chrome/renderer/chrome_render_frame_observer.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/renderer/chrome_render_frame_observer.h"
   6
   7 #include "base/strings/utf_string_conversions.h"
   8 #include "chrome/common/prerender_messages.h"
   9 #include "chrome/common/print_messages.h"
  10 #include "chrome/common/render_messages.h"
  11 #include "chrome/renderer/prerender/prerender_helper.h"
  12 #include "chrome/renderer/printing/print_web_view_helper.h"
  13 #include "content/public/renderer/render_frame.h"
  14 #include "skia/ext/image_operations.h"
  15 #include "skia/ext/platform_canvas.h"
  16 #include "third_party/WebKit/public/platform/WebImage.h"
  17 #include "third_party/WebKit/public/web/WebElement.h"
  18 #include "third_party/WebKit/public/web/WebNode.h"
  19
  20 using blink::WebElement;
  21 using blink::WebNode;
  22
  23 namespace {
  24
  25 // If the source image is null or occupies less area than
  26 // |thumbnail_min_area_pixels|, we return the image unmodified.  Otherwise, we
  27 // scale down the image so that the width and height do not exceed
  28 // |thumbnail_max_size_pixels|, preserving the original aspect ratio.
  29 SkBitmap Downscale(const blink::WebImage& image,
  30                    int thumbnail_min_area_pixels,
  31                    const gfx::Size& thumbnail_max_size_pixels) {
  32   if (image.isNull())
  33     return SkBitmap();
  34
  35   gfx::Size image_size = image.size();
  36
  37   if (image_size.GetArea() < thumbnail_min_area_pixels)
  38     return image.getSkBitmap();
  39
  40   if (image_size.width() <= thumbnail_max_size_pixels.width() &&
  41       image_size.height() <= thumbnail_max_size_pixels.height())
  42     return image.getSkBitmap();
  43
  44   gfx::SizeF scaled_size = image_size;
  45
  46   if (scaled_size.width() > thumbnail_max_size_pixels.width()) {
  47     scaled_size.Scale(thumbnail_max_size_pixels.width() / scaled_size.width());
  48   }
  49
  50   if (scaled_size.height() > thumbnail_max_size_pixels.height()) {
  51     scaled_size.Scale(
  52         thumbnail_max_size_pixels.height() / scaled_size.height());
  53   }
  54
  55   return skia::ImageOperations::Resize(image.getSkBitmap(),
  56                                        skia::ImageOperations::RESIZE_GOOD,
  57                                        static_cast<int>(scaled_size.width()),
  58                                        static_cast<int>(scaled_size.height()));
  59 }
  60
  61 }  // namespace
  62
  63 ChromeRenderFrameObserver::ChromeRenderFrameObserver(
  64     content::RenderFrame* render_frame)
  65     : content::RenderFrameObserver(render_frame) {
  66 }
  67
  68 ChromeRenderFrameObserver::~ChromeRenderFrameObserver() {
  69 }
  70
  71 bool ChromeRenderFrameObserver::OnMessageReceived(const IPC::Message& message) {
  72   // Filter only.
  73   bool handled = true;
  74   IPC_BEGIN_MESSAGE_MAP(ChromeRenderFrameObserver, message)
  75     IPC_MESSAGE_HANDLER(PrerenderMsg_SetIsPrerendering, OnSetIsPrerendering)
  76     IPC_MESSAGE_UNHANDLED(handled = false)
  77   IPC_END_MESSAGE_MAP()
  78   if (handled)
  79     return false;
  80
  81   IPC_BEGIN_MESSAGE_MAP(ChromeRenderFrameObserver, message)
  82     IPC_MESSAGE_HANDLER(ChromeViewMsg_RequestThumbnailForContextNode,
  83                         OnRequestThumbnailForContextNode)
  84     IPC_MESSAGE_HANDLER(PrintMsg_PrintNodeUnderContextMenu,
  85                         OnPrintNodeUnderContextMenu)
  86     IPC_MESSAGE_UNHANDLED(handled = false)
  87   IPC_END_MESSAGE_MAP()
  88
  89   return handled;
  90 }
  91
  92 void ChromeRenderFrameObserver::OnSetIsPrerendering(bool is_prerendering) {
  93   if (is_prerendering) {
  94     // If the PrerenderHelper for this frame already exists, don't create it. It
  95     // can already be created for subframes during handling of
  96     // RenderFrameCreated, if the parent frame was prerendering at time of
  97     // subframe creation.
  98     if (prerender::PrerenderHelper::Get(render_frame()))
  99       return;
 100
 101     // The PrerenderHelper will destroy itself either after recording histograms
 102     // or on destruction of the RenderView.
 103     new prerender::PrerenderHelper(render_frame());
 104   }
 105 }
 106
 107 void ChromeRenderFrameObserver::OnRequestThumbnailForContextNode(
 108     int thumbnail_min_area_pixels,
 109     const gfx::Size& thumbnail_max_size_pixels) {
 110   WebNode context_node = render_frame()->GetContextMenuNode();
 111   SkBitmap thumbnail;
 112   gfx::Size original_size;
 113   if (!context_node.isNull() && context_node.isElementNode()) {
 114     blink::WebImage image = context_node.to<WebElement>().imageContents();
 115     original_size = image.size();
 116     thumbnail = Downscale(image,
 117                           thumbnail_min_area_pixels,
 118                           thumbnail_max_size_pixels);
 119   }
 120   Send(new ChromeViewHostMsg_RequestThumbnailForContextNode_ACK(
 121       routing_id(), thumbnail, original_size));
 122 }
 123
 124 void ChromeRenderFrameObserver::OnPrintNodeUnderContextMenu() {
 125   printing::PrintWebViewHelper* helper =
 126       printing::PrintWebViewHelper::Get(render_frame()->GetRenderView());
 127   if (helper)
 128     helper->PrintNode(render_frame()->GetContextMenuNode());
 129 }