Making Keypad Navigation more usable

All changes of this commit are #ifdef'ed in
QT_KEYPAD_NAVIGATION. Most desktop Qts won't notice
any change.

Navigating between QWidgets was not alwys a pleasure on
keypad devices. This commit fixes the navigation behavior
for some widgets, mostly itemviews.

Furthermore, it adds a 'directional' navigation mode. Until
now, the existing keypad navigation used the tab order
do go back and forth between widgets. The new mode is supposed
to provide a more intuitive navigation. It is the new default
mode on Symbian.
Screens (and their resolutions) become bigger, and also low
resolution screens can be used in landscape mode. That's
why the directional mode was requested.

Another popular request was to put some more convenience into
QSlider: If a (horizontal) slider has focus and the user presses
left/right, the value of the slider may directing change
without being selected (edit mode).

This commit also adds the manual test 'keypadnavigation'.

Reviewed-by: Shane Kearns

1 files changed, 85 insertions, 5 deletions

diff --git a/src/gui/kernel/qwidget.cpp b/src/gui/kernel/qwidget.cpp
index 860b98b..4f1ab94 100644
--- a/src/gui/kernel/qwidget.cpp
+++ b/src/gui/kernel/qwidget.cpp
@@ -410,7 +410,6 @@ void QWidget::setEditFocus(bool on)
         QApplication::sendEvent(f, &event);
         QApplication::sendEvent(f->style(), &event);
     }
-    f->repaint(); // Widget might want to repaint a focus indicator
 }
 #endif
 
@@ -6449,6 +6448,8 @@ void QWidgetPrivate::reparentFocusWidgets(QWidget * oldtlw)
 
   This function is called from QDesktopwidget::screen(QPoint) to find the
   closest screen for a point.
+  In directional KeypadNavigation, it is called to find the closest
+  widget to the current focus widget center.
 */
 int QWidgetPrivate::pointToRect(const QPoint &p, const QRect &r)
 {
@@ -7929,10 +7930,21 @@ bool QWidget::event(QEvent *event)
 #ifdef QT_KEYPAD_NAVIGATION
         if (!k->isAccepted() && QApplication::keypadNavigationEnabled()
             && !(k->modifiers() & (Qt::ControlModifier | Qt::AltModifier | Qt::ShiftModifier))) {
-            if (k->key() == Qt::Key_Up)
-                res = focusNextPrevChild(false);
-            else if (k->key() == Qt::Key_Down)
-                res = focusNextPrevChild(true);
+            if (QApplication::navigationMode() == Qt::NavigationModeKeypadTabOrder) {
+                if (k->key() == Qt::Key_Up)
+                    res = focusNextPrevChild(false);
+                else if (k->key() == Qt::Key_Down)
+                    res = focusNextPrevChild(true);
+            } else if (QApplication::navigationMode() == Qt::NavigationModeKeypadDirectional) {
+                if (k->key() == Qt::Key_Up)
+                    res = QWidgetPrivate::navigateToDirection(QWidgetPrivate::DirectionNorth);
+                else if (k->key() == Qt::Key_Right)
+                    res = QWidgetPrivate::navigateToDirection(QWidgetPrivate::DirectionEast);
+                else if (k->key() == Qt::Key_Down)
+                    res = QWidgetPrivate::navigateToDirection(QWidgetPrivate::DirectionSouth);
+                else if (k->key() == Qt::Key_Left)
+                    res = QWidgetPrivate::navigateToDirection(QWidgetPrivate::DirectionWest);
+            }
             if (res) {
                 k->accept();
                 break;
@@ -11373,6 +11385,74 @@ QRect QWidgetPrivate::frameStrut() const
     return maybeTopData() ? maybeTopData()->frameStrut : QRect();
 }
 
+#ifdef QT_KEYPAD_NAVIGATION
+/*!
+    \internal
+
+    Changes the focus  from the current focusWidget to a widget in
+    the \a direction.
+
+    Returns true, if there was a widget in that direction
+*/
+bool QWidgetPrivate::navigateToDirection(Direction direction)
+{
+    QWidget *targetWidget = widgetInNavigationDirection(direction);
+    if (targetWidget)
+        targetWidget->setFocus();
+    return (targetWidget != 0);
+}
+
+/*!
+    \internal
+
+    Searches for a widget that is positioned in the \a direction, starting
+    from the current focusWidget.
+
+    Returns the pointer to a found widget or 0, if there was no widget in
+    that direction.
+*/
+QWidget *QWidgetPrivate::widgetInNavigationDirection(Direction direction)
+{
+    const QWidget *sourceWidget = QApplication::focusWidget();
+    if (!sourceWidget)
+        return 0;
+    const QRect sourceRect = sourceWidget->rect().translated(sourceWidget->mapToGlobal(QPoint()));
+    const int sourceX =
+            (direction == DirectionNorth || direction == DirectionSouth) ?
+                (sourceRect.left() + (sourceRect.right() - sourceRect.left()) / 2)
+                :(direction == DirectionEast ? sourceRect.right() : sourceRect.left());
+    const int sourceY =
+            (direction == DirectionEast || direction == DirectionWest) ?
+                (sourceRect.top() + (sourceRect.bottom() - sourceRect.top()) / 2)
+                :(direction == DirectionSouth ? sourceRect.bottom() : sourceRect.top());
+    const QPoint sourcePoint(sourceX, sourceY);
+    const QPoint sourceCenter = sourceRect.center();
+    const QWidget *sourceWindow = sourceWidget->window();
+
+    QWidget *targetWidget = 0;
+    int shortestDistance = INT_MAX;
+    foreach(QWidget *targetCandidate, QApplication::allWidgets()) {
+        const QRect targetCandidateRect = targetCandidate->rect().translated(targetCandidate->mapToGlobal(QPoint()));
+        if (       targetCandidate != sourceWidget
+                && targetCandidate->focusPolicy() & Qt::TabFocus
+                && !(direction == DirectionNorth && targetCandidateRect.bottom() > sourceRect.top())
+                && !(direction == DirectionEast  && targetCandidateRect.left()   < sourceRect.right())
+                && !(direction == DirectionSouth && targetCandidateRect.top()    < sourceRect.bottom())
+                && !(direction == DirectionWest  && targetCandidateRect.right()  > sourceRect.left())
+                && targetCandidate->isEnabled()
+                && targetCandidate->isVisible()
+                && targetCandidate->window() == sourceWindow) {
+            const int targetCandidateDistance = pointToRect(sourcePoint, targetCandidateRect);
+            if (targetCandidateDistance < shortestDistance) {
+                shortestDistance = targetCandidateDistance;
+                targetWidget = targetCandidate;
+            }
+        }
+    }
+    return targetWidget;
+}
+#endif
+
 /*!
     \preliminary
     \since 4.2