Improve large tab strip by leveraging touch icons when present

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

Index: chrome/browser/ui/touch/tabs/touch_tab_strip_controller.cc
diff --git a/chrome/browser/ui/touch/tabs/touch_tab_strip_controller.cc b/chrome/browser/ui/touch/tabs/touch_tab_strip_controller.cc
new file mode 100644
index 0000000000000000000000000000000000000000..185f5423f062b8bc0c4bd59f10459c6dc5fcdf3b
--- /dev/null
+++ b/chrome/browser/ui/touch/tabs/touch_tab_strip_controller.cc
@@ -0,0 +1,171 @@
+// 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_strip_controller.h"
+
+#include "chrome/browser/extensions/extension_tab_helper.h"
+#include "chrome/browser/favicon/favicon_tab_helper.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/browser.h"
+#include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
+#include "chrome/browser/ui/touch/tabs/touch_tab.h"
+#include "chrome/browser/ui/touch/tabs/touch_tab_strip.h"
+#include "chrome/browser/ui/views/tabs/tab_renderer_data.h"
+#include "skia/ext/image_operations.h"
+#include "ui/gfx/codec/png_codec.h"
+#include "ui/gfx/favicon_size.h"
+
+namespace {
+
+void CalcTouchIconTargetSize(int* width, int* height) {
+  if (*width > TouchTab::kTouchTargetIconSize ||
+      *height > TouchTab::kTouchTargetIconSize) {
+    // Too big, resize it maintaining the aspect ratio.
+    float aspect_ratio = static_cast<float>(*width) /
+                         static_cast<float>(*height);
+    *height = TouchTab::kTouchTargetIconSize;
+    *width = static_cast<int>(aspect_ratio * *height);
+    if (*width > TouchTab::kTouchTargetIconSize) {
+      *width = TouchTab::kTouchTargetIconSize;
+      *height = static_cast<int>(*width / aspect_ratio);
+    }
+  }
+}
+
+GURL GetURLWithoutFragment(const GURL& gurl) {
+  url_canon::Replacements<char> replacements;
+  replacements.ClearUsername();
+  replacements.ClearPassword();
+  replacements.ClearQuery();
+  replacements.ClearRef();
+  return gurl.ReplaceComponents(replacements);
+}
+
+}  // namespace
+
+TouchTabStripController::TouchTabStripController(Browser* browser,
+                                                 TabStripModel* model)
+    : BrowserTabStripController(browser, model) {
+}
+
+TouchTabStripController::~TouchTabStripController() {
+}
+
+void TouchTabStripController::TabDetachedAt(TabContentsWrapper* contents,
+                                            int model_index) {
+  if (consumer_.HasPendingRequests()) {
+    TouchTab* touch_tab = tabstrip()->GetTouchTabAtModelIndex(model_index);
+    consumer_.CancelAllRequestsForClientData(touch_tab);
+  }
+}
+
+void TouchTabStripController::TabChangedAt(TabContentsWrapper* contents,
+                                           int model_index,
+                                           TabChangeType change_type) {
+  // Clear the large icon if we are loading a different URL in the same tab.
+  if (change_type == LOADING_ONLY) {
+    TouchTab* touch_tab = tabstrip()->GetTouchTabAtModelIndex(model_index);
+    if (!touch_tab->touch_icon().isNull()) {
+      GURL existing_tab_url = GetURLWithoutFragment(touch_tab->data().url);
+      GURL page_url = GetURLWithoutFragment(contents->tab_contents()->GetURL());
+      // Reset touch icon if the url are different.
+      if (existing_tab_url != page_url) {
+        touch_tab->set_touch_icon(SkBitmap());
+        consumer_.CancelAllRequestsForClientData(touch_tab);
+      }
+    }
+  }
+
+  // Always call parent's method.
+  BrowserTabStripController::TabChangedAt(contents, model_index, change_type);
+}
+
+void TouchTabStripController::SetTabRendererDataFromModel(
+    TabContents* contents,
+    int model_index,
+    TabRendererData* data,
+    TabStatus tab_status) {
+  // Call parent first.
+  BrowserTabStripController::SetTabRendererDataFromModel(contents, model_index,
+                                                         data, tab_status);
+  if (tab_status == NEW_TAB)
+    return;
+
+  // Use the touch icon if any.
+  TouchTab* touch_tab = tabstrip()->GetTouchTabAtModelIndex(model_index);
+  if (!touch_tab->touch_icon().isNull()) {
+    data->favicon = touch_tab->touch_icon();
+    return;
+  }
+
+  // In the case where we do not have a touch icon we scale up the small
+  // favicons (16x16) which originally are coming from NavigationEntry.
+  if (data->favicon.width() == kFaviconSize &&
+      data->favicon.height() == kFaviconSize) {
+    data->favicon = skia::ImageOperations::Resize(data->favicon,
+        skia::ImageOperations::RESIZE_BEST, TouchTab::kTouchTargetIconSize,
+        TouchTab::kTouchTargetIconSize);
+  }
+
+  // Check if we have an outstanding request for this tab.
+  if (consumer_.HasPendingRequests())
+    consumer_.CancelAllRequestsForClientData(touch_tab);
+
+  // Request touch icon.
+  GURL page_url = GetURLWithoutFragment(contents->GetURL());
+  FaviconService* favicon_service = profile()->GetFaviconService(
+      Profile::EXPLICIT_ACCESS);
+  if (favicon_service) {
+    CancelableRequestProvider::Handle h =
+        favicon_service->GetFaviconForURL(
+            page_url,
+            history::TOUCH_ICON | history::TOUCH_PRECOMPOSED_ICON,
+            &consumer_,
+            NewCallback(this, &TouchTabStripController::OnTouchIconAvailable));
+    consumer_.SetClientData(favicon_service, h, touch_tab);
+  }
+}
+
+const TouchTabStrip* TouchTabStripController::tabstrip() const {
+  return static_cast<const TouchTabStrip*>(
+      BrowserTabStripController::tabstrip());
+}
+
+void TouchTabStripController::OnTouchIconAvailable(
+    FaviconService::Handle h,
+    history::FaviconData favicon) {
+  // Abandon the request when there is no valid favicon.
+  if (!favicon.is_valid())
+    return;
+
+  // Retrieve the model_index from the TouchTab pointer received.
+  TouchTab* touch_tab = consumer_.GetClientDataForCurrentRequest();
+  int model_index = tabstrip()->GetModelIndexOfBaseTab(touch_tab);
+  if (!IsValidIndex(model_index))
+    return;
+
+  // Try to decode the favicon, return on failure.
+  SkBitmap bitmap;
+  gfx::PNGCodec::Decode(favicon.image_data->front(),
+                        favicon.image_data->size(),
+                        &bitmap);
+  if (bitmap.isNull())
+    return;
+
+  // Rescale output, if needed, and assign to the TouchTab instance.
+  int width = bitmap.width();
+  int height = bitmap.height();
+  if (width == TouchTab::kTouchTargetIconSize &&
+      height == TouchTab::kTouchTargetIconSize) {
+    touch_tab->set_touch_icon(bitmap);
+  } else {
+    CalcTouchIconTargetSize(&width, &height);
+    touch_tab->set_touch_icon(skia::ImageOperations::Resize(bitmap,
+        skia::ImageOperations::RESIZE_BEST, width, height));
+  }
+
+  // Refresh UI since favicon changed.
+  browser()->GetTabContentsAt(model_index)->NotifyNavigationStateChanged(
+      TabContents::INVALIDATE_TAB);
+}