dynamically sized text boxed

There's a clumsy hack where you use sampleImage() to detect the extents of the text. It basically starts at the top of the comp and moves down, one row of pixels at a time looking for the first non-zero alpha. Then it does the same thing bottom up, left-to-right, and right-to-left. There are examples of it in the archives of this forum.

Scripting has a function (sourceRectAtTime) that you can use to directly retrieve the extents of a text layer. If you go the scripting route, that's probably a better way to update your text as well.

Dan

Assuming that your text layer is the first layer in the active comp, you would replace the text like this:

var myTextLayer = app.project.activeItem.layer(1);
var mySourceText = myTextLayer.property("Text").property("Source Text");
var myTextDoc = mySourceText.value;
myTextDoc.text = "new text";
mySourceText.setValue(myTextDoc);

Then you can get the extents of the text like this:

var myRect = myTextLayer.sourceRectAtTime(0,true);

At that point, the width of the text is myRect.width, the height is myRect.height, the left edge (relative to the text layer's anchor point) is myRect.left and the top edge is myRect.top. Given that info and the text layer's position, you should be able to size and position the background layer.

Dan