A long tab on a message object in the chat view can reveal a list of action items that can be perform on the message. Customize the message's context menu in the Chat View using the ChannelFragment class.
Create a custom fragment that extends the ChannelFragment class and override the makeMessageContextMenu method which returns a list of DialogListItem objects that represent the action items. Thus, add a new DialogListItem object to the list for an additional menu item.
To remove an action item, override the makeMessageContextMenu method and remove the menu item from the list by specifying its key in the filter.
Once you've created the custom fragment, set it in the BaseApplication class.
The following code snippets show how to add or remove a Animation button from the context menu.