gecko-dev/widget/nsScreenManagerProxy.cpp

220 lines
5.8 KiB
C++

/* -*- Mode: C++; tab-width: 4; 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 "mozilla/unused.h"
#include "mozilla/dom/ContentChild.h"
#include "nsScreenManagerProxy.h"
#include "nsServiceManagerUtils.h"
#include "nsIAppShell.h"
#include "nsIScreen.h"
#include "nsIScreenManager.h"
#include "nsWidgetsCID.h"
static NS_DEFINE_CID(kAppShellCID, NS_APPSHELL_CID);
using namespace mozilla;
using namespace mozilla::dom;
using namespace mozilla::widget;
NS_IMPL_ISUPPORTS(nsScreenManagerProxy, nsIScreenManager)
nsScreenManagerProxy::nsScreenManagerProxy()
: mNumberOfScreens(-1)
, mSystemDefaultScale(1.0)
, mCacheValid(true)
, mCacheWillInvalidate(false)
{
bool success = false;
Unused << ContentChild::GetSingleton()->SendPScreenManagerConstructor(
this,
&mNumberOfScreens,
&mSystemDefaultScale,
&success);
if (!success) {
// We're in bad shape. We'll return the default values, but we'll basically
// be lying.
NS_WARNING("Setting up communications with the parent nsIScreenManager failed.");
}
InvalidateCacheOnNextTick();
// nsScreenManagerProxy is a service, which will always have a reference
// held to it by the Component Manager once the service is requested.
// However, nsScreenManagerProxy also implements PScreenManagerChild, and
// that means that the manager of the PScreenManager protocol (PContent
// in this case) needs to know how to deallocate this actor. We AddRef here
// so that in the event that PContent tries to deallocate us either before
// or after process shutdown, we don't try to do a double-free.
AddRef();
}
/**
* nsIScreenManager
**/
NS_IMETHODIMP
nsScreenManagerProxy::GetPrimaryScreen(nsIScreen** outScreen)
{
InvalidateCacheOnNextTick();
if (!mPrimaryScreen) {
ScreenDetails details;
bool success = false;
Unused << SendGetPrimaryScreen(&details, &success);
if (!success) {
return NS_ERROR_FAILURE;
}
mPrimaryScreen = new ScreenProxy(this, details);
}
NS_ADDREF(*outScreen = mPrimaryScreen);
return NS_OK;
}
NS_IMETHODIMP
nsScreenManagerProxy::ScreenForId(uint32_t aId, nsIScreen** outScreen)
{
// At this time, there's no need for child processes to query for
// screens by ID.
return NS_ERROR_NOT_IMPLEMENTED;
}
NS_IMETHODIMP
nsScreenManagerProxy::ScreenForRect(int32_t inLeft,
int32_t inTop,
int32_t inWidth,
int32_t inHeight,
nsIScreen** outScreen)
{
bool success = false;
ScreenDetails details;
Unused << SendScreenForRect(inLeft, inTop, inWidth, inHeight, &details, &success);
if (!success) {
return NS_ERROR_FAILURE;
}
RefPtr<ScreenProxy> screen = new ScreenProxy(this, details);
NS_ADDREF(*outScreen = screen);
return NS_OK;
}
NS_IMETHODIMP
nsScreenManagerProxy::ScreenForNativeWidget(void* aWidget,
nsIScreen** outScreen)
{
// Because ScreenForNativeWidget can be called numerous times
// indirectly from content via the DOM Screen API, we cache the
// results for this tick of the event loop.
TabChild* tabChild = static_cast<TabChild*>(aWidget);
// Enumerate the cached screen array, looking for one that has
// the TabChild that we're looking for...
for (uint32_t i = 0; i < mScreenCache.Length(); ++i) {
ScreenCacheEntry& curr = mScreenCache[i];
if (curr.mTabChild == aWidget) {
NS_ADDREF(*outScreen = static_cast<nsIScreen*>(curr.mScreenProxy));
return NS_OK;
}
}
// Never cached this screen, so we have to ask the parent process
// for it.
bool success = false;
ScreenDetails details;
Unused << SendScreenForBrowser(tabChild->GetTabId(), &details, &success);
if (!success) {
return NS_ERROR_FAILURE;
}
ScreenCacheEntry newEntry;
RefPtr<ScreenProxy> screen = new ScreenProxy(this, details);
newEntry.mScreenProxy = screen;
newEntry.mTabChild = tabChild;
mScreenCache.AppendElement(newEntry);
NS_ADDREF(*outScreen = screen);
InvalidateCacheOnNextTick();
return NS_OK;
}
NS_IMETHODIMP
nsScreenManagerProxy::GetNumberOfScreens(uint32_t* aNumberOfScreens)
{
if (!EnsureCacheIsValid()) {
return NS_ERROR_FAILURE;
}
*aNumberOfScreens = mNumberOfScreens;
return NS_OK;
}
NS_IMETHODIMP
nsScreenManagerProxy::GetSystemDefaultScale(float *aSystemDefaultScale)
{
if (!EnsureCacheIsValid()) {
return NS_ERROR_FAILURE;
}
*aSystemDefaultScale = mSystemDefaultScale;
return NS_OK;
}
bool
nsScreenManagerProxy::EnsureCacheIsValid()
{
if (mCacheValid) {
return true;
}
bool success = false;
// Kick off a synchronous IPC call to the parent to get the
// most up-to-date information.
Unused << SendRefresh(&mNumberOfScreens, &mSystemDefaultScale, &success);
if (!success) {
NS_WARNING("Refreshing nsScreenManagerProxy failed in the parent process.");
return false;
}
mCacheValid = true;
InvalidateCacheOnNextTick();
return true;
}
void
nsScreenManagerProxy::InvalidateCacheOnNextTick()
{
if (mCacheWillInvalidate) {
return;
}
mCacheWillInvalidate = true;
nsCOMPtr<nsIRunnable> r =
NS_NewRunnableMethod(this, &nsScreenManagerProxy::InvalidateCache);
nsContentUtils::RunInStableState(r.forget());
}
void
nsScreenManagerProxy::InvalidateCache()
{
mCacheValid = false;
mCacheWillInvalidate = false;
if (mPrimaryScreen) {
mPrimaryScreen = nullptr;
}
for (int32_t i = mScreenCache.Length() - 1; i >= 0; --i) {
mScreenCache.RemoveElementAt(i);
}
}