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Drawables

Much of the drawing protocol is defined in abstract classes. These can be subclassed to support drawing on canvases other than bitmaps and views.

For example, a public domain goodie adds support to draw on a Postscript printer page. Therefore, the same piece of code that did the view redraw can now be used to send a hardcopy to the printer.

View

The View class provides the most of the GUI functionality - although in a very generic and abstract way. It deals with resizing, redrawing, startup and closedown of views.
Most other GUI components inherit (i.e. are subclassed) from this class.

StandardSystemView

This class provides protocol to define a views icon, window title and position on the screen. On systems which support this (i.e. X displays with Shape extension) arbitrary shaped views (like round clocks) are supported.
Also iconification, icon windows, size constrains and manual focus change via the keyboard are supported.


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