author Hiroyuki Ikezoe <>
Sat, 15 Sep 2018 01:00:07 +0000
changeset 492144 67a5acf7363d9dd2c8532967ec1beb0c200abc2c
parent 468506 1224b46e13922d7fd3cec29a441560439d0166cb
child 493166 c5b3caf36ddf3e451feef98e271fea2107af6811
permissions -rw-r--r--
Bug 1486971 - Test for dynamically change of the prefers-reduced-motion setting on MacOSX. r=froydnj,mstange The framework to simulate the setting change works as following; - nsIDOMWindowUtils.setPrefersReducedMotion() calls an IPC function which ends up calling nsChildView::SetPrefersReducedMotion() in the parent process - nsChildView::SetPrefersReducedMotion() sets the given value into nsLookAndFeel::mPrefersReducedMotionCached just like we set the value queried via NSWorkspace.accessibilityDisplayShouldReduceMotion in the parent process and send a notification which is the same notification MacOSX sends when the system setting changed - Normally the cached value is cleared before quering new values since the cache value is stale, but in this case the value is up-to-date one, so nsChildView::SetPrefersReducedMotion() tells that we don't need to clear the cache, and nsIDOMWindowUtils.resetPrefersReducedMotion() resets that state of 'we don't need to clear the cache' There are two test cases with the framework in this commit, one is just setting the value and checking the value queried by window.matchMedia. The other one is receiving 'change' event and checking the value of the event target. Note that to make this test works the patch for bug 1478212 is necessary since the test runs in an iframe. Depends on D5003 Differential Revision:

/* -*- 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 */

#ifndef nsView_h__
#define nsView_h__

#include "nsCoord.h"
#include "nsRect.h"
#include "nsPoint.h"
#include "nsRegion.h"
#include "nsCRT.h"
#include "nsCOMPtr.h"
#include "nsWidgetInitData.h" // for nsWindowType
#include "nsIWidgetListener.h"
#include "Units.h"
#include "mozilla/EventForwards.h"

class nsViewManager;
class nsIWidget;
class nsIFrame;

// Enumerated type to indicate the visibility of a layer.
// hide - the layer is not shown.
// show - the layer is shown irrespective of the visibility of
//        the layer's parent.
enum nsViewVisibility {
  nsViewVisibility_kHide = 0,
  nsViewVisibility_kShow = 1

// Public view flags

// Indicates that the view is using auto z-indexing
#define NS_VIEW_FLAG_AUTO_ZINDEX          0x0004

// Indicates that the view is a floating view.
#define NS_VIEW_FLAG_FLOATING             0x0008


 * View interface
 * Views are NOT reference counted. Use the Destroy() member function to
 * destroy a view.
 * The lifetime of the view hierarchy is bounded by the lifetime of the
 * view manager that owns the views.
 * Most of the methods here are read-only. To set the corresponding properties
 * of a view, go through nsViewManager.

class nsView final : public nsIWidgetListener
  friend class nsViewManager;

  typedef mozilla::LayoutDeviceIntRect LayoutDeviceIntRect;
  typedef mozilla::LayoutDeviceIntRegion LayoutDeviceIntRegion;

  void operator delete(void* ptr) {
    ::operator delete(ptr);

   * Get the view manager which "owns" the view.
   * This method might require some expensive traversal work in the future. If you can get the
   * view manager from somewhere else, do that instead.
   * @result the view manager
  nsViewManager* GetViewManager() const { return mViewManager; }

   * Find the view for the given widget, if there is one.
   * @return the view the widget belongs to, or null if the widget doesn't
   * belong to any view.
  static nsView* GetViewFor(nsIWidget* aWidget);

   * Destroy the view.
   * The view destroys its child views, and destroys and releases its
   * widget (if it has one).
   * Also informs the view manager that the view is destroyed by calling
   * SetRootView(NULL) if the view is the root view and calling RemoveChild()
   * otherwise.
  void Destroy();

   * Called to get the position of a view.
   * The specified coordinates are relative to the parent view's origin, but
   * are in appunits of this.
   * This is the (0, 0) origin of the coordinate space established by this view.
   * @param x out parameter for x position
   * @param y out parameter for y position
  nsPoint GetPosition() const {
    NS_ASSERTION(!IsRoot() || (mPosX == 0 && mPosY == 0),
                 "root views should always have explicit position of (0,0)");
    return nsPoint(mPosX, mPosY);

   * Called to get the dimensions and position of the view's bounds.
   * The view's bounds (x,y) are relative to the origin of the parent view, but
   * are in appunits of this.
   * The view's bounds (x,y) might not be the same as the view's position,
   * if the view has content above or to the left of its origin.
   * @param aBounds out parameter for bounds
  nsRect GetBounds() const { return mDimBounds; }

   * The bounds of this view relative to this view. So this is the same as
   * GetBounds except this is relative to this view instead of the parent view.
  nsRect GetDimensions() const {
    nsRect r = mDimBounds; r.MoveBy(-mPosX, -mPosY); return r;

   * Get the offset between the coordinate systems of |this| and aOther.
   * Adding the return value to a point in the coordinate system of |this|
   * will transform the point to the coordinate system of aOther.
   * The offset is expressed in appunits of |this|. So if you are getting the
   * offset between views in different documents that might have different
   * appunits per devpixel ratios you need to be careful how you use the
   * result.
   * If aOther is null, this will return the offset of |this| from the
   * root of the viewmanager tree.
   * This function is fastest when aOther is an ancestor of |this|.
   * NOTE: this actually returns the offset from aOther to |this|, but
   * that offset is added to transform _coordinates_ from |this| to aOther.
  nsPoint GetOffsetTo(const nsView* aOther) const;

   * Get the offset between the origin of |this| and the origin of aWidget.
   * Adding the return value to a point in the coordinate system of |this|
   * will transform the point to the coordinate system of aWidget.
   * The offset is expressed in appunits of |this|.
  nsPoint GetOffsetToWidget(nsIWidget* aWidget) const;

   * Takes a point aPt that is in the coordinate system of |this|'s parent view
   * and converts it to be in the coordinate system of |this| taking into
   * account the offset and any app unit per dev pixel ratio differences.
  nsPoint ConvertFromParentCoords(nsPoint aPt) const;

   * Called to query the visibility state of a view.
   * @result current visibility state
  nsViewVisibility GetVisibility() const { return mVis; }

   * Get whether the view "floats" above all other views,
   * which tells the compositor not to consider higher views in
   * the view hierarchy that would geometrically intersect with
   * this view. This is a hack, but it fixes some problems with
   * views that need to be drawn in front of all other views.
   * @result true if the view floats, false otherwise.
  bool GetFloating() const { return (mVFlags & NS_VIEW_FLAG_FLOATING) != 0; }

   * Called to query the parent of the view.
   * @result view's parent
  nsView* GetParent() const { return mParent; }

   * The view's first child is the child which is earliest in document order.
   * @result first child
  nsView* GetFirstChild() const { return mFirstChild; }

   * Called to query the next sibling of the view.
   * @result view's next sibling
  nsView* GetNextSibling() const { return mNextSibling; }

   * Set the view's frame.
  void SetFrame(nsIFrame* aRootFrame) { mFrame = aRootFrame; }

   * Retrieve the view's frame.
  nsIFrame* GetFrame() const { return mFrame; }

   * Get the nearest widget in this view or a parent of this view and
   * the offset from the widget's origin to this view's origin
   * @param aOffset - if non-null the offset from this view's origin to the
   * widget's origin (usually positive) expressed in appunits of this will be
   * returned in aOffset.
   * @return the widget closest to this view; can be null because some view trees
   * don't have widgets at all (e.g., printing), but if any view in the view tree
   * has a widget, then it's safe to assume this will not return null
  nsIWidget* GetNearestWidget(nsPoint* aOffset) const;

   * Create a widget to associate with this view.  This variant of
   * CreateWidget*() will look around in the view hierarchy for an
   * appropriate parent widget for the view.
   * @param aWidgetInitData data used to initialize this view's widget before
   *        its create is called.
   * @return error status
  nsresult CreateWidget(nsWidgetInitData *aWidgetInitData = nullptr,
                        bool aEnableDragDrop = true,
                        bool aResetVisibility = true);

   * Create a widget for this view with an explicit parent widget.
   * |aParentWidget| must be nonnull.  The other params are the same
   * as for |CreateWidget()|.
  nsresult CreateWidgetForParent(nsIWidget* aParentWidget,
                                 nsWidgetInitData *aWidgetInitData = nullptr,
                                 bool aEnableDragDrop = true,
                                 bool aResetVisibility = true);

   * Create a popup widget for this view.  Pass |aParentWidget| to
   * explicitly set the popup's parent.  If it's not passed, the view
   * hierarchy will be searched for an appropriate parent widget.  The
   * other params are the same as for |CreateWidget()|, except that
   * |aWidgetInitData| must be nonnull.
  nsresult CreateWidgetForPopup(nsWidgetInitData *aWidgetInitData,
                                nsIWidget* aParentWidget = nullptr,
                                bool aEnableDragDrop = true,
                                bool aResetVisibility = true);

   * Destroys the associated widget for this view.  If this method is
   * not called explicitly, the widget when be destroyed when its
   * view gets destroyed.
  void DestroyWidget();

   * Attach/detach a top level widget from this view. When attached, the view
   * updates the widget's device context and allows the view to begin receiving
   * gecko events. The underlying base window associated with the widget will
   * continues to receive events it expects.
   * An attached widget will not be destroyed when the view is destroyed,
   * allowing the recycling of a single top level widget over multiple views.
   * @param aWidget The widget to attach to / detach from.
  nsresult AttachToTopLevelWidget(nsIWidget* aWidget);
  nsresult DetachFromTopLevelWidget();

   * Returns a flag indicating whether the view owns it's widget
   * or is attached to an existing top level widget.
  bool IsAttachedToTopLevel() const { return mWidgetIsTopLevel; }

   * In 4.0, the "cutout" nature of a view is queryable.
   * If we believe that all cutout view have a native widget, this
   * could be a replacement.
   * @param aWidget out parameter for widget that this view contains,
   *        or nullptr if there is none.
  nsIWidget* GetWidget() const { return mWindow; }

   * The widget which we have attached a listener to can also have a "previous"
   * listener set on it. This is to keep track of the last nsView when navigating
   * to a new one so that we can continue to paint that if the new one isn't ready
   * yet.
  void SetPreviousWidget(nsIWidget* aWidget) { mPreviousWindow = aWidget; }

   * Returns true if the view has a widget associated with it.
  bool HasWidget() const { return mWindow != nullptr; }

  void SetForcedRepaint(bool aForceRepaint) {
    mForcedRepaint = aForceRepaint;

  void SetNeedsWindowPropertiesSync();

   * Make aWidget direct its events to this view.
   * The caller must call DetachWidgetEventHandler before this view
   * is destroyed.
  void AttachWidgetEventHandler(nsIWidget* aWidget);
   * Stop aWidget directing its events to this view.
  void DetachWidgetEventHandler(nsIWidget* aWidget);

#ifdef DEBUG
   * Output debug info to FILE
   * @param out output file handle
   * @param aIndent indentation depth
   * NOTE: virtual so that debugging tools not linked into gklayout can access it
  virtual void List(FILE* out, int32_t aIndent = 0) const;
#endif // DEBUG

   * @result true iff this is the root view for its view manager
  bool IsRoot() const;

  LayoutDeviceIntRect CalcWidgetBounds(nsWindowType aType);

  // This is an app unit offset to add when converting view coordinates to
  // widget coordinates.  It is the offset in view coordinates from widget
  // origin (unlike views, widgets can't extend above or to the left of their
  // origin) to view origin expressed in appunits of this.
  nsPoint ViewToWidgetOffset() const { return mViewToWidgetOffset; }

   * Called to indicate that the position of the view has been changed.
   * The specified coordinates are in the parent view's coordinate space.
   * @param x new x position
   * @param y new y position
  void SetPosition(nscoord aX, nscoord aY);

   * Called to indicate that the z-index of a view has been changed.
   * The z-index is relative to all siblings of the view.
   * @param aAuto Indicate that the z-index of a view is "auto". An "auto" z-index
   * means that the view does not define a new stacking context,
   * which means that the z-indicies of the view's children are
   * relative to the view's siblings.
   * @param zindex new z depth
  void SetZIndex(bool aAuto, int32_t aZIndex);
  bool GetZIndexIsAuto() const { return (mVFlags & NS_VIEW_FLAG_AUTO_ZINDEX) != 0; }
  int32_t GetZIndex() const { return mZIndex; }

  void SetParent(nsView *aParent) { mParent = aParent; }
  void SetNextSibling(nsView *aSibling)
    NS_ASSERTION(aSibling != this, "Can't be our own sibling!");
    mNextSibling = aSibling;

  nsRegion* GetDirtyRegion() {
    if (!mDirtyRegion) {
      NS_ASSERTION(!mParent || GetFloating(),
                   "Only display roots should have dirty regions");
      mDirtyRegion = new nsRegion();
      NS_ASSERTION(mDirtyRegion, "Out of memory!");
    return mDirtyRegion;

  // nsIWidgetListener
  virtual nsIPresShell* GetPresShell() override;
  virtual nsView* GetView() override { return this; }
  virtual bool WindowMoved(nsIWidget* aWidget, int32_t x, int32_t y) override;
  virtual bool WindowResized(nsIWidget* aWidget, int32_t aWidth, int32_t aHeight) override;
  virtual bool RequestWindowClose(nsIWidget* aWidget) override;
  virtual void WillPaintWindow(nsIWidget* aWidget) override;
  virtual bool PaintWindow(nsIWidget* aWidget,
                           LayoutDeviceIntRegion aRegion) override;
  virtual void DidPaintWindow() override;
  virtual void DidCompositeWindow(mozilla::layers::TransactionId aTransactionId,
                                  const mozilla::TimeStamp& aCompositeStart,
                                  const mozilla::TimeStamp& aCompositeEnd) override;
  virtual void RequestRepaint() override;
  virtual nsEventStatus HandleEvent(mozilla::WidgetGUIEvent* aEvent,
                                    bool aUseAttachedEvents) override;

  virtual ~nsView();

  nsPoint GetOffsetTo(const nsView* aOther, const int32_t aAPD) const;
  nsIWidget* GetNearestWidget(nsPoint* aOffset, const int32_t aAPD) const;

  bool IsPrimaryFramePaintSuppressed();

  explicit nsView(nsViewManager* aViewManager = nullptr,
                  nsViewVisibility aVisibility = nsViewVisibility_kShow);

  bool ForcedRepaint() { return mForcedRepaint; }

  // Do the actual work of ResetWidgetBounds, unconditionally.  Don't
  // call this method if we have no widget.
  void DoResetWidgetBounds(bool aMoveOnly, bool aInvalidateChangedSize);
  void InitializeWindow(bool aEnableDragDrop, bool aResetVisibility);

  bool IsEffectivelyVisible();

   * Called to indicate that the dimensions of the view have been changed.
   * The x and y coordinates may be < 0, indicating that the view extends above
   * or to the left of its origin position. The term 'dimensions' indicates it
   * is relative to this view.
  void SetDimensions(const nsRect &aRect, bool aPaint = true,
                     bool aResizeWidget = true);

   * Called to indicate that the visibility of a view has been
   * changed.
   * @param visibility new visibility state
  void SetVisibility(nsViewVisibility visibility);

   * Set/Get whether the view "floats" above all other views,
   * which tells the compositor not to consider higher views in
   * the view hierarchy that would geometrically intersect with
   * this view. This is a hack, but it fixes some problems with
   * views that need to be drawn in front of all other views.
   * @result true if the view floats, false otherwise.
  void SetFloating(bool aFloatingView);

  // Helper function to get mouse grabbing off this view (by moving it to the
  // parent, if we can)
  void DropMouseGrabbing();

  // Same as GetBounds but converts to parent appunits if they are different.
  nsRect GetBoundsInParentUnits() const;

  bool HasNonEmptyDirtyRegion() {
    return mDirtyRegion && !mDirtyRegion->IsEmpty();

  void InsertChild(nsView *aChild, nsView *aSibling);
  void RemoveChild(nsView *aChild);

  void ResetWidgetBounds(bool aRecurse, bool aForceSync);
  void AssertNoWindow();

  void NotifyEffectiveVisibilityChanged(bool aEffectivelyVisible);

  // Update the cached RootViewManager for all view manager descendents.
  void InvalidateHierarchy();

  nsViewManager    *mViewManager;
  nsView           *mParent;
  nsCOMPtr<nsIWidget> mWindow;
  nsCOMPtr<nsIWidget> mPreviousWindow;
  nsView           *mNextSibling;
  nsView           *mFirstChild;
  nsIFrame         *mFrame;
  nsRegion         *mDirtyRegion;
  int32_t           mZIndex;
  nsViewVisibility  mVis;
  // position relative our parent view origin but in our appunits
  nscoord           mPosX, mPosY;
  // relative to parent, but in our appunits
  nsRect            mDimBounds;
  // in our appunits
  nsPoint           mViewToWidgetOffset;
  uint32_t          mVFlags;
  bool              mWidgetIsTopLevel;
  bool              mForcedRepaint;
  bool              mNeedsWindowPropertiesSync;