X11_Graphics

Superclass: W3Input

An abstract W3Kit base class for raw X11 graphics. The main subclass methods are drawX11Graphics and mouseClick:.

Coordinates

The "essential state" of the drawing area consists of the image size.

The coordinate system for drawing is consistent with X11 coordinates, i.e. they are in pixel units, with the origin in the upper left corner, x-axis pointing right, and y-axis pointing down.

- setIntSize:(const IntSize *)theSize;
- getIntSize:(IntSize *)theSize;

Events and Display

Override these in subclass to customize appearance, event response.

- drawX11Graphics;
- mouseClick:(const Point2 *)aPoint;

Different ways to route the output of drawing.

- printHtml;           // print HTML for inlining the image
- display;             // send out-of-line image back to user and exit
- snapshotDocument;    // capture image in a W3Document (returned)

On some systems, it is possible to adjust the image depth.

- setImageBitDepth:(int)bits;
- takeImageBitDepthFrom:sender;

Incremental Drawing

If you need to perform X11 calls prior to drawX11Graphics, surround them with the matched pair of messages below.

(Note that the return value of lockFocus is NOT a success flag. It merely indicates whether focus has already been locked on this widget. The call to lockFocus should be balanced with an unlockFocus in any case.)

- (BOOL)lockFocus;
- unlockFocus;

Up: W3Kit Class Reference

The Geometry Center Home Page

Author: Paul Burchard
Comments to: webmaster@www.geom.uiuc.edu
Created: Apr 18 1994 --- Last modified: Tue Jun 18 10:44:38 1996