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      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/WebFrame.h"
     19 #include "third_party/WebKit/public/web/WebNode.h"
     20 
     21 using blink::WebElement;
     22 using blink::WebNode;
     23 
     24 namespace {
     25 
     26 // If the source image is null or occupies less area than
     27 // |thumbnail_min_area_pixels|, we return the image unmodified.  Otherwise, we
     28 // scale down the image so that the width and height do not exceed
     29 // |thumbnail_max_size_pixels|, preserving the original aspect ratio.
     30 SkBitmap Downscale(blink::WebImage image,
     31                    int thumbnail_min_area_pixels,
     32                    gfx::Size thumbnail_max_size_pixels) {
     33   if (image.isNull())
     34     return SkBitmap();
     35 
     36   gfx::Size image_size = image.size();
     37 
     38   if (image_size.GetArea() < thumbnail_min_area_pixels)
     39     return image.getSkBitmap();
     40 
     41   if (image_size.width() <= thumbnail_max_size_pixels.width() &&
     42       image_size.height() <= thumbnail_max_size_pixels.height())
     43     return image.getSkBitmap();
     44 
     45   gfx::SizeF scaled_size = image_size;
     46 
     47   if (scaled_size.width() > thumbnail_max_size_pixels.width()) {
     48     scaled_size.Scale(thumbnail_max_size_pixels.width() / scaled_size.width());
     49   }
     50 
     51   if (scaled_size.height() > thumbnail_max_size_pixels.height()) {
     52     scaled_size.Scale(
     53         thumbnail_max_size_pixels.height() / scaled_size.height());
     54   }
     55 
     56   return skia::ImageOperations::Resize(image.getSkBitmap(),
     57                                        skia::ImageOperations::RESIZE_GOOD,
     58                                        static_cast<int>(scaled_size.width()),
     59                                        static_cast<int>(scaled_size.height()));
     60 }
     61 
     62 }  // namespace
     63 
     64 ChromeRenderFrameObserver::ChromeRenderFrameObserver(
     65     content::RenderFrame* render_frame)
     66     : content::RenderFrameObserver(render_frame) {
     67 }
     68 
     69 ChromeRenderFrameObserver::~ChromeRenderFrameObserver() {
     70 }
     71 
     72 bool ChromeRenderFrameObserver::OnMessageReceived(const IPC::Message& message) {
     73   // Filter only.
     74   bool handled = true;
     75   IPC_BEGIN_MESSAGE_MAP(ChromeRenderFrameObserver, message)
     76     IPC_MESSAGE_HANDLER(PrerenderMsg_SetIsPrerendering, OnSetIsPrerendering)
     77     IPC_MESSAGE_UNHANDLED(handled = false)
     78   IPC_END_MESSAGE_MAP()
     79   if (handled)
     80     return false;
     81 
     82   IPC_BEGIN_MESSAGE_MAP(ChromeRenderFrameObserver, message)
     83     IPC_MESSAGE_HANDLER(ChromeViewMsg_RequestThumbnailForContextNode,
     84                         OnRequestThumbnailForContextNode)
     85     IPC_MESSAGE_HANDLER(PrintMsg_PrintNodeUnderContextMenu,
     86                         OnPrintNodeUnderContextMenu)
     87     IPC_MESSAGE_UNHANDLED(handled = false)
     88   IPC_END_MESSAGE_MAP()
     89 
     90   return handled;
     91 }
     92 
     93 void ChromeRenderFrameObserver::DidChangeName(
     94     const base::string16& name) {
     95   Send(new ChromeViewHostMsg_UpdateFrameName(
     96       routing_id(),
     97       !render_frame()->GetWebFrame()->parent(),
     98       base::UTF16ToUTF8(name)));
     99 }
    100 
    101 void ChromeRenderFrameObserver::OnSetIsPrerendering(bool is_prerendering) {
    102   if (is_prerendering) {
    103     // If the PrerenderHelper for this frame already exists, don't create it. It
    104     // can already be created for subframes during handling of
    105     // RenderFrameCreated, if the parent frame was prerendering at time of
    106     // subframe creation.
    107     if (prerender::PrerenderHelper::Get(render_frame()))
    108       return;
    109 
    110     // The PrerenderHelper will destroy itself either after recording histograms
    111     // or on destruction of the RenderView.
    112     new prerender::PrerenderHelper(render_frame());
    113   }
    114 }
    115 
    116 void ChromeRenderFrameObserver::OnRequestThumbnailForContextNode(
    117     int thumbnail_min_area_pixels,
    118     const gfx::Size& thumbnail_max_size_pixels) {
    119   WebNode context_node = render_frame()->GetContextMenuNode();
    120   SkBitmap thumbnail;
    121   gfx::Size original_size;
    122   if (!context_node.isNull() && context_node.isElementNode()) {
    123     blink::WebImage image = context_node.to<WebElement>().imageContents();
    124     original_size = image.size();
    125     thumbnail = Downscale(image,
    126                           thumbnail_min_area_pixels,
    127                           thumbnail_max_size_pixels);
    128   }
    129   Send(new ChromeViewHostMsg_RequestThumbnailForContextNode_ACK(
    130       routing_id(), thumbnail, original_size));
    131 }
    132 
    133 void ChromeRenderFrameObserver::OnPrintNodeUnderContextMenu() {
    134   printing::PrintWebViewHelper* helper =
    135       printing::PrintWebViewHelper::Get(render_frame()->GetRenderView());
    136   if (helper)
    137     helper->PrintNode(render_frame()->GetContextMenuNode());
    138 }
    139