view/nsViewManager.cpp
author Kartikaya Gupta <kgupta@mozilla.com>
Sun, 11 Jan 2015 18:26:39 -0500
changeset 223167 5c772b35c40dd6d6d3966f7f3f02c2d9032acaae
parent 219287 a6db8f54f5aa47f79302fc52f11b30694020f879
child 231577 d83e46943d92a5bcc3cc380159340079648b45d2
permissions -rw-r--r--
Bug 1120211 - Don't force the innerwindow size to the outerwindow size if the viewport is overridden. r=dbaron In Fennec, if the root window gets resized, background tabs get a delayed resize event queued up. When those background tabs get painted next, the delayed resize is flushed. However, the code that flushes the delayed resize does not check to see if the viewport is already overridden. This is in contrast to all the other code paths that propagate outerwindow size change to the innerwindow, and is incorrect because it effectively clobbers any meta-viewport tag with the outerwindow dimensions. This patch corrects this code path to also check if the viewport is overridden.

/* -*- 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/. */

#define PL_ARENA_CONST_ALIGN_MASK (sizeof(void*)-1)
#include "plarena.h"

#include "nsAutoPtr.h"
#include "nsViewManager.h"
#include "nsGfxCIID.h"
#include "nsView.h"
#include "nsCOMPtr.h"
#include "mozilla/MouseEvents.h"
#include "nsRegion.h"
#include "nsCOMArray.h"
#include "nsIPluginWidget.h"
#include "nsXULPopupManager.h"
#include "nsIPresShell.h"
#include "nsPresContext.h"
#include "mozilla/StartupTimeline.h"
#include "GeckoProfiler.h"
#include "nsRefreshDriver.h"
#include "mozilla/Preferences.h"
#include "nsContentUtils.h" // for nsAutoScriptBlocker
#include "nsLayoutUtils.h"
#include "Layers.h"
#include "gfxPlatform.h"
#include "gfxPrefs.h"
#include "nsIDocument.h"

/**
   XXX TODO XXX

   DeCOMify newly private methods
   Optimize view storage
*/

/**
   A note about platform assumptions:

   We assume that a widget is z-ordered on top of its parent.
   
   We do NOT assume anything about the relative z-ordering of sibling widgets. Even though
   we ask for a specific z-order, we don't assume that widget z-ordering actually works.
*/

using namespace mozilla;
using namespace mozilla::layers;

#define NSCOORD_NONE      INT32_MIN

#undef DEBUG_MOUSE_LOCATION

// Weakly held references to all of the view managers
nsTArray<nsViewManager*>* nsViewManager::gViewManagers = nullptr;
uint32_t nsViewManager::gLastUserEventTime = 0;

nsViewManager::nsViewManager()
  : mDelayedResize(NSCOORD_NONE, NSCOORD_NONE)
{
  mRootViewManager = this;
  if (gViewManagers == nullptr) {
    // Create an array to hold a list of view managers
    gViewManagers = new nsTArray<nsViewManager*>;
  }
 
  gViewManagers->AppendElement(this);

  // NOTE:  we use a zeroing operator new, so all data members are
  // assumed to be cleared here.
  mHasPendingWidgetGeometryChanges = false;
  mRecursiveRefreshPending = false;
}

nsViewManager::~nsViewManager()
{
  if (mRootView) {
    // Destroy any remaining views
    mRootView->Destroy();
    mRootView = nullptr;
  }

  if (!IsRootVM()) {
    // We have a strong ref to mRootViewManager
    NS_RELEASE(mRootViewManager);
  }

  NS_ASSERTION(gViewManagers != nullptr, "About to use null gViewManagers");

#ifdef DEBUG
  bool removed =
#endif
    gViewManagers->RemoveElement(this);
  NS_ASSERTION(removed, "Viewmanager instance was not in the global list of viewmanagers");

  if (gViewManagers->IsEmpty()) {
    // There aren't any more view managers so
    // release the global array of view managers
    delete gViewManagers;
    gViewManagers = nullptr;
  }

  mPresShell = nullptr;
}

// We don't hold a reference to the presentation context because it
// holds a reference to us.
nsresult
nsViewManager::Init(nsDeviceContext* aContext)
{
  NS_PRECONDITION(nullptr != aContext, "null ptr");

  if (nullptr == aContext) {
    return NS_ERROR_NULL_POINTER;
  }
  if (nullptr != mContext) {
    return NS_ERROR_ALREADY_INITIALIZED;
  }
  mContext = aContext;

  return NS_OK;
}

nsView*
nsViewManager::CreateView(const nsRect& aBounds,
                          nsView* aParent,
                          nsViewVisibility aVisibilityFlag)
{
  nsView *v = new nsView(this, aVisibilityFlag);
  v->SetParent(aParent);
  v->SetPosition(aBounds.x, aBounds.y);
  nsRect dim(0, 0, aBounds.width, aBounds.height);
  v->SetDimensions(dim, false);
  return v;
}

void
nsViewManager::SetRootView(nsView *aView)
{
  NS_PRECONDITION(!aView || aView->GetViewManager() == this,
                  "Unexpected viewmanager on root view");
  
  // Do NOT destroy the current root view. It's the caller's responsibility
  // to destroy it
  mRootView = aView;

  if (mRootView) {
    nsView* parent = mRootView->GetParent();
    if (parent) {
      // Calling InsertChild on |parent| will InvalidateHierarchy() on us, so
      // no need to set mRootViewManager ourselves here.
      parent->InsertChild(mRootView, nullptr);
    } else {
      InvalidateHierarchy();
    }

    mRootView->SetZIndex(false, 0);
  }
  // Else don't touch mRootViewManager
}

void
nsViewManager::GetWindowDimensions(nscoord *aWidth, nscoord *aHeight)
{
  if (nullptr != mRootView) {
    if (mDelayedResize == nsSize(NSCOORD_NONE, NSCOORD_NONE)) {
      nsRect dim = mRootView->GetDimensions();
      *aWidth = dim.width;
      *aHeight = dim.height;
    } else {
      *aWidth = mDelayedResize.width;
      *aHeight = mDelayedResize.height;
    }
  }
  else
    {
      *aWidth = 0;
      *aHeight = 0;
    }
}

void nsViewManager::DoSetWindowDimensions(nscoord aWidth, nscoord aHeight)
{
  nsRect oldDim = mRootView->GetDimensions();
  nsRect newDim(0, 0, aWidth, aHeight);
  // We care about resizes even when one dimension is already zero.
  if (!oldDim.IsEqualEdges(newDim)) {
    // Don't resize the widget. It is already being set elsewhere.
    mRootView->SetDimensions(newDim, true, false);
    if (mPresShell)
      mPresShell->ResizeReflow(aWidth, aHeight);
  }
}

void
nsViewManager::SetWindowDimensions(nscoord aWidth, nscoord aHeight)
{
  if (mRootView) {
    if (mRootView->IsEffectivelyVisible() && mPresShell && mPresShell->IsVisible()) {
      if (mDelayedResize != nsSize(NSCOORD_NONE, NSCOORD_NONE) &&
          mDelayedResize != nsSize(aWidth, aHeight)) {
        // We have a delayed resize; that now obsolete size may already have
        // been flushed to the PresContext so we need to update the PresContext
        // with the new size because if the new size is exactly the same as the
        // root view's current size then DoSetWindowDimensions will not
        // request a resize reflow (which would correct it). See bug 617076.
        mDelayedResize = nsSize(aWidth, aHeight);
        FlushDelayedResize(false);
      }
      mDelayedResize.SizeTo(NSCOORD_NONE, NSCOORD_NONE);
      DoSetWindowDimensions(aWidth, aHeight);
    } else {
      mDelayedResize.SizeTo(aWidth, aHeight);
      if (mPresShell && mPresShell->GetDocument()) {
        mPresShell->GetDocument()->SetNeedStyleFlush();
      }
    }
  }
}

void
nsViewManager::FlushDelayedResize(bool aDoReflow)
{
  if (mDelayedResize != nsSize(NSCOORD_NONE, NSCOORD_NONE)) {
    if (aDoReflow) {
      DoSetWindowDimensions(mDelayedResize.width, mDelayedResize.height);
      mDelayedResize.SizeTo(NSCOORD_NONE, NSCOORD_NONE);
    } else if (mPresShell && !mPresShell->GetIsViewportOverridden()) {
      nsPresContext* presContext = mPresShell->GetPresContext();
      if (presContext) {
        presContext->SetVisibleArea(nsRect(nsPoint(0, 0), mDelayedResize));
      }
    }
  }
}

// Convert aIn from being relative to and in appunits of aFromView, to being
// relative to and in appunits of aToView.
static nsRegion ConvertRegionBetweenViews(const nsRegion& aIn,
                                          nsView* aFromView,
                                          nsView* aToView)
{
  nsRegion out = aIn;
  out.MoveBy(aFromView->GetOffsetTo(aToView));
  out = out.ConvertAppUnitsRoundOut(
    aFromView->GetViewManager()->AppUnitsPerDevPixel(),
    aToView->GetViewManager()->AppUnitsPerDevPixel());
  return out;
}

nsView* nsViewManager::GetDisplayRootFor(nsView* aView)
{
  nsView *displayRoot = aView;
  for (;;) {
    nsView *displayParent = displayRoot->GetParent();
    if (!displayParent)
      return displayRoot;

    if (displayRoot->GetFloating() && !displayParent->GetFloating())
      return displayRoot;

    // If we have a combobox dropdown popup within a panel popup, both the view
    // for the dropdown popup and its parent will be floating, so we need to
    // distinguish this situation. We do this by looking for a widget. Any view
    // with a widget is a display root, except for plugins.
    nsIWidget* widget = displayRoot->GetWidget();
    if (widget && widget->WindowType() == eWindowType_popup) {
      NS_ASSERTION(displayRoot->GetFloating() && displayParent->GetFloating(),
        "this should only happen with floating views that have floating parents");
      return displayRoot;
    }

    displayRoot = displayParent;
  }
}

/**
   aRegion is given in device coordinates!!
   aContext may be null, in which case layers should be used for
   rendering.
*/
void nsViewManager::Refresh(nsView *aView, const nsIntRegion& aRegion)
{
  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");

  if (mPresShell && mPresShell->IsNeverPainting()) {
    return;
  }

  // damageRegion is the damaged area, in twips, relative to the view origin
  nsRegion damageRegion = aRegion.ToAppUnits(AppUnitsPerDevPixel());
  // move region from widget coordinates into view coordinates
  damageRegion.MoveBy(-aView->ViewToWidgetOffset());

  if (damageRegion.IsEmpty()) {
#ifdef DEBUG_roc
    nsRect viewRect = aView->GetDimensions();
    nsRect damageRect = damageRegion.GetBounds();
    printf_stderr("XXX Damage rectangle (%d,%d,%d,%d) does not intersect the widget's view (%d,%d,%d,%d)!\n",
           damageRect.x, damageRect.y, damageRect.width, damageRect.height,
           viewRect.x, viewRect.y, viewRect.width, viewRect.height);
#endif
    return;
  }
  
  nsIWidget *widget = aView->GetWidget();
  if (!widget) {
    return;
  }

  NS_ASSERTION(!IsPainting(), "recursive painting not permitted");
  if (IsPainting()) {
    RootViewManager()->mRecursiveRefreshPending = true;
    return;
  }  

  {
    nsAutoScriptBlocker scriptBlocker;
    SetPainting(true);

    NS_ASSERTION(GetDisplayRootFor(aView) == aView,
                 "Widgets that we paint must all be display roots");

    if (mPresShell) {
#ifdef MOZ_DUMP_PAINTING
      if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
        printf_stderr("--COMPOSITE-- %p\n", mPresShell);
      }
#endif
      uint32_t paintFlags = nsIPresShell::PAINT_COMPOSITE;
      LayerManager *manager = widget->GetLayerManager();
      if (!manager->NeedsWidgetInvalidation()) {
        manager->FlushRendering();
      } else {
        mPresShell->Paint(aView, damageRegion,
                          paintFlags);
      }
#ifdef MOZ_DUMP_PAINTING
      if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
        printf_stderr("--ENDCOMPOSITE--\n");
      }
#endif
      mozilla::StartupTimeline::RecordOnce(mozilla::StartupTimeline::FIRST_PAINT);
    }

    SetPainting(false);
  }

  if (RootViewManager()->mRecursiveRefreshPending) {
    RootViewManager()->mRecursiveRefreshPending = false;
    InvalidateAllViews();
  }
}

void
nsViewManager::ProcessPendingUpdatesForView(nsView* aView,
                                            bool aFlushDirtyRegion)
{
  NS_ASSERTION(IsRootVM(), "Updates will be missed");
  if (!aView) {
    return;
  }

  nsCOMPtr<nsIPresShell> rootShell(mPresShell);
  nsTArray<nsCOMPtr<nsIWidget> > widgets;
  aView->GetViewManager()->ProcessPendingUpdatesRecurse(aView, widgets);
  for (uint32_t i = 0; i < widgets.Length(); ++i) {
    nsView* view = nsView::GetViewFor(widgets[i]);
    if (view) {
      view->ResetWidgetBounds(false, true);
    }
  }
  if (rootShell->GetViewManager() != this) {
    return; // 'this' might have been destroyed
  }
  if (aFlushDirtyRegion) {
    nsAutoScriptBlocker scriptBlocker;
    SetPainting(true);
    for (uint32_t i = 0; i < widgets.Length(); ++i) {
      nsIWidget* widget = widgets[i];
      nsView* view = nsView::GetViewFor(widget);
      if (view) {
        view->GetViewManager()->ProcessPendingUpdatesPaint(widget);
      }
    }
    SetPainting(false);
  }
}

void
nsViewManager::ProcessPendingUpdatesRecurse(nsView* aView,
                                            nsTArray<nsCOMPtr<nsIWidget> >& aWidgets)
{
  if (mPresShell && mPresShell->IsNeverPainting()) {
    return;
  }

  for (nsView* childView = aView->GetFirstChild(); childView;
       childView = childView->GetNextSibling()) {
    childView->GetViewManager()->
      ProcessPendingUpdatesRecurse(childView, aWidgets);
  }

  nsIWidget* widget = aView->GetWidget();
  if (widget) {
    aWidgets.AppendElement(widget);
  } else {
    FlushDirtyRegionToWidget(aView);
  }
}

void
nsViewManager::ProcessPendingUpdatesPaint(nsIWidget* aWidget)
{
  if (aWidget->NeedsPaint()) {
    // If an ancestor widget was hidden and then shown, we could
    // have a delayed resize to handle.
    for (nsViewManager *vm = this; vm;
         vm = vm->mRootView->GetParent()
           ? vm->mRootView->GetParent()->GetViewManager()
           : nullptr) {
      if (vm->mDelayedResize != nsSize(NSCOORD_NONE, NSCOORD_NONE) &&
          vm->mRootView->IsEffectivelyVisible() &&
          vm->mPresShell && vm->mPresShell->IsVisible()) {
        vm->FlushDelayedResize(true);
      }
    }
    nsView* view = nsView::GetViewFor(aWidget);
    if (!view) {
      NS_ERROR("FlushDelayedResize destroyed the nsView?");
      return;
    }

    if (mPresShell) {
#ifdef MOZ_DUMP_PAINTING
      if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
        printf_stderr("---- PAINT START ----PresShell(%p), nsView(%p), nsIWidget(%p)\n",
                      mPresShell, view, aWidget);
      }
#endif

      mPresShell->Paint(view, nsRegion(), nsIPresShell::PAINT_LAYERS);
      view->SetForcedRepaint(false);

#ifdef MOZ_DUMP_PAINTING
      if (nsLayoutUtils::InvalidationDebuggingIsEnabled()) {
        printf_stderr("---- PAINT END ----\n");
      }
#endif
    }
  }
  FlushDirtyRegionToWidget(nsView::GetViewFor(aWidget));
}

void nsViewManager::FlushDirtyRegionToWidget(nsView* aView)
{
  NS_ASSERTION(aView->GetViewManager() == this,
               "FlushDirtyRegionToWidget called on view we don't own");

  if (!aView->HasNonEmptyDirtyRegion())
    return;

  nsRegion* dirtyRegion = aView->GetDirtyRegion();
  nsView* nearestViewWithWidget = aView;
  while (!nearestViewWithWidget->HasWidget() &&
         nearestViewWithWidget->GetParent()) {
    nearestViewWithWidget = nearestViewWithWidget->GetParent();
  }
  nsRegion r =
    ConvertRegionBetweenViews(*dirtyRegion, aView, nearestViewWithWidget);

  // If we draw the frame counter we need to make sure we invalidate the area
  // for it to make it on screen
  if (gfxPrefs::DrawFrameCounter()) {
    nsRect counterBounds = gfxPlatform::FrameCounterBounds().ToAppUnits(AppUnitsPerDevPixel());
    r = r.Or(r, counterBounds);
  }

  nsViewManager* widgetVM = nearestViewWithWidget->GetViewManager();
  widgetVM->InvalidateWidgetArea(nearestViewWithWidget, r);
  dirtyRegion->SetEmpty();
}

void
nsViewManager::InvalidateView(nsView *aView)
{
  // Mark the entire view as damaged
  InvalidateView(aView, aView->GetDimensions());
}

static void
AddDirtyRegion(nsView *aView, const nsRegion &aDamagedRegion)
{
  nsRegion* dirtyRegion = aView->GetDirtyRegion();
  if (!dirtyRegion)
    return;

  dirtyRegion->Or(*dirtyRegion, aDamagedRegion);
  dirtyRegion->SimplifyOutward(8);
}

void
nsViewManager::PostPendingUpdate()
{
  nsViewManager* rootVM = RootViewManager();
  rootVM->mHasPendingWidgetGeometryChanges = true;
  if (rootVM->mPresShell) {
    rootVM->mPresShell->ScheduleViewManagerFlush();
  }
}

/**
 * @param aDamagedRegion this region, relative to aWidgetView, is invalidated in
 * every widget child of aWidgetView, plus aWidgetView's own widget
 */
void
nsViewManager::InvalidateWidgetArea(nsView *aWidgetView,
                                    const nsRegion &aDamagedRegion)
{
  NS_ASSERTION(aWidgetView->GetViewManager() == this,
               "InvalidateWidgetArea called on view we don't own");
  nsIWidget* widget = aWidgetView->GetWidget();

#if 0
  nsRect dbgBounds = aDamagedRegion.GetBounds();
  printf("InvalidateWidgetArea view:%X (%d) widget:%X region: %d, %d, %d, %d\n",
    aWidgetView, aWidgetView->IsAttachedToTopLevel(),
    widget, dbgBounds.x, dbgBounds.y, dbgBounds.width, dbgBounds.height);
#endif

  // If the widget is hidden, it don't cover nothing
  if (widget && !widget->IsVisible()) {
    return;
  }

  if (!widget) {
    // The root view or a scrolling view might not have a widget
    // (for example, during printing). We get here when we scroll
    // during printing to show selected options in a listbox, for example.
    return;
  }

  // Update all child widgets with the damage. In the process,
  // accumulate the union of all the child widget areas, or at least
  // some subset of that.
  nsRegion children;
  if (widget->GetTransparencyMode() != eTransparencyTransparent) {
    for (nsIWidget* childWidget = widget->GetFirstChild();
         childWidget;
         childWidget = childWidget->GetNextSibling()) {
      nsView* view = nsView::GetViewFor(childWidget);
      NS_ASSERTION(view != aWidgetView, "will recur infinitely");
      nsWindowType type = childWidget->WindowType();
      if (view && childWidget->IsVisible() && type != eWindowType_popup) {
        NS_ASSERTION(childWidget->IsPlugin(),
                     "Only plugin or popup widgets can be children!");

        // We do not need to invalidate in plugin widgets, but we should
        // exclude them from the invalidation region IF we're not on
        // Mac. On Mac we need to draw under plugin widgets, because
        // plugin widgets are basically invisible
#ifndef XP_MACOSX
        // GetBounds should compensate for chrome on a toplevel widget
        nsIntRect bounds;
        childWidget->GetBounds(bounds);

        nsTArray<nsIntRect> clipRects;
        childWidget->GetWindowClipRegion(&clipRects);
        for (uint32_t i = 0; i < clipRects.Length(); ++i) {
          nsRect rr = (clipRects[i] + bounds.TopLeft()).
            ToAppUnits(AppUnitsPerDevPixel());
          children.Or(children, rr - aWidgetView->ViewToWidgetOffset()); 
          children.SimplifyInward(20);
        }
#endif
      }
    }
  }

  nsRegion leftOver;
  leftOver.Sub(aDamagedRegion, children);

  if (!leftOver.IsEmpty()) {
    const nsRect* r;
    for (nsRegionRectIterator iter(leftOver); (r = iter.Next());) {
      nsIntRect bounds = ViewToWidget(aWidgetView, *r);
      widget->Invalidate(bounds);
    }
  }
}

static bool
ShouldIgnoreInvalidation(nsViewManager* aVM)
{
  while (aVM) {
    nsIPresShell* shell = aVM->GetPresShell();
    if (!shell || shell->ShouldIgnoreInvalidation()) {
      return true;
    }
    nsView* view = aVM->GetRootView()->GetParent();
    aVM = view ? view->GetViewManager() : nullptr;
  }
  return false;
}

void
nsViewManager::InvalidateView(nsView *aView, const nsRect &aRect)
{
  // If painting is suppressed in the presshell or an ancestor drop all
  // invalidates, it will invalidate everything when it unsuppresses.
  if (ShouldIgnoreInvalidation(this)) {
    return;
  }

  InvalidateViewNoSuppression(aView, aRect);
}

void
nsViewManager::InvalidateViewNoSuppression(nsView *aView,
                                           const nsRect &aRect)
{
  NS_PRECONDITION(nullptr != aView, "null view");

  NS_ASSERTION(aView->GetViewManager() == this,
               "InvalidateViewNoSuppression called on view we don't own");

  nsRect damagedRect(aRect);
  if (damagedRect.IsEmpty()) {
    return;
  }

  nsView* displayRoot = GetDisplayRootFor(aView);
  nsViewManager* displayRootVM = displayRoot->GetViewManager();
  // Propagate the update to the displayRoot, since iframes, for example,
  // can overlap each other and be translucent.  So we have to possibly
  // invalidate our rect in each of the widgets we have lying about.
  damagedRect.MoveBy(aView->GetOffsetTo(displayRoot));
  int32_t rootAPD = displayRootVM->AppUnitsPerDevPixel();
  int32_t APD = AppUnitsPerDevPixel();
  damagedRect = damagedRect.ConvertAppUnitsRoundOut(APD, rootAPD);

  // accumulate this rectangle in the view's dirty region, so we can
  // process it later.
  AddDirtyRegion(displayRoot, nsRegion(damagedRect));
}

void
nsViewManager::InvalidateAllViews()
{
  if (RootViewManager() != this) {
    return RootViewManager()->InvalidateAllViews();
  }
  
  InvalidateViews(mRootView);
}

void nsViewManager::InvalidateViews(nsView *aView)
{
  // Invalidate this view.
  InvalidateView(aView);

  // Invalidate all children as well.
  nsView* childView = aView->GetFirstChild();
  while (nullptr != childView)  {
    childView->GetViewManager()->InvalidateViews(childView);
    childView = childView->GetNextSibling();
  }
}

void nsViewManager::WillPaintWindow(nsIWidget* aWidget)
{
  if (aWidget) {
    nsView* view = nsView::GetViewFor(aWidget);
    LayerManager *manager = aWidget->GetLayerManager();
    if (view &&
        (view->ForcedRepaint() || !manager->NeedsWidgetInvalidation())) {
      ProcessPendingUpdates();
      // Re-get the view pointer here since the ProcessPendingUpdates might have
      // destroyed it during CallWillPaintOnObservers.
      view = nsView::GetViewFor(aWidget);
      if (view) {
        view->SetForcedRepaint(false);
      }
    }
  }

  nsCOMPtr<nsIPresShell> shell = mPresShell;
  if (shell) {
    shell->WillPaintWindow();
  }
}

bool nsViewManager::PaintWindow(nsIWidget* aWidget, nsIntRegion aRegion)
{
  if (!aWidget || !mContext)
    return false;

  NS_ASSERTION(IsPaintingAllowed(),
               "shouldn't be receiving paint events while painting is disallowed!");

  // Get the view pointer here since NS_WILL_PAINT might have
  // destroyed it during CallWillPaintOnObservers (bug 378273).
  nsView* view = nsView::GetViewFor(aWidget);
  if (view && !aRegion.IsEmpty()) {
    Refresh(view, aRegion);
  }

  return true;
}

void nsViewManager::DidPaintWindow()
{
  nsCOMPtr<nsIPresShell> shell = mPresShell;
  if (shell) {
    shell->DidPaintWindow();
  }
}

void
nsViewManager::DispatchEvent(WidgetGUIEvent *aEvent,
                             nsView* aView,
                             nsEventStatus* aStatus)
{
  PROFILER_LABEL("nsViewManager", "DispatchEvent",
    js::ProfileEntry::Category::EVENTS);

  WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent();
  if ((mouseEvent &&
       // Ignore mouse events that we synthesize.
       mouseEvent->reason == WidgetMouseEvent::eReal &&
       // Ignore mouse exit and enter (we'll get moves if the user
       // is really moving the mouse) since we get them when we
       // create and destroy widgets.
       mouseEvent->message != NS_MOUSE_EXIT &&
       mouseEvent->message != NS_MOUSE_ENTER) ||
      aEvent->HasKeyEventMessage() ||
      aEvent->HasIMEEventMessage() ||
      aEvent->message == NS_PLUGIN_INPUT_EVENT) {
    gLastUserEventTime = PR_IntervalToMicroseconds(PR_IntervalNow());
  }

  // Find the view whose coordinates system we're in.
  nsView* view = aView;
  bool dispatchUsingCoordinates = aEvent->IsUsingCoordinates();
  if (dispatchUsingCoordinates) {
    // Will dispatch using coordinates. Pretty bogus but it's consistent
    // with what presshell does.
    view = GetDisplayRootFor(view);
  }

  // If the view has no frame, look for a view that does.
  nsIFrame* frame = view->GetFrame();
  if (!frame &&
      (dispatchUsingCoordinates || aEvent->HasKeyEventMessage() ||
       aEvent->IsIMERelatedEvent() ||
       aEvent->IsNonRetargetedNativeEventDelivererForPlugin() ||
       aEvent->HasPluginActivationEventMessage())) {
    while (view && !view->GetFrame()) {
      view = view->GetParent();
    }

    if (view) {
      frame = view->GetFrame();
    }
  }

  if (nullptr != frame) {
    // Hold a refcount to the presshell. The continued existence of the
    // presshell will delay deletion of this view hierarchy should the event
    // want to cause its destruction in, say, some JavaScript event handler.
    nsCOMPtr<nsIPresShell> shell = view->GetViewManager()->GetPresShell();
    if (shell) {
      shell->HandleEvent(frame, aEvent, false, aStatus);
	  return;
    }
  }

  *aStatus = nsEventStatus_eIgnore;
}

// Recursively reparent widgets if necessary 

void nsViewManager::ReparentChildWidgets(nsView* aView, nsIWidget *aNewWidget)
{
  NS_PRECONDITION(aNewWidget, "");

  if (aView->HasWidget()) {
    // Check to see if the parent widget is the
    // same as the new parent. If not then reparent
    // the widget, otherwise there is nothing more
    // to do for the view and its descendants
    nsIWidget* widget = aView->GetWidget();
    nsIWidget* parentWidget = widget->GetParent();
    if (parentWidget) {
      // Child widget
      if (parentWidget != aNewWidget) {
#ifdef DEBUG
        nsresult rv =
#endif
          widget->SetParent(aNewWidget);
        NS_ASSERTION(NS_SUCCEEDED(rv), "SetParent failed!");
      }
    } else {
      // Toplevel widget (popup, dialog, etc)
      widget->ReparentNativeWidget(aNewWidget);
    }
    return;
  }

  // Need to check each of the views children to see
  // if they have a widget and reparent it.

  for (nsView *kid = aView->GetFirstChild(); kid; kid = kid->GetNextSibling()) {
    ReparentChildWidgets(kid, aNewWidget);
  }
}

// Reparent a view and its descendant views widgets if necessary

void nsViewManager::ReparentWidgets(nsView* aView, nsView *aParent)
{
  NS_PRECONDITION(aParent, "Must have a parent");
  NS_PRECONDITION(aView, "Must have a view");
  
  // Quickly determine whether the view has pre-existing children or a
  // widget. In most cases the view will not have any pre-existing 
  // children when this is called.  Only in the case
  // where a view has been reparented by removing it from
  // a reinserting it into a new location in the view hierarchy do we
  // have to consider reparenting the existing widgets for the view and
  // it's descendants.
  if (aView->HasWidget() || aView->GetFirstChild()) {
    nsIWidget* parentWidget = aParent->GetNearestWidget(nullptr);
    if (parentWidget) {
      ReparentChildWidgets(aView, parentWidget);
      return;
    }
    NS_WARNING("Can not find a widget for the parent view");
  }
}

void
nsViewManager::InsertChild(nsView *aParent, nsView *aChild, nsView *aSibling,
                           bool aAfter)
{
  NS_PRECONDITION(nullptr != aParent, "null ptr");
  NS_PRECONDITION(nullptr != aChild, "null ptr");
  NS_ASSERTION(aSibling == nullptr || aSibling->GetParent() == aParent,
               "tried to insert view with invalid sibling");
  NS_ASSERTION(!IsViewInserted(aChild), "tried to insert an already-inserted view");

  if ((nullptr != aParent) && (nullptr != aChild))
    {
      // if aAfter is set, we will insert the child after 'prev' (i.e. after 'kid' in document
      // order, otherwise after 'kid' (i.e. before 'kid' in document order).

      if (nullptr == aSibling) {
        if (aAfter) {
          // insert at end of document order, i.e., before first view
          // this is the common case, by far
          aParent->InsertChild(aChild, nullptr);
          ReparentWidgets(aChild, aParent);
        } else {
          // insert at beginning of document order, i.e., after last view
          nsView *kid = aParent->GetFirstChild();
          nsView *prev = nullptr;
          while (kid) {
            prev = kid;
            kid = kid->GetNextSibling();
          }
          // prev is last view or null if there are no children
          aParent->InsertChild(aChild, prev);
          ReparentWidgets(aChild, aParent);
        }
      } else {
        nsView *kid = aParent->GetFirstChild();
        nsView *prev = nullptr;
        while (kid && aSibling != kid) {
          //get the next sibling view
          prev = kid;
          kid = kid->GetNextSibling();
        }
        NS_ASSERTION(kid != nullptr,
                     "couldn't find sibling in child list");
        if (aAfter) {
          // insert after 'kid' in document order, i.e. before in view order
          aParent->InsertChild(aChild, prev);
          ReparentWidgets(aChild, aParent);
        } else {
          // insert before 'kid' in document order, i.e. after in view order
          aParent->InsertChild(aChild, kid);
          ReparentWidgets(aChild, aParent);
        }
      }

      // if the parent view is marked as "floating", make the newly added view float as well.
      if (aParent->GetFloating())
        aChild->SetFloating(true);
    }
}

void
nsViewManager::InsertChild(nsView *aParent, nsView *aChild, int32_t aZIndex)
{
  // no-one really calls this with anything other than aZIndex == 0 on a fresh view
  // XXX this method should simply be eliminated and its callers redirected to the real method
  SetViewZIndex(aChild, false, aZIndex);
  InsertChild(aParent, aChild, nullptr, true);
}

void
nsViewManager::RemoveChild(nsView *aChild)
{
  NS_ASSERTION(aChild, "aChild must not be null");

  nsView* parent = aChild->GetParent();

  if (nullptr != parent) {
    NS_ASSERTION(aChild->GetViewManager() == this ||
                 parent->GetViewManager() == this, "wrong view manager");
    parent->RemoveChild(aChild);
  }
}

void
nsViewManager::MoveViewTo(nsView *aView, nscoord aX, nscoord aY)
{
  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");
  aView->SetPosition(aX, aY);
}

void
nsViewManager::ResizeView(nsView *aView, const nsRect &aRect, bool aRepaintExposedAreaOnly)
{
  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");

  nsRect oldDimensions = aView->GetDimensions();
  if (!oldDimensions.IsEqualEdges(aRect)) {
    aView->SetDimensions(aRect, true);
  }

  // Note that if layout resizes the view and the view has a custom clip
  // region set, then we expect layout to update the clip region too. Thus
  // in the case where mClipRect has been optimized away to just be a null
  // pointer, and this resize is implicitly changing the clip rect, it's OK
  // because layout will change it back again if necessary.
}

void
nsViewManager::SetViewFloating(nsView *aView, bool aFloating)
{
  NS_ASSERTION(!(nullptr == aView), "no view");

  aView->SetFloating(aFloating);
}

void
nsViewManager::SetViewVisibility(nsView *aView, nsViewVisibility aVisible)
{
  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");

  if (aVisible != aView->GetVisibility()) {
    aView->SetVisibility(aVisible);
  }
}

bool nsViewManager::IsViewInserted(nsView *aView)
{
  if (mRootView == aView) {
    return true;
  } else if (aView->GetParent() == nullptr) {
    return false;
  } else {
    nsView* view = aView->GetParent()->GetFirstChild();
    while (view != nullptr) {
      if (view == aView) {
        return true;
      }
      view = view->GetNextSibling();
    }
    return false;
  }
}

void
nsViewManager::SetViewZIndex(nsView *aView, bool aAutoZIndex, int32_t aZIndex)
{
  NS_ASSERTION((aView != nullptr), "no view");

  // don't allow the root view's z-index to be changed. It should always be zero.
  // This could be removed and replaced with a style rule, or just removed altogether, with interesting consequences
  if (aView == mRootView) {
    return;
  }

  if (aAutoZIndex) {
    aZIndex = 0;
  }

  aView->SetZIndex(aAutoZIndex, aZIndex);
}

nsViewManager*
nsViewManager::IncrementDisableRefreshCount()
{
  if (!IsRootVM()) {
    return RootViewManager()->IncrementDisableRefreshCount();
  }

  ++mRefreshDisableCount;

  return this;
}

void
nsViewManager::DecrementDisableRefreshCount()
{
  NS_ASSERTION(IsRootVM(), "Should only be called on root");
  --mRefreshDisableCount;
  NS_ASSERTION(mRefreshDisableCount >= 0, "Invalid refresh disable count!");
}

void
nsViewManager::GetRootWidget(nsIWidget **aWidget)
{
  if (!mRootView) {
    *aWidget = nullptr;
    return;
  }
  if (mRootView->HasWidget()) {
    *aWidget = mRootView->GetWidget();
    NS_ADDREF(*aWidget);
    return;
  }
  if (mRootView->GetParent()) {
    mRootView->GetParent()->GetViewManager()->GetRootWidget(aWidget);
    return;
  }
  *aWidget = nullptr;
}

nsIntRect nsViewManager::ViewToWidget(nsView *aView, const nsRect &aRect) const
{
  NS_ASSERTION(aView->GetViewManager() == this, "wrong view manager");

  // account for the view's origin not lining up with the widget's
  nsRect rect = aRect + aView->ViewToWidgetOffset();

  // finally, convert to device coordinates.
  return rect.ToOutsidePixels(AppUnitsPerDevPixel());
}

void
nsViewManager::IsPainting(bool& aIsPainting)
{
  aIsPainting = IsPainting();
}

void
nsViewManager::ProcessPendingUpdates()
{
  if (!IsRootVM()) {
    RootViewManager()->ProcessPendingUpdates();
    return;
  }

  // Flush things like reflows by calling WillPaint on observer presShells.
  if (mPresShell) {
    mPresShell->GetPresContext()->RefreshDriver()->RevokeViewManagerFlush();

    CallWillPaintOnObservers();

    ProcessPendingUpdatesForView(mRootView, true);
  }
}

void
nsViewManager::UpdateWidgetGeometry()
{
  if (!IsRootVM()) {
    RootViewManager()->UpdateWidgetGeometry();
    return;
  }

  if (mHasPendingWidgetGeometryChanges) {
    mHasPendingWidgetGeometryChanges = false;
    ProcessPendingUpdatesForView(mRootView, false);
  }
}

void
nsViewManager::CallWillPaintOnObservers()
{
  NS_PRECONDITION(IsRootVM(), "Must be root VM for this to be called!");

  if (NS_WARN_IF(!gViewManagers)) {
    return;
  }

  uint32_t index;
  for (index = 0; index < gViewManagers->Length(); index++) {
    nsViewManager* vm = gViewManagers->ElementAt(index);
    if (vm->RootViewManager() == this) {
      // One of our kids.
      if (vm->mRootView && vm->mRootView->IsEffectivelyVisible()) {
        nsCOMPtr<nsIPresShell> shell = vm->GetPresShell();
        if (shell) {
          shell->WillPaint();
        }
      }
    }
  }
}

void
nsViewManager::GetLastUserEventTime(uint32_t& aTime)
{
  aTime = gLastUserEventTime;
}

void
nsViewManager::InvalidateHierarchy()
{
  if (mRootView) {
    if (!IsRootVM()) {
      NS_RELEASE(mRootViewManager);
    }
    nsView *parent = mRootView->GetParent();
    if (parent) {
      mRootViewManager = parent->GetViewManager()->RootViewManager();
      NS_ADDREF(mRootViewManager);
      NS_ASSERTION(mRootViewManager != this,
                   "Root view had a parent, but it has the same view manager");
    } else {
      mRootViewManager = this;
    }
  }
}