Is it possible in ExtJS 4.0 to set a column header as a image, or custom rendered HTML?
The API for column text says:
text : String
The header text to be used as innerHTML (html tags are accepted) to display in the Grid.
Which means you can pass in something like <span class="mySpan"></span>
and define a css class that has a background image.
EDIT: Here is an example: http://jsfiddle.net/HSVj8/102/