RadRibbonGroup fill space

[Maurício]

Hello

I would like to know how I could fill all empty space in a RadRibbonTab with a RadRibbonGroup.

[Martin Ivanov]

Hello Maurício,

There is no out-of-the-box approach for expanding a ribbon group in all available space of its ribbon tab. However, you can achieve this with custom code. Basically you can create a custom groups panel that inherits the RibbonGroupsPanel and override its ArrangeOverride() method. 

public class CustomPanel : RibbonGroupsPanel
{
    private const double Padding = 5d;
    protected override Size ArrangeOverride(Size finalSize)
    {
        var size = base.ArrangeOverride(finalSize);

        var groups = this.Children.OfType<RadRibbonGroup>();
        double x = 0d;
        for (int i = 0; i < groups.Count(); i++)
        {
            var group = groups.ElementAt(i);
            double width = group.DesiredSize.Width;
            if (i == groups.Count()-1)
            {
                var ribbon = this.ParentOfType<RadRibbonView>();
                width = Math.Max(0, ribbon.ActualWidth - x - Padding);
                group.Arrange(new Rect(x, 0, width, finalSize.Height));
            }
            if (width > 0)
            {
                x += width + this.ItemSpacing;
            }
        }

        return finalSize;
    }
}

Then set it as an ItemsPanel of the RadRibbonTabs.

<Window.Resources>
    <ItemsPanelTemplate x:Key="RadRibbonGroupPanelTemplate">
        <local:CustomPanel/>
    </ItemsPanelTemplate>
    <Style TargetType="telerik:RadRibbonTab">
        <Setter Property="ItemsPanel" Value="{StaticResource RadRibbonGroupPanelTemplate}" />
    </Style>
</Window.Resources>

I also attached a sample project demonstrating this approach. Please give it a try and let me know if it works for you.

Regards,
Martin
Telerik