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User Interface for .NET / User's Guide / Command Bars / Manager / Extending the Manager

In This Topic
    Extending the Manager
    In This Topic
     Overview
    The NCommandBarsManager component is highly customizable regarding behaviour and children elements appearance. Being the root element of the docking toolbars framework, all commands delegate their functionality to the manager, which makes it possible to perform application specific customizations at the manager's level.
     Customizing Appearance

    You can customize the appearance of the entire framework by using the manager's Palette property.
    The following example demonstrates how to change the look-and-feel of the framework by using a predefined ColorScheme:

    C#
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    this.nCommandBarsManager.Palette.Scheme = ColorScheme.LunaSilver;
    
    Visual Basic
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    Me.nCommandBarsManager.Palette.Scheme = ColorScheme.LunaSilver
    
    For more information about palettes see Using Palettes.

    You may also extend docks by providing your custom renderers.
    The following example demonstrates how to achieve this:

    C#
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    //create a class that derives from the default NToolbarDockRenderer
    public class MyToolbarDockRenderer : NToolbarDockRenderer
    {
        public MyToolbarDockRenderer()
        {
        }
    
        protected override void DrawParentBackground(Graphics g)
        {
      Control dock = Parent;
      if(dock == null)
           return;
    
      Rectangle bounds = dock.ClientRectangle;
      Color begin = Color.FromArgb(51, 51, 51);
      Color end = NColorHelper.LightLight(begin);
    
      //create a gradient like one found in Longhorn
      LinearGradientBrush brush = new LinearGradientBrush(bounds, begin, end, 0.0f, false);
    
      brush.SetSigmaBellShape(0.5f);
    
      g.FillRectangle(brush, bounds);
    
      Font f = null;
    
      try
      {
           //draw sample text
           f = new Font("Trebuchet MS", 14, FontStyle.Bold);
           //use cashed renderer's brush to speed up performance
           Brush.Color = Color.Yellow;
           g.DrawString("Longhorn Style Toolbar Dock", f, Brush, bounds, StringFormat);
      }
      finally
      {
           brush.Dispose();
           if(f != null)
                {
                    f.Dispose();
                }
      }
        }
    }
    
    //assign an instance of this renderer to the top dock
    this.nCommandBarsManager.GetDock(DockStyle.Top).Renderer = new MyToolbarDockRenderer();
    
    Visual Basic
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    'create a class that derives from the default NToolbarDockRenderer
    Public class MyToolbarDockRenderer 
       Inherits NToolbarDockRenderer
        Public Sub New()
        End Sub
    
        Protected Overrides Sub DrawParentBackground(ByVal g As Graphics)
            Dim dock As Control = Parent
            If dock == null Than 
                return
            End If
    
            Dim bounds As Rectangle = dock.ClientRectangle
            Dim beginColor As Color = Color.FromArgb(51, 51, 51)
            Dim endColor As Color = NColorHelper.LightLight(beginColor)
    
            'create a gradient like one found in Longhorn
            Dim brush As LinearGradientBrush = New LinearGradientBrush(bounds, beginColor, endColor, 0.0F, False)
    
            brush.SetSigmaBellShape(0.5F)
    
            g.FillRectangle(brush, bounds)
    
            Dim f As Font = Nothing
    
            Try
                'draw sample text
                f = New Font("Trebuchet MS", 14, FontStyle.Bold)
                'use cashed renderer's brush to speed up performance
                Brush.Color = Color.Yellow
                g.DrawString("Longhorn Style Toolbar Dock", f, Brush, bounds, StringFormat)
            Finally
                brush.Dispose()
                If f <> Nothing Than 
                    f.Dispose()
                End If
            End Finally
        End Sub
    End Class
    
    'assign an instance of this renderer to the top dock
    Me.nCommandBarsManager.GetDock(DockStyle.Top).Renderer = New MyToolbarDockRenderer()
    

    The result of our custom renderer.

     Providing Custom Behaviour

    The behaviour of the NCommandBarsManager component can be extended with ease. All notifications and framework specific methods are overridable, thus allowing you to provide custom functionality/implementation.

    The following example demonstrates how to extend the OnQueryCommandUIState method:

    C#
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    //override the method and provide custom logic
    protected override void OnQueryCommandUIState(ref NCommandUIState state)
    {
        NCommandContext context = state.Context;
        if(context != myContext)
        {
      base.OnQueryCommandUIState(ref state);
      return;
        }
    
        //apply our custom logic for the specified context
        state.ImageIndex = 0;
        state.Enabled = this.CanEnableMyContext();
    }
    
    Visual Basic
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    'override the method and provide custom logic
    Protected Overrides Sub OnQueryCommandUIState(ByRef state As NCommandUIState)
        Dim context As NCommandContext = state.Context
        If context <> myContext Than
            MyBase.OnQueryCommandUIState(state)
            Return
        End If
    
        'apply our custom logic for the specified context
        state.ImageIndex = 0
        state.Enabled = Me.CanEnableMyContext()
    }
    
    See Also