gecko-dev/dom/base/SelectionChangeEventDispatc...

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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/. */
/*
* Implementation of mozilla::SelectionChangeEventDispatcher
*/
#include "SelectionChangeEventDispatcher.h"
#include "mozilla/AsyncEventDispatcher.h"
#include "mozilla/BasePrincipal.h"
#include "mozilla/IntegerRange.h"
#include "mozilla/StaticPrefs_dom.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/Selection.h"
#include "nsCOMPtr.h"
#include "nsContentUtils.h"
#include "nsFrameSelection.h"
#include "nsRange.h"
namespace mozilla {
using namespace dom;
SelectionChangeEventDispatcher::RawRangeData::RawRangeData(
const nsRange* aRange) {
if (aRange->IsPositioned()) {
mStartContainer = aRange->GetStartContainer();
mEndContainer = aRange->GetEndContainer();
mStartOffset = aRange->StartOffset();
mEndOffset = aRange->EndOffset();
} else {
mStartContainer = nullptr;
mEndContainer = nullptr;
mStartOffset = 0;
mEndOffset = 0;
}
}
bool SelectionChangeEventDispatcher::RawRangeData::Equals(
const nsRange* aRange) {
if (!aRange->IsPositioned()) {
return !mStartContainer;
}
return mStartContainer == aRange->GetStartContainer() &&
mEndContainer == aRange->GetEndContainer() &&
mStartOffset == aRange->StartOffset() &&
mEndOffset == aRange->EndOffset();
}
inline void ImplCycleCollectionTraverse(
nsCycleCollectionTraversalCallback& aCallback,
SelectionChangeEventDispatcher::RawRangeData& aField, const char* aName,
uint32_t aFlags = 0) {
ImplCycleCollectionTraverse(aCallback, aField.mStartContainer,
"mStartContainer", aFlags);
ImplCycleCollectionTraverse(aCallback, aField.mEndContainer, "mEndContainer",
aFlags);
}
NS_IMPL_CYCLE_COLLECTION_CLASS(SelectionChangeEventDispatcher)
NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(SelectionChangeEventDispatcher)
tmp->mOldRanges.Clear();
NS_IMPL_CYCLE_COLLECTION_UNLINK_END
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(SelectionChangeEventDispatcher)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mOldRanges);
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
void SelectionChangeEventDispatcher::OnSelectionChange(Document* aDoc,
Selection* aSel,
int16_t aReason) {
// Check if the ranges have actually changed
// Don't bother checking this if we are hiding changes.
if (mOldRanges.Length() == aSel->RangeCount() &&
!aSel->IsBlockingSelectionChangeEvents()) {
bool changed = mOldDirection != aSel->GetDirection();
if (!changed) {
for (const uint32_t i : IntegerRange(mOldRanges.Length())) {
if (!mOldRanges[i].Equals(aSel->GetRangeAt(i))) {
changed = true;
break;
}
}
}
if (!changed) {
return;
}
}
// The ranges have actually changed, update the mOldRanges array
mOldRanges.ClearAndRetainStorage();
for (const uint32_t i : IntegerRange(aSel->RangeCount())) {
mOldRanges.AppendElement(RawRangeData(aSel->GetRangeAt(i)));
}
mOldDirection = aSel->GetDirection();
// If we are hiding changes, then don't do anything else. We do this after we
// update mOldRanges so that changes after the changes stop being hidden don't
// incorrectly trigger a change, even though they didn't change anything
if (aSel->IsBlockingSelectionChangeEvents()) {
return;
}
const Document* doc = aSel->GetParentObject();
if (MOZ_UNLIKELY(!doc)) {
return;
}
const nsPIDOMWindowInner* inner = doc->GetInnerWindow();
if (MOZ_UNLIKELY(!inner)) {
return;
}
const bool maybeHasSelectionChangeEventListeners =
!inner || inner->HasSelectionChangeEventListeners();
const bool maybeHasFormSelectEventListeners =
!inner || inner->HasFormSelectEventListeners();
if (!maybeHasSelectionChangeEventListeners &&
!maybeHasFormSelectEventListeners) {
return;
}
// Be aware, don't call GetTextControlFromSelectionLimiter once you might
// run script because selection limit may have already been changed by it.
nsCOMPtr<nsIContent> textControl;
if ((maybeHasFormSelectEventListeners &&
(aReason & nsISelectionListener::JS_REASON)) ||
maybeHasSelectionChangeEventListeners) {
if (const nsFrameSelection* fs = aSel->GetFrameSelection()) {
if (nsCOMPtr<nsIContent> root = fs->GetLimiter()) {
textControl = root->GetClosestNativeAnonymousSubtreeRootParentOrHost();
MOZ_ASSERT_IF(textControl,
textControl->IsTextControlElement() &&
!textControl->IsInNativeAnonymousSubtree());
}
}
};
// Selection changes with non-JS reason only cares about whether the new
// selection is collapsed or not. See TextInputListener::OnSelectionChange.
if (textControl && maybeHasFormSelectEventListeners &&
(aReason & nsISelectionListener::JS_REASON)) {
RefPtr<AsyncEventDispatcher> asyncDispatcher =
new AsyncEventDispatcher(textControl, eFormSelect, CanBubble::eYes);
asyncDispatcher->PostDOMEvent();
}
if (!maybeHasSelectionChangeEventListeners) {
return;
}
// The spec currently doesn't say that we should dispatch this event on text
// controls, so for now we only support doing that under a pref, disabled by
// default.
// See https://github.com/w3c/selection-api/issues/53.
if (textControl &&
!StaticPrefs::dom_select_events_textcontrols_selectionchange_enabled()) {
return;
}
nsINode* target =
textControl ? static_cast<nsINode*>(textControl.get()) : aDoc;
if (target) {
CanBubble canBubble = textControl ? CanBubble::eYes : CanBubble::eNo;
RefPtr<AsyncEventDispatcher> asyncDispatcher =
new AsyncEventDispatcher(target, eSelectionChange, canBubble);
asyncDispatcher->PostDOMEvent();
}
}
} // namespace mozilla