private void panelRegionSelectionToolStripMenuItem_Click(object sender, EventArgs e)
{
ThumbnailPanel panel = (ThumbnailPanel)panelContextMenuStrip.SourceControl;
RegionSelector selector = new RegionSelector();
selector.Load += (eventSender, eventArgs) =>
{
selector.SetWindow(panel.GetWindow(), panel.ClientAreaOnly);
selector.DrawnRegion = panel.DrawnRegion;
};
if (selector.ShowDialog(this) == DialogResult.OK)
{
panel.DrawnRegion = selector.DrawnRegion;
}
}