Property change events

To handle the property change events of MSketchPane, the java.beans.PropertyChangeListener interface must be implemented.

Property name	Type	Meaning
`"mol"`	`Molecule`	The molecule is replaced or altered.
`"file"`	`java.io.File`	Molecule file changed from File/Open or File/Save As.
`"implicitH"`	`String`	Implicit Hydrogen display style changed.
`"explicitH"`	`Boolean`	Explicit Hydrogen display style changed. `true`: show explicit H atoms `false`: hide explicit H atoms
`"colorScheme"`	`String`	Color scheme changed.
`"autoscale"`	`Boolean`	Autoscale changed.
`"rendering"`	`String`	Rendering style changed.
`"wireThickness"`	`Double`	Wire thickness changed.
`"stickThickness"`	`Double`	Sticks diameter changed.
`"ballRadius"`	`Double`	Ball radius changed.
`"grinvVisible"`	`Boolean`	Graph invariants displayed/not displayed.
`"downWedge"`	`String`	Down wedge bond orientation changed.
`"objectAtPointer"`	`Object`	The MolAtom or MolBond object at the mouse pointer.
`"invisibleSets"`	`Long`	Visibility of atom sets changed.
`"`~~`atomNumbersVisible`~~"		Deprecated
`"atomNumberingType"`	Integer	Visibility of atom numbers changed.
`"valencePropertyVisible"`	`Boolean`	Visibility of valence properties changed.
`"ligandErrorVisible"`	`Boolean`	Visibility of ligand error changed.
`"atomMappingVisible"`	`Boolean`	Visibility of atom mapping changed.
`"popupMenusEnabled"`	`Boolean`	Popup menus are enabled/disabled.
`"valenceErrorVisible"`	`Boolean`	Visibility of valence errors changed.
`"reactionErrorVisible"`	`Boolean`	Visibility of reaction errors changed.

Example:

    sketchPane.addPropertyChangeListener(this);
    ...
 
public void propertyChange(PropertyChangeEvent ev) {
    String name = ev.getPropertyName();
    if("file".equals(name)) {
	File f = (File)ev.getNewValue();
	if(f != null) {
	    setTitle("MarvinSketch: "+f.getName());
	}	    
    }
}