Ribbon ToggleButton
The RadRibbonToggleButton represents an extension of the RadToggleButton. It provides an easier interaction with the RadRibbonView control. What is special about the RadRibbonToggleButton is that it has two states - checked and unchecked. To switch between these states just click on it.
To learn more about the RadToggleButtonButton control read its documentation. RadRibbonToggleButton
This button has its initial size set to Large and its text label set to "Symbol". As the IsAutoSize property is set to True the button will change its size depending on the RadRibbonGroup's size. The button will also never collapse to its Medium size and will collapse to its Small size when the RadRibbonGroup collapses to Medium.
Handling Changes in the the Button's Checked State
Besides the Click event, the RadRibbonToggleButton control exposes two additional events - Checked and Unchecked. They are meant to notify for changes in the checked state of the toggle button.