Jcombobox

[sean beacham]

Hi guys,

Im new to the forum i have been programming on and off for 3 years now i wouldnt call myself a great programmer in the slightest however im making a complex program atm which i hope you can all help me with if i need any help

right now ive just made 2 little static combo boxes with Hour & Minute when i try and print out the selection of either hour and minute it keeps doubling up for no reason :\

	public void boilertimer() {
		frame4 = new JFrame();
		frame4.setTitle("my Thermostat Boiler Timer");
		frame4.setSize(300, 200);

		//sets up panel
		panel4 = new JPanel();
		panel4.setBackground(Color.WHITE);
		panel4.setLayout(null);
		frame4.getContentPane().add(panel4);
		frame4.setVisible(true);
		panel4.setVisible(true);
		
		String[] hourStrings = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16" , "17", "18", "19", "20", "21", "22", "23"};
		String[] minuteStrings = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16" , "17", "18", "19", "20", "21", "22", "23","24", "25", "26" , "27", "28", "29", "30", "40", "41", "42", "43", "44", "45", "46" , "47", "48", "49", "50", "51", "52", "53","54", "55", "56" , "57", "58", "59"};


		final JComboBox hour = new JComboBox(hourStrings);
		hour.setBounds(10,10,45,25);
		panel4.add(hour);
		 hour.addItemListener(new ItemListener(){
		      public void itemStateChanged(ItemEvent ie){
		        String str = (String)hour.getSelectedItem();
		       System.out.print(str);
		      }
		    });
		
		final JComboBox minute = new JComboBox(minuteStrings);
		minute.setBounds(55,10,45,25);
		panel4.add(minute);
		 minute.addItemListener(new ItemListener(){
		      public void itemStateChanged(ItemEvent ie){
		               String str = (String)minute.getSelectedItem();		       
                               System.out.print(str);
		      }
		    });

		
	}

[Joanne Neal]

Run your code through a debugger (or put some System.out.println calls in your code) and see how often your itemStateChanged methods are called.
Then see what value ie.getStateChange() returns for each of those calls.

[Maneesh Godbole]

Welcome to the Ranch.

The recommended way of listening to JComboBox events is using ActionListeners http://download.oracle.com/javase/tutorial/uiswing/components/combobox.html#listeners

[sean beacham]

Maneesh Godbole wrote:Welcome to the Ranch.

The recommended way of listening to JComboBox events is using ActionListeners http://download.oracle.com/javase/tutorial/uiswing/components/combobox.html#listeners

i think when i highlight when the itemlistener and then click off it jotted it down twice soon as i changed it to an actionlistner it works perfectly.

many thanks

[Maneesh Godbole]

You are welcome.

Actually it is logical. If you had checked what Joanne suggested you would have noticed one event for deselection and another for selection. A similar pitfall is for a JList when you use a ListSelectionListener. When using it, one should use the ListSelectionEvent#getValueIsAdjusting()