/// <summary>
/// Event raised on mouse down in the NetworkView.
/// </summary>
private void NetworkControl_MouseDown(object sender, MouseButtonEventArgs e)
{
NetworkView networkView = sender as NetworkView;
networkView.Focus();
Keyboard.Focus(networkView);
mouseButtonDown = e.ChangedButton;
origZoomAndPanControlMouseDownPoint = e.GetPosition(zoomAndPanControl);
origContentMouseDownPoint = e.GetPosition(networkView);
if ((Keyboard.Modifiers & ModifierKeys.Shift) != 0 &&
(e.ChangedButton == MouseButton.Left ||
e.ChangedButton == MouseButton.Right))
{
// Shift + left- or right-down initiates zooming mode.
mouseHandlingMode = MouseHandlingMode.Zooming;
}
else if (mouseButtonDown == MouseButton.Left &&
(Keyboard.Modifiers & ModifierKeys.Control) == 0)
{
//
// Initiate panning, when control is not held down.
// When control is held down left dragging is used for drag selection.
// After panning has been initiated the user must drag further than the threshold value to actually start drag panning.
//
mouseHandlingMode = MouseHandlingMode.Panning;
}
if (mouseHandlingMode != MouseHandlingMode.None)
{
// Capture the mouse so that we eventually receive the mouse up event.
networkView.CaptureMouse();
e.Handled = true;
}
}