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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
#include "ActiveElementManager.h"
#include "mozilla/EventStateManager.h"
#include "mozilla/PresShell.h"
#include "mozilla/StaticPrefs_ui.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/Document.h"
#include "mozilla/layers/APZEventState.h"
#include "mozilla/layers/APZUtils.h"
#include "nsITimer.h"
static mozilla::LazyLogModule sApzAemLog("apz.activeelement");
#define AEM_LOG(...) MOZ_LOG(sApzAemLog, LogLevel::Debug, (__VA_ARGS__))
namespace mozilla {
namespace layers {
class DelayedClearElementActivation final : public nsITimerCallback,
public nsINamed {
private:
explicit DelayedClearElementActivation(RefPtr<dom::Element>& aTarget,
const nsCOMPtr<nsITimer>& aTimer)
: mTarget(aTarget)
// Hold the reference count until we are called back.
,
mTimer(aTimer),
mProcessedSingleTap(false) {}
public:
NS_DECL_ISUPPORTS
static RefPtr<DelayedClearElementActivation> Create(
RefPtr<dom::Element>& aTarget);
NS_IMETHOD Notify(nsITimer*) override;
NS_IMETHOD GetName(nsACString& aName) override;
void MarkSingleTapProcessed();
bool ProcessedSingleTap() const { return mProcessedSingleTap; }
void StartTimer();
/**
* Clear the Event State Manager's global active content.
*/
void ClearGlobalActiveContent();
void ClearTimer() {
if (mTimer) {
mTimer->Cancel();
mTimer = nullptr;
}
}
dom::Element* GetTarget() const { return mTarget; }
private:
~DelayedClearElementActivation() = default;
RefPtr<dom::Element> mTarget;
nsCOMPtr<nsITimer> mTimer;
bool mProcessedSingleTap;
};
static nsPresContext* GetPresContextFor(nsIContent* aContent) {
if (!aContent) {
return nullptr;
}
PresShell* presShell = aContent->OwnerDoc()->GetPresShell();
if (!presShell) {
return nullptr;
}
return presShell->GetPresContext();
}
RefPtr<DelayedClearElementActivation> DelayedClearElementActivation::Create(
RefPtr<dom::Element>& aTarget) {
nsCOMPtr<nsITimer> timer = NS_NewTimer();
if (!timer) {
return nullptr;
}
RefPtr<DelayedClearElementActivation> event =
new DelayedClearElementActivation(aTarget, timer);
return event;
}
NS_IMETHODIMP DelayedClearElementActivation::Notify(nsITimer*) {
AEM_LOG("DelayedClearElementActivation notification ready=%d",
mProcessedSingleTap);
// If the single tap has been processed and the timer has expired,
// clear the active element state.
if (mProcessedSingleTap) {
AEM_LOG("DelayedClearElementActivation clearing active content\n");
ClearGlobalActiveContent();
}
mTimer = nullptr;
return NS_OK;
}
NS_IMETHODIMP DelayedClearElementActivation::GetName(nsACString& aName) {
aName.AssignLiteral("DelayedClearElementActivation");
return NS_OK;
}
void DelayedClearElementActivation::StartTimer() {
MOZ_ASSERT(mTimer);
// If the timer is null, active content state has already been cleared.
if (!mTimer) {
return;
}
nsresult rv = mTimer->InitWithCallback(
this, StaticPrefs::ui_touch_activation_duration_ms(),
nsITimer::TYPE_ONE_SHOT);
if (NS_FAILED(rv)) {
ClearTimer();
}
}
void DelayedClearElementActivation::MarkSingleTapProcessed() {
mProcessedSingleTap = true;
if (!mTimer) {
AEM_LOG("Clear activation immediate!");
ClearGlobalActiveContent();
}
}
void DelayedClearElementActivation::ClearGlobalActiveContent() {
if (nsPresContext* pc = GetPresContextFor(mTarget)) {
EventStateManager::ClearGlobalActiveContent(pc->EventStateManager());
}
mTarget = nullptr;
}
NS_IMPL_ISUPPORTS(DelayedClearElementActivation, nsITimerCallback, nsINamed)
ActiveElementManager::ActiveElementManager()
: mCanBePanOrZoom(false),
mCanBePanOrZoomSet(false),
mSingleTapBeforeActivation(false),
mSingleTapState(apz::SingleTapState::NotClick),
mSetActiveTask(nullptr) {}
ActiveElementManager::~ActiveElementManager() = default;
void ActiveElementManager::SetTargetElement(dom::EventTarget* aTarget) {
if (mTarget) {
// Multiple fingers on screen (since HandleTouchEnd clears mTarget).
AEM_LOG("Multiple fingers on-screen, clearing target element\n");
CancelTask();
ResetActive();
ResetTouchBlockState();
return;
}
mTarget = dom::Element::FromEventTargetOrNull(aTarget);
AEM_LOG("Setting target element to %p\n", mTarget.get());
TriggerElementActivation();
}
void ActiveElementManager::HandleTouchStart(bool aCanBePanOrZoom) {
AEM_LOG("Touch start, aCanBePanOrZoom: %d\n", aCanBePanOrZoom);
if (mCanBePanOrZoomSet) {
// Multiple fingers on screen (since HandleTouchEnd clears mCanBePanSet).
AEM_LOG("Multiple fingers on-screen, clearing touch block state\n");
CancelTask();
ResetActive();
ResetTouchBlockState();
return;
}
mCanBePanOrZoom = aCanBePanOrZoom;
mCanBePanOrZoomSet = true;
TriggerElementActivation();
}
void ActiveElementManager::TriggerElementActivation() {
// Reset mSingleTapState here either when HandleTouchStart() or
// SetTargetElement() gets called.
// NOTE: It's possible that ProcessSingleTap() gets called in between
// HandleTouchStart() and SetTargetElement() calls. I.e.,
// mSingleTapBeforeActivation is true, in such cases it doesn't matter that
// mSingleTapState was reset once and referred it in ProcessSingleTap() and
// then reset here again because in ProcessSingleTap() `NotYetDetermined` is
// the only one state we need to care, and it should NOT happen in the
// scenario. In other words the case where we need to care `NotYetDetermined`
// is when ProcessSingleTap() gets called later than any other events and
// notifications.
mSingleTapState = apz::SingleTapState::NotClick;
// Both HandleTouchStart() and SetTargetElement() call this. They can be
// called in either order. One will set mCanBePanOrZoomSet, and the other,
// mTarget. We want to actually trigger the activation once both are set.
if (!(mTarget && mCanBePanOrZoomSet)) {
return;
}
RefPtr<DelayedClearElementActivation> delayedEvent =
DelayedClearElementActivation::Create(mTarget);
if (mDelayedClearElementActivation) {
mDelayedClearElementActivation->ClearTimer();
mDelayedClearElementActivation->ClearGlobalActiveContent();
}
mDelayedClearElementActivation = delayedEvent;
// If the touch cannot be a pan, make mTarget :active right away.
// Otherwise, wait a bit to see if the user will pan or not.
if (!mCanBePanOrZoom) {
SetActive(mTarget);
if (mDelayedClearElementActivation) {
if (mSingleTapBeforeActivation) {
mDelayedClearElementActivation->MarkSingleTapProcessed();
}
mDelayedClearElementActivation->StartTimer();
}
} else {
// bug properly should make this unnecessary.
MOZ_ASSERT(mSetActiveTask == nullptr);
RefPtr<CancelableRunnable> task =
NewCancelableRunnableMethod<nsCOMPtr<dom::Element>>(
"layers::ActiveElementManager::SetActiveTask", this,
&ActiveElementManager::SetActiveTask, mTarget);
mSetActiveTask = task;
NS_GetCurrentThread()->DelayedDispatch(
task.forget(), StaticPrefs::ui_touch_activation_delay_ms());
AEM_LOG("Scheduling mSetActiveTask %p\n", mSetActiveTask.get());
}
AEM_LOG(
"Got both touch-end event and end touch notiication, clearing pan "
"state\n");
mCanBePanOrZoomSet = false;
}
void ActiveElementManager::ClearActivation() {
AEM_LOG("Clearing element activation\n");
CancelTask();
ResetActive();
}
bool ActiveElementManager::HandleTouchEndEvent(apz::SingleTapState aState) {
AEM_LOG("Touch end event, state: %hhu\n", static_cast<uint8_t>(aState));
mTouchEndState += TouchEndState::GotTouchEndEvent;
return MaybeChangeActiveState(aState);
}
bool ActiveElementManager::HandleTouchEnd(apz::SingleTapState aState) {
AEM_LOG("Touch end\n");
mTouchEndState += TouchEndState::GotTouchEndNotification;
return MaybeChangeActiveState(aState);
}
bool ActiveElementManager::MaybeChangeActiveState(apz::SingleTapState aState) {
if (mTouchEndState !=
TouchEndStates(TouchEndState::GotTouchEndEvent,
TouchEndState::GotTouchEndNotification)) {
return false;
}
CancelTask();
mSingleTapState = aState;
if (aState == apz::SingleTapState::WasClick) {
// Scrollbar thumbs use a different mechanism for their active
// highlight (the "active" attribute), so don't set the active state
// on them because nothing will clear it.
if (mCanBePanOrZoom &&
!(mTarget && mTarget->IsXULElement(nsGkAtoms::thumb))) {
SetActive(mTarget);
}
} else {
// We might reach here if mCanBePanOrZoom was false on touch-start and
// so we set the element active right away. Now it turns out the
// action was not a click so we need to reset the active element.
ResetActive();
}
ResetTouchBlockState();
return true;
}
void ActiveElementManager::ProcessSingleTap() {
if (!mDelayedClearElementActivation) {
// We have not received touch-start notification yet. We will have to run
// MarkSingleTapProcessed() when we receive the touch-start notification.
mSingleTapBeforeActivation = true;
return;
}
if (mSingleTapState == apz::SingleTapState::NotYetDetermined) {
// If we got `NotYetDetermined`, which means at the moment we don't know for
// sure whether double-tapping will be incoming or not, but now we are sure
// that no double-tapping will happen, thus it's time to activate the target
// element.
if (auto* target = mDelayedClearElementActivation->GetTarget()) {
SetActive(target);
}
}
mDelayedClearElementActivation->MarkSingleTapProcessed();
if (mCanBePanOrZoom) {
// In the case that we have not started the delayed reset of the element
// activation state, start the timer now.
mDelayedClearElementActivation->StartTimer();
}
// We don't need to keep a reference to the element activation
// clearing, because the event and its timer keep each other alive
// until the timer expires
mDelayedClearElementActivation = nullptr;
}
void ActiveElementManager::Destroy() {
if (mDelayedClearElementActivation) {
mDelayedClearElementActivation->ClearTimer();
mDelayedClearElementActivation = nullptr;
}
}
void ActiveElementManager::SetActive(dom::Element* aTarget) {
AEM_LOG("Setting active %p\n", aTarget);
if (nsPresContext* pc = GetPresContextFor(aTarget)) {
pc->EventStateManager()->SetContentState(aTarget,
dom::ElementState::ACTIVE);
}
}
void ActiveElementManager::ResetActive() {
AEM_LOG("Resetting active from %p\n", mTarget.get());
// Clear the :active flag from mTarget by setting it on the document root.
if (mTarget) {
dom::Element* root = mTarget->OwnerDoc()->GetDocumentElement();
if (root) {
AEM_LOG("Found root %p, making active\n", root);
SetActive(root);
}
}
}
void ActiveElementManager::ResetTouchBlockState() {
mTarget = nullptr;
mCanBePanOrZoomSet = false;
mTouchEndState.clear();
mSingleTapBeforeActivation = false;
// NOTE: Do not reset mSingleTapState here since it will be necessary in
// ProcessSingleTap() to tell whether we need to activate the target element
// because on environments where double-tap is enabled ProcessSingleTap()
// gets called after both of touch-end event and end touch notiication
// arrived.
}
void ActiveElementManager::SetActiveTask(
const nsCOMPtr<dom::Element>& aTarget) {
AEM_LOG("mSetActiveTask %p running\n", mSetActiveTask.get());
// This gets called from mSetActiveTask's Run() method. The message loop
// deletes the task right after running it, so we need to null out
// mSetActiveTask to make sure we're not left with a dangling pointer.
mSetActiveTask = nullptr;
SetActive(aTarget);
}
void ActiveElementManager::CancelTask() {
AEM_LOG("Cancelling task %p\n", mSetActiveTask.get());
if (mSetActiveTask) {
mSetActiveTask->Cancel();
mSetActiveTask = nullptr;
}
}
} // namespace layers
} // namespace mozilla