Improve large tab strip by leveraging touch icons when present

chrome/browser/ui/touch/tabs/touch_tab.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/touch/tabs/touch_tab.h"
 
 #include "base/logging.h"
 #include "chrome/browser/themes/theme_service.h"
 #include "grit/app_resources.h"
 #include "grit/theme_resources.h"
 #include "grit/theme_resources_standard.h"
+#include "skia/ext/image_operations.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/canvas_skia.h"
 #include "ui/gfx/favicon_size.h"
 #include "ui/gfx/path.h"
 #include "ui/gfx/skbitmap_operations.h"
 
 static const int kLeftPadding = 16;
 static const int kRightPadding = 15;
 static const int kDropShadowHeight = 2;
 
-// The size of the favicon touch area. This generally would be the same as
-// kFaviconSize in ui/gfx/favicon_size.h
-static const int kTouchTabIconSize = 32;
-
 TouchTab::TouchTabImage TouchTab::tab_alpha = {0};
 TouchTab::TouchTabImage TouchTab::tab_active = {0};
 TouchTab::TouchTabImage TouchTab::tab_inactive = {0};
 
 ////////////////////////////////////////////////////////////////////////////////
 // TouchTab, public:
 
 TouchTab::TouchTab(TabController* controller)
     : BaseTab(controller) {
   InitTabResources();
@@ skipping 137 matching lines @@
 
   // Now draw the highlights/shadows around the tab edge.
   canvas->DrawBitmapInt(*tab_image->image_l, 0, y_base);
   canvas->TileImageInt(*tab_image->image_c, tab_image->l_width, y_base,
       width() - tab_image->l_width - tab_image->r_width, image_height);
   canvas->DrawBitmapInt(*tab_image->image_r, width() - tab_image->r_width,
                         y_base);
 }
 
 void TouchTab::PaintIcon(gfx::Canvas* canvas) {
-  // TODO(wyck): use thumbnailer to get better page images
   int x = favicon_bounds_.x();
   int y = favicon_bounds_.y();
 
   TouchTabImage* tab_image = &tab_active;
   int x_base = tab_image->image_l->width();
 
   x += x_base;
 
   if (base::i18n::IsRTL()) {
-    x = width() - x -
-        (data().favicon.isNull() ? kFaviconSize : data().favicon.width());
+    x = width() - x - (data().favicon.isNull()
+        ? kTouchTargetIconSize : data().favicon.width());
   }
 
-  int favicon_x = x;
-  if (!data().favicon.isNull() && data().favicon.width() != kFaviconSize)
-    favicon_x += (data().favicon.width() - kFaviconSize) / 2;
-
   if (data().network_state != TabRendererData::NETWORK_STATE_NONE) {
     ui::ThemeProvider* tp = GetThemeProvider();
     SkBitmap frames(*tp->GetBitmapNamed(
-        (data().network_state == TabRendererData::NETWORK_STATE_WAITING) ?
-        IDR_THROBBER_WAITING : IDR_THROBBER));
+        (data().network_state == TabRendererData::NETWORK_STATE_WAITING)
+                ? IDR_THROBBER_WAITING : IDR_THROBBER));
     int image_size = frames.height();
     int image_offset = loading_animation_frame() * image_size;
-    canvas->DrawBitmapInt(frames, image_offset, 0, image_size, image_size, x, y,
-                          kTouchTabIconSize, kTouchTabIconSize, false);
+    canvas->DrawBitmapInt(frames, image_offset, 0, image_size, image_size, x,
+        y, kTouchTargetIconSize, kTouchTargetIconSize, false);
   } else {
     canvas->Save();
     canvas->ClipRectInt(0, 0, width(), height());
     if (should_display_crashed_favicon()) {
       ResourceBundle& rb = ResourceBundle::GetSharedInstance();
       SkBitmap crashed_favicon(*rb.GetBitmapNamed(IDR_SAD_FAVICON));
       canvas->DrawBitmapInt(crashed_favicon, 0, 0, crashed_favicon.width(),
           crashed_favicon.height(), x, y + favicon_hiding_offset(),
-          kTouchTabIconSize, kTouchTabIconSize, true);
+          kTouchTargetIconSize, kTouchTargetIconSize, true);
     } else {
       if (!data().favicon.isNull()) {
-
-        if ((data().favicon.width() == kTouchTabIconSize) &&
-            (data().favicon.height() == kTouchTabIconSize)) {
-          canvas->DrawBitmapInt(data().favicon, 0, 0,
-                                data().favicon.width(), data().favicon.height(),
-                                x, y + favicon_hiding_offset(),
-                                kTouchTabIconSize, kTouchTabIconSize, true);
+        // At this stage small favicons (16x16) are copied from NavigationEntry
+        // and need to be scaled every time, touch icons on the other hand
+        // should have been rescaled properly (to 32x32) in method:
+        // TouchTabStripController::OnTouchIconAvailable().
+        if (data().favicon.width() == kFaviconSize
+            && data().favicon.height() == kFaviconSize) {

[sky, 2011/06/16 15:43:41]

&& should be on the previous line.
Also, you should change SetTabRendererDataFromModel to scale the image there.
That way, you only scale once no matter how many times you might end up
painting.

[Emmanuel Saint-loubert-Bié, 2011/06/17 00:01:44]

Done.

+          SkBitmap scaled_image = skia::ImageOperations::Resize(data().favicon,
+              skia::ImageOperations::RESIZE_BEST, kTouchTargetIconSize,
+              kTouchTargetIconSize);
+          canvas->DrawBitmapInt(scaled_image, 0, 0, kTouchTargetIconSize,
+              kTouchTargetIconSize, x, y + favicon_hiding_offset(),
+              kTouchTargetIconSize, kTouchTargetIconSize, true);
         } else {
-          // Draw a background around target touch area in case the favicon
-          // is smaller than touch area (e.g www.google.com is 16x16 now)
-          canvas->DrawRectInt(
-              GetThemeProvider()->GetColor(
-                  ThemeService::COLOR_BUTTON_BACKGROUND),
-              x, y, kTouchTabIconSize, kTouchTabIconSize);
-
-          // We center the image
-          // TODO(saintlou): later request larger image from HistoryService
           canvas->DrawBitmapInt(data().favicon, 0, 0, data().favicon.width(),
-              data().favicon.height(),
-              x + ((kTouchTabIconSize - data().favicon.width()) / 2),
-              y + ((kTouchTabIconSize - data().favicon.height()) / 2) +
-                                                     favicon_hiding_offset(),
-              data().favicon.width(), data().favicon.height(), true);
+              data().favicon.height(), x, y + favicon_hiding_offset(),
+              kTouchTargetIconSize, kTouchTargetIconSize, true);
         }
       }
     }
     canvas->Restore();
   }
 }
 
 // static
 void TouchTab::InitTabResources() {
   static bool initialized = false;
   if (initialized)
     return;
 
   initialized = true;
 
   // Load the tab images once now, and maybe again later if the theme changes.
   LoadTabImages();
 }
 
-
 // static
 void TouchTab::LoadTabImages() {
   // We're not letting people override tab images just yet.
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
 
   tab_alpha.image_l = rb.GetBitmapNamed(IDR_TAB_ALPHA_LEFT);
   tab_alpha.image_r = rb.GetBitmapNamed(IDR_TAB_ALPHA_RIGHT);
 
   tab_active.image_l = rb.GetBitmapNamed(IDR_TAB_ACTIVE_LEFT);
   tab_active.image_c = rb.GetBitmapNamed(IDR_TAB_ACTIVE_CENTER);
   tab_active.image_r = rb.GetBitmapNamed(IDR_TAB_ACTIVE_RIGHT);
   tab_active.l_width = tab_active.image_l->width();
   tab_active.r_width = tab_active.image_r->width();
 
   tab_inactive.image_l = rb.GetBitmapNamed(IDR_TAB_INACTIVE_LEFT);
   tab_inactive.image_c = rb.GetBitmapNamed(IDR_TAB_INACTIVE_CENTER);
   tab_inactive.image_r = rb.GetBitmapNamed(IDR_TAB_INACTIVE_RIGHT);
   tab_inactive.l_width = tab_inactive.image_l->width();
   tab_inactive.r_width = tab_inactive.image_r->width();
 }