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