Mobile/Fennec/Extensions/UserInterface/Context Menu

The context menu appears when a user does a "long tap" (touch and hold) on a link, image, or other page/UI element. See Mark Finkle's blog post for more details.

To add a new command to the context menu, add a richlistitem element to the #context-commands list. For example, the Show Image Title add-on uses a XUL overlay like this:

 <richlistbox id="context-commands">
   <richlistitem id="showtitle-context-command"
                 class="context-command"
                 type="image"
                 onclick="ShowTitle.onclick();">
     <label value="Show Title"/>
   </richlistitem>
 </richlistbox>

Target types

The type attribute contains a space-delimited list of type names. If the the element that the user touches matches any of the included types, then the menu item will be displayed. Otherwise

The available types are:

image

An image (<img>) element.

image-loaded

An image that has finished loading succesfully.

link

A link (<a href="...">) element.

mailto

A link to a mailto: URI.

callto

A link to a telphone URI (callto:, tel:, sip:, or voipto:).

video

(new in Fennec 2.0b1) A <video> element.

link-saveable

(new in Fennec 2.0a1) Any link type except mailto:, javascript:, and news:.

link-shareable, image-shareable, video-shareable

(new in Fennec 2.0a1): Any link type except chrome:, about:, file:, javascript:, or resource:.

New in Fennec 2.0a1: If the built-in types do not work for your add-on, you can use ContextHandler.registerType to add one of your own:

 ContextHandler.registerType(name, callback); // Requires Fennec 2.0a1 or higher

registerType takes two arguments: the type name (a string), and a callback function. The callback should take two arguments: the popupState object and the target DOM element. It can modify the popupState to add new data that will be passed to the commands' onclick handlers (see below). The callback can return true if the element "matches" the new type, or false otherwise.

ContextHandler.registerType must be called in the content process using a loadFrameScript.

For example, if we want to change the "Show Image Title" example above to show the menu item only for images that actually have titles, then we could change type="image" to type="show-title" in the XUL, and add the following code in a content script:

 ContextHandler.registerType("show-title", function(popupState, element) {
   if (element.title) {
     popupState.title = element.title;
     return true;
   }
   // Otherwise, do not show commands with type="show-title":
   return false;
 });

Handling context command clicks

When the user taps a context command, its onclick handler is called. This handler can use the ContextHelper object to get more information about the element that was the target of the long-tap gesture.

ContextHelper is changing in Fennec 2.0. The "popupNode" property is no longer accessible because of Electrolysis, so it is replaced by the new "popupState" object.

The "Show Image Title" example above uses a handler like this, which works in both 1.1 and 2.0:

ShowTitle.onclick = function() {
  var state = ContextHelper.popupState || ContextHelper.popupNode;
  var text = ContextHelper.popupNode.title || ContextHelper.popupNode.title || 'no text';
  setTimeout(function() {
    var promptService =
      Components.classes['@mozilla.org/embedcomp/prompt-service;1'].
        getService(Components.interfaces.nsIPromptService);
    promptService.alert(null, 'Image Title', text);
  }, 0);
};

Here is a reference to the ContextHelper API:

Fennec 1.1

ContextHelper.popupNode

The DOM element that received the long-tap gesture.

ContextHelper.linkURL

The address of the link.

ContextHelper.mediaURL

The address of the image.

ContextHelper.onSaveableLink

(boolean) true if the link is not a javascript/mailto/news link.

Fennec 2.0

ContextHelper.popupState

An object containing more information about the target element.

ContextHelper.popupState.types

An array of the type names that the target element matched.

ContextHelper.popupState.label

A string describing the target element.

ContextHelper.popupState.linkTitle

The text of the link.

ContextHelper.popupState.linkURL

The address of the link (or null).

ContextHelper.popupState.linkProtocol

The URI scheme of the link href (or null).

ContextHelper.popupState.mediaURL

The image's src address (or null).

Sample Code

• Show Image Title source code