GEOS SDK TechDocs
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3 Keyboard Input
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5 Input Hierarchies
GEOS supports pen-based systems and applications by means of the Ink data structure formats. Ink is simply a standard way of representing raw pen input as a data structure.
At the lowest level, individual visible objects can receive Ink input directly, much like they receive mouse input normally. (In addition, the VisText object has some Ink handling and handwriting recognition built into it.)
The Pen Library exports InkClass, a visible object class which accepts and stores pen input. It stores the ink compactly. The ink object allows the pen to act as an eraser, removing part or all of a pen stroke, perhaps splitting some strokes in two. See the Pen Object Library chapter for more information.
If GEOS is running on a pen-based system, it will set a particular flag in its private data. It will also install a special input monitor to alter the events the Input Manager receives from the device driver. The Input Manager and the UI then react to input events in a different manner and do not send them directly as with mouse events.
Because Ink events are not passed on immediately by the UI, the UI actually takes care of drawing them directly to the screen. This provides the user direct, immediate feedback.
GEOS SDK TechDocs
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| 3 Keyboard Input
| 5 Input Hierarchies