BrowserPlugin/WebView - Move plugin lifetime to DOM

Source/core/rendering/RenderWidget.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2006, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #include "config.h"
 #include "core/rendering/RenderWidget.h"
 
 #include "core/accessibility/AXObjectCache.h"
 #include "core/frame/Frame.h"
+#include "core/html/HTMLFrameOwnerElement.h"
+#include "core/html/HTMLPlugInElement.h"
 #include "core/rendering/CompositedLayerMapping.h"
 #include "core/rendering/GraphicsContextAnnotator.h"
 #include "core/rendering/HitTestResult.h"
 #include "core/rendering/LayoutRectRecorder.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderView.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "wtf/HashMap.h"
 
 namespace WebCore {
 
-typedef HashMap<RefPtr<Widget>, FrameView*> WidgetToParentMap;
-static WidgetToParentMap& widgetNewParentMap()
-{
-    DEFINE_STATIC_LOCAL(WidgetToParentMap, map, ());
-    return map;
-}
-
-static unsigned s_updateSuspendCount = 0;
-
-RenderWidget::UpdateSuspendScope::UpdateSuspendScope()
-{
-    ++s_updateSuspendCount;
-}
-
-RenderWidget::UpdateSuspendScope::~UpdateSuspendScope()
-{
-    ASSERT(s_updateSuspendCount > 0);
-    if (s_updateSuspendCount == 1) {
-        WidgetToParentMap map;
-        widgetNewParentMap().swap(map);
-        WidgetToParentMap::iterator end = map.end();
-        for (WidgetToParentMap::iterator it = map.begin(); it != end; ++it) {
-            Widget* child = it->key.get();
-            ScrollView* currentParent = toScrollView(child->parent());
-            FrameView* newParent = it->value;
-            if (newParent != currentParent) {
-                if (currentParent)
-                    currentParent->removeChild(child);
-                if (newParent)
-                    newParent->addChild(child);
-            }
-        }
-    }
-    --s_updateSuspendCount;
-}
-
-static void moveWidgetToParentSoon(Widget* child, FrameView* parent)
-{
-    if (!s_updateSuspendCount) {
-        if (parent)
-            parent->addChild(child);
-        else
-            toScrollView(child->parent())->removeChild(child);
-        return;
-    }
-    widgetNewParentMap().set(child, parent);
-}
-
 RenderWidget::RenderWidget(Element* element)
     : RenderReplaced(element)
-    , m_widget(0)
     , m_frameView(element->document().view())
     // Reference counting is used to prevent the widget from being
     // destroyed while inside the Widget code, which might not be
     // able to handle that.
     , m_refCount(1)
 {
     view()->addWidget(this);
 }
 
 void RenderWidget::willBeDestroyed()
 {
     if (RenderView* v = view())
         v->removeWidget(this);
 
     if (AXObjectCache* cache = document().existingAXObjectCache()) {
         cache->childrenChanged(this->parent());
         cache->remove(this);
     }
 
-    setWidget(0);
+    Element* element = toElement(node());
+    if (element && element->isFrameOwnerElement())
+        toHTMLFrameOwnerElement(element)->setWidget(0);
 
     RenderReplaced::willBeDestroyed();
 }
 
 void RenderWidget::destroy()
 {
     willBeDestroyed();
     clearNode();
     deref();
 }
 
 RenderWidget::~RenderWidget()
 {
     ASSERT(m_refCount <= 0);
-    clearWidget();
+}
+
+Widget* RenderWidget::widget() const
+{
+    // Plugin widgets are stored in their DOM node. This includes HTMLAppletElement.
+    Element* element = toElement(node());
+
+    if (element && element->isFrameOwnerElement())
+        return toHTMLFrameOwnerElement(element)->widget();
+
+    return 0;
 }
 
 // Widgets are always placed on integer boundaries, so rounding the size is actually
 // the desired behavior. This function is here because it's otherwise seldom what we
 // want to do with a LayoutRect.
 static inline IntRect roundedIntRect(const LayoutRect& rect)
 {
     return IntRect(roundedIntPoint(rect.location()), roundedIntSize(rect.size()));
 }
 
 bool RenderWidget::setWidgetGeometry(const LayoutRect& frame)
 {
     if (!node())
         return false;
 
+    Widget* widget = this->widget();
+    ASSERT(widget);
+
     IntRect clipRect = roundedIntRect(enclosingLayer()->childrenClipRect());
     IntRect newFrame = roundedIntRect(frame);
     bool clipChanged = m_clipRect != clipRect;
-    bool frameRectChanged = m_widget->frameRect() != newFrame;
+    bool frameRectChanged = widget->frameRect() != newFrame;
 
     if (!frameRectChanged && !clipChanged)
         return false;
 
     m_clipRect = clipRect;
 
     RefPtr<RenderWidget> protector(this);
     RefPtr<Node> protectedNode(node());
-    m_widget->setFrameRect(newFrame);
+    widget->setFrameRect(newFrame);
 
     if (clipChanged && !frameRectChanged)
-        m_widget->clipRectChanged();
+        widget->clipRectChanged();
 
     if (hasLayer() && layer()->compositingState() == PaintsIntoOwnBacking)
         layer()->compositedLayerMapping()->updateAfterWidgetResize();
 
-    bool boundsChanged = m_widget->frameRect().size() != newFrame.size();
+    bool boundsChanged = widget->frameRect().size() != newFrame.size();
     return boundsChanged;
 }
 
 bool RenderWidget::updateWidgetGeometry()
 {
+    Widget* widget = this->widget();
+
     LayoutRect contentBox = contentBoxRect();
     LayoutRect absoluteContentBox(localToAbsoluteQuad(FloatQuad(contentBox)).boundingBox());
-    if (m_widget->isFrameView()) {
+    if (widget->isFrameView()) {
         contentBox.setLocation(absoluteContentBox.location());
         return setWidgetGeometry(contentBox);
     }
 
     return setWidgetGeometry(absoluteContentBox);
 }
 
-void RenderWidget::setWidget(PassRefPtr<Widget> widget)
-{
-    if (widget == m_widget)
-        return;
-
-    if (m_widget) {
-        moveWidgetToParentSoon(m_widget.get(), 0);
-        clearWidget();
-    }
-    m_widget = widget;
-    if (m_widget) {
-        // If we've already received a layout, apply the calculated space to the
-        // widget immediately, but we have to have really been fully constructed (with a non-null
-        // style pointer).
-        if (style()) {
-            if (!needsLayout())
-                updateWidgetGeometry();
-
-            if (style()->visibility() != VISIBLE)
-                m_widget->hide();
-            else {
-                m_widget->show();
-                repaint();
-            }
-        }
-        moveWidgetToParentSoon(m_widget.get(), m_frameView);
-    }
-
-    if (AXObjectCache* cache = document().existingAXObjectCache())
-        cache->childrenChanged(this);
-}
-
 void RenderWidget::layout()
 {
     ASSERT(needsLayout());
 
     LayoutRectRecorder recorder(*this);
     clearNeedsLayout();
 }
 
 void RenderWidget::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
 {
     RenderReplaced::styleDidChange(diff, oldStyle);
-    if (m_widget) {
+    Widget* widget = this->widget();
+
+    if (widget) {
         if (style()->visibility() != VISIBLE)
-            m_widget->hide();
+            widget->hide();
         else
-            m_widget->show();
+            widget->show();
     }
 }
 
 void RenderWidget::paintContents(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     LayoutPoint adjustedPaintOffset = paintOffset + location();
 
+    Widget* widget = this->widget();
+    ASSERT(widget);
+
     // Tell the widget to paint now. This is the only time the widget is allowed
     // to paint itself. That way it will composite properly with z-indexed layers.
-    IntPoint widgetLocation = m_widget->frameRect().location();
+    IntPoint widgetLocation = widget->frameRect().location();
     IntPoint paintLocation(roundToInt(adjustedPaintOffset.x() + borderLeft() + paddingLeft()),
         roundToInt(adjustedPaintOffset.y() + borderTop() + paddingTop()));
     IntRect paintRect = paintInfo.rect;
 
     IntSize widgetPaintOffset = paintLocation - widgetLocation;
     // When painting widgets into compositing layers, tx and ty are relative to the enclosing compositing layer,
     // not the root. In this case, shift the CTM and adjust the paintRect to be root-relative to fix plug-in drawing.
     if (!widgetPaintOffset.isZero()) {
         paintInfo.context->translate(widgetPaintOffset);
         paintRect.move(-widgetPaintOffset);
     }
-    m_widget->paint(paintInfo.context, paintRect);
+    widget->paint(paintInfo.context, paintRect);
 
     if (!widgetPaintOffset.isZero())
         paintInfo.context->translate(-widgetPaintOffset);
 
-    if (m_widget->isFrameView()) {
-        FrameView* frameView = toFrameView(m_widget.get());
+    if (widget->isFrameView()) {
+        FrameView* frameView = toFrameView(widget);
         bool runOverlapTests = !frameView->useSlowRepaintsIfNotOverlapped() || frameView->hasCompositedContent();
         if (paintInfo.overlapTestRequests && runOverlapTests) {
             ASSERT(!paintInfo.overlapTestRequests->contains(this));
-            paintInfo.overlapTestRequests->set(this, m_widget->frameRect());
+            paintInfo.overlapTestRequests->set(this, widget->frameRect());
         }
     }
 }
 
 void RenderWidget::paint(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     ANNOTATE_GRAPHICS_CONTEXT(paintInfo, this);
 
     if (!shouldPaint(paintInfo, paintOffset))
         return;
@@ skipping 20 matching lines @@
         if (borderRect.isEmpty())
             return;
 
         // Push a clip if we have a border radius, since we want to round the foreground content that gets painted.
         paintInfo.context->save();
         RoundedRect roundedInnerRect = style()->getRoundedInnerBorderFor(borderRect,
             paddingTop() + borderTop(), paddingBottom() + borderBottom(), paddingLeft() + borderLeft(), paddingRight() + borderRight(), true, true);
         clipRoundedInnerRect(paintInfo.context, borderRect, roundedInnerRect);
     }
 
-    if (m_widget)
+    Widget* widget = this->widget();
+    if (widget)
         paintContents(paintInfo, paintOffset);
 
     if (style()->hasBorderRadius())
         paintInfo.context->restore();
 
     // Paint a partially transparent wash over selected widgets.
     if (isSelected() && !document().printing()) {
         // FIXME: selectionRect() is in absolute, not painting coordinates.
         paintInfo.context->fillRect(pixelSnappedIntRect(selectionRect()), selectionBackgroundColor());
     }
 
     if (canResize())
         layer()->scrollableArea()->paintResizer(paintInfo.context, roundedIntPoint(adjustedPaintOffset), paintInfo.rect);
 }
 
 void RenderWidget::setIsOverlapped(bool isOverlapped)
 {
-    ASSERT(m_widget);
-    ASSERT(m_widget->isFrameView());
-    toFrameView(m_widget.get())->setIsOverlapped(isOverlapped);
+    Widget* widget = this->widget();
+    ASSERT(widget);
+    ASSERT(widget->isFrameView());
+    toFrameView(widget)->setIsOverlapped(isOverlapped);
 }
 
 void RenderWidget::deref()
 {
     if (--m_refCount <= 0)
         postDestroy();
 }
 
+void RenderWidget::updateOnWidgetChange()
+{
+    Widget* widget = this->widget();
+    if (!widget)
+        return;
+
+    if (style()) {

[eseidel, 2013/12/18 18:38:18]

nit: early return if (!style) return;

[wjmaclean, 2013/12/23 23:49:53]

Done.

+        if (!needsLayout())
+            updateWidgetGeometry();
+
+        if (style()->visibility() != VISIBLE) {
+            widget->hide();

[eseidel, 2013/12/18 18:38:18]

Do we need to cause a repaint to when hiding (to repaint the content behind?) 
If not, then why do we have to cause one on show?

[wjmaclean, 2013/12/23 23:49:53]

I'm afraid I don't really know the answer to that ... I'm just replicating the
previous behaviour.

+        } else {
+            widget->show();
+            repaint();
+        }
+    }
+}
+
 void RenderWidget::updateWidgetPosition()
 {
-    if (!m_widget || !node()) // Check the node in case destroy() has been called.
+    Widget* widget = this->widget();
+    if (!widget || !node()) // Check the node in case destroy() has been called.
         return;
 
     bool boundsChanged = updateWidgetGeometry();
 
     // if the frame bounds got changed, or if view needs layout (possibly indicating
     // content size is wrong) we have to do a layout to set the right widget size
-    if (m_widget && m_widget->isFrameView()) {
-        FrameView* frameView = toFrameView(m_widget.get());
+    if (widget && widget->isFrameView()) {
+        FrameView* frameView = toFrameView(widget);
         // Check the frame's page to make sure that the frame isn't in the process of being destroyed.
         if ((boundsChanged || frameView->needsLayout()) && frameView->frame().page())
             frameView->layout();
     }
 }
 
 void RenderWidget::widgetPositionsUpdated()
 {
-    if (!m_widget)
+    Widget* widget = this->widget();
+    if (!widget)
         return;
-    m_widget->widgetPositionsUpdated();
-}
-
-void RenderWidget::clearWidget()
-{
-    m_widget = 0;
+    widget->widgetPositionsUpdated();
 }
 
 bool RenderWidget::nodeAtPoint(const HitTestRequest& request, HitTestResult& result, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction action)
 {
     bool hadResult = result.innerNode();
     bool inside = RenderReplaced::nodeAtPoint(request, result, locationInContainer, accumulatedOffset, action);
 
     // Check to see if we are really over the widget itself (and not just in the border/padding area).
     if ((inside || result.isRectBasedTest()) && !hadResult && result.innerNode() == node())
         result.setIsOverWidget(contentBoxRect().contains(result.localPoint()));
     return inside;
 }
 
 CursorDirective RenderWidget::getCursor(const LayoutPoint& point, Cursor& cursor) const
 {
     if (widget() && widget()->isPluginView()) {
         // A plug-in is responsible for setting the cursor when the pointer is over it.
         return DoNotSetCursor;
     }
     return RenderReplaced::getCursor(point, cursor);
 }
 
 } // namespace WebCore