cpython: 59cc3bfdac4b (original) (raw)

Mercurial > cpython

changeset 92103:59cc3bfdac4b

Issue #22065: Try the delete demohelp.txt part again. [#22065]

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deleted file mode 100644 --- a/Lib/turtledemo/demohelp.txt +++ /dev/null @@ -1,83 +0,0 @@ - -

• ---------------------------------------------- -

•  turtleDemo - Help[](#l1.9)

-

• ---------------------------------------------- -
• 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.[](#l1.34)

-

•  - Until the EVENTLOOP is entered everything works[](#l1.36)

•  as in an ordinary demo script.[](#l1.37)

-

•  - When the EVENTLOOP is entered, you control the[](#l1.39)

•  application by using the mouse and/or keys (or it's[](#l1.40)

•  controlled by some timer events)[](#l1.41)

•  To stop it you can and must press the STOP button.[](#l1.42)

-

•  While the EVENTLOOP is running, the examples menu is disabled.[](#l1.44)

-

•  - Only after having pressed the STOP button, you may[](#l1.46)

•  restart it or choose another example script.[](#l1.47)

-

• • • • • • • • *
• 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 the file in the same directory as turtledemo/main.py

• IMPORTANT! When imported, the demo should not modify the system[](#l1.61)

• by calling functions in other modules, such as sys, tkinter, or[](#l1.62)

• turtle. Global variables should be initialized in main().[](#l1.63)

-

• • The code must contain a main() function which will

• be executed by the viewer (see provided example scripts).[](#l1.66)

• It may return a string which will be displayed in the Label below[](#l1.67)

• the source code window (when execution has finished.)[](#l1.68)

-

• • In order to run mydemo.py by itself, such as during development,

• add the following at the end of the file:[](#l1.71)

-

• if name == 'main':

•    main()[](#l1.74)

•    mainloop()  # keep window open[](#l1.75)

-

• python -m turtledemo.mydemo # will then run it

-

• • If the demo is EVENT DRIVEN, main must return the string

• "EVENTLOOP". This informs the demo viewer that the script is[](#l1.80)

• still running and must be stopped by the user![](#l1.81)

-

• If an "EVENTLOOP" demo runs by itself, as with clock, which uses[](#l1.83)

• ontimer, or minimal_hanoi, which loops by recursion, then the[](#l1.84)

• code should catch the turtle.Terminator exception that will be[](#l1.85)

• raised when the user presses the STOP button.  (Paint is not such[](#l1.86)

• a demo; it only acts in response to mouse clicks and movements.)[](#l1.87)