get-extent

Calculates the snip's width, height, descent (amount of height which is drawn below the baseline), space (amount of height which is ``filler'' space at the top), and horizontal spaces (amount of width which is ``filler'' space at the left and right).

A drawing context is provided for the purpose of finding font sizes, etc., but no drawing should occur. The get-extent and partial-offset methods must not make any assumptions about the state of the drawing context; in particular, the snip's style settings (e.g., the font) are not automatically set before the method is called. Before get-extent or partial-offset returns, it must restore any drawing context settings that it changes.

The snip's left and top locations are provided in buffer corrdinates. In an editor buffer, the y-coordinate is the line's top location; the snip's actual top location is potentially undetermined until its height is known.

This method is called by the snip's adninistrator; it should not be called directly by others. To get the extent of a snip, use get-snip-location in wx:media-buffer% .

The snip's buffer is usually internally locked for writing and reflowing when this method is called (see also Locks).

• (send a-wx:snip get-extent dc x y w h descent space lspace rspace) -> void
      dc : wx:dc% object
      x : inexact real
      y : inexact real
      w = null : boxed inexact real or null
      h = null : boxed inexact real or null
      descent = null : boxed inexact real or null
      space = null : boxed inexact real or null
      lspace = null : boxed inexact real or null
      rspace = null : boxed inexact real or null

  Fills in all boxes with 0.0.