You may want to report this over with the CKEditor people, it's out of our scope really (don't want to take up responsibility for CKEditor usability).

The CKEditor config file could be changed in order to control the editor's behaviour. Examples:

// To disable resizing
CKEDITOR.editorConfig = function( config )
{
config.resize_enabled = false;
};

// To adjust the size
CKEDITOR.editorConfig = function( config )
{
// Sizes are in pixels
// config.resize_minWidth = 550;
config.resize_maxWidth = 500;
// config.resize_minHeight = 200;
// config.resize_maxHeight = 500;
};

Ah, that helps! However it can only be hard-coded if Composr is set to fixed width. It may be possible to do findWidth(element) on the containing box. If you want to make a patch, it would be gladly accepted, it's just too low priority for me.

Closing this, as it's a minor problem IMO, and solving it would create a bigger one.

That is, if the browser window is resized, the editor width would be too narrow.

We'd therefore have to set up an event listener to accomodate for that, but then we'd be modifying CKEditor which is something we really want to avoid, as it means forking it further.