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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 "ZoomConstraintsClient.h"
#include <inttypes.h>
#include "mozilla/layers/APZCCallbackHelper.h"
#include "mozilla/layers/ScrollableLayerGuid.h"
#include "mozilla/layers/ZoomConstraints.h"
#include "mozilla/Preferences.h"
#include "mozilla/PresShell.h"
#include "mozilla/StaticPrefs_apz.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/Event.h"
#include "nsIFrame.h"
#include "nsIScrollableFrame.h"
#include "nsLayoutUtils.h"
#include "nsPoint.h"
#include "nsView.h"
#include "nsViewportInfo.h"
#include "Units.h"
#include "UnitTransforms.h"
static mozilla::LazyLogModule sApzZoomLog("apz.zoom");
#define ZCC_LOG(...) MOZ_LOG(sApzZoomLog, LogLevel::Debug, (__VA_ARGS__))
NS_IMPL_ISUPPORTS(ZoomConstraintsClient, nsIDOMEventListener, nsIObserver)
#define DOM_META_ADDED u"DOMMetaAdded"_ns
#define DOM_META_CHANGED u"DOMMetaChanged"_ns
#define FULLSCREEN_CHANGED u"fullscreenchange"_ns
#define BEFORE_FIRST_PAINT "before-first-paint"_ns
#define COMPOSITOR_REINITIALIZED "compositor-reinitialized"_ns
#define NS_PREF_CHANGED "nsPref:changed"_ns
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::layers;
ZoomConstraintsClient::ZoomConstraintsClient()
: mDocument(nullptr),
mPresShell(nullptr),
mZoomConstraints(false, false, CSSToParentLayerScale(1.f),
CSSToParentLayerScale(1.f)) {}
ZoomConstraintsClient::~ZoomConstraintsClient() = default;
static nsIWidget* GetWidget(PresShell* aPresShell) {
if (!aPresShell) {
return nullptr;
}
if (nsIFrame* rootFrame = aPresShell->GetRootFrame()) {
if (nsView* view = rootFrame->GetView()) {
return view->GetWidget();
}
}
return nullptr;
}
void ZoomConstraintsClient::Destroy() {
if (!(mPresShell && mDocument)) {
return;
}
ZCC_LOG("Destroying %p\n", this);
if (mEventTarget) {
mEventTarget->RemoveEventListener(DOM_META_ADDED, this, false);
mEventTarget->RemoveEventListener(DOM_META_CHANGED, this, false);
mEventTarget->RemoveSystemEventListener(FULLSCREEN_CHANGED, this, false);
mEventTarget = nullptr;
}
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
if (observerService) {
observerService->RemoveObserver(this, BEFORE_FIRST_PAINT.Data());
observerService->RemoveObserver(this, COMPOSITOR_REINITIALIZED.Data());
}
Preferences::RemoveObserver(this, "browser.ui.zoom.force-user-scalable");
if (mGuid) {
if (nsIWidget* widget = GetWidget(mPresShell)) {
ZCC_LOG("Sending null constraints in %p for { %u, %" PRIu64 " }\n", this,
mGuid->mPresShellId, mGuid->mScrollId);
widget->UpdateZoomConstraints(mGuid->mPresShellId, mGuid->mScrollId,
Nothing());
mGuid = Nothing();
}
}
mDocument = nullptr;
mPresShell = nullptr;
}
void ZoomConstraintsClient::Init(PresShell* aPresShell, Document* aDocument) {
if (!(aPresShell && aDocument)) {
return;
}
mPresShell = aPresShell;
mDocument = aDocument;
if (nsCOMPtr<nsPIDOMWindowOuter> window = mDocument->GetWindow()) {
mEventTarget = window->GetParentTarget();
}
if (mEventTarget) {
mEventTarget->AddEventListener(DOM_META_ADDED, this, false);
mEventTarget->AddEventListener(DOM_META_CHANGED, this, false);
mEventTarget->AddSystemEventListener(FULLSCREEN_CHANGED, this, false);
}
nsCOMPtr<nsIObserverService> observerService =
mozilla::services::GetObserverService();
if (observerService) {
observerService->AddObserver(this, BEFORE_FIRST_PAINT.Data(), false);
observerService->AddObserver(this, COMPOSITOR_REINITIALIZED.Data(), false);
}
Preferences::AddStrongObserver(this, "browser.ui.zoom.force-user-scalable");
}
NS_IMETHODIMP
ZoomConstraintsClient::HandleEvent(dom::Event* event) {
nsAutoString type;
event->GetType(type);
if (type.Equals(DOM_META_ADDED)) {
ZCC_LOG("Got a dom-meta-added event in %p\n", this);
RefreshZoomConstraints();
} else if (type.Equals(DOM_META_CHANGED)) {
ZCC_LOG("Got a dom-meta-changed event in %p\n", this);
RefreshZoomConstraints();
} else if (type.Equals(FULLSCREEN_CHANGED)) {
ZCC_LOG("Got a fullscreen-change event in %p\n", this);
RefreshZoomConstraints();
}
return NS_OK;
}
NS_IMETHODIMP
ZoomConstraintsClient::Observe(nsISupports* aSubject, const char* aTopic,
const char16_t* aData) {
if (SameCOMIdentity(aSubject, ToSupports(mDocument)) &&
BEFORE_FIRST_PAINT.EqualsASCII(aTopic)) {
ZCC_LOG("Got a before-first-paint event in %p\n", this);
RefreshZoomConstraints();
} else if (COMPOSITOR_REINITIALIZED.EqualsASCII(aTopic)) {
ZCC_LOG("Got a compositor-reinitialized notification in %p\n", this);
RefreshZoomConstraints();
} else if (NS_PREF_CHANGED.EqualsASCII(aTopic)) {
ZCC_LOG("Got a pref-change event in %p\n", this);
// We need to run this later because all the pref change listeners need
// to execute before we can be guaranteed that
// StaticPrefs::browser_ui_zoom_force_user_scalable() returns the updated
// value.
RefPtr<nsRunnableMethod<ZoomConstraintsClient>> event =
NewRunnableMethod("ZoomConstraintsClient::RefreshZoomConstraints", this,
&ZoomConstraintsClient::RefreshZoomConstraints);
mDocument->Dispatch(event.forget());
}
return NS_OK;
}
void ZoomConstraintsClient::ScreenSizeChanged() {
ZCC_LOG("Got a screen-size change notification in %p\n", this);
RefreshZoomConstraints();
}
static mozilla::layers::ZoomConstraints ComputeZoomConstraintsFromViewportInfo(
const nsViewportInfo& aViewportInfo, Document* aDocument) {
mozilla::layers::ZoomConstraints constraints;
constraints.mAllowZoom = aViewportInfo.IsZoomAllowed() &&
nsLayoutUtils::AllowZoomingForDocument(aDocument);
constraints.mAllowDoubleTapZoom =
constraints.mAllowZoom && StaticPrefs::apz_allow_double_tap_zooming();
if (constraints.mAllowZoom) {
constraints.mMinZoom.scale = aViewportInfo.GetMinZoom().scale;
constraints.mMaxZoom.scale = aViewportInfo.GetMaxZoom().scale;
} else {
constraints.mMinZoom.scale = aViewportInfo.GetDefaultZoom().scale;
constraints.mMaxZoom.scale = aViewportInfo.GetDefaultZoom().scale;
}
return constraints;
}
void ZoomConstraintsClient::RefreshZoomConstraints() {
mZoomConstraints = ZoomConstraints(false, false, CSSToParentLayerScale(1.f),
CSSToParentLayerScale(1.f));
nsIWidget* widget = GetWidget(mPresShell);
if (!widget) {
return;
}
uint32_t presShellId = 0;
ScrollableLayerGuid::ViewID viewId = ScrollableLayerGuid::NULL_SCROLL_ID;
bool scrollIdentifiersValid =
APZCCallbackHelper::GetOrCreateScrollIdentifiers(
mDocument->GetDocumentElement(), &presShellId, &viewId);
if (!scrollIdentifiersValid) {
return;
}
LayoutDeviceIntSize screenSize;
if (!nsLayoutUtils::GetDocumentViewerSize(mPresShell->GetPresContext(),
screenSize)) {
return;
}
nsViewportInfo viewportInfo = mDocument->GetViewportInfo(ViewAs<ScreenPixel>(
screenSize, PixelCastJustification::LayoutDeviceIsScreenForBounds));
mZoomConstraints =
ComputeZoomConstraintsFromViewportInfo(viewportInfo, mDocument);
if (mDocument->Fullscreen()) {
ZCC_LOG("%p is in fullscreen, disallowing zooming\n", this);
mZoomConstraints.mAllowZoom = false;
mZoomConstraints.mAllowDoubleTapZoom = false;
}
if (mDocument->IsStaticDocument()) {
ZCC_LOG("%p is in print or print preview, disallowing double tap zooming\n",
this);
mZoomConstraints.mAllowDoubleTapZoom = false;
}
if (nsContentUtils::IsPDFJS(mDocument->GetPrincipal())) {
ZCC_LOG("%p is pdf.js viewer, disallowing double tap zooming\n", this);
mZoomConstraints.mAllowDoubleTapZoom = false;
}
// On macOS the OS can send us a double tap zoom event from the touchpad and
// there are no touch screen macOS devices so we never wait to see if a second
// tap is coming so we can always allow double tap zooming on mac. We need
// this because otherwise the width check usually disables it.
bool allow_double_tap_always = false;
#ifdef XP_MACOSX
allow_double_tap_always =
StaticPrefs::apz_mac_enable_double_tap_zoom_touchpad_gesture();
#endif
if (!allow_double_tap_always && mZoomConstraints.mAllowDoubleTapZoom) {
// If the CSS viewport is narrower than the screen (i.e. width <=
// device-width) then we disable double-tap-to-zoom behaviour.
CSSToLayoutDeviceScale scale =
mPresShell->GetPresContext()->CSSToDevPixelScale();
if ((viewportInfo.GetSize() * scale).width <= screenSize.width) {
mZoomConstraints.mAllowDoubleTapZoom = false;
}
}
// We only ever create a ZoomConstraintsClient for an RCD, so the RSF of
// the presShell must be the RCD-RSF (if it exists).
MOZ_ASSERT(mPresShell->GetPresContext()->IsRootContentDocumentCrossProcess());
if (nsIScrollableFrame* rcdrsf =
mPresShell->GetRootScrollFrameAsScrollable()) {
ZCC_LOG("Notifying RCD-RSF that it is zoomable: %d\n",
mZoomConstraints.mAllowZoom);
rcdrsf->SetZoomableByAPZ(mZoomConstraints.mAllowZoom);
}
ScrollableLayerGuid newGuid(LayersId{0}, presShellId, viewId);
if (mGuid && mGuid.value() != newGuid) {
ZCC_LOG("Clearing old constraints in %p for { %u, %" PRIu64 " }\n", this,
mGuid->mPresShellId, mGuid->mScrollId);
// If the guid changes, send a message to clear the old one
widget->UpdateZoomConstraints(mGuid->mPresShellId, mGuid->mScrollId,
Nothing());
}
mGuid = Some(newGuid);
ZCC_LOG("Sending constraints %s in %p for { %u, %" PRIu64 " }\n",
ToString(mZoomConstraints).c_str(), this, presShellId, viewId);
widget->UpdateZoomConstraints(presShellId, viewId, Some(mZoomConstraints));
}