gecko-dev/layout/generic/ScrollbarActivity.cpp

470 lines
13 KiB
C++

/* -*- 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