Checkbox objects can clicked (i.e., selected or deselected) by the user.
The following function creates a new Checkbox, so you need to save each in a unique variable (so you can use them later).
| Function | Description |
| Checkbox(text, function) | Creates a new checkbox with the specified text label (a string) and a function (optional) to be called everytime the checkbox changes state. If provided, this function should expect one parameter (boolean – signifies the changed state of the checkbox – True means checkbox was just checked, False means checkbox was just unchecked). |
For example, a checkbox may be created as follows:
checkbox1 = Checkbox()
Once a Checkbox has been created, it may be added to a Display specifying where to place its top-left corner.
d.add(checkbox1, 50, 50)
If you create a Checkbox without using a callback function, then it is a passive GUI element. In other words, a different part of your program needs to check the state (selected, deselected) of the Checkbox. This can be done using the following functions:
| Function | Description |
| checkbox1.isChecked() | Returns Trueif checkbox1 is checked, Falseif unchecked. |
| checkbox1.check() | Sets checkbox1 (i.e., makes it appear checked). |
| checkbox1.uncheck() | Clears checkbox1 (i.e., makes it appear unchecked). |
If you create a Checkbox with a callback function, then that function will be called anytime the changes state (checked, unchecked) by the user. The function should accept one parameter.
Making Music with Computers 