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, 65 insertions, 4 deletions

diff --git a/src/gui/widgets/qabstractslider.cpp b/src/gui/widgets/qabstractslider.cpp
index 34fe340..a50c105 100644
--- a/src/gui/widgets/qabstractslider.cpp
+++ b/src/gui/widgets/qabstractslider.cpp
@@ -47,6 +47,9 @@
 #ifndef QT_NO_ACCESSIBILITY
 #include "qaccessible.h"
 #endif
+#ifdef QT_KEYPAD_NAVIGATION
+#include "qtabwidget.h" // Needed in inTabWidget()
+#endif // QT_KEYPAD_NAVIGATION
 #include <limits.h>
 
 QT_BEGIN_NAMESPACE
@@ -724,6 +727,45 @@ void QAbstractSlider::wheelEvent(QWheelEvent * e)
     }
 }
 #endif
+#ifdef QT_KEYPAD_NAVIGATION
+/*!
+    \internal
+
+    Tells us if it there is currently a reachable widget by keypad navigation in
+    a certain \a orientation.
+    If no navigation is possible, occuring key events in that \a orientation may
+    be used to interact with the value in the focussed widget, even though it
+    currently has not the editFocus.
+
+    \sa QWidgetPrivate::widgetInNavigationDirection(), QWidget::hasEditFocus()
+*/
+inline static bool canKeypadNavigate(Qt::Orientation orientation)
+{
+    return orientation == Qt::Horizontal?
+            (QWidgetPrivate::widgetInNavigationDirection(QWidgetPrivate::DirectionEast)
+                    || QWidgetPrivate::widgetInNavigationDirection(QWidgetPrivate::DirectionWest))
+            :(QWidgetPrivate::widgetInNavigationDirection(QWidgetPrivate::DirectionNorth)
+                    || QWidgetPrivate::widgetInNavigationDirection(QWidgetPrivate::DirectionSouth));
+}
+/*!
+    \internal
+
+    Checks, if the \a widget is inside a QTabWidget. If is is inside
+    one, left/right key events will be used to switch between tabs in keypad
+    navigation. If there is no QTabWidget, the horizontal key events can be used to
+    interact with the value in the focussed widget, even though it currently has
+    not the editFocus.
+
+    \sa QWidget::hasEditFocus()
+*/
+inline static bool inTabWidget(QWidget *widget)
+{
+    for (QWidget *tabWidget = widget; tabWidget; tabWidget = tabWidget->parentWidget())
+        if (qobject_cast<const QTabWidget*>(tabWidget))
+            return true;
+    return false;
+}
+#endif // QT_KEYPAD_NAVIGATION
 /*!
     \reimp
 */
@@ -751,7 +793,13 @@ void QAbstractSlider::keyPressEvent(QKeyEvent *ev)
         // It seems we need to use invertedAppearance for Left and right, otherwise, things look weird.
         case Qt::Key_Left:
 #ifdef QT_KEYPAD_NAVIGATION
-            if (QApplication::keypadNavigationEnabled() && !hasEditFocus()) {
+            // In QApplication::KeypadNavigationDirectional, we want to change the slider
+            // value if there is no left/right navigation possible and if this slider is not
+            // inside a tab widget.
+            if (QApplication::keypadNavigationEnabled()
+                    && (!hasEditFocus() && QApplication::navigationMode() == Qt::NavigationModeKeypadTabOrder
+                    || d->orientation == Qt::Vertical
+                    || !hasEditFocus() && (canKeypadNavigate(Qt::Horizontal) || inTabWidget(this)))) {
                 ev->ignore();
                 return;
             }
@@ -766,7 +814,11 @@ void QAbstractSlider::keyPressEvent(QKeyEvent *ev)
             break;
         case Qt::Key_Right:
 #ifdef QT_KEYPAD_NAVIGATION
-            if (QApplication::keypadNavigationEnabled() && !hasEditFocus()) {
+            // Same logic as in Qt::Key_Left
+            if (QApplication::keypadNavigationEnabled()
+                    && (!hasEditFocus() && QApplication::navigationMode() == Qt::NavigationModeKeypadTabOrder
+                    || d->orientation == Qt::Vertical
+                    || !hasEditFocus() && (canKeypadNavigate(Qt::Horizontal) || inTabWidget(this)))) {
                 ev->ignore();
                 return;
             }
@@ -781,7 +833,12 @@ void QAbstractSlider::keyPressEvent(QKeyEvent *ev)
             break;
         case Qt::Key_Up:
 #ifdef QT_KEYPAD_NAVIGATION
-            if (QApplication::keypadNavigationEnabled()) {
+            // In QApplication::KeypadNavigationDirectional, we want to change the slider
+            // value if there is no up/down navigation possible.
+            if (QApplication::keypadNavigationEnabled()
+                    && (QApplication::navigationMode() == Qt::NavigationModeKeypadTabOrder
+                    || d->orientation == Qt::Horizontal
+                    || !hasEditFocus() && canKeypadNavigate(Qt::Vertical))) {
                 ev->ignore();
                 break;
             }
@@ -790,7 +847,11 @@ void QAbstractSlider::keyPressEvent(QKeyEvent *ev)
             break;
         case Qt::Key_Down:
 #ifdef QT_KEYPAD_NAVIGATION
-            if (QApplication::keypadNavigationEnabled()) {
+            // Same logic as in Qt::Key_Up
+            if (QApplication::keypadNavigationEnabled()
+                    && (QApplication::navigationMode() == Qt::NavigationModeKeypadTabOrder
+                    || d->orientation == Qt::Horizontal
+                    || !hasEditFocus() && canKeypadNavigate(Qt::Vertical))) {
                 ev->ignore();
                 break;
             }