Actionscript Cookbook

11.8. Aligning Radio Buttons Automatically

Problem

You want to align all the radio buttons in a group into one or more columns.

Solution

Create and invoke a custom setPositions( ) method for FRadioButtonGroupClass.

Discussion

Another problem that very quickly presents itself after you add more than one radio button is that of placement on the Stage. You can position each radio button (each of which is a movie clip) individually using the _x and _y properties. On the other hand, you can also add a custom method to FRadioButtonGroupClass that automatically aligns all the radio buttons within the group. You can use the radioInstances property (see Recipe 11.7) to loop through each button in a radio button group and space them evenly.

Our custom setPositions( ) method accepts up to four parameters:

x

The x coordinate within the parent movie clip where the first radio button should be placed. If undefined, then 0 is assumed.

y

The y coordinate within the parent movie clip where the first radio button should be placed. If undefined, then 0 is assumed.

cols

The number of columns into which the radio buttons should be organized. If undefined, the radio buttons are aligned in one vertical column.

spacing

The vertical spacing between the radio buttons, in pixels. If undefined, defaults to 15. The horizontal spacing is five pixels more than the widest item in the column

Here, then, is our custom setPositions( ) method, which you should add to your Form.as file for easy inclusion in future projects: ...