Bug 952456 - Part 2: Support copy image in BrowserElement. r=kchen

Add a new context menu option, copy image.

--HG--
extra : histedit_source : 5af95cb5fa11727ad1034fcbe5fb855d914b2b62

dom/browser-element/BrowserElementChildPreload.js

@@ -63,6 +63,7 @@ const OBSERVED_EVENTS = [
 const COMMAND_MAP = {
   'cut': 'cmd_cut',
   'copy': 'cmd_copyAndCollapseToEnd',
+  'copyImage': 'cmd_copyImage',
   'paste': 'cmd_paste',
   'selectall': 'cmd_selectAll'
 };
@@ -855,6 +856,11 @@ BrowserElementChild.prototype = {
     var elem = e.target;
     var menuData = {systemTargets: [], contextmenu: null};
     var ctxMenuId = null;
+    var hasImgElement = false;
+
+    // Set the event target as the copy image command needs it to
+    // determine what was context-clicked on.
+    docShell.contentViewer.QueryInterface(Ci.nsIContentViewerEdit).setCommandNode(elem);
 
     while (elem && elem.parentNode) {
       var ctxData = this._getSystemCtxMenuData(elem);
@@ -868,14 +874,21 @@ BrowserElementChild.prototype = {
       if (!ctxMenuId && 'hasAttribute' in elem && elem.hasAttribute('contextmenu')) {
         ctxMenuId = elem.getAttribute('contextmenu');
       }
+
+      // Enable copy image option
+      if (elem.nodeName == 'IMG') {
+        hasImgElement = true;
+      }
+
       elem = elem.parentNode;
     }
 
+    if (ctxMenuId || hasImgElement) {
+      var menu = null;
       if (ctxMenuId) {
-      var menu = e.target.ownerDocument.getElementById(ctxMenuId);
+        menu = e.target.ownerDocument.getElementById(ctxMenuId);
-      if (menu) {
-        menuData.contextmenu = this._buildMenuObj(menu, '');
       }
+      menuData.contextmenu = this._buildMenuObj(menu, '', hasImgElement);
     }
 
     // Pass along the position where the context menu should be located
@@ -1208,22 +1221,29 @@ BrowserElementChild.prototype = {
 
   _recvFireCtxCallback: function(data) {
     debug("Received fireCtxCallback message: (" + data.json.menuitem + ")");
-    // We silently ignore if the embedder uses an incorrect id in the callback
+
-    if (data.json.menuitem in this._ctxHandlers) {
+    if (data.json.menuitem == 'copy-image') {
+      // Set command
+      data.json.command = 'copyImage';
+      this._recvDoCommand(data);
+    } else if (data.json.menuitem in this._ctxHandlers) {
       this._ctxHandlers[data.json.menuitem].click();
       this._ctxHandlers = {};
     } else {
+      // We silently ignore if the embedder uses an incorrect id in the callback
       debug("Ignored invalid contextmenu invocation");
     }
   },
 
-  _buildMenuObj: function(menu, idPrefix) {
+  _buildMenuObj: function(menu, idPrefix, hasImgElement) {
     var menuObj = {type: 'menu', items: []};
+    // Customized context menu
+    if (menu) {
       this._maybeCopyAttribute(menu, menuObj, 'label');
 
       for (var i = 0, child; child = menu.children[i++];) {
         if (child.nodeName === 'MENU') {
-        menuObj.items.push(this._buildMenuObj(child, idPrefix + i + '_'));
+          menuObj.items.push(this._buildMenuObj(child, idPrefix + i + '_', false));
         } else if (child.nodeName === 'MENUITEM') {
           var id = this._ctxCounter + '_' + idPrefix + i;
           var menuitem = {id: id, type: 'menuitem'};
@@ -1233,6 +1253,12 @@ BrowserElementChild.prototype = {
           menuObj.items.push(menuitem);
         }
       }
+    }
+    // "Copy Image" menu item
+    if (hasImgElement) {
+      menuObj.items.push({id: 'copy-image'});
+    }
+
     return menuObj;
   },