alternate ntp: implement searchbox api for instant overlay to adopt themes

chrome/browser/ui/browser_instant_controller.cc

 // Copyright 2012 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/browser_instant_controller.h"
 
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/themes/theme_service.h"
+#include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/omnibox/location_bar.h"
 #include "chrome/browser/ui/search/search.h"
 #include "chrome/browser/ui/search/search_model.h"
 #include "chrome/browser/ui/search/search_tab_helper.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/webui/ntp/app_launcher_handler.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/web_contents.h"
+#include "grit/theme_resources.h"
+#include "ui/gfx/color_utils.h"
+#include "ui/gfx/sys_color_change_listener.h"
+
 
 namespace chrome {
 
 ////////////////////////////////////////////////////////////////////////////////
 // BrowserInstantController, public:
 
 BrowserInstantController::BrowserInstantController(Browser* browser)
     : browser_(browser),
       instant_(ALLOW_THIS_IN_INITIALIZER_LIST(this),
                chrome::search::IsInstantExtendedAPIEnabled(browser->profile())),
-      instant_unload_handler_(browser) {
+      instant_unload_handler_(browser),
+      initialized_theme_info_(false),
+      theme_area_height_(0) {
   profile_pref_registrar_.Init(browser_->profile()->GetPrefs());
   profile_pref_registrar_.Add(prefs::kInstantEnabled, this);
   instant_.SetInstantEnabled(IsInstantEnabled(browser_->profile()));
   browser_->search_model()->AddObserver(this);
+
+#if defined(ENABLE_THEMES)
+  // Listen for theme installation.
+  registrar_.Add(this, chrome::NOTIFICATION_BROWSER_THEME_CHANGED,
+                 content::Source<ThemeService>(
+                     ThemeServiceFactory::GetForProfile(browser_->profile())));
+#endif  // defined(ENABLE_THEMES)
 }
 
 BrowserInstantController::~BrowserInstantController() {
   browser_->search_model()->RemoveObserver(this);
 }
 
 bool BrowserInstantController::IsInstantEnabled(Profile* profile) {
   return profile && !profile->IsOffTheRecord() && profile->GetPrefs() &&
          profile->GetPrefs()->GetBoolean(prefs::kInstantEnabled);
 }
@@ skipping 62 matching lines @@
 }
 
 TabContents* BrowserInstantController::GetActiveTabContents() const {
   return browser_->tab_strip_model()->GetActiveTabContents();
 }
 
 void BrowserInstantController::ActiveTabChanged() {
   instant_.ActiveTabChanged();
 }
 
+void BrowserInstantController::SetContentHeight(int height) {
+  OnThemeAreaHeightChanged(height);
+}
+
+void BrowserInstantController::UpdateThemeInfoForPreview() {
+  // Update theme background info and theme area height.
+  // Initialize |theme_info| if necessary.
+  // |OnThemeChanged| also updates theme area height if necessary.
+  if (!initialized_theme_info_)
+    OnThemeChanged(ThemeServiceFactory::GetForProfile(browser_->profile()));
+  else
+    OnThemeChanged(NULL);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // BrowserInstantController, PrefObserver implementation:
 
 void BrowserInstantController::OnPreferenceChanged(
     PrefServiceBase* service,
     const std::string& pref_name) {
   instant_.SetInstantEnabled(IsInstantEnabled(browser_->profile()));
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // BrowserInstantController, search::SearchModelObserver implementation:
 
 void BrowserInstantController::ModeChanged(const search::Mode& old_mode,
                                            const search::Mode& new_mode) {
   instant_.SearchModeChanged(old_mode, new_mode);
+
+  // If mode is now |NTP|, send theme-related information to instant.
+  if (new_mode.is_ntp())
+    UpdateThemeInfoForPreview();

[sreeram, 2012/11/20 17:37:58]

Wait, why do we need to send the theme info the preview _every_ time the mode
changes to NTP? I thought we only need to send if either the theme info changes
(Observe() is called) or if Instant creates a new preview
(UpdateThemeInfoForPreview() is called).

[kuan, 2012/11/20 17:52:24]

i don't send the theme-related info when the mode is not NTP (@255, @271), so if
theme or theme area height changes during non-ntp modes, instant overlay doesn't
get updated, which means it needs the latest theme-related info when mode
switches to NTP.

[sreeram, 2012/11/20 17:55:11]

I think that's wasteful. The common case will not be the theme changing. The
common case will be the user creating an NTP. It's wasteful to send these huge
data structures over to the preview when in fact, nothing has changed. Why not
send the info to the preview when the theme changes? The preview already knows
when it's supposed to show the NTP, so it can cache the theme info until it
needs to use it.

[kuan, 2012/11/20 18:07:36]

the structure i'm sending over consists of 4 short words, 1 int, and a url.
if i were to do as u say, the theme area height would be an overkill to send
when mode is not ntp, 'cos that happens while the window is being resized.
shld i send the theme info as long as theme changes, but the theme area height
only when mode switches to ntp?

[sreeram, 2012/11/20 18:16:29]

Ok, never mind then. (I thought incorrectly that you were sending the entire
background image as a string.)

However, do swap the lines above so that you send the theme info _before_
calling instant_.SearchModeChanged(). This way, the preview can be sure that
whenever it receives a modechanged to NTP, it can immediately layout based on
the last received theme info.

[kuan, 2012/11/20 18:50:48]

Done.

+}
+
+////////////////////////////////////////////////////////////////////////////////
+// BrowserInstantController, content::NotificationObserver implementation:
+
+void BrowserInstantController::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+#if defined(ENABLE_THEMES)
+  DCHECK_EQ(chrome::NOTIFICATION_BROWSER_THEME_CHANGED, type);
+  OnThemeChanged(content::Source<ThemeService>(source).ptr());
+#endif  // defined(ENABLE_THEMES)
+}
+
+void BrowserInstantController::OnThemeChanged(ThemeService* theme_service) {
+  if (theme_service) {  // Get theme information from theme service.
+    theme_info_ = ThemeBackgroundInfo();
+
+    // Set theme background color.
+    SkColor background_color =
+        theme_service->GetColor(ThemeService::COLOR_NTP_BACKGROUND);
+    if (gfx::IsInvertedColorScheme())
+      background_color = color_utils::InvertColor(background_color);
+    theme_info_.color_r = SkColorGetR(background_color);
+    theme_info_.color_g = SkColorGetG(background_color);
+    theme_info_.color_b = SkColorGetB(background_color);
+    theme_info_.color_a = SkColorGetA(background_color);
+
+    if (theme_service->HasCustomImage(IDR_THEME_NTP_BACKGROUND)) {
+      // Set theme id for theme background image url.
+      theme_info_.theme_id = theme_service->GetThemeID();
+
+      // Set theme background image horizontal alignment.
+      int alignment = 0;
+      theme_service->GetDisplayProperty(ThemeService::NTP_BACKGROUND_ALIGNMENT,
+                                        &alignment);
+      if (alignment & ThemeService::ALIGN_LEFT) {
+        theme_info_.image_horizontal_alignment = THEME_BKGRND_IMAGE_ALIGN_LEFT;
+      } else if (alignment & ThemeService::ALIGN_RIGHT) {
+        theme_info_.image_horizontal_alignment = THEME_BKGRND_IMAGE_ALIGN_RIGHT;
+      } else {  // ALIGN_CENTER
+        theme_info_.image_horizontal_alignment =
+            THEME_BKGRND_IMAGE_ALIGN_CENTER;
+      }
+
+      // Set theme background image vertical alignment.
+      if (alignment & ThemeService::ALIGN_TOP)
+        theme_info_.image_vertical_alignment = THEME_BKGRND_IMAGE_ALIGN_TOP;
+      else if (alignment & ThemeService::ALIGN_BOTTOM)
+        theme_info_.image_vertical_alignment = THEME_BKGRND_IMAGE_ALIGN_BOTTOM;
+      else // ALIGN_CENTER
+        theme_info_.image_vertical_alignment = THEME_BKGRND_IMAGE_ALIGN_CENTER;
+
+      // Set theme background image tiling.
+      int tiling = 0;
+      theme_service->GetDisplayProperty(ThemeService::NTP_BACKGROUND_TILING,
+                                        &tiling);
+      switch (tiling) {
+        case ThemeService::NO_REPEAT:
+            theme_info_.image_tiling = THEME_BKGRND_IMAGE_NO_REPEAT;
+            break;
+        case ThemeService::REPEAT_X:
+            theme_info_.image_tiling = THEME_BKGRND_IMAGE_REPEAT_X;
+            break;
+        case ThemeService::REPEAT_Y:
+            theme_info_.image_tiling = THEME_BKGRND_IMAGE_REPEAT_Y;
+            break;
+        case ThemeService::REPEAT:
+            theme_info_.image_tiling = THEME_BKGRND_IMAGE_REPEAT;
+            break;
+      }
+
+      // Set theme background image height.
+      gfx::ImageSkia* image = theme_service->GetImageSkiaNamed(
+          IDR_THEME_NTP_BACKGROUND);
+      DCHECK(image);
+      theme_info_.image_height = image->height();
+    }
+
+    initialized_theme_info_ = true;
+  }
+
+  DCHECK(initialized_theme_info_);
+
+  if (browser_->search_model()->mode().is_ntp()) {
+    instant_.ThemeChanged(theme_info_);
+
+    // Theme area height is only sent to preview for non-top-aligned images;
+    // new theme may have a different alignment that requires preview to know
+    // theme area height.
+    OnThemeAreaHeightChanged(theme_area_height_);
+  }
+}
+
+void BrowserInstantController::OnThemeAreaHeightChanged(int height) {
+  theme_area_height_ = height;
+
+  // Notify preview only if mode is |NTP| and theme background image is not top-
+  // aligned; top-aligned images don't need theme area height to determine which
+  // part of the image overlay should draw, 'cos the origin is top-left.
+  if (!browser_->search_model()->mode().is_ntp() ||
+      theme_info_.theme_id.empty() ||
+      theme_info_.image_vertical_alignment == THEME_BKGRND_IMAGE_ALIGN_TOP) {
+    return;
+  }
+  instant_.ThemeAreaHeightChanged(theme_area_height_);
 }
 
 }  // namespace chrome