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Basic Input

 

Upon startup, the program is in ``draw mode'' which permits the user to enter strokes into the system by drawing with the pen on the drawing tablet. As the user writes, the system automatically interprets their strokes, after waiting for the user to get a number of strokes ahead before it begins processing. Since the processing, described in Section 4.3.4, annotates the user's input, this delay helps avoid any potential distraction for the user, and also ensures that the processing will not interfere with the symbol that the user is currently drawing.

Processing also automatically begins after a user definable period of inactivity, defaulting to one second. Thus, the system will ``notice'' that the user has finished entering their formula, and automatically catch up recognition of all outstanding strokes. Alternatively, the user can tap the pen on the tablet or choose a menu option for the same effect.

Other basic editing operations such as selection, moving and cutting are provided as well, through a select and move mode. This lets the user drag a box around a region containing the characters that they wish to be selected. The contents of the selection can then be dragged around the screen at will, or deleted.

The user interface supports multi-level undo and redo, and allows for the loading, saving and printing of formulae that the user has entered.


next up previous
Next: Stroke Segmentation Up: A Pen Based Formula Previous: The Character Recogniser
Steve Smithies
1999-11-13