gecko-dev/layout/base/ZoomConstraintsClient.cpp

258 строки
8.3 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 "ZoomConstraintsClient.h"
#include <inttypes.h>
#include "FrameMetrics.h"
#include "gfxPrefs.h"
#include "LayersLogging.h"
#include "mozilla/layers/APZCCallbackHelper.h"
#include "mozilla/Preferences.h"
#include "mozilla/PresShell.h"
#include "mozilla/dom/Event.h"
#include "nsDocument.h"
#include "nsIFrame.h"
#include "nsLayoutUtils.h"
#include "nsPoint.h"
#include "nsView.h"
#include "nsViewportInfo.h"
#include "Units.h"
#include "UnitTransforms.h"
#define ZCC_LOG(...)
// #define ZCC_LOG(...) printf_stderr("ZCC: " __VA_ARGS__)
NS_IMPL_ISUPPORTS(ZoomConstraintsClient, nsIDOMEventListener, nsIObserver)
static const nsLiteralString DOM_META_ADDED = NS_LITERAL_STRING("DOMMetaAdded");
static const nsLiteralString DOM_META_CHANGED = NS_LITERAL_STRING("DOMMetaChanged");
static const nsLiteralString FULLSCREEN_CHANGED = NS_LITERAL_STRING("fullscreenchange");
static const nsLiteralCString BEFORE_FIRST_PAINT = NS_LITERAL_CSTRING("before-first-paint");
static const nsLiteralCString NS_PREF_CHANGED = NS_LITERAL_CSTRING("nsPref:changed");
using namespace mozilla;
using namespace mozilla::layers;
ZoomConstraintsClient::ZoomConstraintsClient() :
mDocument(nullptr),
mPresShell(nullptr)
{
}
ZoomConstraintsClient::~ZoomConstraintsClient()
{
}
static nsIWidget*
GetWidget(nsIPresShell* aShell)
{
if (!aShell) {
return nullptr;
}
if (nsIFrame* rootFrame = aShell->GetRootFrame()) {
#if defined(MOZ_WIDGET_ANDROID) || defined(MOZ_WIDGET_UIKIT)
return rootFrame->GetNearestWidget();
#else
if (nsView* view = rootFrame->GetView()) {
return view->GetWidget();
}
#endif
}
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());
}
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(nsIPresShell* aPresShell, nsIDocument* 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);
}
Preferences::AddStrongObserver(this, "browser.ui.zoom.force-user-scalable");
}
NS_IMETHODIMP
ZoomConstraintsClient::HandleEvent(nsIDOMEvent* 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, mDocument) && BEFORE_FIRST_PAINT.EqualsASCII(aTopic)) {
ZCC_LOG("Got a before-first-paint event 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 gfxPrefs::ForceUserScalable()
// returns the updated value.
RefPtr<nsRunnableMethod<ZoomConstraintsClient>> event =
NewRunnableMethod(this, &ZoomConstraintsClient::RefreshZoomConstraints);
mDocument->Dispatch("ZoomConstraintsClient::RefreshZoomConstraints",
TaskCategory::Other,
event.forget());
}
return NS_OK;
}
void
ZoomConstraintsClient::ScreenSizeChanged()
{
ZCC_LOG("Got a screen-size change notification in %p\n", this);
RefreshZoomConstraints();
}
mozilla::layers::ZoomConstraints
ComputeZoomConstraintsFromViewportInfo(const nsViewportInfo& aViewportInfo)
{
mozilla::layers::ZoomConstraints constraints;
constraints.mAllowZoom = aViewportInfo.IsZoomAllowed() && gfxPrefs::APZAllowZooming();
constraints.mAllowDoubleTapZoom = constraints.mAllowZoom;
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()
{
nsIWidget* widget = GetWidget(mPresShell);
if (!widget) {
return;
}
uint32_t presShellId = 0;
FrameMetrics::ViewID viewId = FrameMetrics::NULL_SCROLL_ID;
bool scrollIdentifiersValid = APZCCallbackHelper::GetOrCreateScrollIdentifiers(
mDocument->GetDocumentElement(),
&presShellId, &viewId);
if (!scrollIdentifiersValid) {
return;
}
LayoutDeviceIntSize screenSize;
if (!nsLayoutUtils::GetContentViewerSize(mPresShell->GetPresContext(), screenSize)) {
return;
}
nsViewportInfo viewportInfo = mDocument->GetViewportInfo(
ViewAs<ScreenPixel>(screenSize, PixelCastJustification::LayoutDeviceIsScreenForBounds));
mozilla::layers::ZoomConstraints zoomConstraints =
ComputeZoomConstraintsFromViewportInfo(viewportInfo);
if (mDocument->Fullscreen()) {
ZCC_LOG("%p is in fullscreen, disallowing zooming\n", this);
zoomConstraints.mAllowZoom = false;
zoomConstraints.mAllowDoubleTapZoom = false;
}
if (zoomConstraints.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) {
zoomConstraints.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()->IsRootContentDocument());
if (nsIScrollableFrame* rcdrsf = mPresShell->GetRootScrollFrameAsScrollable()) {
ZCC_LOG("Notifying RCD-RSF that it is zoomable: %d\n", zoomConstraints.mAllowZoom);
rcdrsf->SetZoomableByAPZ(zoomConstraints.mAllowZoom);
}
ScrollableLayerGuid newGuid(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",
Stringify(zoomConstraints).c_str(), this, presShellId, viewId);
widget->UpdateZoomConstraints(presShellId, viewId, Some(zoomConstraints));
}