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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 "nsIFrame.h"
#include "nsContentUtils.h"
#include "nsITimer.h"
#include "nsQueryFrame.h"
#include "PresShell.h"
#include "nsLayoutUtils.h"
#include "nsScrollbarFrame.h"
#include "nsRefreshDriver.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/Event.h"
#include "mozilla/dom/Document.h"
#include "mozilla/LookAndFeel.h"
#include "mozilla/ScrollContainerFrame.h"
namespace mozilla::layout {
using mozilla::dom::Element;
NS_IMPL_ISUPPORTS(ScrollbarActivity, nsIDOMEventListener)
static bool DisplayOnMouseMove() {
return LookAndFeel::GetInt(LookAndFeel::IntID::ScrollbarDisplayOnMouseMove);
}
void ScrollbarActivity::Destroy() {
StopListeningForScrollAreaEvents();
CancelFadeTimer();
}
void ScrollbarActivity::ActivityOccurred() {
ActivityStarted();
ActivityStopped();
}
static void SetScrollbarActive(Element* aScrollbar, bool aIsActive) {
if (!aScrollbar) {
return;
}
if (aIsActive) {
if (nsScrollbarFrame* sf = do_QueryFrame(aScrollbar->GetPrimaryFrame())) {
sf->WillBecomeActive();
}
}
aScrollbar->SetBoolAttr(nsGkAtoms::active, aIsActive);
}
void ScrollbarActivity::ActivityStarted() {
const bool wasActive = IsActive();
mNestedActivityCounter++;
if (wasActive) {
return;
}
CancelFadeTimer();
if (mScrollbarEffectivelyVisible) {
return;
}
StartListeningForScrollAreaEvents();
SetScrollbarActive(GetHorizontalScrollbar(), true);
SetScrollbarActive(GetVerticalScrollbar(), true);
mScrollbarEffectivelyVisible = true;
}
void ScrollbarActivity::ActivityStopped() {
if (!IsActive()) {
// 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;
}
mNestedActivityCounter--;
if (IsActive()) {
return;
}
StartFadeTimer();
}
NS_IMETHODIMP
ScrollbarActivity::HandleEvent(dom::Event* aEvent) {
if (!mScrollbarEffectivelyVisible && !DisplayOnMouseMove()) {
return NS_OK;
}
nsAutoString type;
aEvent->GetType(type);
auto* targetContent =
nsIContent::FromEventTargetOrNull(aEvent->GetOriginalTarget());
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);
ScrollContainerFrame* scrollContainerFrame = do_QueryFrame(scrollFrame);
nsIFrame* targetFrame =
targetContent ? targetContent->GetPrimaryFrame() : nullptr;
if ((scrollContainerFrame &&
scrollContainerFrame->IsRootScrollFrameOfDocument()) ||
!targetFrame ||
nsLayoutUtils::IsAncestorFrameCrossDocInProcess(
scrollFrame, targetFrame,
scrollFrame->PresShell()->GetRootFrame())) {
ActivityOccurred();
}
return NS_OK;
}
return NS_OK;
}
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::CancelFadeTimer() {
if (mFadeTimer) {
mFadeTimer->Cancel();
}
}
void ScrollbarActivity::StartFadeTimer() {
CancelFadeTimer();
if (StaticPrefs::layout_testing_overlay_scrollbars_always_visible()) {
return;
}
if (!mFadeTimer) {
mFadeTimer = NS_NewTimer();
}
mFadeTimer->InitWithNamedFuncCallback(
[](nsITimer*, void* aClosure) {
RefPtr<ScrollbarActivity> activity =
static_cast<ScrollbarActivity*>(aClosure);
activity->BeginFade();
},
this, LookAndFeel::GetInt(LookAndFeel::IntID::ScrollbarFadeBeginDelay),
nsITimer::TYPE_ONE_SHOT, "ScrollbarActivity::FadeBeginTimerFired");
}
void ScrollbarActivity::BeginFade() {
MOZ_ASSERT(!IsActive());
mScrollbarEffectivelyVisible = false;
SetScrollbarActive(GetHorizontalScrollbar(), false);
SetScrollbarActive(GetVerticalScrollbar(), false);
}
Element* ScrollbarActivity::GetScrollbarContent(bool aVertical) {
nsIFrame* box = mScrollableFrame->GetScrollbarBox(aVertical);
return box ? box->GetContent()->AsElement() : nullptr;
}
} // namespace mozilla::layout
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