnScrollbars) {
sOwnScrollbars = false;
ScrollbarsForWheel::OwnWheelTransaction(false);
ScrollbarsForWheel::Inactivate();
}
}
/* static */
bool WheelTransaction::WillHandleDefaultAction(
WidgetWheelEvent* aWheelEvent, AutoWeakFrame& aScrollTargetWeakFrame,
AutoWeakFrame& aEventTargetWeakFrame) {
nsIFrame* lastTargetFrame = GetScrollTargetFrame();
if (!lastTargetFrame) {
BeginTransaction(aScrollTargetWeakFrame.GetFrame(),
aEventTargetWeakFrame.GetFrame(), aWheelEvent);
} else if (lastTargetFrame != aScrollTargetWeakFrame.GetFrame()) {
EndTransaction();
BeginTransaction(aScrollTargetWeakFrame.GetFrame(),
aEventTargetWeakFrame.GetFrame(), aWheelEvent);
} else {
UpdateTransaction(aWheelEvent);
}
// When the wheel event will not be handled with any frames,
// UpdateTransaction() fires MozMouseScrollFailed event which is for
// automated testing. In the event handler, the target frame might be
// destroyed. Then, the caller shouldn't try to handle the default action.
if (!aScrollTargetWeakFrame.IsAlive()) {
EndTransaction();
return false;
}
return true;
}
/* static */
void WheelTransaction::OnEvent(WidgetEvent* aEvent) {
if (!sScrollTargetFrame) {
return;
}
if (OutOfTime(sTime, StaticPrefs::mousewheel_transaction_timeout())) {
// Even if the scroll event which is handled after timeout, but onTimeout
// was not fired by timer, then the scroll event will scroll old frame,
// therefore, we should call OnTimeout here and ensure to finish the old
// transaction.
OnTimeout(nullptr, nullptr);
return;
}
switch (aEvent->mMessage) {
case eWheel:
if (sMouseMoved != 0 &&
OutOfTime(sMouseMoved,
StaticPrefs::mousewheel_transaction_ignoremovedelay())) {
// Terminate the current mousewheel transaction if the mouse moved more
// than ignoremovedelay milliseconds ago
EndTransaction();
}
return;
case eMouseMove:
case eDragOver: {
WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent();
if (mouseEvent->IsReal()) {
// If the cursor is moving to be outside the frame,
// terminate the scrollwheel transaction.
LayoutDeviceIntPoint pt = GetScreenPoint(mouseEvent);
auto r = LayoutDeviceIntRect::FromAppUnitsToNearest(
sScrollTargetFrame->GetScreenRectInAppUnits(),
sScrollTargetFrame->PresContext()->AppUnitsPerDevPixel());
if (!r.Contains(pt)) {
EndTransaction();
return;
}
// For mouse move events where the wheel transaction is still valid, the
// stored event target should be reset.
sEventTargetFrame = nullptr;
// If the cursor is moving inside the frame, and it is less than
// ignoremovedelay milliseconds since the last scroll operation, ignore
// the mouse move; otherwise, record the current mouse move time to be
// checked later
if (!sMouseMoved &&
OutOfTime(sTime,
StaticPrefs::mousewheel_transaction_ignoremovedelay())) {
sMouseMoved = PR_IntervalToMilliseconds(PR_IntervalNow());
}
}
return;
}
case eKeyPress:
case eKeyUp:
case eKeyDown:
case eMouseUp:
case eMouseDown:
case eMouseDoubleClick:
case eMouseAuxClick:
case eMouseClick:
case eContextMenu:
case eDrop:
EndTransaction();
return;
default:
break;
}
}
/* static */
void WheelTransaction::OnRemoveElement(nsIContent* aContent) {
// If dom.event.wheel-event-groups.enabled is not set or we have no current
// wheel event transaction there is no internal state to be updated.
if (!sEventTargetFrame) {
return;
}
if (sEventTargetFrame->GetContent() == aContent) {
// Only invalidate the wheel transaction event target frame when the
// remove target is the event target of the wheel event group. The
// scroll target frame of the wheel event group may still be valid.
//
// With the stored event target unset, the target for any following
// events will be the frame found using the input coordinates.
sEventTargetFrame = nullptr;
}
}
/* static */
void WheelTransaction::Shutdown() { NS_IF_RELEASE(sTimer); }
/* static */
void WheelTransaction::OnFailToScrollTarget() {
MOZ_ASSERT(sScrollTargetFrame, "We don't have mouse scrolling transaction");
if (StaticPrefs::test_mousescroll()) {
nsContentUtils::DispatchEventOnlyToChrome(
sScrollTargetFrame->GetContent()->OwnerDoc(),
sScrollTargetFrame->GetContent(), u"MozMouseScrollFailed"_ns,
CanBubble::eYes, Cancelable::eYes);
}
// The target frame might be destroyed in the event handler, at that time,
// we need to finish the current transaction
if (!sScrollTargetFrame) {
EndTransaction();
}
}
/* static */
void WheelTransaction::OnTimeout(nsITimer* aTimer, void* aClosure) {
if (!sScrollTargetFrame) {
// The transaction target was destroyed already
EndTransaction();
return;
}
// Store the sScrollTargetFrame, the variable becomes null in EndTransaction.
nsIFrame* frame = sScrollTargetFrame;
// We need to finish current transaction before DOM event firing. Because
// the next DOM event might create strange situation for us.
MayEndTransaction();
if (StaticPrefs::test_mousescroll()) {
nsContentUtils::DispatchEventOnlyToChrome(
frame->GetContent()->OwnerDoc(), frame->GetContent(),
u"MozMouseScrollTransactionTimeout"_ns, CanBubble::eYes,
Cancelable::eYes);
}
}
/* static */
void WheelTransaction::SetTimeout() {
if (!sTimer) {
sTimer = NS_NewTimer().take();
if (!sTimer) {
return;
}
}
sTimer->Cancel();
DebugOnly<nsresult> rv = sTimer->InitWithNamedFuncCallback(
OnTimeout, nullptr, StaticPrefs::mousewheel_transaction_timeout(),
nsITimer::TYPE_ONE_SHOT, "WheelTransaction::SetTimeout");
NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
"nsITimer::InitWithFuncCallback failed");
}
/* static */
LayoutDeviceIntPoint WheelTransaction::GetScreenPoint(WidgetGUIEvent* aEvent) {
NS_ASSERTION(aEvent, "aEvent is null");
NS_ASSERTION(aEvent->mWidget, "aEvent-mWidget is null");
return aEvent->mRefPoint + aEvent->mWidget->WidgetToScreenOffset();
}
/* static */
DeltaValues WheelTransaction::AccelerateWheelDelta(WidgetWheelEvent* aEvent) {
DeltaValues result = OverrideSystemScrollSpeed(aEvent);
// Don't accelerate the delta values if the event isn't line scrolling.
if (aEvent->mDeltaMode != dom::WheelEvent_Binding::DOM_DELTA_LINE) {
return result;
}
// Accelerate by the sScrollSeriesCounter
int32_t start = StaticPrefs::mousewheel_acceleration_start();
if (start >= 0 && sScrollSeriesCounter >= start) {
int32_t factor = StaticPrefs::mousewheel_acceleration_factor();
if (factor > 0) {
result.deltaX = ComputeAcceleratedWheelDelta(result.deltaX, factor);
result.deltaY = ComputeAcceleratedWheelDelta(result.deltaY, factor);
}
}
return result;
}
/* static */
double WheelTransaction::ComputeAcceleratedWheelDelta(double aDelta,
int32_t aFactor) {
return mozilla::ComputeAcceleratedWheelDelta(aDelta, sScrollSeriesCounter,
aFactor);
}
/* static */
DeltaValues WheelTransaction::OverrideSystemScrollSpeed(
WidgetWheelEvent* aEvent) {
MOZ_ASSERT(sScrollTargetFrame, "We don't have mouse scrolling transaction");
// If the event doesn't scroll to both X and Y, we don't need to do anything
// here.
if (!aEvent->mDeltaX && !aEvent->mDeltaY) {
return DeltaValues(aEvent);
}
return DeltaValues(aEvent->OverriddenDeltaX(), aEvent->OverriddenDeltaY());
}
/******************************************************************/
/* mozilla::ScrollbarsForWheel */
/******************************************************************/
const DeltaValues ScrollbarsForWheel::directions[kNumberOfTargets] = {
DeltaValues(-1, 0), DeltaValues(+1, 0), DeltaValues(0, -1),
DeltaValues(0, +1)};
AutoWeakFrame ScrollbarsForWheel::sActiveOwner = nullptr;
AutoWeakFrame ScrollbarsForWheel::sActivatedScrollTargets[kNumberOfTargets] = {
nullptr, nullptr, nullptr, nullptr};
bool ScrollbarsForWheel::sHadWheelStart = false;
bool ScrollbarsForWheel::sOwnWheelTransaction = false;
/* static */
void ScrollbarsForWheel::PrepareToScrollText(EventStateManager* aESM,
nsIFrame* aTargetFrame,
WidgetWheelEvent* aEvent) {
if (aEvent->mMessage == eWheelOperationStart) {
WheelTransaction::OwnScrollbars(false);
if (!IsActive()) {
TemporarilyActivateAllPossibleScrollTargets(aESM, aTargetFrame, aEvent);
sHadWheelStart = true;
}
} else {
DeactivateAllTemporarilyActivatedScrollTargets();
}
}
/* static */
void ScrollbarsForWheel::SetActiveScrollTarget(
nsIScrollableFrame* aScrollTarget) {
if (!sHadWheelStart) {
return;
}
nsIScrollbarMediator* scrollbarMediator = do_QueryFrame(aScrollTarget);
if (!scrollbarMediator) {
return;
}
sHadWheelStart = false;
sActiveOwner = do_QueryFrame(aScrollTarget);
scrollbarMediator->ScrollbarActivityStarted();
}
/* static */
void ScrollbarsForWheel::MayInactivate() {
if (!sOwnWheelTransaction && WheelTransaction::GetScrollTargetFrame()) {
WheelTransaction::OwnScrollbars(true);
} else {
Inactivate();
}
}
/* static */
void ScrollbarsForWheel::Inactivate() {
nsIScrollbarMediator* scrollbarMediator = do_QueryFrame(sActiveOwner);
if (scrollbarMediator) {
scrollbarMediator->ScrollbarActivityStopped();
}
sActiveOwner = nullptr;
DeactivateAllTemporarilyActivatedScrollTargets();
if (sOwnWheelTransaction) {
sOwnWheelTransaction = false;
WheelTransaction::OwnScrollbars(false);
WheelTransaction::EndTransaction();
}
}
/* static */
bool ScrollbarsForWheel::IsActive() {
if (sActiveOwner) {
return true;
}
for (size_t i = 0; i < kNumberOfTargets; ++i) {
if (sActivatedScrollTargets[i]) {
return true;
}
}
return false;
}
/* static */
void ScrollbarsForWheel::OwnWheelTransaction(bool aOwn) {
sOwnWheelTransaction = aOwn;
}
/* static */
void ScrollbarsForWheel::TemporarilyActivateAllPossibleScrollTargets(
EventStateManager* aESM, nsIFrame* aTargetFrame, WidgetWheelEvent* aEvent) {
for (size_t i = 0; i < kNumberOfTargets; i++) {
const DeltaValues* dir = &directions[i];
AutoWeakFrame* scrollTarget = &sActivatedScrollTargets[i];
MOZ_ASSERT(!*scrollTarget, "scroll target still temporarily activated!");
nsIScrollableFrame* target = do_QueryFrame(aESM->ComputeScrollTarget(
aTargetFrame, dir->deltaX, dir->deltaY, aEvent,
EventStateManager::COMPUTE_DEFAULT_ACTION_TARGET));
nsIScrollbarMediator* scrollbarMediator = do_QueryFrame(target);
if (scrollbarMediator) {
nsIFrame* targetFrame = do_QueryFrame(target);
*scrollTarget = targetFrame;
scrollbarMediator->ScrollbarActivityStarted();
}
}
}
/* static */
void ScrollbarsForWheel::DeactivateAllTemporarilyActivatedScrollTargets() {
for (size_t i = 0; i < kNumberOfTargets; i++) {
AutoWeakFrame* scrollTarget = &sActivatedScrollTargets[i];
if (*scrollTarget) {
nsIScrollbarMediator* scrollbarMediator = do_QueryFrame(*scrollTarget);
if (scrollbarMediator) {
scrollbarMediator->ScrollbarActivityStopped();
}
*scrollTarget = nullptr;
}
}
}
/******************************************************************/
/* mozilla::WheelDeltaHorizontalizer */
/******************************************************************/
void WheelDeltaHorizontalizer::Horizontalize() {
MOZ_ASSERT(!mWheelEvent.mDeltaValuesHorizontalizedForDefaultHandler,
"Wheel delta values in one wheel scroll event are being adjusted "
"a second time");
// Log the old values.
mOldDeltaX = mWheelEvent.mDeltaX;
mOldDeltaZ = mWheelEvent.mDeltaZ;
mOldOverflowDeltaX = mWheelEvent.mOverflowDeltaX;
mOldLineOrPageDeltaX = mWheelEvent.mLineOrPageDeltaX;
// Move deltaY values to deltaX and set both deltaY and deltaZ to 0.
mWheelEvent.mDeltaX = mWheelEvent.mDeltaY;
mWheelEvent.mDeltaY = 0.0;
mWheelEvent.mDeltaZ = 0.0;
mWheelEvent.mOverflowDeltaX = mWheelEvent.mOverflowDeltaY;
mWheelEvent.mOverflowDeltaY = 0.0;
mWheelEvent.mLineOrPageDeltaX = mWheelEvent.mLineOrPageDeltaY;
mWheelEvent.mLineOrPageDeltaY = 0;
// Mark it horizontalized in order to restore the delta values when this
// instance is being destroyed.
mWheelEvent.mDeltaValuesHorizontalizedForDefaultHandler = true;
mHorizontalized = true;
}
void WheelDeltaHorizontalizer::CancelHorizontalization() {
// Restore the horizontalized delta.
if (mHorizontalized &&
mWheelEvent.mDeltaValuesHorizontalizedForDefaultHandler) {
mWheelEvent.mDeltaY = mWheelEvent.mDeltaX;
mWheelEvent.mDeltaX = mOldDeltaX;
mWheelEvent.mDeltaZ = mOldDeltaZ;
mWheelEvent.mOverflowDeltaY = mWheelEvent.mOverflowDeltaX;
mWheelEvent.mOverflowDeltaX = mOldOverflowDeltaX;
mWheelEvent.mLineOrPageDeltaY = mWheelEvent.mLineOrPageDeltaX;
mWheelEvent.mLineOrPageDeltaX = mOldLineOrPageDeltaX;
mWheelEvent.mDeltaValuesHorizontalizedForDefaultHandler = false;
mHorizontalized = false;
}
}
WheelDeltaHorizontalizer::~WheelDeltaHorizontalizer() {
CancelHorizontalization();
}
/******************************************************************/
/* mozilla::AutoDirWheelDeltaAdjuster */
/******************************************************************/
bool AutoDirWheelDeltaAdjuster::ShouldBeAdjusted() {
// Sometimes, this function can be called more than one time. If we have
// already checked if the scroll should be adjusted, there's no need to check
// it again.
if (mCheckedIfShouldBeAdjusted) {
return mShouldBeAdjusted;
}
mCheckedIfShouldBeAdjusted = true;
// For an auto-dir wheel scroll, if all the following conditions are met, we
// should adjust X and Y values:
// 1. There is only one non-zero value between DeltaX and DeltaY.
// 2. There is only one direction for the target that overflows and is
// scrollable with wheel.
// 3. The direction described in Condition 1 is orthogonal to the one
// described in Condition 2.
if ((mDeltaX && mDeltaY) || (!mDeltaX && !mDeltaY)) {
return false;
}
if (mDeltaX) {
if (CanScrollAlongXAxis()) {
return false;
}
if (IsHorizontalContentRightToLeft()) {
mShouldBeAdjusted =
mDeltaX > 0 ? CanScrollUpwards() : CanScrollDownwards();
} else {
mShouldBeAdjusted =
mDeltaX < 0 ? CanScrollUpwards() : CanScrollDownwards();
}
return mShouldBeAdjusted;
}
MOZ_ASSERT(0 != mDeltaY);
if (CanScrollAlongYAxis()) {
return false;
}
if (IsHorizontalContentRightToLeft()) {
mShouldBeAdjusted =
mDeltaY > 0 ? CanScrollLeftwards() : CanScrollRightwards();
} else {
mShouldBeAdjusted =
mDeltaY < 0 ? CanScrollLeftwards() : CanScrollRightwards();
}
return mShouldBeAdjusted;
}
void AutoDirWheelDeltaAdjuster::Adjust() {
if (!ShouldBeAdjusted()) {
return;
}
std::swap(mDeltaX, mDeltaY);
if (IsHorizontalContentRightToLeft()) {
mDeltaX *= -1;
mDeltaY *= -1;
}
mShouldBeAdjusted = false;
OnAdjusted();
}
/******************************************************************/
/* mozilla::ESMAutoDirWheelDeltaAdjuster */
/******************************************************************/
ESMAutoDirWheelDeltaAdjuster::ESMAutoDirWheelDeltaAdjuster(
WidgetWheelEvent& aEvent, nsIFrame& aScrollFrame, bool aHonoursRoot)
: AutoDirWheelDeltaAdjuster(aEvent.mDeltaX, aEvent.mDeltaY),
mLineOrPageDeltaX(aEvent.mLineOrPageDeltaX),
mLineOrPageDeltaY(aEvent.mLineOrPageDeltaY),
mOverflowDeltaX(aEvent.mOverflowDeltaX),
mOverflowDeltaY(aEvent.mOverflowDeltaY) {
mScrollTargetFrame = aScrollFrame.GetScrollTargetFrame();
MOZ_ASSERT(mScrollTargetFrame);
nsIFrame* honouredFrame = nullptr;
if (aHonoursRoot) {
// If we are going to honour root, first try to get the frame for <body> as
// the honoured root, because <body> is in preference to <html> if the
// current document is an HTML document.
dom::Document* document = aScrollFrame.PresShell()->GetDocument();
if (document) {
dom::Element* bodyElement = document->GetBodyElement();
if (bodyElement) {
honouredFrame = bodyElement->GetPrimaryFrame();
}
}
if (!honouredFrame) {
// If there is no <body> frame, fall back to the real root frame.
honouredFrame = aScrollFrame.PresShell()->GetRootScrollFrame();
}
if (!honouredFrame) {
// If there is no root scroll frame, fall back to the current scrolling
// frame.
honouredFrame = &aScrollFrame;
}
} else {
honouredFrame = &aScrollFrame;
}
WritingMode writingMode = honouredFrame->GetWritingMode();
// Get whether the honoured frame's content in the horizontal direction starts
// from right to left(E.g. it's true either if "writing-mode: vertical-rl", or
// if "writing-mode: horizontal-tb; direction: rtl;" in CSS).
mIsHorizontalContentRightToLeft = writingMode.IsPhysicalRTL();
}
void ESMAutoDirWheelDeltaAdjuster::OnAdjusted() {
// Adjust() only adjusted basic deltaX and deltaY, which are not enough for
// ESM, we should continue to adjust line-or-page and overflow values.
if (mDeltaX) {
// A vertical scroll was adjusted to be horizontal.
MOZ_ASSERT(0 == mDeltaY);
mLineOrPageDeltaX = mLineOrPageDeltaY;
mLineOrPageDeltaY = 0;
mOverflowDeltaX = mOverflowDeltaY;
mOverflowDeltaY = 0;
} else {
// A horizontal scroll was adjusted to be vertical.
MOZ_ASSERT(0 != mDeltaY);
mLineOrPageDeltaY = mLineOrPageDeltaX;
mLineOrPageDeltaX = 0;
mOverflowDeltaY = mOverflowDeltaX;
mOverflowDeltaX = 0;
}
if (mIsHorizontalContentRightToLeft) {
// If in RTL writing mode, reverse the side the scroll will go towards.
mLineOrPageDeltaX *= -1;
mLineOrPageDeltaY *= -1;
mOverflowDeltaX *= -1;
mOverflowDeltaY *= -1;
}
}
bool ESMAutoDirWheelDeltaAdjuster::CanScrollAlongXAxis() const {
return mScrollTargetFrame->GetAvailableScrollingDirections().contains(
layers::ScrollDirection::eHorizontal);
}
bool ESMAutoDirWheelDeltaAdjuster::CanScrollAlongYAxis() const {
return mScrollTargetFrame->GetAvailableScrollingDirections().contains(
layers::ScrollDirection::eVertical);
}
bool ESMAutoDirWheelDeltaAdjuster::CanScrollUpwards() const {
nsPoint scrollPt = mScrollTargetFrame->GetScrollPosition();
nsRect scrollRange = mScrollTargetFrame->GetScrollRange();
return static_cast<double>(scrollRange.y) < scrollPt.y;
}
bool ESMAutoDirWheelDeltaAdjuster::CanScrollDownwards() const {
nsPoint scrollPt = mScrollTargetFrame->GetScrollPosition();
nsRect scrollRange = mScrollTargetFrame->GetScrollRange();
return static_cast<double>(scrollRange.YMost()) > scrollPt.y;
}
bool ESMAutoDirWheelDeltaAdjuster::CanScrollLeftwards() const {
nsPoint scrollPt = mScrollTargetFrame->GetScrollPosition();
nsRect scrollRange = mScrollTargetFrame->GetScrollRange();
return static_cast<double>(scrollRange.x) < scrollPt.x;
}
bool ESMAutoDirWheelDeltaAdjuster::CanScrollRightwards() const {
nsPoint scrollPt = mScrollTargetFrame->GetScrollPosition();
nsRect scrollRange = mScrollTargetFrame->GetScrollRange();
return static_cast<double>(scrollRange.XMost()) > scrollPt.x;
}
bool ESMAutoDirWheelDeltaAdjuster::IsHorizontalContentRightToLeft() const {
return mIsHorizontalContentRightToLeft;
}
/******************************************************************/
/* mozilla::ESMAutoDirWheelDeltaRestorer */
/******************************************************************/
/*explicit*/
ESMAutoDirWheelDeltaRestorer::ESMAutoDirWheelDeltaRestorer(
WidgetWheelEvent& aEvent)
: mEvent(aEvent),
mOldDeltaX(aEvent.mDeltaX),
mOldDeltaY(aEvent.mDeltaY),
mOldLineOrPageDeltaX(aEvent.mLineOrPageDeltaX),
mOldLineOrPageDeltaY(aEvent.mLineOrPageDeltaY),
mOldOverflowDeltaX(aEvent.mOverflowDeltaX),
mOldOverflowDeltaY(aEvent.mOverflowDeltaY) {}
ESMAutoDirWheelDeltaRestorer::~ESMAutoDirWheelDeltaRestorer() {
if (mOldDeltaX == mEvent.mDeltaX || mOldDeltaY == mEvent.mDeltaY) {
// The delta of the event wasn't adjusted during the lifetime of this
// |ESMAutoDirWheelDeltaRestorer| instance. No need to restore it.
return;
}
bool forRTL = false;
// First, restore the basic deltaX and deltaY.
std::swap(mEvent.mDeltaX, mEvent.mDeltaY);
if (mOldDeltaX != mEvent.mDeltaX || mOldDeltaY != mEvent.mDeltaY) {
// If X and Y still don't equal to their original values after being
// swapped, then it must be because they were adjusted for RTL.
forRTL = true;
mEvent.mDeltaX *= -1;
mEvent.mDeltaY *= -1;
MOZ_ASSERT(mOldDeltaX == mEvent.mDeltaX && mOldDeltaY == mEvent.mDeltaY);
}
if (mEvent.mDeltaX) {
// A horizontal scroll was adjusted to be vertical during the lifetime of
// this instance.
MOZ_ASSERT(0 == mEvent.mDeltaY);
// Restore the line-or-page and overflow values to be horizontal.
mEvent.mOverflowDeltaX = mEvent.mOverflowDeltaY;
mEvent.mLineOrPageDeltaX = mEvent.mLineOrPageDeltaY;
if (forRTL) {
mEvent.mOverflowDeltaX *= -1;
mEvent.mLineOrPageDeltaX *= -1;
}
mEvent.mOverflowDeltaY = mOldOverflowDeltaY;
mEvent.mLineOrPageDeltaY = mOldLineOrPageDeltaY;
} else {
// A vertical scroll was adjusted to be horizontal during the lifetime of
// this instance.
MOZ_ASSERT(0 != mEvent.mDeltaY);
// Restore the line-or-page and overflow values to be vertical.
mEvent.mOverflowDeltaY = mEvent.mOverflowDeltaX;
mEvent.mLineOrPageDeltaY = mEvent.mLineOrPageDeltaX;
if (forRTL) {
mEvent.mOverflowDeltaY *= -1;
mEvent.mLineOrPageDeltaY *= -1;
}
mEvent.mOverflowDeltaX = mOldOverflowDeltaX;
mEvent.mLineOrPageDeltaX = mOldLineOrPageDeltaX;
}
}
} // namespace mozilla