Obtains the width and height needed to render the column.
This is used primarily by the `GtkTreeView`.
this |
A `GtkTreeViewColumn`. |
x_offset |
location to return x offset of a cell relative to |
y_offset |
location to return y offset of a cell relative to |
width |
location to return width needed to render a cell |
height |
location to return height needed to render a cell |