Menu bar
As for a “classical” GUI, GENIUS proposes to have a main bar menu with the GMenuBar class (on the same principle as the swing JMenuBar).
First, we will have to create a class that extends GPanel
class myPanel extends GPanel { myPanel () { } }
In the constructor of this class, we will create the different items of the menu(s) using the GMenuItem class.
class myPanel extends GPanel { private GMenuItem itemLoad ; private GMenuItem itemSave; private GMenuItem itemQuit; private GMenuItem itemHelp; myPanel () { // We create menu items itemLoad = new GMenuItem("Load"); itemSave = new GMenuItem("Save"); itemQuit = new GMenuItem("Quit"); itemHelp = new GMenuItem("?"); } }
Then, we will create the different menu(s) present in the GMenuBar using the GMenu class and associate items to this menu(s) using the add() method.
class myPanel extends GPanel { private GMenuItem itemLoad ; private GMenuItem itemSave; private GMenuItem itemQuit; private GMenuItem itemHelp; private GMenu fileMenu; private GMenu aboutMenu; myPanel () { // We create menu items itemLoad = new GMenuItem("Load"); itemSave = new GMenuItem("Save"); itemQuit = new GMenuItem("Quit"); itemHelp = new GMenuItem("?"); // We create the “File” and the "About" menu containing the previous items fileMenu= new GMenu("File"); aboutMenu= new GMenu("About"); // We link items to menus fileMenu.add(itemLoad); fileMenu.add(itemWrite); fileMenu.add(itemQuit); aboutMenu.add(itemHelp); } }
We will initialize the menubar using the GMenuBar class, associate menu(s) to the menubar using the add() method and create a getMenuBar() method that will return it.
class myPanel extends GPanel { private GMenuItem itemLoad ; private GMenuItem itemSave; private GMenuItem itemQuit; private GMenuItem itemHelp; private GMenu fileMenu; private GMenu aboutMenu; private GMenuBar bar; myPanel () { // We create menu items itemLoad = new GMenuItem("Load"); itemSave = new GMenuItem("Save"); itemQuit = new GMenuItem("Quit"); itemHelp = new GMenuItem("?"); // We create the “File” and the "About" menu containing the previous items fileMenu= new GMenu("File"); aboutMenu= new GMenu("About"); // We link items to menus fileMenu.add(itemLoad); fileMenu.add(itemWrite); fileMenu.add(itemQuit); aboutMenu.add(itemHelp); // Menu Bar initialization bar = new GMenuBar(this); bar.add(fileMenu); bar.add(aboutMenu); } public GMenuBar getBar() { return bar; } }
The GMenuBar will be associated to the main frame as this:
myPanel pan = new MyPanel(); GFrame frame = new GFrame("Test GChoice", pan, pan.getBar());
At last, we will check the action on this menu bar using the GListener interface:
public void after(GEvent e) throws Exception { if (e.contains(itemQuit) ){ System.exit(0); } }
Note that since the V1.2 version, it is now possible to get several menu levels.
level1Menu = new GMenu("level 1"); itemLevel11 = new GMenuItem("level 1-1"); itemLevel12 = new GMenuItem("level 1-2"); level1Menu.add(itemLevel11); level1Menu.add(itemLevel12); // FileMenu initialization level0Menu = new GMenu("Level 0"); level0Menu.add(level1Menu);
