`TfpgTreeView`
pl		OnChange
pl		OnExpand
pl	ro	OnDoubleClick
pl	ro	OnShowHint
pl		OnStateImageClicked

`TfpgWidget`
		OnDragEnter
		OnDragLeave
		OnDragDrop

`TfpgWindow`

`TfpgWindowImpl`

`TfpgX11Window`

`TfpgWindowBase`

`TfpgComponent`