Several improvements to the buttons pages of the widgets sample:
- Use a valid font when creating the bitmap.
- Create the bitmap with an DPI independent size.
- Use different images for different button states, as described by the
checkbox options.
- Add a checkbox to disable the bitmap.
- Recreate the button when changing label, so the bitmap is updated.
- Implement the 'fit exactly' option on ToggleButton page.
- Use more wxSizerFlags in widgets sample.
See https://github.com/wxWidgets/wxWidgets/pull/1188