Add Linux support for getting the thumbnail and wire into the switcher.

Review URL: http://codereview.chromium.org/144006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19064 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 79 insertions, 38 deletions

diff --git a/chrome/browser/gtk/tabs/dragged_tab_gtk.cc b/chrome/browser/gtk/tabs/dragged_tab_gtk.cc
index b91cf7b..9a25ca9 100644
--- a/chrome/browser/gtk/tabs/dragged_tab_gtk.cc
+++ b/chrome/browser/gtk/tabs/dragged_tab_gtk.cc
@@ -287,11 +287,9 @@ void DraggedTabGtk::PaintScreenshotIntoCanvas(gfx::Canvas* canvas,
                                               const gfx::Rect& target_bounds) {
   gfx::Rect rect(0, 0,
                  contents_->allocation.width, contents_->allocation.height);
-  SkBitmap* bitmap = backing_store_->PaintRectToBitmap(rect);
-  if (bitmap) {
-    canvas->DrawBitmapInt(*bitmap, 0, renderer_->bounds().height());
-    delete bitmap;
-  }
+  SkBitmap bitmap = backing_store_->PaintRectToBitmap(rect);
+  if (!bitmap.isNull())
+    canvas->DrawBitmapInt(bitmap, 0, renderer_->bounds().height());
 }
 
 // static
diff --git a/chrome/browser/renderer_host/backing_store.h b/chrome/browser/renderer_host/backing_store.h
index 3438bda3..977553f 100644
--- a/chrome/browser/renderer_host/backing_store.h
+++ b/chrome/browser/renderer_host/backing_store.h
@@ -57,14 +57,18 @@ class BackingStore {
 #elif defined(OS_MACOSX)
   skia::PlatformCanvas* canvas() { return &canvas_; }
 #elif defined(OS_LINUX)
+  Display* display() const { return display_; }
+  XID root_window() const { return root_window_; };
+
   // Copy from the server-side backing store to the target window
   //   display: the display of the backing store and target window
   //   damage: the area to copy
   //   target: the X id of the target window
   void ShowRect(const gfx::Rect& damage, XID target);
 
-  // Paints the server-side backing store data to a SkBitmap.
-  SkBitmap* PaintRectToBitmap(const gfx::Rect& rect);
+  // Paints the server-side backing store data to a SkBitmap. On failure, the
+  // return bitmap will be isNull().
+  SkBitmap PaintRectToBitmap(const gfx::Rect& rect);
 #endif
 
   // Paints the bitmap from the renderer onto the backing store.
diff --git a/chrome/browser/renderer_host/backing_store_x.cc b/chrome/browser/renderer_host/backing_store_x.cc
index 9083dfc..a2397a2 100644
--- a/chrome/browser/renderer_host/backing_store_x.cc
+++ b/chrome/browser/renderer_host/backing_store_x.cc
@@ -313,7 +313,7 @@ void BackingStore::ShowRect(const gfx::Rect& rect, XID target) {
             rect.x(), rect.y());
 }
 
-SkBitmap* BackingStore::PaintRectToBitmap(const gfx::Rect& rect) {
+SkBitmap BackingStore::PaintRectToBitmap(const gfx::Rect& rect) {
   static const int kBytesPerPixel = 4;
 
   const int width = rect.width();
@@ -322,18 +322,20 @@ SkBitmap* BackingStore::PaintRectToBitmap(const gfx::Rect& rect) {
                             rect.x(), rect.y(),
                             width, height,
                             AllPlanes, ZPixmap);
+
+  SkBitmap bitmap;
+
   // TODO(jhawkins): Need to convert the image data if the image bits per pixel
   // is not 32.
   if (image->bits_per_pixel != 32) {
     XFree(image);
-    return NULL;
+    return bitmap;  // Return the empty bitmap to indicate failure.
   }
 
-  SkBitmap* bitmap = new SkBitmap();
-  bitmap->setConfig(SkBitmap::kARGB_8888_Config, width, height);
-  bitmap->allocPixels();
+  bitmap.setConfig(SkBitmap::kARGB_8888_Config, width, height);
+  bitmap.allocPixels();
   unsigned char* bitmap_data =
-    reinterpret_cast<unsigned char*>(bitmap->getAddr32(0, 0));
+    reinterpret_cast<unsigned char*>(bitmap.getAddr32(0, 0));
   memcpy(bitmap_data, image->data, width * height * kBytesPerPixel);
 
   XFree(image);
diff --git a/chrome/browser/tab_contents/thumbnail_generator.cc b/chrome/browser/tab_contents/thumbnail_generator.cc
index 681c0c8..e8ed550 100755
--- a/chrome/browser/tab_contents/thumbnail_generator.cc
+++ b/chrome/browser/tab_contents/thumbnail_generator.cc
@@ -59,6 +59,8 @@ static const int kThumbnailHeight = 204;
 // painted in this time.
 static const int kVisibilitySlopMS = 3000;
 
+static const char kThumbnailHistogramName[] = "Thumbnail.ComputeMS";
+
 struct WidgetThumbnail {
   SkBitmap thumbnail;
 
@@ -85,9 +87,27 @@ WidgetThumbnail* GetDataForHost(RenderWidgetHost* host) {
   return GetThumbnailAccessor()->GetProperty(host->property_bag());
 }
 
+#if defined(OS_WIN)
+
+// PlatformDevices/Canvases can't be copied like a regular SkBitmap (at least
+// on Windows). So the second parameter is the canvas to draw into. It should
+// be sized to the size of the backing store.
+void GetBitmapForBackingStore(BackingStore* backing_store,
+                              skia::PlatformCanvas* canvas) {
+  HDC dc = canvas->beginPlatformPaint();
+  BitBlt(dc, 0, 0,
+         backing_store->size().width(), backing_store->size().height(),
+         backing_store->hdc(), 0, 0, SRCCOPY);
+  canvas->endPlatformPaint();
+}
+
+#endif
+
 // Creates a downsampled thumbnail for the given backing store. The returned
 // bitmap will be isNull if there was an error creating it.
 SkBitmap GetThumbnailForBackingStore(BackingStore* backing_store) {
+  base::TimeTicks begin_compute_thumbnail = base::TimeTicks::Now();
+
   SkBitmap result;
 
   // TODO(brettw) write this for other platforms. If you enable this, be sure
@@ -97,37 +117,45 @@ SkBitmap GetThumbnailForBackingStore(BackingStore* backing_store) {
   // Get the bitmap as a Skia object so we can resample it. This is a large
   // allocation and we can tolerate failure here, so give up if the allocation
   // fails.
-  base::TimeTicks begin_compute_thumbnail = base::TimeTicks::Now();
-
   skia::PlatformCanvas temp_canvas;
   if (!temp_canvas.initialize(backing_store->size().width(),
                               backing_store->size().height(), true))
-    return SkBitmap();
-  HDC temp_dc = temp_canvas.beginPlatformPaint();
-  BitBlt(temp_dc,
-         0, 0, backing_store->size().width(), backing_store->size().height(),
-         backing_store->hdc(), 0, 0, SRCCOPY);
-  temp_canvas.endPlatformPaint();
+    return result;
+  GetBitmapForBackingStore(backing_store, &temp_canvas);
 
-  // Get the bitmap out of the canvas and resample it.
+  // Get the bitmap out of the canvas and resample it. It would be nice if this
+  // whole Windows-specific block could be put into a function, but the memory
+  // management wouldn't work out because the bitmap is a PlatformDevice which
+  // can't actually be copied.
   const SkBitmap& bmp = temp_canvas.getTopPlatformDevice().accessBitmap(false);
+
+#elif defined(OS_LINUX)
+  SkBitmap bmp = backing_store->PaintRectToBitmap(
+      gfx::Rect(0, 0,
+                backing_store->size().width(), backing_store->size().height()));
+
+#elif defined(OS_MAC)
+  SkBitmap bmp;
+  NOTEIMPLEMENTED();
+#endif
+
   result = skia::ImageOperations::DownsampleByTwoUntilSize(
       bmp,
       kThumbnailWidth, kThumbnailHeight);
-  if (bmp.width() == result.width() && bmp.height() == result.height()) {
-    // This is a bit subtle. SkBitmaps are refcounted, but the magic ones in
-    // PlatformCanvas can't be ssigned to SkBitmap with proper refcounting.
-    // If the bitmap doesn't change, then the downsampler will return the input
-    // bitmap, which will be the reference to the weird PlatformCanvas one
-    // insetad of a regular one. To get a regular refcounted bitmap, we need to
-    // copy it.
-    bmp.copyTo(&result, SkBitmap::kARGB_8888_Config);
-  }
 
-  HISTOGRAM_TIMES("Thumbnail.ComputeOnDestroyMS",
-                  base::TimeTicks::Now() - begin_compute_thumbnail);
+#if defined(OS_WIN)
+  // This is a bit subtle. SkBitmaps are refcounted, but the magic ones in
+  // PlatformCanvas on Windows can't be ssigned to SkBitmap with proper
+  // refcounting.  If the bitmap doesn't change, then the downsampler will
+  // return the input bitmap, which will be the reference to the weird
+  // PlatformCanvas one insetad of a regular one. To get a regular refcounted
+  // bitmap, we need to copy it.
+  if (bmp.width() == result.width() && bmp.height() == result.height())
+    bmp.copyTo(&result, SkBitmap::kARGB_8888_Config);
 #endif
 
+  HISTOGRAM_TIMES(kThumbnailHistogramName,
+                  base::TimeTicks::Now() - begin_compute_thumbnail);
   return result;
 }
 
@@ -165,9 +193,8 @@ SkBitmap ThumbnailGenerator::GetThumbnailForRenderer(
     RenderWidgetHost* renderer) const {
   // Return a cached one if we have it and it's still valid. This will only be
   // valid when there used to be a backing store, but there isn't now.
-  WidgetThumbnail* wt = GetThumbnailAccessor()->GetProperty(
-      renderer->property_bag());
-  if (wt && !wt->thumbnail.isNull() &&
+  WidgetThumbnail* wt = GetDataForHost(renderer);
+  if (!wt->thumbnail.isNull() &&
       (no_timeout_ ||
        base::TimeTicks::Now() -
        base::TimeDelta::FromMilliseconds(kVisibilitySlopMS) < wt->last_shown))
diff --git a/chrome/browser/views/tabs/tab_overview_cell.cc b/chrome/browser/views/tabs/tab_overview_cell.cc
index c05aae3..b0b5f9f 100644
--- a/chrome/browser/views/tabs/tab_overview_cell.cc
+++ b/chrome/browser/views/tabs/tab_overview_cell.cc
@@ -6,6 +6,7 @@
 
 #include "app/gfx/favicon_size.h"
 #include "base/string_util.h"
+#include "skia/ext/image_operations.h"
 #include "views/border.h"
 #include "views/controls/image_view.h"
 #include "views/controls/label.h"
@@ -64,7 +65,10 @@ TabOverviewCell::TabOverviewCell() {
 }
 
 void TabOverviewCell::SetThumbnail(const SkBitmap& thumbnail) {
-  thumbnail_view_->SetImage(thumbnail);
+  // Do mipmapped-based resampling to get closer to the correct size. The
+  // input bitmap isn't guaranteed to have any specific resolution.
+  thumbnail_view_->SetImage(skia::ImageOperations::DownsampleByTwoUntilSize(
+      thumbnail, kThumbnailWidth, kThumbnailHeight));
 }
 
 void TabOverviewCell::SetTitle(const string16& title) {
diff --git a/chrome/browser/views/tabs/tab_overview_controller.cc b/chrome/browser/views/tabs/tab_overview_controller.cc
index 86456c1..fb7dfa4 100644
--- a/chrome/browser/views/tabs/tab_overview_controller.cc
+++ b/chrome/browser/views/tabs/tab_overview_controller.cc
@@ -5,8 +5,10 @@
 #include "chrome/browser/views/tabs/tab_overview_controller.h"
 
 #include "chrome/browser/browser.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/gtk/browser_window_gtk.h"
 #include "chrome/browser/tab_contents/tab_contents.h"
+#include "chrome/browser/tab_contents/thumbnail_generator.h"
 #include "chrome/browser/views/tabs/tab_overview_cell.h"
 #include "chrome/browser/views/tabs/tab_overview_container.h"
 #include "chrome/browser/views/tabs/tab_overview_grid.h"
@@ -107,10 +109,14 @@ void TabOverviewController::Show() {
 
 void TabOverviewController::ConfigureCell(TabOverviewCell* cell,
                                           TabContents* contents) {
-  // TODO: need to set thumbnail here.
   if (contents) {
     cell->SetTitle(contents->GetTitle());
     cell->SetFavIcon(contents->GetFavIcon());
+
+    ThumbnailGenerator* generator = g_browser_process->GetThumbnailGenerator();
+    cell->SetThumbnail(
+        generator->GetThumbnailForRenderer(contents->render_view_host()));
+
     cell->SchedulePaint();
   } else {
     // Need to figure out under what circumstances this is null and deal.