qt-bugs@ issue : 25122
applied: no
author: Lubos Lunak <l.lunak@kde.org>
Hello,
for example: Open Konqueror window, showing some files. Start dragging one
desktop icon. If you press/release Ctrl, there'll be a '+' attached to the
icon, showing the DND operation. Now, while still doing DND, make the
Konqueror window active (Alt+Tab with KDE-3.1.2+, hover over its taskbar
entry, Ctrl+Fn to switch to a different virtual desktop, etc.). As soon as
the app performing DND is not the active application, and the mouse is not
moving, pressing/releasing Ctrl doesn't do anything, the state only updates
when the mouse is moved.
This is caused by the fact that Qt has only pointer grab when doing DND, but
doesn't have keyboard grab. I actually consider this a good thing, because
the only keys important for DND are modifiers, and they come together with
pointer events, and not having keyboard grab allows using keyboard shortcuts
like Alt+Tab while DND. However, when the mouse is not moved, and only a
modifier key is pressed/released, the app won't get any mouse event, and
won't also get the keyboard event.
The attached patch changes Qt to explicitly check the modifiers state using
XQueryPointer() if there's wasn't recently any mouse/keyboard event, which
ensures the state is updated even in the situation described above.
--- src/kernel/qapplication_x11.cpp.sav 2003-06-21 12:31:35.000000000 +0200
+++ src/kernel/qapplication_x11.cpp 2003-06-21 12:35:44.000000000 +0200
@@ -4053,7 +4053,7 @@ void QApplication::closePopup( QWidget *
// Keyboard event translation
//
-static int translateButtonState( int s )
+int qt_x11_translateButtonState( int s )
{
int bst = 0;
if ( s & Button1Mask )
@@ -4119,7 +4119,7 @@ bool QETWidget::translateMouseEvent( con
pos.ry() = lastMotion.y;
globalPos.rx() = lastMotion.x_root;
globalPos.ry() = lastMotion.y_root;
- state = translateButtonState( lastMotion.state );
+ state = qt_x11_translateButtonState( lastMotion.state );
if ( qt_button_down && (state & (LeftButton |
MidButton |
RightButton ) ) == 0 )
@@ -4143,7 +4143,7 @@ bool QETWidget::translateMouseEvent( con
pos.ry() = xevent->xcrossing.y;
globalPos.rx() = xevent->xcrossing.x_root;
globalPos.ry() = xevent->xcrossing.y_root;
- state = translateButtonState( xevent->xcrossing.state );
+ state = qt_x11_translateButtonState( xevent->xcrossing.state );
if ( qt_button_down && (state & (LeftButton |
MidButton |
RightButton ) ) == 0 )
@@ -4155,7 +4155,7 @@ bool QETWidget::translateMouseEvent( con
pos.ry() = event->xbutton.y;
globalPos.rx() = event->xbutton.x_root;
globalPos.ry() = event->xbutton.y_root;
- state = translateButtonState( event->xbutton.state );
+ state = qt_x11_translateButtonState( event->xbutton.state );
switch ( event->xbutton.button ) {
case Button1: button = LeftButton; break;
case Button2: button = MidButton; break;
@@ -4950,7 +4950,7 @@ bool QETWidget::translateKeyEventInterna
XKeyEvent xkeyevent = event->xkey;
// save the modifier state, we will use the keystate uint later by passing
- // it to translateButtonState
+ // it to qt_x11_translateButtonState
uint keystate = event->xkey.state;
// remove the modifiers where mode_switch exists... HPUX machines seem
// to have alt *AND* mode_switch both in Mod1Mask, which causes
@@ -5064,7 +5064,7 @@ bool QETWidget::translateKeyEventInterna
}
#endif // !QT_NO_XIM
- state = translateButtonState( keystate );
+ state = qt_x11_translateButtonState( keystate );
static int directionKeyEvent = 0;
if ( qt_use_rtl_extensions && type == QEvent::KeyRelease ) {
--- src/kernel/qdnd_x11.cpp.sav 2003-06-30 15:26:42.000000000 +0200
+++ src/kernel/qdnd_x11.cpp 2003-06-30 15:32:23.000000000 +0200
@@ -114,6 +114,8 @@ Atom qt_xdnd_finished;
Atom qt_xdnd_type_list;
const int qt_xdnd_version = 4;
+extern int qt_x11_translateButtonState( int s );
+
// Actions
//
// The Xdnd spec allows for user-defined actions. This could be implemented
@@ -198,6 +200,8 @@ static Atom qt_xdnd_source_current_time;
static int qt_xdnd_current_screen = -1;
// state of dragging... true if dragging, false if not
bool qt_xdnd_dragging = FALSE;
+// need to check state of keyboard modifiers
+static bool need_modifiers_check = FALSE;
// dict of payload data, sorted by type atom
static QIntDict<QByteArray> * qt_xdnd_target_data = 0;
@@ -879,8 +883,20 @@ void qt_handle_xdnd_finished( QWidget *,
void QDragManager::timerEvent( QTimerEvent* e )
{
- if ( e->timerId() == heartbeat && qt_xdnd_source_sameanswer.isNull() )
- move( QCursor::pos() );
+ if ( e->timerId() == heartbeat ) {
+ if( need_modifiers_check ) {
+ Window root, child;
+ int root_x, root_y, win_x, win_y;
+ unsigned int mask;
+ XQueryPointer( qt_xdisplay(), qt_xrootwin( qt_xdnd_current_screen ),
+ &root, &child, &root_x, &root_y, &win_x, &win_y, &mask );
+ if( updateMode( (ButtonState)qt_x11_translateButtonState( mask )))
+ qt_xdnd_source_sameanswer = QRect(); // force move
+ }
+ need_modifiers_check = TRUE;
+ if( qt_xdnd_source_sameanswer.isNull() )
+ move( QCursor::pos() );
+ }
}
static bool qt_xdnd_was_move = false;
@@ -948,6 +964,7 @@ bool QDragManager::eventFilter( QObject
updateMode(me->stateAfter());
move( me->globalPos() );
}
+ need_modifiers_check = FALSE;
return TRUE;
} else if ( e->type() == QEvent::MouseButtonRelease ) {
qApp->removeEventFilter( this );
@@ -986,9 +1003,11 @@ bool QDragManager::eventFilter( QObject
beingCancelled = FALSE;
qApp->exit_loop();
} else {
- updateMode(ke->stateAfter());
- qt_xdnd_source_sameanswer = QRect(); // force move
- move( QCursor::pos() );
+ if( updateMode(ke->stateAfter())) {
+ qt_xdnd_source_sameanswer = QRect(); // force move
+ move( QCursor::pos() );
+ }
+ need_modifiers_check = FALSE;
}
return TRUE; // Eat all key events
}
@@ -1014,10 +1033,10 @@ bool QDragManager::eventFilter( QObject
static Qt::ButtonState oldstate;
-void QDragManager::updateMode( ButtonState newstate )
+bool QDragManager::updateMode( ButtonState newstate )
{
if ( newstate == oldstate )
- return;
+ return false;
const int both = ShiftButton|ControlButton;
if ( (newstate & both) == both ) {
global_requested_action = QDropEvent::Link;
@@ -1041,6 +1060,7 @@ void QDragManager::updateMode( ButtonSta
}
}
oldstate = newstate;
+ return true;
}
@@ -1707,6 +1727,7 @@ bool QDragManager::drag( QDragObject * o
qt_xdnd_source_sameanswer = QRect();
move(QCursor::pos());
heartbeat = startTimer(200);
+ need_modifiers_check = FALSE;
#ifndef QT_NO_CURSOR
qApp->setOverrideCursor( arrowCursor );
--- src/kernel/qdragobject.h.sav 2003-05-19 22:34:43.000000000 +0200
+++ src/kernel/qdragobject.h 2001-01-01 01:01:00.000000000 +0100
@@ -248,7 +248,7 @@ private:
private:
QDragObject * object;
- void updateMode( ButtonState newstate );
+ bool updateMode( ButtonState newstate );
void updateCursor();
QWidget * dragSource;
