Source code
Revision control
Copy as Markdown
Other Tools
/* -*- 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 "mozilla/layers/FocusTarget.h"
#include "mozilla/dom/BrowserBridgeChild.h" // for BrowserBridgeChild
#include "mozilla/dom/EventTarget.h" // for EventTarget
#include "mozilla/dom/RemoteBrowser.h" // For RemoteBrowser
#include "mozilla/EventDispatcher.h" // for EventDispatcher
#include "mozilla/PresShell.h" // For PresShell
#include "mozilla/StaticPrefs_apz.h"
#include "nsIContentInlines.h" // for nsINode::IsEditable()
#include "nsLayoutUtils.h" // for nsLayoutUtils
static mozilla::LazyLogModule sApzFtgLog("apz.focustarget");
#define FT_LOG(...) MOZ_LOG(sApzFtgLog, LogLevel::Debug, (__VA_ARGS__))
using namespace mozilla::dom;
using namespace mozilla::layout;
namespace mozilla {
namespace layers {
static PresShell* GetRetargetEventPresShell(PresShell* aRootPresShell) {
MOZ_ASSERT(aRootPresShell);
// Use the last focused window in this PresShell and its
// associated PresShell
nsCOMPtr<nsPIDOMWindowOuter> window =
aRootPresShell->GetFocusedDOMWindowInOurWindow();
if (!window) {
return nullptr;
}
RefPtr<Document> retargetEventDoc = window->GetExtantDoc();
if (!retargetEventDoc) {
return nullptr;
}
return retargetEventDoc->GetPresShell();
}
// _BOUNDARY because Dispatch() with `targets` must not handle the event.
MOZ_CAN_RUN_SCRIPT_BOUNDARY static bool HasListenersForKeyEvents(
nsIContent* aContent) {
if (!aContent) {
return false;
}
WidgetEvent event(true, eVoidEvent);
nsTArray<EventTarget*> targets;
nsresult rv = EventDispatcher::Dispatch(aContent, nullptr, &event, nullptr,
nullptr, nullptr, &targets);
NS_ENSURE_SUCCESS(rv, false);
for (size_t i = 0; i < targets.Length(); i++) {
if (targets[i]->HasNonSystemGroupListenersForUntrustedKeyEvents()) {
return true;
}
}
return false;
}
// _BOUNDARY because Dispatch() with `targets` must not handle the event.
MOZ_CAN_RUN_SCRIPT_BOUNDARY static bool HasListenersForNonPassiveKeyEvents(
nsIContent* aContent) {
if (!aContent) {
return false;
}
WidgetEvent event(true, eVoidEvent);
nsTArray<EventTarget*> targets;
nsresult rv = EventDispatcher::Dispatch(aContent, nullptr, &event, nullptr,
nullptr, nullptr, &targets);
NS_ENSURE_SUCCESS(rv, false);
for (size_t i = 0; i < targets.Length(); i++) {
if (targets[i]
->HasNonPassiveNonSystemGroupListenersForUntrustedKeyEvents()) {
return true;
}
}
return false;
}
static bool IsEditableNode(nsINode* aNode) {
return aNode && aNode->IsEditable();
}
FocusTarget::FocusTarget()
: mSequenceNumber(0),
mFocusHasKeyEventListeners(false),
mData(AsVariant(NoFocusTarget())) {}
FocusTarget::FocusTarget(PresShell* aRootPresShell,
uint64_t aFocusSequenceNumber)
: mSequenceNumber(aFocusSequenceNumber),
mFocusHasKeyEventListeners(false),
mData(AsVariant(NoFocusTarget())) {
MOZ_ASSERT(aRootPresShell);
MOZ_ASSERT(NS_IsMainThread());
// Key events can be retargeted to a child PresShell when there is an iframe
RefPtr<PresShell> presShell = GetRetargetEventPresShell(aRootPresShell);
if (!presShell) {
FT_LOG("Creating nil target with seq=%" PRIu64
" (can't find retargeted presshell)\n",
aFocusSequenceNumber);
return;
}
RefPtr<Document> document = presShell->GetDocument();
if (!document) {
FT_LOG("Creating nil target with seq=%" PRIu64 " (no document)\n",
aFocusSequenceNumber);
return;
}
// Find the focused content and use it to determine whether there are key
// event listeners or whether key events will be targeted at a different
// process through a remote browser.
nsCOMPtr<nsIContent> focusedContent =
presShell->GetFocusedContentInOurWindow();
nsCOMPtr<nsIContent> keyEventTarget = focusedContent;
// If there is no focused element then event dispatch goes to the body of
// the page if it exists or the root element.
if (!keyEventTarget) {
keyEventTarget = document->GetUnfocusedKeyEventTarget();
}
// Check if there are key event listeners that could prevent default or change
// the focus or selection of the page.
if (StaticPrefs::apz_keyboard_passive_listeners()) {
mFocusHasKeyEventListeners =
HasListenersForNonPassiveKeyEvents(keyEventTarget.get());
} else {
mFocusHasKeyEventListeners = HasListenersForKeyEvents(keyEventTarget.get());
}
// Check if the key event target is content editable or if the document
// is in design mode.
if (IsEditableNode(keyEventTarget) || IsEditableNode(document)) {
FT_LOG("Creating nil target with seq=%" PRIu64
", kl=%d (disabling for editable node)\n",
aFocusSequenceNumber, static_cast<int>(mFocusHasKeyEventListeners));
return;
}
// Check if the key event target is a remote browser
if (RemoteBrowser* remoteBrowser = RemoteBrowser::GetFrom(keyEventTarget)) {
LayersId layersId = remoteBrowser->GetLayersId();
// The globally focused element for scrolling is in a remote layer tree
if (layersId.IsValid()) {
FT_LOG("Creating reflayer target with seq=%" PRIu64 ", kl=%d, lt=%" PRIu64
"\n",
aFocusSequenceNumber, mFocusHasKeyEventListeners, layersId.mId);
mData = AsVariant<LayersId>(std::move(layersId));
return;
}
FT_LOG("Creating nil target with seq=%" PRIu64
", kl=%d (remote browser missing layers id)\n",
aFocusSequenceNumber, mFocusHasKeyEventListeners);
return;
}
// The content to scroll is either the focused element or the focus node of
// the selection. It's difficult to determine if an element is an interactive
// element requiring async keyboard scrolling to be disabled. So we only
// allow async key scrolling based on the selection, which doesn't have
// this problem and is more common.
if (focusedContent) {
FT_LOG("Creating nil target with seq=%" PRIu64
", kl=%d (disabling for focusing an element)\n",
aFocusSequenceNumber, mFocusHasKeyEventListeners);
return;
}
nsCOMPtr<nsIContent> selectedContent =
presShell->GetSelectedContentForScrolling();
// Gather the scrollable frames that would be scrolled in each direction
// for this scroll target
nsIScrollableFrame* horizontal =
presShell->GetScrollableFrameToScrollForContent(
selectedContent.get(), HorizontalScrollDirection);
nsIScrollableFrame* vertical =
presShell->GetScrollableFrameToScrollForContent(selectedContent.get(),
VerticalScrollDirection);
// We might have the globally focused element for scrolling. Gather a ViewID
// for the horizontal and vertical scroll targets of this element.
ScrollTargets target;
target.mHorizontal = nsLayoutUtils::FindIDForScrollableFrame(horizontal);
target.mVertical = nsLayoutUtils::FindIDForScrollableFrame(vertical);
mData = AsVariant(target);
FT_LOG("Creating scroll target with seq=%" PRIu64 ", kl=%d, h=%" PRIu64
", v=%" PRIu64 "\n",
aFocusSequenceNumber, mFocusHasKeyEventListeners, target.mHorizontal,
target.mVertical);
}
bool FocusTarget::operator==(const FocusTarget& aRhs) const {
return mSequenceNumber == aRhs.mSequenceNumber &&
mFocusHasKeyEventListeners == aRhs.mFocusHasKeyEventListeners &&
mData == aRhs.mData;
}
const char* FocusTarget::Type() const {
if (mData.is<LayersId>()) {
return "LayersId";
}
if (mData.is<ScrollTargets>()) {
return "ScrollTargets";
}
if (mData.is<NoFocusTarget>()) {
return "NoFocusTarget";
}
return "<unknown>";
}
} // namespace layers
} // namespace mozilla