calculate the height and width of text blocks when pdf repositions the cursor

[olivetthered]

calculate the height and width of text blocks when pdf repositions the cursor. it should be fairly easy to keep track of the x and y origins and widths and heights as the cursor is repositioned in bodies of continuous text.

doing so should make it more easy to validate if the repositioning of the cursor is actually in the same body of text or a different body of text should be created. This is also the case if the cursor is repositioned at the same time that the text style changes mid flow.

[olivetthered]

the continuation part of this is done, all that remains to be done is the setting of the width and height elements.