--- /dev/null
+package jalview.gui;
+
+import static org.junit.Assert.assertEquals;
+
+import javax.swing.JScrollBar;
+
+import org.junit.Test;
+
+public class JvSwingUtilsTest
+{
+
+ @Test
+ public void testGetScrollBarProportion()
+ {
+ /*
+ * orientation, value, extent (width), min, max
+ */
+ JScrollBar sb = new JScrollBar(0, 125, 50, 0, 450);
+
+ /*
+ * operating range is 25 - 425 (400 wide) so value 125 is 100/400ths of this
+ * range
+ */
+ assertEquals(0.25f, JvSwingUtils.getScrollBarProportion(sb), 0.001f);
+ }
+
+ @Test
+ public void testGetScrollValueForProportion()
+ {
+ /*
+ * orientation, value, extent (width), min, max
+ */
+ JScrollBar sb = new JScrollBar(0, 125, 50, 0, 450);
+
+ /*
+ * operating range is 25 - 425 (400 wide) so value 125 is a quarter of this
+ * range
+ */
+ assertEquals(125, JvSwingUtils.getScrollValueForProportion(sb, 0.25f));
+ }
+}