Add a QApplication::queryKeyboardModifiers() method.

QApplication::keyboardModifiers returns the keyboard modifiers
from the last keypress event in this process, as documented. However
there are use cases for querying keyboard modifiers as they currently are,
see QTBUG-11243.

Merge-request: 585
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@nokia.com>
(cherry picked from commit 3b5354386225974ea6db78c12f32cb81e2d50104)

Change-Id: I9b4e54ac79fc225e3ed8d2bcaba953a6eb59f0d2
Reviewed-on: http://codereview.qt.nokia.com/3581
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@nokia.com>

8 files changed, 60 insertions, 17 deletions

diff --git a/src/gui/kernel/qapplication.cpp b/src/gui/kernel/qapplication.cpp
index 9cd1b7bb09..593a3209a8 100644
--- a/src/gui/kernel/qapplication.cpp
+++ b/src/gui/kernel/qapplication.cpp
@@ -3319,7 +3319,7 @@ bool QApplication::desktopSettingsAware()
     one of the above events. If no keys are being held Qt::NoModifier is
     returned.
 
-    \sa mouseButtons()
+    \sa mouseButtons(), queryKeyboardModifiers()
 */
 
 Qt::KeyboardModifiers QApplication::keyboardModifiers()
@@ -3328,6 +3328,25 @@ Qt::KeyboardModifiers QApplication::keyboardModifiers()
 }
 
 /*!
+    \fn Qt::KeyboardModifiers QApplication::queryKeyboardModifiers()
+
+    Queries and returns the state of the modifier keys on the keyboard.
+    Unlike keyboardModifiers, this method returns the actual keys held
+    on the input device at the time of calling the method.
+
+    It does not rely on the keypress events having been received by this
+    process, which makes it possible to check the modifiers while moving
+    a window, for instance. Note that in most cases, you should use
+    keyboardModifiers(), which is faster and more accurate since it contains
+    the state of the modifiers as they were when the currently processed
+    event was received.
+
+    \sa keyboardModifiers()
+
+    \since 4.8
+*/
+
+/*!
     Returns the current state of the buttons on the mouse. The current state is
     updated syncronously as the event queue is emptied of events that will
     spontaneously change the mouse state (QEvent::MouseButtonPress and
diff --git a/src/gui/kernel/qapplication.h b/src/gui/kernel/qapplication.h
index 01a246a0c6..15488490d1 100644
--- a/src/gui/kernel/qapplication.h
+++ b/src/gui/kernel/qapplication.h
@@ -198,6 +198,7 @@ public:
     static void alert(QWidget *widget, int duration = 0);
 
     static Qt::KeyboardModifiers keyboardModifiers();
+    static Qt::KeyboardModifiers queryKeyboardModifiers();
     static Qt::MouseButtons mouseButtons();
 
     static void setDesktopSettingsAware(bool);
diff --git a/src/gui/kernel/qapplication_mac.mm b/src/gui/kernel/qapplication_mac.mm
index cb1f0cdbe4..e06756c86a 100644
--- a/src/gui/kernel/qapplication_mac.mm
+++ b/src/gui/kernel/qapplication_mac.mm
@@ -1395,6 +1395,11 @@ void QApplication::restoreOverrideCursor()
 }
 #endif // QT_NO_CURSOR
 
+Qt::KeyboardModifiers QApplication::queryKeyboardModifiers()
+{
+    return qt_mac_get_modifiers(GetCurrentEventKeyModifiers());
+}
+
 QWidget *QApplication::topLevelAt(const QPoint &p)
 {
 #ifndef QT_MAC_USE_COCOA
diff --git a/src/gui/kernel/qapplication_qws.cpp b/src/gui/kernel/qapplication_qws.cpp
index 14f779008c..428f558023 100644
--- a/src/gui/kernel/qapplication_qws.cpp
+++ b/src/gui/kernel/qapplication_qws.cpp
@@ -2707,6 +2707,11 @@ void QApplication::alert(QWidget *, int)
 {
 }
 
+Qt::KeyboardModifiers QApplication::queryKeyboardModifiers()
+{
+    return keyboardModifiers(); // TODO proper implementation
+}
+
 int QApplication::qwsProcessEvent(QWSEvent* event)
 {
     Q_D(QApplication);
diff --git a/src/gui/kernel/qapplication_s60.cpp b/src/gui/kernel/qapplication_s60.cpp
index f0739cdd9f..e277765eff 100644
--- a/src/gui/kernel/qapplication_s60.cpp
+++ b/src/gui/kernel/qapplication_s60.cpp
@@ -114,6 +114,8 @@ QWidget *qt_button_down = 0;                     // widget got last button-down
 
 QSymbianControl *QSymbianControl::lastFocusedControl = 0;
 
+static Qt::KeyboardModifiers app_keyboardModifiers = Qt::NoModifier;
+
 QS60Data* qGlobalS60Data()
 {
     return qt_s60Data();
@@ -712,6 +714,7 @@ void QSymbianControl::HandlePointerEvent(const TPointerEvent& pEvent)
     Qt::MouseButton button;
     mapS60MouseEventTypeToQt(&type, &button, &pEvent);
     Qt::KeyboardModifiers modifiers = mapToQtModifiers(pEvent.iModifiers);
+    app_keyboardModifiers = modifiers;
 
     QPoint widgetPos = translatePointForFixedNativeOrientation(pEvent.iPosition);
     TPoint controlScreenPos = PositionRelativeToScreen();
@@ -2541,6 +2544,11 @@ void QApplication::setEffectEnabled(Qt::UIEffect /* effect */, bool /* enable */
     // TODO: Implement QApplication::setEffectEnabled(Qt::UIEffect effect, bool enable)
 }
 
+Qt::KeyboardModifiers QApplication::queryKeyboardModifiers()
+{
+    return app_keyboardModifiers;
+}
+
 TUint QApplicationPrivate::resolveS60ScanCode(TInt scanCode, TUint keysym)
 {
     if (!scanCode)
diff --git a/src/gui/kernel/qapplication_win.cpp b/src/gui/kernel/qapplication_win.cpp
index c34e75ffcc..756cb56b58 100644
--- a/src/gui/kernel/qapplication_win.cpp
+++ b/src/gui/kernel/qapplication_win.cpp
@@ -1319,6 +1319,11 @@ Qt::KeyboardModifiers qt_win_getKeyboardModifiers()
     return modifiers;
 }
 
+Qt::KeyboardModifiers QApplication::queryKeyboardModifiers()
+{
+    return qt_win_getKeyboardModifiers();
+}
+
 /*****************************************************************************
   Routines to find a Qt widget from a screen position
  *****************************************************************************/
diff --git a/src/gui/kernel/qapplication_x11.cpp b/src/gui/kernel/qapplication_x11.cpp
index 8d5a0b8a50..311b147976 100644
--- a/src/gui/kernel/qapplication_x11.cpp
+++ b/src/gui/kernel/qapplication_x11.cpp
@@ -3061,6 +3061,21 @@ void QApplicationPrivate::_q_alertTimeOut()
     }
 }
 
+Qt::KeyboardModifiers QApplication::queryKeyboardModifiers()
+{
+    Window root;
+    Window child;
+    int root_x, root_y, win_x, win_y;
+    uint keybstate;
+    for (int i = 0; i < ScreenCount(X11->display); ++i) {
+        if (XQueryPointer(X11->display, QX11Info::appRootWindow(i), &root, &child,
+                          &root_x, &root_y, &win_x, &win_y, &keybstate))
+            return X11->translateModifiers(keybstate & 0x00ff);
+    }
+    return 0;
+
+}
+
 /*****************************************************************************
   Special lookup functions for windows that have been reparented recently
  *****************************************************************************/
diff --git a/src/gui/kernel/qdnd_x11.cpp b/src/gui/kernel/qdnd_x11.cpp
index 750ddf892e..11e87e96f3 100644
--- a/src/gui/kernel/qdnd_x11.cpp
+++ b/src/gui/kernel/qdnd_x11.cpp
@@ -1112,21 +1112,6 @@ void qt_xdnd_send_leave()
     waiting_for_status = false;
 }
 
-// TODO: remove and use QApplication::currentKeyboardModifiers() in Qt 4.8.
-static Qt::KeyboardModifiers currentKeyboardModifiers()
-{
-    Window root;
-    Window child;
-    int root_x, root_y, win_x, win_y;
-    uint keybstate;
-    for (int i = 0; i < ScreenCount(X11->display); ++i) {
-        if (XQueryPointer(X11->display, QX11Info::appRootWindow(i), &root, &child,
-                          &root_x, &root_y, &win_x, &win_y, &keybstate))
-            return X11->translateModifiers(keybstate & 0x00ff);
-    }
-    return 0;
-}
-
 void QX11Data::xdndHandleDrop(QWidget *, const XEvent * xe, bool passive)
 {
     DEBUG("xdndHandleDrop");
@@ -1175,7 +1160,7 @@ void QX11Data::xdndHandleDrop(QWidget *, const XEvent * xe, bool passive)
 
         // Drop coming from another app? Update keyboard modifiers.
         if (!qt_xdnd_dragging) {
-            QApplicationPrivate::modifier_buttons = currentKeyboardModifiers();
+            QApplicationPrivate::modifier_buttons = QApplication::queryKeyboardModifiers();
         }
 
         QDropEvent de(qt_xdnd_current_position, possible_actions, dropData,