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-rw-r--r--layout/generic/ScrollbarActivity.cpp431
1 files changed, 431 insertions, 0 deletions
diff --git a/layout/generic/ScrollbarActivity.cpp b/layout/generic/ScrollbarActivity.cpp
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+++ b/layout/generic/ScrollbarActivity.cpp
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+/* -*- 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 "ScrollbarActivity.h"
+#include "nsIScrollbarMediator.h"
+#include "nsIContent.h"
+#include "nsICSSDeclaration.h"
+#include "nsIFrame.h"
+#include "nsContentUtils.h"
+#include "nsAString.h"
+#include "nsQueryFrame.h"
+#include "nsIScrollableFrame.h"
+#include "PresShell.h"
+#include "nsLayoutUtils.h"
+#include "nsScrollbarFrame.h"
+#include "nsRefreshDriver.h"
+#include "nsComponentManagerUtils.h"
+#include "nsStyledElement.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/Event.h"
+#include "mozilla/LookAndFeel.h"
+#include "mozilla/StaticPrefs_layout.h"
+
+namespace mozilla {
+namespace layout {
+
+using mozilla::dom::Element;
+
+NS_IMPL_ISUPPORTS(ScrollbarActivity, nsIDOMEventListener)
+
+void ScrollbarActivity::QueryLookAndFeelVals() {
+ // Fade animation constants
+ mScrollbarFadeBeginDelay =
+ LookAndFeel::GetInt(LookAndFeel::IntID::ScrollbarFadeBeginDelay);
+ mScrollbarFadeDuration =
+ LookAndFeel::GetInt(LookAndFeel::IntID::ScrollbarFadeDuration);
+ // Controls whether we keep the mouse move listener so we can display the
+ // scrollbars whenever the user moves the mouse within the scroll area.
+ mDisplayOnMouseMove =
+ LookAndFeel::GetInt(LookAndFeel::IntID::ScrollbarDisplayOnMouseMove);
+}
+
+void ScrollbarActivity::Destroy() {
+ StopListeningForScrollbarEvents();
+ StopListeningForScrollAreaEvents();
+ UnregisterFromRefreshDriver();
+ CancelFadeBeginTimer();
+}
+
+void ScrollbarActivity::ActivityOccurred() {
+ ActivityStarted();
+ ActivityStopped();
+}
+
+void ScrollbarActivity::ActivityStarted() {
+ mNestedActivityCounter++;
+ CancelFadeBeginTimer();
+ if (!SetIsFading(false)) {
+ return;
+ }
+ UnregisterFromRefreshDriver();
+ StartListeningForScrollbarEvents();
+ StartListeningForScrollAreaEvents();
+ SetIsActive(true);
+
+ NS_ASSERTION(mIsActive, "need to be active during activity");
+ NS_ASSERTION(!mIsFading, "must not be fading during activity");
+}
+
+void ScrollbarActivity::ActivityStopped() {
+ if (!IsActivityOngoing()) {
+ // This can happen if there was a frame reconstruction while the activity
+ // was ongoing. In this case we just do nothing. We should probably handle
+ // this case better.
+ return;
+ }
+ NS_ASSERTION(mIsActive, "need to be active during activity");
+ NS_ASSERTION(!mIsFading, "must not be fading during ongoing activity");
+
+ mNestedActivityCounter--;
+
+ if (!IsActivityOngoing()) {
+ StartFadeBeginTimer();
+
+ NS_ASSERTION(mIsActive, "need to be active right after activity");
+ NS_ASSERTION(!mIsFading, "must not be fading right after activity");
+ }
+}
+
+NS_IMETHODIMP
+ScrollbarActivity::HandleEvent(dom::Event* aEvent) {
+ if (!mDisplayOnMouseMove && !mIsActive) return NS_OK;
+
+ nsAutoString type;
+ aEvent->GetType(type);
+
+ if (type.EqualsLiteral("mousemove")) {
+ // Mouse motions anywhere in the scrollable frame should keep the
+ // scrollbars visible, but we have to be careful as content descendants of
+ // our scrollable content aren't necessarily scrolled by our scroll frame
+ // (if they are out of flow and their containing block is not a descendant
+ // of our scroll frame) and we don't want those to activate us.
+ nsIFrame* scrollFrame = do_QueryFrame(mScrollableFrame);
+ MOZ_ASSERT(scrollFrame);
+ nsIScrollableFrame* scrollableFrame = do_QueryFrame(mScrollableFrame);
+ nsCOMPtr<nsIContent> targetContent =
+ do_QueryInterface(aEvent->GetOriginalTarget());
+ nsIFrame* targetFrame =
+ targetContent ? targetContent->GetPrimaryFrame() : nullptr;
+ if ((scrollableFrame && scrollableFrame->IsRootScrollFrameOfDocument()) ||
+ !targetFrame ||
+ nsLayoutUtils::IsAncestorFrameCrossDocInProcess(
+ scrollFrame, targetFrame,
+ scrollFrame->PresShell()->GetRootFrame())) {
+ ActivityOccurred();
+ }
+ return NS_OK;
+ }
+
+ nsCOMPtr<nsIContent> targetContent =
+ do_QueryInterface(aEvent->GetOriginalTarget());
+
+ HandleEventForScrollbar(type, targetContent, GetHorizontalScrollbar(),
+ &mHScrollbarHovered);
+ HandleEventForScrollbar(type, targetContent, GetVerticalScrollbar(),
+ &mVScrollbarHovered);
+
+ return NS_OK;
+}
+
+void ScrollbarActivity::WillRefresh(TimeStamp aTime) {
+ NS_ASSERTION(mIsActive, "should only fade while scrollbars are visible");
+ NS_ASSERTION(!IsActivityOngoing(),
+ "why weren't we unregistered from the refresh driver when "
+ "scrollbar activity started?");
+ NS_ASSERTION(mIsFading, "should only animate fading during fade");
+
+ if (!UpdateOpacity(aTime)) {
+ return;
+ }
+
+ if (!IsStillFading(aTime)) {
+ EndFade();
+ }
+}
+
+bool ScrollbarActivity::IsStillFading(TimeStamp aTime) {
+ return !mFadeBeginTime.IsNull() && (aTime - mFadeBeginTime < FadeDuration());
+}
+
+void ScrollbarActivity::HandleEventForScrollbar(const nsAString& aType,
+ nsIContent* aTarget,
+ Element* aScrollbar,
+ bool* aStoredHoverState) {
+ if (!aTarget || !aScrollbar || !aTarget->IsInclusiveDescendantOf(aScrollbar))
+ return;
+
+ if (aType.EqualsLiteral("mousedown")) {
+ ActivityStarted();
+ } else if (aType.EqualsLiteral("mouseup")) {
+ ActivityStopped();
+ } else if (aType.EqualsLiteral("mouseover") ||
+ aType.EqualsLiteral("mouseout")) {
+ bool newHoveredState = aType.EqualsLiteral("mouseover");
+ if (newHoveredState && !*aStoredHoverState) {
+ ActivityStarted();
+ HoveredScrollbar(aScrollbar);
+ } else if (*aStoredHoverState && !newHoveredState) {
+ ActivityStopped();
+ // Don't call HoveredScrollbar(nullptr) here because we want the hover
+ // attribute to stick until the scrollbars are hidden.
+ }
+ *aStoredHoverState = newHoveredState;
+ }
+}
+
+void ScrollbarActivity::StartListeningForScrollbarEvents() {
+ if (mListeningForScrollbarEvents) return;
+
+ mHorizontalScrollbar = GetHorizontalScrollbar();
+ mVerticalScrollbar = GetVerticalScrollbar();
+
+ AddScrollbarEventListeners(mHorizontalScrollbar);
+ AddScrollbarEventListeners(mVerticalScrollbar);
+
+ mListeningForScrollbarEvents = true;
+}
+
+void ScrollbarActivity::StopListeningForScrollbarEvents() {
+ if (!mListeningForScrollbarEvents) return;
+
+ RemoveScrollbarEventListeners(mHorizontalScrollbar);
+ RemoveScrollbarEventListeners(mVerticalScrollbar);
+
+ mHorizontalScrollbar = nullptr;
+ mVerticalScrollbar = nullptr;
+ mListeningForScrollbarEvents = false;
+}
+
+void ScrollbarActivity::StartListeningForScrollAreaEvents() {
+ if (mListeningForScrollAreaEvents) return;
+
+ nsIFrame* scrollArea = do_QueryFrame(mScrollableFrame);
+ scrollArea->GetContent()->AddEventListener(u"mousemove"_ns, this, true);
+ mListeningForScrollAreaEvents = true;
+}
+
+void ScrollbarActivity::StopListeningForScrollAreaEvents() {
+ if (!mListeningForScrollAreaEvents) return;
+
+ nsIFrame* scrollArea = do_QueryFrame(mScrollableFrame);
+ scrollArea->GetContent()->RemoveEventListener(u"mousemove"_ns, this, true);
+ mListeningForScrollAreaEvents = false;
+}
+
+void ScrollbarActivity::AddScrollbarEventListeners(
+ dom::EventTarget* aScrollbar) {
+ if (aScrollbar) {
+ aScrollbar->AddEventListener(u"mousedown"_ns, this, true);
+ aScrollbar->AddEventListener(u"mouseup"_ns, this, true);
+ aScrollbar->AddEventListener(u"mouseover"_ns, this, true);
+ aScrollbar->AddEventListener(u"mouseout"_ns, this, true);
+ }
+}
+
+void ScrollbarActivity::RemoveScrollbarEventListeners(
+ dom::EventTarget* aScrollbar) {
+ if (aScrollbar) {
+ aScrollbar->RemoveEventListener(u"mousedown"_ns, this, true);
+ aScrollbar->RemoveEventListener(u"mouseup"_ns, this, true);
+ aScrollbar->RemoveEventListener(u"mouseover"_ns, this, true);
+ aScrollbar->RemoveEventListener(u"mouseout"_ns, this, true);
+ }
+}
+
+void ScrollbarActivity::BeginFade() {
+ NS_ASSERTION(mIsActive, "can't begin fade when we're already inactive");
+ NS_ASSERTION(!IsActivityOngoing(),
+ "why wasn't the fade begin timer cancelled when scrollbar "
+ "activity started?");
+ NS_ASSERTION(!mIsFading, "shouldn't be fading just yet");
+
+ CancelFadeBeginTimer();
+ mFadeBeginTime = TimeStamp::Now();
+ if (!SetIsFading(true)) {
+ return;
+ }
+ RegisterWithRefreshDriver();
+
+ NS_ASSERTION(mIsActive, "only fade while scrollbars are visible");
+ NS_ASSERTION(mIsFading, "should be fading now");
+}
+
+void ScrollbarActivity::EndFade() {
+ NS_ASSERTION(mIsActive, "still need to be active at this point");
+ NS_ASSERTION(!IsActivityOngoing(),
+ "why wasn't the fade end timer cancelled when scrollbar "
+ "activity started?");
+
+ if (!SetIsFading(false)) {
+ return;
+ }
+ SetIsActive(false);
+ UnregisterFromRefreshDriver();
+ StopListeningForScrollbarEvents();
+ if (!mDisplayOnMouseMove) {
+ StopListeningForScrollAreaEvents();
+ }
+
+ NS_ASSERTION(!mIsActive, "should have gone inactive after fade end");
+ NS_ASSERTION(!mIsFading, "shouldn't be fading anymore");
+}
+
+void ScrollbarActivity::RegisterWithRefreshDriver() {
+ nsRefreshDriver* refreshDriver = GetRefreshDriver();
+ if (refreshDriver) {
+ refreshDriver->AddRefreshObserver(this, FlushType::Style,
+ "Scrollbar fade animation");
+ }
+}
+
+void ScrollbarActivity::UnregisterFromRefreshDriver() {
+ nsRefreshDriver* refreshDriver = GetRefreshDriver();
+ if (refreshDriver) {
+ refreshDriver->RemoveRefreshObserver(this, FlushType::Style);
+ }
+}
+
+static void SetBooleanAttribute(Element* aElement, nsAtom* aAttribute,
+ bool aValue) {
+ if (aElement) {
+ if (aValue) {
+ aElement->SetAttr(kNameSpaceID_None, aAttribute, u"true"_ns, true);
+ } else {
+ aElement->UnsetAttr(kNameSpaceID_None, aAttribute, true);
+ }
+ }
+}
+
+void ScrollbarActivity::SetIsActive(bool aNewActive) {
+ if (mIsActive == aNewActive) return;
+
+ mIsActive = aNewActive;
+ if (!mIsActive) {
+ // Clear sticky scrollbar hover status.
+ HoveredScrollbar(nullptr);
+ }
+
+ SetBooleanAttribute(GetHorizontalScrollbar(), nsGkAtoms::active, mIsActive);
+ SetBooleanAttribute(GetVerticalScrollbar(), nsGkAtoms::active, mIsActive);
+}
+
+static void SetOpacityOnElement(nsIContent* aContent, double aOpacity) {
+ if (RefPtr<nsStyledElement> inlineStyleContent =
+ nsStyledElement::FromNodeOrNull(aContent)) {
+ nsICSSDeclaration* decl = inlineStyleContent->Style();
+ nsAutoCString str;
+ str.AppendFloat(aOpacity);
+ decl->SetProperty("opacity"_ns, str, EmptyCString(), IgnoreErrors());
+ }
+}
+
+bool ScrollbarActivity::UpdateOpacity(TimeStamp aTime) {
+ // Avoid division by zero if mScrollbarFadeDuration is zero, just jump
+ // to the end of the fade animation
+ double progress = mScrollbarFadeDuration
+ ? ((aTime - mFadeBeginTime) / FadeDuration())
+ : 1.0;
+ double opacity = 1.0 - std::max(0.0, std::min(1.0, progress));
+
+ // 'this' may be getting destroyed during SetOpacityOnElement calls.
+ AutoWeakFrame weakFrame((do_QueryFrame(mScrollableFrame)));
+ SetOpacityOnElement(GetHorizontalScrollbar(), opacity);
+ if (!weakFrame.IsAlive()) {
+ return false;
+ }
+ SetOpacityOnElement(GetVerticalScrollbar(), opacity);
+ if (!weakFrame.IsAlive()) {
+ return false;
+ }
+ return true;
+}
+
+static void UnsetOpacityOnElement(nsIContent* aContent) {
+ if (RefPtr<nsStyledElement> inlineStyleContent =
+ nsStyledElement::FromNodeOrNull(aContent)) {
+ nsICSSDeclaration* decl = inlineStyleContent->Style();
+ nsAutoCString dummy;
+ decl->RemoveProperty("opacity"_ns, dummy, IgnoreErrors());
+ }
+}
+
+bool ScrollbarActivity::SetIsFading(bool aNewFading) {
+ if (mIsFading == aNewFading) return true;
+
+ mIsFading = aNewFading;
+ if (!mIsFading) {
+ mFadeBeginTime = TimeStamp();
+ // 'this' may be getting destroyed during UnsetOpacityOnElement calls.
+ AutoWeakFrame weakFrame((do_QueryFrame(mScrollableFrame)));
+ UnsetOpacityOnElement(GetHorizontalScrollbar());
+ if (!weakFrame.IsAlive()) {
+ return false;
+ }
+ UnsetOpacityOnElement(GetVerticalScrollbar());
+ if (!weakFrame.IsAlive()) {
+ return false;
+ }
+ }
+ return true;
+}
+
+void ScrollbarActivity::StartFadeBeginTimer() {
+ if (StaticPrefs::layout_testing_overlay_scrollbars_always_visible()) {
+ return;
+ }
+ if (!mFadeBeginTimer) {
+ mFadeBeginTimer = NS_NewTimer();
+ }
+ mFadeBeginTimer->InitWithNamedFuncCallback(
+ FadeBeginTimerFired, this, mScrollbarFadeBeginDelay,
+ nsITimer::TYPE_ONE_SHOT, "ScrollbarActivity::FadeBeginTimerFired");
+}
+
+void ScrollbarActivity::CancelFadeBeginTimer() {
+ if (mFadeBeginTimer) {
+ mFadeBeginTimer->Cancel();
+ }
+}
+
+static void MaybeInvalidateScrollbarForHover(
+ Element* aScrollbarToInvalidate, Element* aScrollbarAboutToGetHover) {
+ if (aScrollbarToInvalidate) {
+ bool hasHover =
+ aScrollbarToInvalidate->HasAttr(kNameSpaceID_None, nsGkAtoms::hover);
+ bool willHaveHover = (aScrollbarAboutToGetHover == aScrollbarToInvalidate);
+
+ if (hasHover != willHaveHover) {
+ if (nsIFrame* f = aScrollbarToInvalidate->GetPrimaryFrame()) {
+ f->SchedulePaint();
+ }
+ }
+ }
+}
+
+void ScrollbarActivity::HoveredScrollbar(Element* aScrollbar) {
+ Element* vertScrollbar = GetVerticalScrollbar();
+ Element* horzScrollbar = GetHorizontalScrollbar();
+ MaybeInvalidateScrollbarForHover(vertScrollbar, aScrollbar);
+ MaybeInvalidateScrollbarForHover(horzScrollbar, aScrollbar);
+
+ SetBooleanAttribute(horzScrollbar, nsGkAtoms::hover, false);
+ SetBooleanAttribute(vertScrollbar, nsGkAtoms::hover, false);
+ SetBooleanAttribute(aScrollbar, nsGkAtoms::hover, true);
+}
+
+nsRefreshDriver* ScrollbarActivity::GetRefreshDriver() {
+ nsIFrame* scrollableFrame = do_QueryFrame(mScrollableFrame);
+ return scrollableFrame->PresContext()->RefreshDriver();
+}
+
+Element* ScrollbarActivity::GetScrollbarContent(bool aVertical) {
+ nsIFrame* box = mScrollableFrame->GetScrollbarBox(aVertical);
+ return box ? box->GetContent()->AsElement() : nullptr;
+}
+
+} // namespace layout
+} // namespace mozilla