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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 "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"
static mozilla::LazyLogModule sApzAemLog("apz.activeelement");
#define AEM_LOG(...) MOZ_LOG(sApzAemLog, LogLevel::Debug, (__VA_ARGS__))
namespace mozilla {
namespace layers {
ActiveElementManager::ActiveElementManager()
: mCanBePan(false), mCanBePanSet(false), 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 aCanBePan) {
AEM_LOG("Touch start, aCanBePan: %d\n", aCanBePan);
if (mCanBePanSet) {
// Multiple fingers on screen (since HandleTouchEnd clears mCanBePanSet).
AEM_LOG("Multiple fingers on-screen, clearing touch block state\n");
CancelTask();
ResetActive();
ResetTouchBlockState();
return;
}
mCanBePan = aCanBePan;
mCanBePanSet = true;
TriggerElementActivation();
}
void ActiveElementManager::TriggerElementActivation() {
// Both HandleTouchStart() and SetTargetElement() call this. They can be
// called in either order. One will set mCanBePanSet, and the other, mTarget.
// We want to actually trigger the activation once both are set.
if (!(mTarget && mCanBePanSet)) {
return;
}
// 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 (!mCanBePan) {
SetActive(mTarget);
} else {
CancelTask(); // this is only needed because of bug 1169802. Fixing that
// 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());
}
}
void ActiveElementManager::ClearActivation() {
AEM_LOG("Clearing element activation\n");
CancelTask();
ResetActive();
}
void ActiveElementManager::HandleTouchEndEvent(bool aWasClick) {
AEM_LOG("Touch end event, aWasClick: %d\n", aWasClick);
// If the touch was a click, make mTarget :active right away.
// nsEventStateManager will reset the active element when processing
// the mouse-down event generated by the click.
CancelTask();
if (aWasClick) {
// 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 (!(mTarget && mTarget->IsXULElement(nsGkAtoms::thumb))) {
SetActive(mTarget);
}
} else {
// We might reach here if mCanBePan 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();
}
void ActiveElementManager::HandleTouchEnd() {
AEM_LOG("Touch end, clearing pan state\n");
mCanBePanSet = false;
}
static nsPresContext* GetPresContextFor(nsIContent* aContent) {
if (!aContent) {
return nullptr;
}
PresShell* presShell = aContent->OwnerDoc()->GetPresShell();
if (!presShell) {
return nullptr;
}
return presShell->GetPresContext();
}
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;
mCanBePanSet = false;
}
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
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