1 /*
2 * Copyright (C) 2011 Google Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following disclaimer
12 * in the documentation and/or other materials provided with the
13 * distribution.
14 * * Neither the name of Google Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived from
16 * this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "config.h"
32 #include "IFrameShimSupport.h"
33
34 #include "Element.h"
35 #include "FrameView.h"
36 #include "HTMLElement.h"
37 #include "HTMLFrameOwnerElement.h"
38 #include "HTMLNames.h"
39 #include "RenderBox.h"
40 #include "RenderObject.h"
41 #include "Widget.h"
42
43 #include <wtf/HashSet.h>
44
45 // This file provides plugin-related utility functions for iframe shims and is shared by platforms that inherit
46 // from PluginView (e.g. Qt) and those that do not (e.g. Chromium).
47
48 namespace WebCore {
49
getObjectStack(const RenderObject * ro,Vector<const RenderObject * > * roStack)50 static void getObjectStack(const RenderObject* ro, Vector<const RenderObject*>* roStack)
51 {
52 roStack->clear();
53 while (ro) {
54 roStack->append(ro);
55 ro = ro->parent();
56 }
57 }
58
59 // Returns true if stack1 is at or above stack2
iframeIsAbovePlugin(const Vector<const RenderObject * > & iframeZstack,const Vector<const RenderObject * > & pluginZstack)60 static bool iframeIsAbovePlugin(const Vector<const RenderObject*>& iframeZstack, const Vector<const RenderObject*>& pluginZstack)
61 {
62 for (size_t i = 0; i < iframeZstack.size() && i < pluginZstack.size(); i++) {
63 // The root is at the end of these stacks. We want to iterate
64 // root-downwards so we index backwards from the end.
65 const RenderObject* ro1 = iframeZstack[iframeZstack.size() - 1 - i];
66 const RenderObject* ro2 = pluginZstack[pluginZstack.size() - 1 - i];
67
68 if (ro1 != ro2) {
69 // When we find nodes in the stack that are not the same, then
70 // we've found the nodes just below the lowest comment ancestor.
71 // Determine which should be on top.
72
73 // See if z-index determines an order.
74 if (ro1->style() && ro2->style()) {
75 int z1 = ro1->style()->zIndex();
76 int z2 = ro2->style()->zIndex();
77 if (z1 > z2)
78 return true;
79 if (z1 < z2)
80 return false;
81 }
82
83 // If the plugin does not have an explicit z-index it stacks behind the iframe.
84 // This is for maintaining compatibility with IE.
85 if (ro2->style()->position() == StaticPosition) {
86 // The 0'th elements of these RenderObject arrays represent the plugin node and
87 // the iframe.
88 const RenderObject* pluginRenderObject = pluginZstack[0];
89 const RenderObject* iframeRenderObject = iframeZstack[0];
90
91 if (pluginRenderObject->style() && iframeRenderObject->style()) {
92 if (pluginRenderObject->style()->zIndex() > iframeRenderObject->style()->zIndex())
93 return false;
94 }
95 return true;
96 }
97
98 // Inspect the document order. Later order means higher stacking.
99 const RenderObject* parent = ro1->parent();
100 if (!parent)
101 return false;
102 ASSERT(parent == ro2->parent());
103
104 for (const RenderObject* ro = parent->firstChild(); ro; ro = ro->nextSibling()) {
105 if (ro == ro1)
106 return false;
107 if (ro == ro2)
108 return true;
109 }
110 ASSERT(false); // We should have seen ro1 and ro2 by now.
111 return false;
112 }
113 }
114 return true;
115 }
116
117 // Return a set of rectangles that should not be overdrawn by the
118 // plugin ("cutouts"). This helps implement the "iframe shim"
119 // technique of overlaying a windowed plugin with content from the
120 // page. In a nutshell, iframe elements should occlude plugins when
121 // they occur higher in the stacking order.
getPluginOcclusions(Element * element,Widget * parentWidget,const IntRect & frameRect,Vector<IntRect> & occlusions)122 void getPluginOcclusions(Element* element, Widget* parentWidget, const IntRect& frameRect, Vector<IntRect>& occlusions)
123 {
124 RenderObject* pluginNode = element->renderer();
125 ASSERT(pluginNode);
126 if (!pluginNode->style())
127 return;
128 Vector<const RenderObject*> pluginZstack;
129 Vector<const RenderObject*> iframeZstack;
130 getObjectStack(pluginNode, &pluginZstack);
131
132 if (!parentWidget->isFrameView())
133 return;
134
135 FrameView* parentFrameView = static_cast<FrameView*>(parentWidget);
136
137 const HashSet<RefPtr<Widget> >* children = parentFrameView->children();
138 for (HashSet<RefPtr<Widget> >::const_iterator it = children->begin(); it != children->end(); ++it) {
139 // We only care about FrameView's because iframes show up as FrameViews.
140 if (!(*it)->isFrameView())
141 continue;
142
143 const FrameView* frameView = static_cast<const FrameView*>((*it).get());
144 // Check to make sure we can get both the element and the RenderObject
145 // for this FrameView, if we can't just move on to the next object.
146 if (!frameView->frame() || !frameView->frame()->ownerElement()
147 || !frameView->frame()->ownerElement()->renderer())
148 continue;
149
150 HTMLElement* element = frameView->frame()->ownerElement();
151 RenderObject* iframeRenderer = element->renderer();
152
153 if (element->hasTagName(HTMLNames::iframeTag)
154 && iframeRenderer->absoluteBoundingBoxRect().intersects(frameRect)
155 && (!iframeRenderer->style() || iframeRenderer->style()->visibility() == VISIBLE)) {
156 getObjectStack(iframeRenderer, &iframeZstack);
157 if (iframeIsAbovePlugin(iframeZstack, pluginZstack)) {
158 IntPoint point = roundedIntPoint(iframeRenderer->localToAbsolute());
159 RenderBox* rbox = toRenderBox(iframeRenderer);
160 IntSize size(rbox->width(), rbox->height());
161 occlusions.append(IntRect(point, size));
162 }
163 }
164 }
165 }
166
167 } // namespace WebCore
168