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The Java Developers Almanac 1.4Order this book from Amazon. |
e765. Listening for Changes to the Selected Item in a JComboBox ComponentItem events are generated whenever the selected item changes. These events are generated even while the user is moving through items in the displayed popup menu. If the combobox is editable, this event does not indicate whether the new item is taken from the predefined list or not. If this information is necessary, see e766 Listening for Action Events from a JComboBox Component.// Create an editable combobox String[] items = {"item1", "item2"}; JComboBox cb = new JComboBox(items); cb.setEditable(true); // Create and register listener MyItemListener actionListener = new MyItemListener(); cb.addItemListener(actionListener); class MyItemListener implements ItemListener { // This method is called only if a new item has been selected. public void itemStateChanged(ItemEvent evt) { JComboBox cb = (JComboBox)evt.getSource(); // Get the affected item Object item = evt.getItem(); if (evt.getStateChange() == ItemEvent.SELECTED) { // Item was just selected } else if (evt.getStateChange() == ItemEvent.DESELECTED) { // Item is no longer selected } } }
e757. Getting and Setting the Selected Item in a JComboBox Component e758. Getting the Items in a JComboBox Component e759. Adding and Removing an Item in a JComboBox Component e760. Selecting an Item in a JComboBox Component with Multiple Keystrokes e761. Determining If the Menu of a JComboBox Component Is Visible e762. Displaying the Menu in a JComboBox Component Using a Keystroke e763. Displaying the Menu in a JComboBox Component Using a Keystroke If the Selected Item Is Not Unique e764. Setting the Number of Visible Items in the Menu of a JComboBox Component e766. Listening for Action Events from a JComboBox Component e767. Determining When the Menu of a JComboBox Component Is Displayed © 2002 Addison-Wesley. |