☜	MWAPI - Keyboard Events Draft MDC Standard					☞

9.1.3 Keyboard Events

Keyboard events (i.e. key down, key up, and character events) occur when the user presses or releases one or more keyboard keys.

If focus is on a gadget for which a keyboard event can occur, then the keyboard event occurs for that gadget. Otherwise, if focus is on a window for which a keyboard event can occur, then the keyboard event occurs for that window.

No behavior is defined for key sequences which are not mapped to key codes or character codes.

A key down event, indicated by an etype value equal to "KEYDOWN", occurs when the user presses a key.

A key up event, indicated by an etype value equal to "KEYUP", occurs when the user releases a key.

A character event, indicated by an etype value equal to "CHAR", occurs when one or more key transitions results in the production of a character.

A keyboard event does not occur if (a) the character code represents an accelerator or has a special meaning for the underlying windowing platform or (b) the FILTERIN especattribute is present for the event and the keycode or charcode associated with the event is not one of the keycodes or charcodes present in the value of that FILTERIN especattribute.

For gadgets that accept text input, only character codes that consist of a single graphic are included in the value of the gadget’s VALUE elattribute. When a keyboard event occurs for which call back processing is enabled, the gadget’s VALUE elattribute is not modified by the underlying windowing platform or the MWAPI. The application can modify the VALUE elattribute, by assigning a value explicitly.

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Copyright © Examples: 1995-2024 Ed de Moel;
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Copyright © Annotations: 2008-2024 Ed de Moel.

Some specifications are "approved for inclusion in a future standard". Note that the MUMPS Development Committee cannot guarantee that such future standards will indeed be published.

This page most recently updated on 14-Nov-2023, 22:11:37.

For comments, contact Ed de Moel (demoel@jacquardsystems.com)