Reland "Implement random wallpaper feature"

chrome/browser/resources/options2/chromeos/set_wallpaper_options.js

Index: chrome/browser/resources/options2/chromeos/set_wallpaper_options.js
diff --git a/chrome/browser/resources/options2/chromeos/set_wallpaper_options.js b/chrome/browser/resources/options2/chromeos/set_wallpaper_options.js
index 3910569d18fa37a3739d6837fe1e3607487ac7e2..689e78328db4ad41176fc069b08c7ca3c55eaf5c 100644
--- a/chrome/browser/resources/options2/chromeos/set_wallpaper_options.js
+++ b/chrome/browser/resources/options2/chromeos/set_wallpaper_options.js
@@ -45,6 +45,7 @@ cr.define('options', function() {
       wallpaperGrid.addEventListener('activate',
                                      function() { OptionsPage.closeOverlay() });
 
+      $('use-random-wallpaper').onclick = this.handleCheckboxClick_.bind(this);
       $('set-wallpaper-overlay-confirm').onclick = function() {
         OptionsPage.closeOverlay();
       };
@@ -103,7 +104,7 @@ cr.define('options', function() {
       if (url &&
           !wallpaperGrid.inProgramSelection) {
         this.setWallpaperAttribution_(url);
-        chrome.send('selectWallpaper', [url]);
+        chrome.send('selectDefaultWallpaper', [url]);
       }
     },
 
@@ -112,19 +113,51 @@ cr.define('options', function() {
      * @param {Event} e Double click Event.
      */
     handleImageDblClick_: function(e) {
+      var wallpaperGrid = $('wallpaper-grid');
+      if (wallpaperGrid.disabled)
+        return;
       // Close page unless the click target is the grid itself.
       if (e.target instanceof HTMLImageElement)
         OptionsPage.closeOverlay();
     },
 
     /**
-     * Selects corresponding wallpaper thumbnail with the given URL.
+     * Handles click on the "I'm feeling lucky" checkbox.
+     * @private
+     */
+    handleCheckboxClick_: function() {
+      var wallpaperGrid = $('wallpaper-grid');
+      if ($('use-random-wallpaper').checked) {
+        wallpaperGrid.disabled = true;
+        chrome.send('selectRandomWallpaper');
+        wallpaperGrid.classList.add('grayout');
+      } else {
+        wallpaperGrid.disabled = false;
+        wallpaperGrid.classList.remove('grayout');
+        // Set the wallpaper type to User::DEFAULT.
+        this.handleImageSelected_();
+      }
+    },
+
+    /**
+     * Selects corresponding wallpaper thumbnail with the given URL and toggle
+     * the "I'm feeling lucky" checkbox.
      * @param {string} url URL of the wallpaper thumbnail to select.
+     * @param {boolean} isRandom True if user checked "I'm feeling lucky"
+     * checkbox.
      * @private
      */
-    setSelectedImage_: function(url) {
-      $('wallpaper-grid').selectedItemUrl = url;
+    setSelectedImage_: function(url, isRandom) {
+      var wallpaperGrid = $('wallpaper-grid');
+      wallpaperGrid.selectedItemUrl = url;
       this.setWallpaperAttribution_(url);
+      if (isRandom) {
+        // Do not call chrome.send('selectRandomWallpaper'), it is not
+        // neccessary to generate a new random index here.
+        $('use-random-wallpaper').checked = true;
+        wallpaperGrid.disabled = true;
+        wallpaperGrid.classList.add('grayout');
+      }
     },
 
     /**