JezK
Edit File: demohelp.txt
---------------------------------------------- turtleDemo - Help ---------------------------------------------- This document has two sections: (1) How to use the demo viewer (2) How to add your own demos to the demo repository (1) How to use the demo viewer. Select a demoscript from the example menu. The (syntax coloured) source code appears in the left source code window. IT CANNOT BE EDITED, but ONLY VIEWED! - Press START button to start the demo. - Stop execution by pressing the STOP button. - Clear screen by pressing the CLEAR button. - Restart by pressing the START button again. SPECIAL demos are those which run EVENTDRIVEN. (For example clock.py - or oldTurtleDemo.py which in the end expects a mouse click.): Press START button to start the demo. - Until the EVENTLOOP is entered everything works as in an ordinary demo script. - When the EVENTLOOP is entered, you control the application by using the mouse and/or keys (or it's controlled by some timer events) To stop it you can and must press the STOP button. While the EVENTLOOP is running, the examples menu is disabled. - Only after having pressed the STOP button, you may restart it or choose another example script. * * * * * * * * In some rare situations there may occur interferences/conflicts between events concerning the demo script and those concerning the demo-viewer. (They run in the same process.) Strange behaviour may be the consequence and in the worst case you must close and restart the viewer. * * * * * * * * (2) How to add your own demos to the demo repository - place: same directory as turtledemo/__main__.py - requirements on source code: code must contain a main() function which will be executed by the viewer (see provided example scripts) main() may return a string which will be displayed in the Label below the source code window (when execution has finished.) !! For programs, which are EVENT DRIVEN, main must return !! the string "EVENTLOOP". This informs the viewer, that the !! script is still running and must be stopped by the user!