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| -rw-r--r-- | widget/windows/WinWindowOcclusionTracker.h | 333 |
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diff --git a/widget/windows/WinWindowOcclusionTracker.h b/widget/windows/WinWindowOcclusionTracker.h new file mode 100644 index 0000000000..b82a41b984 --- /dev/null +++ b/widget/windows/WinWindowOcclusionTracker.h @@ -0,0 +1,333 @@ +/* -*- 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/. */ + +#ifndef widget_windows_WinWindowOcclusionTracker_h +#define widget_windows_WinWindowOcclusionTracker_h + +#include <string> +#include <unordered_map> +#include <unordered_set> +#include <vector> + +#include "nsIWeakReferenceUtils.h" +#include "mozilla/Monitor.h" +#include "mozilla/StaticPtr.h" +#include "mozilla/WindowsVersion.h" +#include "mozilla/ThreadSafeWeakPtr.h" +#include "mozilla/widget/WindowOcclusionState.h" +#include "mozilla/widget/WinEventObserver.h" +#include "Units.h" +#include "nsThreadUtils.h" + +class nsBaseWidget; +struct IVirtualDesktopManager; +class WinWindowOcclusionTrackerTest; +class WinWindowOcclusionTrackerInteractiveTest; + +namespace base { +class Thread; +} // namespace base + +namespace mozilla { + +namespace widget { + +class OcclusionUpdateRunnable; +class SerializedTaskDispatcher; +class UpdateOcclusionStateRunnable; + +// This class handles window occlusion tracking by using HWND. +// Implementation is borrowed from chromium's NativeWindowOcclusionTrackerWin. +class WinWindowOcclusionTracker final : public DisplayStatusListener, + public SessionChangeListener { + public: + NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WinWindowOcclusionTracker) + + /// Can only be called from the main thread. + static WinWindowOcclusionTracker* Get(); + + /// Can only be called from the main thread. + static void Ensure(); + + /// Can only be called from the main thread. + static void ShutDown(); + + /// Can be called from any thread. + static MessageLoop* OcclusionCalculatorLoop(); + + /// Can be called from any thread. + static bool IsInWinWindowOcclusionThread(); + + /// Can only be called from the main thread. + void EnsureDisplayStatusObserver(); + + /// Can only be called from the main thread. + void EnsureSessionChangeObserver(); + + // Enables notifying to widget via NotifyOcclusionState() when the occlusion + // state has been computed. + void Enable(nsBaseWidget* aWindow, HWND aHwnd); + + // Disables notifying to widget via NotifyOcclusionState() when the occlusion + // state has been computed. + void Disable(nsBaseWidget* aWindow, HWND aHwnd); + + // Called when widget's visibility is changed + void OnWindowVisibilityChanged(nsBaseWidget* aWindow, bool aVisible); + + SerializedTaskDispatcher* GetSerializedTaskDispatcher() { + return mSerializedTaskDispatcher; + } + + void TriggerCalculation(); + + void DumpOccludingWindows(HWND aHWnd); + + private: + friend class ::WinWindowOcclusionTrackerTest; + friend class ::WinWindowOcclusionTrackerInteractiveTest; + + explicit WinWindowOcclusionTracker(UniquePtr<base::Thread> aThread); + virtual ~WinWindowOcclusionTracker(); + + // This class computes the occlusion state of the tracked windows. + // It runs on a separate thread, and notifies the main thread of + // the occlusion state of the tracked windows. + class WindowOcclusionCalculator { + NS_INLINE_DECL_THREADSAFE_REFCOUNTING(WindowOcclusionCalculator) + public: + // Creates WindowOcclusionCalculator instance. + static void CreateInstance(); + + // Clear WindowOcclusionCalculator instance. + static void ClearInstance(); + + // Returns existing WindowOcclusionCalculator instance. + static WindowOcclusionCalculator* GetInstance() { return sCalculator; } + + void Initialize(); + void Shutdown(); + + void EnableOcclusionTrackingForWindow(HWND hwnd); + void DisableOcclusionTrackingForWindow(HWND hwnd); + + // If a window becomes visible, makes sure event hooks are registered. + void HandleVisibilityChanged(bool aVisible); + + void HandleTriggerCalculation(); + + private: + WindowOcclusionCalculator(); + ~WindowOcclusionCalculator(); + + // Registers event hooks, if not registered. + void MaybeRegisterEventHooks(); + + // This is the callback registered to get notified of various Windows + // events, like window moving/resizing. + static void CALLBACK EventHookCallback(HWINEVENTHOOK aWinEventHook, + DWORD aEvent, HWND aHwnd, + LONG aIdObject, LONG aIdChild, + DWORD aEventThread, + DWORD aMsEventTime); + + // EnumWindows callback used to iterate over all hwnds to determine + // occlusion status of all tracked root windows. Also builds up + // |current_pids_with_visible_windows_| and registers event hooks for newly + // discovered processes with visible hwnds. + static BOOL CALLBACK + ComputeNativeWindowOcclusionStatusCallback(HWND hwnd, LPARAM lParam); + + // EnumWindows callback used to update the list of process ids with + // visible hwnds, |pids_for_location_change_hook_|. + static BOOL CALLBACK UpdateVisibleWindowProcessIdsCallback(HWND aHwnd, + LPARAM aLParam); + + // Determines which processes owning visible application windows to set the + // EVENT_OBJECT_LOCATIONCHANGE event hook for and stores the pids in + // |pids_for_location_change_hook_|. + void UpdateVisibleWindowProcessIds(); + + // Computes the native window occlusion status for all tracked root gecko + // windows in |root_window_hwnds_occlusion_state_| and notifies them if + // their occlusion status has changed. + void ComputeNativeWindowOcclusionStatus(); + + // Schedules an occlusion calculation , if one isn't already scheduled. + void ScheduleOcclusionCalculationIfNeeded(); + + // Registers a global event hook (not per process) for the events in the + // range from |event_min| to |event_max|, inclusive. + void RegisterGlobalEventHook(DWORD aEventMin, DWORD aEventMax); + + // Registers the EVENT_OBJECT_LOCATIONCHANGE event hook for the process with + // passed id. The process has one or more visible, opaque windows. + void RegisterEventHookForProcess(DWORD aPid); + + // Registers/Unregisters the event hooks necessary for occlusion tracking + // via calls to RegisterEventHook. These event hooks are disabled when all + // tracked windows are minimized. + void RegisterEventHooks(); + void UnregisterEventHooks(); + + // EnumWindows callback for occlusion calculation. Returns true to + // continue enumeration, false otherwise. Currently, always returns + // true because this function also updates currentPidsWithVisibleWindows, + // and needs to see all HWNDs. + bool ProcessComputeNativeWindowOcclusionStatusCallback( + HWND aHwnd, std::unordered_set<DWORD>* aCurrentPidsWithVisibleWindows); + + // Processes events sent to OcclusionEventHookCallback. + // It generally triggers scheduling of the occlusion calculation, but + // ignores certain events in order to not calculate occlusion more than + // necessary. + void ProcessEventHookCallback(HWINEVENTHOOK aWinEventHook, DWORD aEvent, + HWND aHwnd, LONG aIdObject, LONG aIdChild); + + // EnumWindows callback for determining which processes to set the + // EVENT_OBJECT_LOCATIONCHANGE event hook for. We set that event hook for + // processes hosting fully visible, opaque windows. + void ProcessUpdateVisibleWindowProcessIdsCallback(HWND aHwnd); + + // Returns true if the window is visible, fully opaque, and on the current + // virtual desktop, false otherwise. + bool WindowCanOccludeOtherWindowsOnCurrentVirtualDesktop( + HWND aHwnd, LayoutDeviceIntRect* aWindowRect); + + // Returns true if aHwnd is definitely on the current virtual desktop, + // false if it's definitely not on the current virtual desktop, and Nothing + // if we we can't tell for sure. + Maybe<bool> IsWindowOnCurrentVirtualDesktop(HWND aHwnd); + + static StaticRefPtr<WindowOcclusionCalculator> sCalculator; + + // Map of root app window hwnds and their occlusion state. This contains + // both visible and hidden windows. + // It is accessed from WinWindowOcclusionTracker::UpdateOcclusionState() + // without using mutex. The access is safe by using + // SerializedTaskDispatcher. + std::unordered_map<HWND, OcclusionState> mRootWindowHwndsOcclusionState; + + // Values returned by SetWinEventHook are stored so that hooks can be + // unregistered when necessary. + std::vector<HWINEVENTHOOK> mGlobalEventHooks; + + // Map from process id to EVENT_OBJECT_LOCATIONCHANGE event hook. + std::unordered_map<DWORD, HWINEVENTHOOK> mProcessEventHooks; + + // Pids of processes for which the EVENT_OBJECT_LOCATIONCHANGE event hook is + // set. + std::unordered_set<DWORD> mPidsForLocationChangeHook; + + // Used as a timer to delay occlusion update. + RefPtr<CancelableRunnable> mOcclusionUpdateRunnable; + + // Used to determine if a window is occluded. As we iterate through the + // hwnds in z-order, we subtract each opaque window's rect from + // mUnoccludedDesktopRegion. When we get to a root window, we subtract + // it from mUnoccludedDesktopRegion, and if mUnoccludedDesktopRegion + // doesn't change, the root window was already occluded. + LayoutDeviceIntRegion mUnoccludedDesktopRegion; + + // Keeps track of how many root windows we need to compute the occlusion + // state of in a call to ComputeNativeWindowOcclusionStatus. Once we've + // determined the state of all root windows, we can stop subtracting + // windows from mUnoccludedDesktopRegion;. + int mNumRootWindowsWithUnknownOcclusionState; + + // This is true if the task bar thumbnails or the alt tab thumbnails are + // showing. + bool mShowingThumbnails = false; + + // Used to keep track of the window that's currently moving. That window + // is ignored for calculation occlusion so that tab dragging won't + // ignore windows occluded by the dragged window. + HWND mMovingWindow = 0; + + // Only used on Win10+. + RefPtr<IVirtualDesktopManager> mVirtualDesktopManager; + + // Used to serialize tasks related to mRootWindowHwndsOcclusionState. + RefPtr<SerializedTaskDispatcher> mSerializedTaskDispatcher; + + // This is an alias to the singleton WinWindowOcclusionTracker mMonitor, + // and is used in ShutDown(). + Monitor& mMonitor; + + friend class OcclusionUpdateRunnable; + }; + + static BOOL CALLBACK DumpOccludingWindowsCallback(HWND aHWnd, LPARAM aLParam); + + // Returns true if we are interested in |hwnd| for purposes of occlusion + // calculation. We are interested in |hwnd| if it is a window that is + // visible, opaque, bounded, and not a popup or floating window. If we are + // interested in |hwnd|, stores the window rectangle in |window_rect|. + static bool IsWindowVisibleAndFullyOpaque(HWND aHwnd, + LayoutDeviceIntRect* aWindowRect); + + void Destroy(); + + static void CallUpdateOcclusionState( + std::unordered_map<HWND, OcclusionState>* aMap, bool aShowAllWindows); + + // Updates root windows occclusion state. If aShowAllWindows is true, + // all non-hidden windows will be marked visible. This is used to force + // rendering of thumbnails. + void UpdateOcclusionState(std::unordered_map<HWND, OcclusionState>* aMap, + bool aShowAllWindows); + + // This is called with session changed notifications. If the screen is locked + // by the current session, it marks app windows as occluded. + void OnSessionChange(WPARAM aStatusCode, + Maybe<bool> aIsCurrentSession) override; + + // This is called when the display is put to sleep. If the display is sleeping + // it marks app windows as occluded. + void OnDisplayStateChanged(bool aDisplayOn) override; + + // Marks all root windows as either occluded, or if hwnd IsIconic, hidden. + void MarkNonIconicWindowsOccluded(); + + static StaticRefPtr<WinWindowOcclusionTracker> sTracker; + + // "WinWindowOcclusionCalc" thread. + UniquePtr<base::Thread> mThread; + Monitor mMonitor; + + // Has ShutDown been called on us? We might have survived if our thread join + // timed out. + bool mHasAttemptedShutdown = false; + + // Map of HWND to widget. Maintained on main thread, and used to send + // occlusion state notifications to Windows from + // mRootWindowHwndsOcclusionState. + std::unordered_map<HWND, nsWeakPtr> mHwndRootWindowMap; + + // This is set by UpdateOcclusionState(). It is currently only used by tests. + int mNumVisibleRootWindows = 0; + + // If the screen is locked, windows are considered occluded. + bool mScreenLocked = false; + + // If the display is off, windows are considered occluded. + bool mDisplayOn = true; + + RefPtr<DisplayStatusObserver> mDisplayStatusObserver; + + RefPtr<SessionChangeObserver> mSessionChangeObserver; + + // Used to serialize tasks related to mRootWindowHwndsOcclusionState. + RefPtr<SerializedTaskDispatcher> mSerializedTaskDispatcher; + + friend class OcclusionUpdateRunnable; + friend class UpdateOcclusionStateRunnable; +}; + +} // namespace widget +} // namespace mozilla + +#endif // widget_windows_WinWindowOcclusionTracker_h |