Widgets: Stop cursor blink timer when QLineEdit is read-only

This prevents unnecessary updates, since the cursor is not visible.

Change-Id: Iec54ed338a0cb526a03cd611de4d823e26f3d804
Reviewed-by: Jan Arve Sæther <jan-arve.saether@digia.com>

src/widgets/widgets/qwidgetlinecontrol.cpp

@@ -1456,6 +1456,15 @@ void QWidgetLineControl::complete(int key)
 }
 #endif
 
+void QWidgetLineControl::setReadOnly(bool enable)
+{
+    m_readOnly = enable;
+    if (enable)
+        setCursorBlinkPeriod(0);
+    else
+        setCursorBlinkPeriod(QApplication::cursorFlashTime());
+}
+
 void QWidgetLineControl::setCursorBlinkPeriod(int msec)
 {
     if (msec == m_blinkPeriod)
@@ -1463,7 +1472,7 @@ void QWidgetLineControl::setCursorBlinkPeriod(int msec)
     if (m_blinkTimer) {
         killTimer(m_blinkTimer);
     }
-    if (msec) {
+    if (msec && !m_readOnly) {
         m_blinkTimer = startTimer(msec / 2);
         m_blinkStatus = 1;
     } else {
@@ -1474,15 +1483,6 @@ void QWidgetLineControl::setCursorBlinkPeriod(int msec)
     m_blinkPeriod = msec;
 }
 
-void QWidgetLineControl::resetCursorBlinkTimer()
-{
-    if (m_blinkPeriod == 0 || m_blinkTimer == 0)
-        return;
-    killTimer(m_blinkTimer);
-    m_blinkTimer = startTimer(m_blinkPeriod / 2);
-    m_blinkStatus = 1;
-}
-
 void QWidgetLineControl::timerEvent(QTimerEvent *event)
 {
     if (event->timerId() == m_blinkTimer) {

src/widgets/widgets/qwidgetlinecontrol_p.h

@@ -213,7 +213,7 @@ public:
     }
 
     bool isReadOnly() const { return m_readOnly; }
-    void setReadOnly(bool enable) { m_readOnly = enable; }
+    void setReadOnly(bool enable);
 
     QString text() const
     {
@@ -338,7 +338,6 @@ public:
 
     int cursorBlinkPeriod() const { return m_blinkPeriod; }
     void setCursorBlinkPeriod(int msec);
-    void resetCursorBlinkTimer();
 
     bool cursorBlinkStatus() const { return m_blinkStatus; }
 

tests/auto/widgets/widgets/qlineedit/tst_qlineedit.cpp

@@ -189,6 +189,8 @@ private slots:
 
     void isReadOnly();
 
+    void noCursorBlinkWhenReadOnly();
+
     void cursorPosition();
 
     void cursorPositionChanged_data();
@@ -1828,6 +1830,42 @@ void tst_QLineEdit::isReadOnly()
     QCOMPARE(testWidget->text(), QString("the quick dark brown fox"));
 }
 
+class BlinkTestLineEdit : public QLineEdit
+{
+public:
+    void paintEvent(QPaintEvent *e)
+    {
+        ++updates;
+        QLineEdit::paintEvent(e);
+    }
+
+    int updates;
+};
+
+void tst_QLineEdit::noCursorBlinkWhenReadOnly()
+{
+    int cursorFlashTime = QApplication::cursorFlashTime();
+    if (cursorFlashTime == 0)
+        return;
+    BlinkTestLineEdit le;
+    le.show();
+    le.setFocus();
+    QTest::qWaitForWindowActive(&le);
+    le.updates = 0;
+    QTest::qWait(cursorFlashTime);
+    QVERIFY(le.updates > 0);
+    le.setReadOnly(true);
+    QTest::qWait(10);
+    le.updates = 0;
+    QTest::qWait(cursorFlashTime);
+    QCOMPARE(le.updates, 0);
+    le.setReadOnly(false);
+    QTest::qWait(10);
+    le.updates = 0;
+    QTest::qWait(cursorFlashTime);
+    QVERIFY(le.updates > 0);
+}
+
 static void figureOutProperKey(Qt::Key &key, Qt::KeyboardModifiers &pressState)
 {
 #ifdef Q_OS_MAC