/// <summary>
/// Event raised on mouse down in the NetworkView.
/// </summary>
private void networkControl_MouseDown(object sender, MouseButtonEventArgs e)
{
NetworkControl.Focus();
Keyboard.Focus(NetworkControl);
_mouseButtonDown = e.ChangedButton;
_origZoomAndPanControlMouseDownPoint = e.GetPosition(ZoomAndPanControl);
_origContentMouseDownPoint = e.GetPosition(NetworkControl);
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.
NetworkControl.CaptureMouse();
e.Handled = true;
}
}