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