private GLButton AddTaskAddButton(GLControl parent, Action <Data.Task> callback, bool leafTasksSelectable = true)
{
var button = parent.Add(new GLButton(Gui)
{
Text = "###"
});
button.SkinDisabled = addButtonDisabled;
button.SkinEnabled = addButtonEnabled;
button.SkinHover = addButtonHover;
button.SkinPressed = addButtonPressed;
button.Click += (s, e) =>
{
var t = Editor.TreeContainer.InnerSize;
var p = Editor.TreeContainer.ScrollPosition;
Editor.TreeContainer.Add(new PBTTaskBrowserForm(Gui, Editor, callback, leafTasksSelectable)
{
Location = new Point(p.X + t.Width / 2 - 200, p.Y + t.Height / 2 - 225)
});
};
return(button);
}