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-rw-r--r--layout/generic/ScrollbarActivity.cpp469
1 files changed, 469 insertions, 0 deletions
diff --git a/layout/generic/ScrollbarActivity.cpp b/layout/generic/ScrollbarActivity.cpp
new file mode 100644
index 000000000..78859bc2b
--- /dev/null
+++ b/layout/generic/ScrollbarActivity.cpp
@@ -0,0 +1,469 @@
+/* -*- Mode: C++; tab-width: 2; 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
+ * 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 "nsIDOMEvent.h"
+#include "nsIDOMCSSStyleDeclaration.h"
+#include "nsIFrame.h"
+#include "nsContentUtils.h"
+#include "nsAString.h"
+#include "nsQueryFrame.h"
+#include "nsComponentManagerUtils.h"
+#include "nsStyledElement.h"
+#include "mozilla/LookAndFeel.h"
+#include "mozilla/Preferences.h"
+
+namespace mozilla {
+namespace layout {
+
+NS_IMPL_ISUPPORTS(ScrollbarActivity, nsIDOMEventListener)
+
+static bool
+GetForceAlwaysVisiblePref()
+{
+ static bool sForceAlwaysVisible;
+ static bool sForceAlwaysVisiblePrefCached = false;
+ if (!sForceAlwaysVisiblePrefCached) {
+ Preferences::AddBoolVarCache(&sForceAlwaysVisible,
+ "layout.testing.overlay-scrollbars.always-visible");
+ sForceAlwaysVisiblePrefCached = true;
+ }
+ return sForceAlwaysVisible;
+}
+
+void
+ScrollbarActivity::QueryLookAndFeelVals()
+{
+ // Fade animation constants
+ mScrollbarFadeBeginDelay =
+ LookAndFeel::GetInt(LookAndFeel::eIntID_ScrollbarFadeBeginDelay);
+ mScrollbarFadeDuration =
+ LookAndFeel::GetInt(LookAndFeel::eIntID_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::eIntID_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(nsIDOMEvent* 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.
+ ActivityOccurred();
+ return NS_OK;
+ }
+
+ nsCOMPtr<nsIDOMEventTarget> target;
+ aEvent->GetOriginalTarget(getter_AddRefs(target));
+ nsCOMPtr<nsIContent> targetContent = do_QueryInterface(target);
+
+ 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,
+ nsIContent* aScrollbar,
+ bool* aStoredHoverState)
+{
+ if (!aTarget || !aScrollbar ||
+ !nsContentUtils::ContentIsDescendantOf(aTarget, 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 = do_QueryInterface(GetHorizontalScrollbar());
+ mVerticalScrollbar = do_QueryInterface(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);
+ nsCOMPtr<nsIDOMEventTarget> scrollAreaTarget
+ = do_QueryInterface(scrollArea->GetContent());
+ if (scrollAreaTarget) {
+ scrollAreaTarget->AddEventListener(NS_LITERAL_STRING("mousemove"), this,
+ true);
+ }
+ mListeningForScrollAreaEvents = true;
+}
+
+void
+ScrollbarActivity::StopListeningForScrollAreaEvents()
+{
+ if (!mListeningForScrollAreaEvents)
+ return;
+
+ nsIFrame* scrollArea = do_QueryFrame(mScrollableFrame);
+ nsCOMPtr<nsIDOMEventTarget> scrollAreaTarget = do_QueryInterface(scrollArea->GetContent());
+ if (scrollAreaTarget) {
+ scrollAreaTarget->RemoveEventListener(NS_LITERAL_STRING("mousemove"), this, true);
+ }
+ mListeningForScrollAreaEvents = false;
+}
+
+void
+ScrollbarActivity::AddScrollbarEventListeners(nsIDOMEventTarget* aScrollbar)
+{
+ if (aScrollbar) {
+ aScrollbar->AddEventListener(NS_LITERAL_STRING("mousedown"), this, true);
+ aScrollbar->AddEventListener(NS_LITERAL_STRING("mouseup"), this, true);
+ aScrollbar->AddEventListener(NS_LITERAL_STRING("mouseover"), this, true);
+ aScrollbar->AddEventListener(NS_LITERAL_STRING("mouseout"), this, true);
+ }
+}
+
+void
+ScrollbarActivity::RemoveScrollbarEventListeners(nsIDOMEventTarget* aScrollbar)
+{
+ if (aScrollbar) {
+ aScrollbar->RemoveEventListener(NS_LITERAL_STRING("mousedown"), this, true);
+ aScrollbar->RemoveEventListener(NS_LITERAL_STRING("mouseup"), this, true);
+ aScrollbar->RemoveEventListener(NS_LITERAL_STRING("mouseover"), this, true);
+ aScrollbar->RemoveEventListener(NS_LITERAL_STRING("mouseout"), 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, Flush_Style);
+ }
+}
+
+void
+ScrollbarActivity::UnregisterFromRefreshDriver()
+{
+ nsRefreshDriver* refreshDriver = GetRefreshDriver();
+ if (refreshDriver) {
+ refreshDriver->RemoveRefreshObserver(this, Flush_Style);
+ }
+}
+
+static void
+SetBooleanAttribute(nsIContent* aContent, nsIAtom* aAttribute, bool aValue)
+{
+ if (aContent) {
+ if (aValue) {
+ aContent->SetAttr(kNameSpaceID_None, aAttribute,
+ NS_LITERAL_STRING("true"), true);
+ } else {
+ aContent->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)
+{
+ nsCOMPtr<nsStyledElement> inlineStyleContent =
+ do_QueryInterface(aContent);
+ if (inlineStyleContent) {
+ nsICSSDeclaration* decl = inlineStyleContent->Style();
+ nsAutoString str;
+ str.AppendFloat(aOpacity);
+ decl->SetProperty(NS_LITERAL_STRING("opacity"), str, EmptyString());
+ }
+}
+
+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.
+ nsWeakFrame 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)
+{
+ nsCOMPtr<nsStyledElement> inlineStyleContent =
+ do_QueryInterface(aContent);
+ if (inlineStyleContent) {
+ nsICSSDeclaration* decl = inlineStyleContent->Style();
+ nsAutoString dummy;
+ decl->RemoveProperty(NS_LITERAL_STRING("opacity"), dummy);
+ }
+}
+
+bool
+ScrollbarActivity::SetIsFading(bool aNewFading)
+{
+ if (mIsFading == aNewFading)
+ return true;
+
+ mIsFading = aNewFading;
+ if (!mIsFading) {
+ mFadeBeginTime = TimeStamp();
+ // 'this' may be getting destroyed during UnsetOpacityOnElement calls.
+ nsWeakFrame weakFrame((do_QueryFrame(mScrollableFrame)));
+ UnsetOpacityOnElement(GetHorizontalScrollbar());
+ if (!weakFrame.IsAlive()) {
+ return false;
+ }
+ UnsetOpacityOnElement(GetVerticalScrollbar());
+ if (!weakFrame.IsAlive()) {
+ return false;
+ }
+ }
+ return true;
+}
+
+void
+ScrollbarActivity::StartFadeBeginTimer()
+{
+ if (GetForceAlwaysVisiblePref()) {
+ return;
+ }
+ if (!mFadeBeginTimer) {
+ mFadeBeginTimer = do_CreateInstance("@mozilla.org/timer;1");
+ }
+ mFadeBeginTimer->InitWithNamedFuncCallback(
+ FadeBeginTimerFired, this, mScrollbarFadeBeginDelay,
+ nsITimer::TYPE_ONE_SHOT, "ScrollbarActivity::FadeBeginTimerFired");
+}
+
+void
+ScrollbarActivity::CancelFadeBeginTimer()
+{
+ if (mFadeBeginTimer) {
+ mFadeBeginTimer->Cancel();
+ }
+}
+
+void
+ScrollbarActivity::HoveredScrollbar(nsIContent* aScrollbar)
+{
+ SetBooleanAttribute(GetHorizontalScrollbar(), nsGkAtoms::hover, false);
+ SetBooleanAttribute(GetVerticalScrollbar(), nsGkAtoms::hover, false);
+ SetBooleanAttribute(aScrollbar, nsGkAtoms::hover, true);
+}
+
+nsRefreshDriver*
+ScrollbarActivity::GetRefreshDriver()
+{
+ nsIFrame* scrollableFrame = do_QueryFrame(mScrollableFrame);
+ return scrollableFrame->PresContext()->RefreshDriver();
+}
+
+nsIContent*
+ScrollbarActivity::GetScrollbarContent(bool aVertical)
+{
+ nsIFrame* box = mScrollableFrame->GetScrollbarBox(aVertical);
+ return box ? box->GetContent() : nullptr;
+}
+
+} // namespace layout
+} // namespace mozilla