OLE Drag and Drop

RadMap is capable of performing drag and drop operation using the native OLE drag and drop support. The example below handles a scenario in which pins are dragged from the map to a RadListView control.

Figure 1: Drag and Drop Between RadMap and RadListView

In order to achieve the desired result the MouseMove, MouseUp, and DragEnter events need to be handled by RadMap. The drag operation will be started in the handler of the MouseMove event. RadListView needs to be subscribed to the DragEnter and DragDrop events.

This example uses the OpenStreetMapProvider and utilizes the MapPin objects added to a predefined layer.

RadMap allows panning out of the box. The built-in panning functionality will interfere with the custom drag and drop behavior and it needs to be disabled for the duration of the drag and drop operation.

Subscribe to Events

public DragAndDropRadMapForm()
{
    InitializeComponent();
    this.SetupProviders();
    this.SetupLayer();
    this.SetupLegend();
    this.SetupData();
    this.radMap1.AllowDrop = true;
    this.radListView1.AllowDrop = true;
    this.radMap1.MouseMove += RadMap1_MouseMove;
    this.radMap1.MouseUp += RadMap1_MouseUp;
    this.radMap1.DragEnter += RadMap1_DragEnter;
    this.radListView1.DragEnter += RadListView1_DragEnter;
    this.radListView1.DragDrop += RadListView1_DragDrop;
}

Public Sub New()
    InitializeComponent()
    Me.SetupProviders()
    Me.SetupLayer()
    Me.SetupLegend()
    Me.SetupData()
    Me.radMap1.AllowDrop = True
    Me.radListView1.AllowDrop = True
    AddHandler Me.radMap1.MouseMove, AddressOf RadMap1_MouseMove
    AddHandler Me.radMap1.MouseUp, AddressOf RadMap1_MouseUp
    AddHandler Me.radMap1.DragEnter, AddressOf RadMap1_DragEnter
    AddHandler Me.radListView1.DragEnter, AddressOf RadListView1_DragEnter
    AddHandler Me.radListView1.DragDrop, AddressOf RadListView1_DragDrop
End Sub

Handling Events

The RadMapElement.EnablePanning property will be set in the MouseMove event handler. RadListView will read the Text property of the dragged pin and add a new member item in its Items collection.

Drag and Drop Events

private void RadMap1_MouseMove(object sender, MouseEventArgs e)
{
    if (!(e.Button == MouseButtons.Left))
    {
        return;
    }
    PointL point = new PointL(e.X - this.radMap1.MapElement.PanOffset.Width, e.Y - this.radMap1.MapElement.PanOffset.Height);
    MapPin pin = this.radMap1.Layers.HitTest(point) as MapPin;
    if (pin != null && this.radMap1.MapElement.EnablePanning)
    {
        this.radMap1.MapElement.EnablePanning = false;
    }
    if (pin == null && !this.radMap1.MapElement.EnablePanning)
    {
        this.radMap1.MapElement.EnablePanning = true;
    }
    if (pin != null)
    {
        ((RadMap)sender).DoDragDrop(pin, DragDropEffects.Move);
    }
}
private void RadMap1_DragEnter(object sender, DragEventArgs e)
{
    MapPin pin = e.Data.GetData(typeof(MapPin)) as MapPin;
    e.Effect = pin == null ? DragDropEffects.None : DragDropEffects.Move;
}
private void RadMap1_MouseUp(object sender, MouseEventArgs e)
{
    this.radMap1.MapElement.EnablePanning = true;
}
private void RadListView1_DragEnter(object sender, DragEventArgs e)
{
    MapPin pin = e.Data.GetData(typeof(MapPin)) as MapPin;
    e.Effect = pin == null ? DragDropEffects.None : DragDropEffects.Move;
}
private void RadListView1_DragDrop(object sender, DragEventArgs e)
{
    MapPin pin = e.Data.GetData(typeof(MapPin)) as MapPin;
    this.radMap1.Layers["Pins"].Remove(pin);
    this.radListView1.Items.Add(pin.Text);
    this.radMap1.MapElement.Invalidate();
}

Private Sub RadMap1_MouseMove(sender As Object, e As MouseEventArgs)
    If Not (e.Button = MouseButtons.Left) Then
        Return
    End If
    Dim point As New PointL(e.X - Me.radMap1.MapElement.PanOffset.Width, e.Y - Me.radMap1.MapElement.PanOffset.Height)
    Dim pin As MapPin = TryCast(Me.radMap1.Layers.HitTest(point), MapPin)
    If pin IsNot Nothing AndAlso Me.radMap1.MapElement.EnablePanning Then
        Me.radMap1.MapElement.EnablePanning = False
    End If
    If pin Is Nothing AndAlso Not Me.radMap1.MapElement.EnablePanning Then
        Me.radMap1.MapElement.EnablePanning = True
    End If
    If pin IsNot Nothing Then
        DirectCast(sender, RadMap).DoDragDrop(pin, DragDropEffects.Move)
    End If
End Sub
Private Sub RadMap1_MouseUp(sender As Object, e As MouseEventArgs)
    Me.radMap1.MapElement.EnablePanning = True
End Sub
Private Sub RadMap1_DragEnter(sender As Object, e As DragEventArgs)
    Dim pin As MapPin = TryCast(e.Data.GetData(GetType(MapPin)), MapPin)
    e.Effect = If(pin Is Nothing, DragDropEffects.None, DragDropEffects.Move)
End Sub
Private Sub RadListView1_DragDrop(sender As Object, e As DragEventArgs)
    Dim pin As MapPin = TryCast(e.Data.GetData(GetType(MapPin)), MapPin)
    Me.radMap1.Layers("Pins").Remove(pin)
    Me.radListView1.Items.Add(pin.Text)
    Me.radMap1.MapElement.Invalidate()
End Sub
Private Sub RadListView1_DragEnter(sender As Object, e As DragEventArgs)
    Dim pin As MapPin = TryCast(e.Data.GetData(GetType(MapPin)), MapPin)
    e.Effect = If(pin Is Nothing, DragDropEffects.None, DragDropEffects.Move)
End Sub

See Also

• RadListView
• Map Providers
• Layers