Generate thumbnails in the browser process.

chrome/renderer/render_view.cc

Index: chrome/renderer/render_view.cc
diff --git a/chrome/renderer/render_view.cc b/chrome/renderer/render_view.cc
index 9b71058a5375da46a4f53eb6786e1754e80be856..6cad6a36b3c7a3ad954636c4f5d57613ba5ef291 100644
--- a/chrome/renderer/render_view.cc
+++ b/chrome/renderer/render_view.cc
@@ -42,7 +42,6 @@
 #include "chrome/common/pepper_plugin_registry.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/renderer_preferences.h"
-#include "chrome/common/thumbnail_score.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/common/web_apps.h"
 #include "chrome/common/window_container_type.h"
@@ -283,20 +282,11 @@ using webkit_glue::WebAccessibility;
 typedef std::map<WebKit::WebView*, RenderView*> ViewMap;
 static base::LazyInstance<ViewMap> g_view_map(base::LINKER_INITIALIZED);
 
-// define to write the time necessary for thumbnail/DOM text retrieval,
-// respectively, into the system debug log
-// #define TIME_TEXT_RETRIEVAL
-
 // maximum number of characters in the document to index, any text beyond this
 // point will be clipped
 static const size_t kMaxIndexChars = 65535;
 
-// Size of the thumbnails that we'll generate
-static const int kThumbnailWidth = 212;
-static const int kThumbnailHeight = 132;
-
-// Delay in milliseconds that we'll wait before capturing the page contents
-// and thumbnail.
+// Delay in milliseconds that we'll wait before capturing the page contents.
 static const int kDelayForCaptureMs = 500;
 
 // Typically, we capture the page data once the page is loaded.
@@ -345,19 +335,6 @@ static bool PaintViewIntoCanvas(WebView* view,
   return true;
 }
 
-// Calculates how "boring" a thumbnail is. The boring score is the
-// 0,1 ranged percentage of pixels that are the most common
-// luma. Higher boring scores indicate that a higher percentage of a
-// bitmap are all the same brightness.
-static double CalculateBoringScore(SkBitmap* bitmap) {
-  int histogram[256] = {0};
-  color_utils::BuildLumaHistogram(bitmap, histogram);
-
-  int color_count = *std::max_element(histogram, histogram + 256);
-  int pixel_count = bitmap->width() * bitmap->height();
-  return static_cast<double>(color_count) / pixel_count;
-}
-
 // True if |frame| contains content that is white-listed for content settings.
 static bool IsWhitelistedForContentSettings(WebFrame* frame) {
   WebSecurityOrigin origin = frame->securityOrigin();
@@ -963,7 +940,6 @@ bool RenderView::OnMessageReceived(const IPC::Message& message) {
 
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(RenderView, message)
-    IPC_MESSAGE_HANDLER(ViewMsg_CaptureThumbnail, OnCaptureThumbnail)
     IPC_MESSAGE_HANDLER(ViewMsg_CaptureSnapshot, OnCaptureSnapshot)
     IPC_MESSAGE_HANDLER(ViewMsg_PrintPages, OnPrintPages)
     IPC_MESSAGE_HANDLER(ViewMsg_PrintingDone, OnPrintingDone)
@@ -1102,29 +1078,6 @@ bool RenderView::OnMessageReceived(const IPC::Message& message) {
   return handled;
 }
 
-void RenderView::OnCaptureThumbnail() {
-  WebFrame* main_frame = webview()->mainFrame();
-  if (!main_frame)
-    return;
-
-  // get the URL for this page
-  GURL url(main_frame->url());
-  if (url.is_empty())
-    return;
-
-  if (size_.IsEmpty())
-    return;  // Don't create an empty thumbnail!
-
-  ThumbnailScore score;
-  SkBitmap thumbnail;
-  if (!CaptureThumbnail(webview(), kThumbnailWidth, kThumbnailHeight,
-                        &thumbnail, &score))
-    return;
-
-  // send the thumbnail message to the browser process
-  Send(new ViewHostMsg_Thumbnail(routing_id_, url, score, thumbnail));
-}
-
 void RenderView::OnCaptureSnapshot() {
   SkBitmap snapshot;
   bool error = false;
@@ -1206,7 +1159,7 @@ void RenderView::CapturePageInfo(int load_id, bool preliminary_capture) {
     return;
 
   // Don't index/capture pages that failed to load.  This only checks the top
-  // level frame so the thumbnail may contain a frame that failed to load.
+  // level frame.
   WebDataSource* ds = main_frame->dataSource();
   if (ds && ds->hasUnreachableURL())
     return;
@@ -1241,8 +1194,6 @@ void RenderView::CapturePageInfo(int load_id, bool preliminary_capture) {
         TranslateHelper::IsPageTranslatable(&document)));
   }
 
-  OnCaptureThumbnail();
-
   if (phishing_delegate_.get())
     phishing_delegate_->FinishedLoad(&contents);
 }
@@ -1278,75 +1229,6 @@ void RenderView::CaptureText(WebFrame* frame, string16* contents) {
   }
 }
 
-bool RenderView::CaptureThumbnail(WebView* view,

[brettw, 2011/01/18 18:25:42]

I think we probably want to keep the old code and have your new feature
controlled by a command-line switch. This way, you can land a
partially-implemented patch and continue to work without disturbing people on
the dev channel, and it can be turned off on the beta channel if we think it
might be causing problems or isn't ready.

Hopefully adding this is self-explanatory. The thing that people usually forget
is to modify BrowserRenderProcessHost::PropagateBrowserCommandLineToRenderer if
they need the command line switch in the renderer.

[satorux1, 2011/01/19 01:36:36]

That's a great idea. I'll change it accordingly.

-                                  int w,
-                                  int h,
-                                  SkBitmap* thumbnail,
-                                  ThumbnailScore* score) {
-  base::TimeTicks beginning_time = base::TimeTicks::Now();
-
-  skia::PlatformCanvas canvas;
-
-  // Paint |view| into |canvas|.
-  if (!PaintViewIntoCanvas(view, canvas))
-    return false;
-
-  skia::BitmapPlatformDevice& device =
-      static_cast<skia::BitmapPlatformDevice&>(canvas.getTopPlatformDevice());
-
-  const SkBitmap& src_bmp = device.accessBitmap(false);
-
-  SkRect dest_rect = { 0, 0, SkIntToScalar(w), SkIntToScalar(h) };
-  float dest_aspect = dest_rect.width() / dest_rect.height();
-
-  // Get the src rect so that we can preserve the aspect ratio while filling
-  // the destination.
-  SkIRect src_rect;
-  if (src_bmp.width() < dest_rect.width() ||
-      src_bmp.height() < dest_rect.height()) {
-    // Source image is smaller: we clip the part of source image within the
-    // dest rect, and then stretch it to fill the dest rect. We don't respect
-    // the aspect ratio in this case.
-    src_rect.set(0, 0, static_cast<S16CPU>(dest_rect.width()),
-                 static_cast<S16CPU>(dest_rect.height()));
-    score->good_clipping = false;
-  } else {
-    float src_aspect = static_cast<float>(src_bmp.width()) / src_bmp.height();
-    if (src_aspect > dest_aspect) {
-      // Wider than tall, clip horizontally: we center the smaller thumbnail in
-      // the wider screen.
-      S16CPU new_width = static_cast<S16CPU>(src_bmp.height() * dest_aspect);
-      S16CPU x_offset = (src_bmp.width() - new_width) / 2;
-      src_rect.set(x_offset, 0, new_width + x_offset, src_bmp.height());
-      score->good_clipping = false;
-    } else {
-      src_rect.set(0, 0, src_bmp.width(),
-                   static_cast<S16CPU>(src_bmp.width() / dest_aspect));
-      score->good_clipping = true;
-    }
-  }
-
-  score->at_top = (view->mainFrame()->scrollOffset().height == 0);
-
-  SkBitmap subset;
-  device.accessBitmap(false).extractSubset(&subset, src_rect);
-
-  // First do a fast downsample by powers of two to get close to the final size.
-  SkBitmap downsampled_subset =
-      SkBitmapOperations::DownsampleByTwoUntilSize(subset, w, h);
-
-  // Do a high-quality resize from the downscaled size to the final size.
-  *thumbnail = skia::ImageOperations::Resize(
-      downsampled_subset, skia::ImageOperations::RESIZE_LANCZOS3, w, h);
-
-  score->boring_score = CalculateBoringScore(thumbnail);
-
-  HISTOGRAM_TIMES("Renderer4.Thumbnail",
-                  base::TimeTicks::Now() - beginning_time);
-
-  return true;
-}
-
 bool RenderView::CaptureSnapshot(WebView* view, SkBitmap* snapshot) {
   base::TimeTicks beginning_time = base::TimeTicks::Now();
 
@@ -5091,6 +4973,10 @@ void RenderView::DidInitiatePaint() {
            current_oldstyle_pepper_plugins_.begin();
        i != current_oldstyle_pepper_plugins_.end(); ++i)
     (*i)->RenderViewInitiatedPaint();
+
+  WebKit::WebSize scroll_offset = webview()->mainFrame()->scrollOffset();
+  gfx::Size gfx_scroll_offset(scroll_offset.width, scroll_offset.height);
+  Send(new ViewHostMsg_UpdateScrollOffset(routing_id_, gfx_scroll_offset));

[brettw, 2011/01/18 18:25:42]

If you need something in RenderWidget, you can just make a virtual function that
RenderView provides an implementation for. An example is
GetBitmapForOptimizedPluginPaint. Potentially the default one could just return
Size(0, 0) and then RenderView would provide the "real" one. Would this allow
you to implement this more cleanly?

[satorux1, 2011/01/19 01:36:36]

Sounds like a good idea. I'll give it a try.

 }
 
 void RenderView::DidFlushPaint() {