Formula button properties
| BackgroundColor | The background color, which is used to paint the area behind the button text. |
| Enabled | Whether the button is enabled. |
| ForegroundColor | The foreground color, which is used to paint the label. |
| Label | The label. |
| Name | The name, as assigned in Calcapp Creator. |
| OnPress | Invoked when the user presses the button. |
| Reference | A reference to the formula button. |
| Visible | Whether the button is visible. |