The file called
chrome.manifest tells Thunderbird what packages and overlays are provided by the extension. Open the file called
chrome.manifest that you created and add this code:
content myfirstext chrome/content/
contentspecifies the type of material in the package
myfirstextis the name of the chrome package (specified in the first segment of
chrome/content/is the location of the package's files within the
So, this line says that for a chrome package
myfirstext, we can find its content files in the directory
content/ (which is a path relative to the location of
To change the Thunderbird user interface to support the extension, you create an overlay and then merge it with the default Thunderbird interface. Later in the tutorial we will create a XUL overlay file that will merge with the default
messenger.xul file. At this point we are going to specify in
chrome.manifest the existence of the overlay (which we will create later).
Add this line at the end of
This tells Thunderbird to merge
messenger.xul loads. For more information on chrome manifests and the properties they support, see the Chrome Manifest Reference.