get-text-extent in dc<%>

Gets the dimensions of a string drawn into this drawing context. The result is four real numbers:

• the total width of the text (depends on both the font and the text);

• the total height of the font (depends only on the font);

• the distance from the baseline of the font to the bottom of the descender (included in the height, depends only on the font); and

• extra vertical space added to the font by the font designer (included in the height, and often zero; depends only on the font).

The returned width and height define a rectangle is that guaranteed to contain the text string when it is drawn, but the fit is not necessarily tight. Some undefined number of pixels on the left, right, top, and bottom of the drawn string may be ``whitespace,'' depending on the whims of the font designer and the platform-specific font-scaling mechanism.

Unlike most methods, this method can be called for a bitmap-dc% object without a bitmap installed.

• (send a-dc get-text-extent string font combine? offset) -> four non-negative real numbers: width, height, descent, and space
     string : string
     font = #f : font% object or #f
   combine? = #f : boolean
     offset = 0 : exact non-negative integer

  Returns the size of string at it would be drawn in the drawing context, starting from the offset character of string, and continuing until the end of string or the first null character. The font argument specifies the font to use in measuring the text; if it is #f, the current font of the drawing area is used. (See also set-font.)

  If combine? is #t, then text may be drawn with adjacent characters combined to ligature glyphs, with Unicode combining characters as a single glyph, with kerning, with right-to-left ordering of characters, etc. If combine? is #f, then the result is the same as if each character is drawn separately, and Unicode control characters are ignored.