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 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above
12 * copyright notice, this list of conditions and the following disclaimer
13 * in the documentation and/or other materials provided with the
14 * distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. AND ITS CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GOOGLE INC.
20 * OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include "config.h"
30#include "web/PageOverlay.h"
31
32#include "core/frame/Settings.h"
33#include "core/page/Page.h"
34#include "platform/graphics/GraphicsContext.h"
35#include "platform/graphics/GraphicsLayer.h"
36#include "platform/graphics/GraphicsLayerClient.h"
37#include "public/platform/WebLayer.h"
38#include "public/web/WebPageOverlay.h"
39#include "public/web/WebViewClient.h"
40#include "web/WebViewImpl.h"
41
42using namespace WebCore;
43
44namespace blink {
45
46namespace {
47
48WebCanvas* ToWebCanvas(GraphicsContext* gc)
49{
50    return gc->canvas();
51}
52
53} // namespace
54
55PassOwnPtr<PageOverlay> PageOverlay::create(WebViewImpl* viewImpl, WebPageOverlay* overlay)
56{
57    return adoptPtr(new PageOverlay(viewImpl, overlay));
58}
59
60PageOverlay::PageOverlay(WebViewImpl* viewImpl, WebPageOverlay* overlay)
61    : m_viewImpl(viewImpl)
62    , m_overlay(overlay)
63    , m_zOrder(0)
64{
65}
66
67class OverlayGraphicsLayerClientImpl : public WebCore::GraphicsLayerClient {
68public:
69    static PassOwnPtr<OverlayGraphicsLayerClientImpl> create(WebPageOverlay* overlay)
70    {
71        return adoptPtr(new OverlayGraphicsLayerClientImpl(overlay));
72    }
73
74    virtual ~OverlayGraphicsLayerClientImpl() { }
75
76    virtual void notifyAnimationStarted(const GraphicsLayer*, double monotonicTime) OVERRIDE { }
77
78    virtual void paintContents(const GraphicsLayer*, GraphicsContext& gc, GraphicsLayerPaintingPhase, const IntRect& inClip)
79    {
80        if (gc.paintingDisabled())
81            return;
82        gc.save();
83        m_overlay->paintPageOverlay(ToWebCanvas(&gc));
84        gc.restore();
85    }
86
87    virtual String debugName(const GraphicsLayer* graphicsLayer) OVERRIDE
88    {
89        return String("WebViewImpl Page Overlay Content Layer");
90    }
91
92private:
93    explicit OverlayGraphicsLayerClientImpl(WebPageOverlay* overlay)
94        : m_overlay(overlay)
95    {
96    }
97
98    WebPageOverlay* m_overlay;
99};
100
101void PageOverlay::clear()
102{
103    invalidateWebFrame();
104
105    if (m_layer) {
106        m_layer->removeFromParent();
107        if (WebCore::Page* page = m_viewImpl->page())
108            page->inspectorController().didRemovePageOverlay(m_layer.get());
109        m_layer = nullptr;
110        m_layerClient = nullptr;
111    }
112}
113
114void PageOverlay::update()
115{
116    invalidateWebFrame();
117
118    if (!m_layer) {
119        m_layerClient = OverlayGraphicsLayerClientImpl::create(m_overlay);
120        m_layer = GraphicsLayer::create(m_viewImpl->graphicsLayerFactory(), m_layerClient.get());
121        m_layer->setDrawsContent(true);
122
123        if (WebCore::Page* page = m_viewImpl->page())
124            page->inspectorController().willAddPageOverlay(m_layer.get());
125
126        // This is required for contents of overlay to stay in sync with the page while scrolling.
127        WebLayer* platformLayer = m_layer->platformLayer();
128        platformLayer->setShouldScrollOnMainThread(true);
129    }
130
131    FloatSize size(m_viewImpl->size());
132    if (size != m_layer->size()) {
133        // Triggers re-adding to root layer to ensure that we are on top of
134        // scrollbars.
135        m_layer->removeFromParent();
136        m_layer->setSize(size);
137    }
138
139    m_viewImpl->setOverlayLayer(m_layer.get());
140    m_layer->setNeedsDisplay();
141}
142
143void PageOverlay::paintWebFrame(GraphicsContext& gc)
144{
145    if (!m_viewImpl->isAcceleratedCompositingActive() && !gc.paintingDisabled()) {
146        gc.save();
147        m_overlay->paintPageOverlay(ToWebCanvas(&gc));
148        gc.restore();
149    }
150}
151
152void PageOverlay::invalidateWebFrame()
153{
154    // WebPageOverlay does the actual painting of the overlay.
155    // Here we just make sure to invalidate.
156    if (!m_viewImpl->isAcceleratedCompositingActive()) {
157        // FIXME: able to invalidate a smaller rect.
158        // FIXME: Is it important to just invalidate a smaller rect given that
159        // this is not on a critical codepath? In order to do so, we'd
160        // have to take scrolling into account.
161        const WebSize& size = m_viewImpl->size();
162        WebRect damagedRect(0, 0, size.width, size.height);
163        if (m_viewImpl->client())
164            m_viewImpl->client()->didInvalidateRect(damagedRect);
165    }
166}
167
168} // namespace blink
169