All widgets that take part in the ribbon layout implement the INRibbonWidget interface. It provides the following properties:

• CurrentState - the state in which the ribbon widget is currently in. The value of this property is automatically updated by Nevron and you should not set it manually.
• InitialState - the initial state of the ribbon widget. This is also its largest allowed state. The current and initial state properties are of integer type in order to allow support for multiple intermediate states, but in most cases you can use the ENRibbonWidgetState enumeration to set them. For example, to set the initial state of a ribbon button to Medium use the following code:

  Setting Ribbon Button Initial State	Copy Code
  ribbonButton.InitialState = ENRibbonWidgetState.Medium;

• CollapseToMedium - determines when the widget should collapse to Medium state.
• CollapseToSmall - determines when the widget should collapse to Small state. The collapse properties are of type ENCollapseCondition and can be one of the following:

  Value	Description
  Never	The widget never collapses.
  WhenParentIsMedium	The widget collapses when its parent is in medium state.
  WhenParentIsSmall	The widget collapses when its parent is in small state.

By default the CollapseToMedium property is set to WhenParentIsMedium and CollapseToSmall property is set to WhenParentIsSmall, but you can change them when needed for any ribbon widget. Note that if you set the CollapseToMedium to Never, then the widget will always remain in it initial state - Large.

The INRibbonWidget interface also provides several methods, one of which is the GetSize method. It takes a state as a parameter and returns the size of the ribbon widget in this state. This method is used by the layout engine to determine how much space can be saved when collapsing the given widget from a larger to a smaller state. That is why it is very important to implement it correctly when you create custom widgets, which should take part in the ribbon layout.

When creating custom ribbon widgets, you can use the GetWidgetStateForGroupState and the OnInitialStateChanged static methods of the NRibbonHelpers class to help you with the implementation of the similarly named methods of the INRibbonWidget interface:

public int GetStateForGroupState(int groupState)
{
    return (int)NRibbonHelpers.GetWidgetStateForGroupState(this, groupState);
}

void INRibbonWidget.OnInitialStateChanged(NValueChangeData data)
{
    NRibbonHelpers.OnInitialStateChanged(this);
}