DevCaps Property

Applies To: Printer, Root

Description

This property reports the device capabilities of the screen or printer. It is a 4-element nested vector as follows:

[1]	Height and Width:2-element numeric vector of device in pixels
[2]	Height and Width:2-element numeric vector of device in mm
[3]	Number of colours or ¯1
[4]	Windows scaling factor as a percentage (100=no scaling). This value is the same as reported in the Display section of the Windows Control Panel

This property is useful if you want to make objects of a specific physical size. For example, to draw a 10mm square in a Form 'F' at (5,5):

      Size ← 10× ⊃÷/2↑'.' ⎕WG 'DevCaps'
      'F.R' ⎕WC 'Rect' (5 5) Size ('Coord' 'Pixel')

Notes

• the physical size reported for the screen is typically only a nominal size, because, if you use a generic video driver, Windows has no way to tell what size of screen is attached to your computer.
• The number of colours is reported only if the device has a colour depth of no more than 8 bits per pixel. For devices with greater colour depths, ¯1 is returned.
• new elements may be added to DevCaps in future releases.