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The moose likes Swing / AWT / SWT and the fly likes SWT code not using a receiving object Big Moose Saloon
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SWT code not using a receiving object

bob connolly
Ranch Hand

Joined: Mar 10, 2004
Posts: 204
Hello, i am running this example in eclipse and it works fine, but i'm baffled by the strucuture of a particular statement:

Please notice that the:

"createMenuBar();" statement below does not have a receiving object, for example something like: "Menu m = createMenuBar(); and notice that the createMenuBar() funtion is returning a "Menu", but there isn't a Menu object on the receiving end!? , is this a new 5.0 feature by any chance?

<code>
public Shell open(Display display) {
shell = new Shell(display);
shell.setLayout(new FillLayout());
shell.addShellListener(new ShellAdapter() {
public void shellClosed(ShellEvent e) {
e.doit = closeAddressBook();
}
});

createMenuBar(); <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

..........

}

private Menu createMenuBar() { <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
Menu menuBar = new Menu(shell, SWT.BAR);
shell.setMenuBar(menuBar);

// create each header and subMenu for the menuBar
createFileMenu(menuBar);
createEditMenu(menuBar);
createSearchMenu(menuBar);
createHelpMenu(menuBar);

return menuBar;
}

</code>
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 39791
    
  28
Obviously you can return the Menu object, and not do anything with it.
There are quite a lot of methods which have a return type one doesn't use, particularly boolean returns, in the J2SE API (not that I can remember the name of one offhand): does this mean it is a general rule that a return value can be ignored???

CR
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 39791
    
  28
I have tried a little app with methods in which return an Exception, an ArrayList, a "C" from the thread about protected methods and inheritance from today's Java(advanced) forum, a primitive value (a double) and a JWindow; all of them can return their values without anything being done with it, eg
not necessarily in that order. It seems to compile and run quite happily.

CR
[ April 19, 2006: Message edited by: Campbell Ritchie ]
bob connolly
Ranch Hand

Joined: Mar 10, 2004
Posts: 204
Thanks Campbell!

Also Campbell, if you've had a chance to use SWT and Swing, which would you prefer to use on your next project?

I heard from a coworker that SWT is somewhat easier to use than Swing and faster as well!

Thanks again Campbell!
Campbell Ritchie
Sheriff

Joined: Oct 13, 2005
Posts: 39791
    
  28
Only too pleased to help. I have never used SWT, so don't know.

Anybody else?
 
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