Determining the Selected Items
As you can see, adding a list to a window and
populating it with items is a fairly simple exercise, requiring
mastery of only a few simple methods. Most of the methods of the
List
class deal with interacting with the list and
its items in some meaningful fashion. The interaction that we will
almost always need to perform is to obtain the item or items that the
user has selected from the list.
Note
This is what lists are all about, after all is said and done.
How do I do that?
Consider the following code:
l.addSelectionListener(new SelectionListener( ) { public void widgetSelected(SelectionEvent e) { String selected[] = l.getSelection( ); System.out.println(selected[0]); } public void widgetDefaultSelected(SelectionEvent e) { } });
Here a
SelectionListener
is created and added to the list. In the
widgetSelected( )
method, which is called each
time the user clicks an item in the list, you call
getSelection( )
to print out the item selected to
the Console.
Recall that a list may enable the user to select more than one item,
if it is an SWT.MULTI
-style
List
. getSelection( )
returns an array of strings that contain every item that is currently
selected. In this example, only the 0 position is referenced when the
print to the Console is performed. Why? Since this is a single
selection list only one position in the string array is
populated—position 0.
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