X-Git-Url: http://gitweb.fperrin.net/?p=GpsPrune.git;a=blobdiff_plain;f=src%2Ftim%2Fprune%2Fsave%2FUpDownToggler.java;fp=src%2Ftim%2Fprune%2Fsave%2FUpDownToggler.java;h=ffdc1d662725ea77e3fc52a6bf9e86f8961168a8;hp=0000000000000000000000000000000000000000;hb=ce6f2161b8596f7018d6a76bff79bc9e571f35fd;hpb=2d8cb72e84d5cc1089ce77baf1e34ea3ea2f8465

diff --git a/src/tim/prune/save/UpDownToggler.java b/src/tim/prune/save/UpDownToggler.java
new file mode 100644
index 0000000..ffdc1d6
--- /dev/null
+++ b/src/tim/prune/save/UpDownToggler.java
@@ -0,0 +1,58 @@
+package tim.prune.save;
+
+import javax.swing.JButton;
+import javax.swing.ListSelectionModel;
+import javax.swing.event.ListSelectionEvent;
+import javax.swing.event.ListSelectionListener;
+
+
+/**
+ * Class to enable and disable a pair of up and down buttons
+ */
+public class UpDownToggler implements ListSelectionListener
+{
+	private JButton _upButton = null;
+	private JButton _downButton = null;
+	private int _maxIndex = 2;
+
+	/**
+	 * Constructor giving buttons to enable/disable
+	 * @param inUpButton up button
+	 * @param inDownButton down button
+	 */
+	public UpDownToggler(JButton inUpButton, JButton inDownButton)
+	{
+		_upButton = inUpButton;
+		_downButton = inDownButton;
+	}
+
+	/**
+	 * Set the list size
+	 * @param inListSize number of items in list
+	 */
+	public void setListSize(int inListSize)
+	{
+		_maxIndex = inListSize - 1;
+	}
+
+	/**
+	 * list selection has changed
+	 */
+	public void valueChanged(ListSelectionEvent e)
+	{
+		ListSelectionModel lsm = (ListSelectionModel) e.getSource();
+		if (lsm.isSelectionEmpty())
+		{
+			// no rows are selected
+			_upButton.setEnabled(false);
+			_downButton.setEnabled(false);
+		}
+		else
+		{
+			// single row is selected
+			int row = lsm.getMinSelectionIndex();
+			_upButton.setEnabled(row > 0);
+			_downButton.setEnabled(row >= 0 && row < _maxIndex);
+		}
+	}
+}