Bug 484525: StyledText sends unexpected selection changed event

2 files changed, 76 insertions, 3 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledText.java b/bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledText.java
index 922d8d0560..53ac145dc4 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledText.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledText.java
@@ -115,7 +115,7 @@ public class StyledText extends Canvas {
 	int columnX;						// keep track of the horizontal caret position when changing lines/pages. Fixes bug 5935
 	int caretOffset;
 	int caretAlignment;
-	Point selection = new Point(0, 0);	// x and y are start and end caret offsets of selection
+	Point selection = new Point(0, 0);	// x and y are start and end caret offsets of selection (x <= y)
 	Point clipboardSelection;           // x and y are start and end caret offsets of previous selection
 	int selectionAnchor;				// position of selection anchor. 0 based offset from beginning of text
 	Point doubleClickSelection;			// selection after last mouse double click
@@ -1437,7 +1437,10 @@ public void addPaintObjectListener(PaintObjectListener listener) {
  * user changes the selection.
  * <p>
  * When <code>widgetSelected</code> is called, the event x and y fields contain
- * the start and end caret indices of the selection.
+ * the start and end caret indices of the selection. The selection values returned are visual
+ * (i.e., x will always always be <= y).
+ * No event is sent when the caret is moved while the selection length is 0.
+ * </p><p>
  * <code>widgetDefaultSelected</code> is not called for StyledTexts.
  * </p>
  *
@@ -9670,6 +9673,8 @@ void setSelection(int start, int length, boolean sendEvent, boolean doBlock) {
 				setBlockSelectionOffset(start, end, sendEvent);
 			}
 		} else {
+			int oldStart = selection.x;
+			int oldLength = selection.y - selection.x;
 			int charCount = content.getCharCount();
 			// called internally to remove selection after text is removed
 			// therefore make sure redraw range is valid.
@@ -9689,7 +9694,7 @@ void setSelection(int start, int length, boolean sendEvent, boolean doBlock) {
 			if (redrawY - redrawX > 0) {
 				internalRedrawRange(redrawX, redrawY - redrawX);
 			}
-			if (sendEvent) {
+			if (sendEvent && (oldLength != end - start || (oldLength != 0 && oldStart != start))) {
 				sendSelectionEvent();
 			}
 			sendAccessibleTextCaretMoved();
diff --git a/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_StyledText.java b/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_StyledText.java
index 6c6eecc772..867008aaa8 100644
--- a/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_StyledText.java
+++ b/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_custom_StyledText.java
@@ -3621,6 +3621,74 @@ public void test_setSelectionII(){
 }
 
 @Test
+public void test_addSelectionListener() {
+	text.setText("0123456789");
+	class TestSelectionListener extends SelectionAdapter {
+		public int counter;
+		public Point eventSelection = new Point(0, 0);
+		@Override
+		public void widgetSelected(SelectionEvent e) {
+			eventSelection.x = e.x;
+			eventSelection.y = e.y;
+			counter++;
+		}
+	}
+	final TestSelectionListener selectionListener = new TestSelectionListener();
+	text.addSelectionListener(selectionListener);
+	
+	assertEquals(0, selectionListener.counter);
+	assertEquals(new Point(0, 0), selectionListener.eventSelection);
+	
+	text.invokeAction(ST.COLUMN_NEXT);
+	assertEquals(new Point(1, 1), text.getSelection());
+	
+	text.invokeAction(ST.SELECT_COLUMN_NEXT);
+	assertEquals(1, selectionListener.counter);
+	assertEquals(new Point(1, 2), selectionListener.eventSelection);
+	
+	text.invokeAction(ST.SELECT_COLUMN_NEXT);
+	assertEquals(2, selectionListener.counter);
+	assertEquals(new Point(1, 3), selectionListener.eventSelection);
+	
+	// replace text while selection is non-empty:
+	text.replaceTextRange(0, 1, "a");
+	assertEquals(2, selectionListener.counter);
+	assertEquals(new Point(1, 3), selectionListener.eventSelection);
+	
+	text.replaceTextRange(9, 1, "z");
+	assertEquals(2, selectionListener.counter);
+	assertEquals(new Point(1, 3), selectionListener.eventSelection);
+	
+	text.replaceTextRange(0, 1, "ab");
+	assertEquals(3, selectionListener.counter);
+	assertEquals(new Point(2, 4), selectionListener.eventSelection);
+	assertEquals(new Point(2, 4), text.getSelection());
+	
+	text.invokeAction(ST.COLUMN_NEXT);
+	assertEquals(4, selectionListener.counter);
+	assertEquals(new Point(4, 4), selectionListener.eventSelection);
+	assertEquals(new Point(4, 4), text.getSelection());
+	
+	// replace text while selection is empty:
+	text.replaceTextRange(0, 2, "a");
+	assertEquals(4, selectionListener.counter);
+	assertEquals(new Point(3, 3), text.getSelection());
+	
+	text.replaceTextRange(9, 1, "9");
+	assertEquals(4, selectionListener.counter);
+	assertEquals(new Point(3, 3), text.getSelection());
+	
+	text.replaceTextRange(0, 1, "0");
+	assertEquals(4, selectionListener.counter);
+	assertEquals(new Point(3, 3), text.getSelection());
+	
+	// replace text that overlaps empty selection:
+	text.replaceTextRange(0, 9, "");
+	assertEquals(4, selectionListener.counter);
+	assertEquals(new Point(0, 0), text.getSelection());
+}
+
+@Test
 public void test_setSelectionBackgroundLorg_eclipse_swt_graphics_Color(){
 	text.setSelectionBackground(getColor(YELLOW));
 	assertTrue(":1a:", text.getSelectionBackground() ==  getColor(YELLOW));