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 <limits>
   8 #include <string>
   9 #include <vector>
  10
  11 #include "base/strings/utf_string_conversions.h"
  12 #include "chrome/common/prerender_messages.h"
  13 #include "chrome/common/render_messages.h"
  14 #include "chrome/renderer/prerender/prerender_helper.h"
  15 #include "components/printing/common/print_messages.h"
  16 #include "components/printing/renderer/print_web_view_helper.h"
  17 #include "content/public/renderer/render_frame.h"
  18 #include "skia/ext/image_operations.h"
  19 #include "third_party/WebKit/public/platform/WebImage.h"
  20 #include "third_party/WebKit/public/web/WebElement.h"
  21 #include "third_party/WebKit/public/web/WebNode.h"
  22 #include "third_party/skia/include/core/SkBitmap.h"
  23 #include "ui/gfx/codec/jpeg_codec.h"
  24
  25 using blink::WebElement;
  26 using blink::WebNode;
  27
  28 namespace {
  29
  30 // If the source image is null or occupies less area than
  31 // |thumbnail_min_area_pixels|, we return the image unmodified.  Otherwise, we
  32 // scale down the image so that the width and height do not exceed
  33 // |thumbnail_max_size_pixels|, preserving the original aspect ratio.
  34 SkBitmap Downscale(const blink::WebImage& image,
  35                    int thumbnail_min_area_pixels,
  36                    const gfx::Size& thumbnail_max_size_pixels) {
  37   if (image.isNull())
  38     return SkBitmap();
  39
  40   gfx::Size image_size = image.size();
  41
  42   if (image_size.GetArea() < thumbnail_min_area_pixels)
  43     return image.getSkBitmap();
  44
  45   if (image_size.width() <= thumbnail_max_size_pixels.width() &&
  46       image_size.height() <= thumbnail_max_size_pixels.height())
  47     return image.getSkBitmap();
  48
  49   gfx::SizeF scaled_size = image_size;
  50
  51   if (scaled_size.width() > thumbnail_max_size_pixels.width()) {
  52     scaled_size.Scale(thumbnail_max_size_pixels.width() / scaled_size.width());
  53   }
  54
  55   if (scaled_size.height() > thumbnail_max_size_pixels.height()) {
  56     scaled_size.Scale(
  57         thumbnail_max_size_pixels.height() / scaled_size.height());
  58   }
  59
  60   return skia::ImageOperations::Resize(image.getSkBitmap(),
  61                                        skia::ImageOperations::RESIZE_GOOD,
  62                                        static_cast<int>(scaled_size.width()),
  63                                        static_cast<int>(scaled_size.height()));
  64 }
  65
  66 }  // namespace
  67
  68 ChromeRenderFrameObserver::ChromeRenderFrameObserver(
  69     content::RenderFrame* render_frame)
  70     : content::RenderFrameObserver(render_frame) {
  71 }
  72
  73 ChromeRenderFrameObserver::~ChromeRenderFrameObserver() {
  74 }
  75
  76 bool ChromeRenderFrameObserver::OnMessageReceived(const IPC::Message& message) {
  77   // Filter only.
  78   bool handled = true;
  79   IPC_BEGIN_MESSAGE_MAP(ChromeRenderFrameObserver, message)
  80     IPC_MESSAGE_HANDLER(PrerenderMsg_SetIsPrerendering, OnSetIsPrerendering)
  81     IPC_MESSAGE_UNHANDLED(handled = false)
  82   IPC_END_MESSAGE_MAP()
  83   if (handled)
  84     return false;
  85
  86   IPC_BEGIN_MESSAGE_MAP(ChromeRenderFrameObserver, message)
  87     IPC_MESSAGE_HANDLER(ChromeViewMsg_RequestThumbnailForContextNode,
  88                         OnRequestThumbnailForContextNode)
  89     IPC_MESSAGE_HANDLER(PrintMsg_PrintNodeUnderContextMenu,
  90                         OnPrintNodeUnderContextMenu)
  91     IPC_MESSAGE_UNHANDLED(handled = false)
  92   IPC_END_MESSAGE_MAP()
  93
  94   return handled;
  95 }
  96
  97 void ChromeRenderFrameObserver::OnSetIsPrerendering(bool is_prerendering) {
  98   if (is_prerendering) {
  99     // If the PrerenderHelper for this frame already exists, don't create it. It
 100     // can already be created for subframes during handling of
 101     // RenderFrameCreated, if the parent frame was prerendering at time of
 102     // subframe creation.
 103     if (prerender::PrerenderHelper::Get(render_frame()))
 104       return;
 105
 106     // The PrerenderHelper will destroy itself either after recording histograms
 107     // or on destruction of the RenderView.
 108     new prerender::PrerenderHelper(render_frame());
 109   }
 110 }
 111
 112 void ChromeRenderFrameObserver::OnRequestThumbnailForContextNode(
 113     int thumbnail_min_area_pixels,
 114     const gfx::Size& thumbnail_max_size_pixels) {
 115   WebNode context_node = render_frame()->GetContextMenuNode();
 116   SkBitmap thumbnail;
 117   gfx::Size original_size;
 118   if (!context_node.isNull() && context_node.isElementNode()) {
 119     blink::WebImage image = context_node.to<WebElement>().imageContents();
 120     original_size = image.size();
 121     thumbnail = Downscale(image,
 122                           thumbnail_min_area_pixels,
 123                           thumbnail_max_size_pixels);
 124   }
 125
 126   SkBitmap bitmap;
 127   if (thumbnail.colorType() == kN32_SkColorType)
 128     bitmap = thumbnail;
 129   else
 130     thumbnail.copyTo(&bitmap, kN32_SkColorType);
 131
 132   std::string thumbnail_data;
 133   SkAutoLockPixels lock(bitmap);
 134   if (bitmap.getPixels()) {
 135     const int kDefaultQuality = 90;
 136     std::vector<unsigned char> data;
 137     if (gfx::JPEGCodec::Encode(
 138             reinterpret_cast<unsigned char*>(bitmap.getAddr32(0, 0)),
 139             gfx::JPEGCodec::FORMAT_SkBitmap, bitmap.width(), bitmap.height(),
 140             static_cast<int>(bitmap.rowBytes()), kDefaultQuality, &data))
 141       thumbnail_data = std::string(data.begin(), data.end());
 142   }
 143
 144   Send(new ChromeViewHostMsg_RequestThumbnailForContextNode_ACK(
 145       routing_id(), thumbnail_data, original_size));
 146 }
 147
 148 void ChromeRenderFrameObserver::OnPrintNodeUnderContextMenu() {
 149   printing::PrintWebViewHelper* helper =
 150       printing::PrintWebViewHelper::Get(render_frame()->GetRenderView());
 151   if (helper)
 152     helper->PrintNode(render_frame()->GetContextMenuNode());
 153 }