Qt::DropAction QDrag::exec(Qt::DropActions supportedActions, Qt::DropAction defaultDropAction)
{
Q_D(QDrag);
if (!d->data) {
qWarning("QDrag: No mimedata set before starting the drag");
return d->executed_action;
}
QDragManager *manager = QDragManager::self();
d->defaultDropAction = Qt::IgnoreAction;
d->possible_actions = supportedActions;
if (manager) {
if (defaultDropAction == Qt::IgnoreAction) {
if (supportedActions & Qt::MoveAction) {
d->defaultDropAction = Qt::MoveAction;
} else if (supportedActions & Qt::CopyAction) {
d->defaultDropAction = Qt::CopyAction;
} else if (supportedActions & Qt::LinkAction) {
d->defaultDropAction = Qt::LinkAction;
}
} else {
d->defaultDropAction = defaultDropAction;
}
d->executed_action = manager->drag(this);
}
return d->executed_action;
}
/*!
Destroys the drag object.
*/
QDrag::~QDrag()
{
Q_D(QDrag);
delete d->data;
QDragManager *manager = QDragManager::self();
if (manager && manager->object == this)
manager->cancel(false);
}
/*!
\obsolete
\bold{Note:} It is recommended to use exec() instead of this function.
Starts the drag and drop operation and returns a value indicating the requested
drop action when it is completed. The drop actions that the user can choose
from are specified in \a request. Qt::CopyAction is always allowed.
\bold{Note:} Although the drag and drop operation can take some time, this function
does not block the event loop. Other events are still delivered to the application
while the operation is performed.
\sa exec()
*/
Qt::DropAction QDrag::start(Qt::DropActions request)
{
Q_D(QDrag);
if (!d->data) {
qWarning("QDrag: No mimedata set before starting the drag");
return d->executed_action;
}
QDragManager *manager = QDragManager::self();
d->defaultDropAction = Qt::IgnoreAction;
d->possible_actions = request | Qt::CopyAction;
if (manager)
d->executed_action = manager->drag(this);
return d->executed_action;
}
bool QDragManager::eventFilter(QObject *o, QEvent *e)
{
if (beingCancelled) {
if (e->type() == QEvent::KeyRelease && static_cast<QKeyEvent*>(e)->key() == Qt::Key_Escape) {
qApp->removeEventFilter(this);
Q_ASSERT(object == 0);
beingCancelled = false;
#ifndef QT_NO_LOCALEVENTLOOP
eventLoop->exit();
#else
asyncDragFinished();
#endif
return true; // block the key release
}
return false;
}
if (!o->isWidgetType())
return false;
switch(e->type()) {
case QEvent::ShortcutOverride:
// prevent accelerators from firing while dragging
e->accept();
return true;
case QEvent::KeyPress:
case QEvent::KeyRelease:
{
QKeyEvent *ke = ((QKeyEvent*)e);
if (ke->key() == Qt::Key_Escape && e->type() == QEvent::KeyPress) {
cancel();
qApp->removeEventFilter(this);
beingCancelled = false;
#ifndef QT_NO_LOCALEVENTLOOP
eventLoop->exit();
#else
asyncDragFinished();
#endif
} else {
updateCursor();
}
return true; // Eat all key events
}
case QEvent::MouseButtonPress:
case QEvent::MouseMove:
{
if (!object) { //#### this should not happen
qWarning("QDragManager::eventFilter: No object");
return true;
}
QDragManager *manager = QDragManager::self();
QMimeData *dropData = manager->object ? manager->dragPrivate()->data : manager->dropData;
if (manager->object)
possible_actions = manager->dragPrivate()->possible_actions;
else
possible_actions = Qt::IgnoreAction;
QMouseEvent *me = (QMouseEvent *)e;
if (me->buttons()) {
Qt::DropAction prevAction = global_accepted_action;
QWidget *cw = QApplication::widgetAt(me->globalPos());
// Fix for when we move mouse on to the deco widget
if (qt_qws_dnd_deco && cw == qt_qws_dnd_deco)
cw = object->target();
while (cw && !cw->acceptDrops() && !cw->isWindow())
cw = cw->parentWidget();
if (object->target() != cw) {
if (object->target()) {
QDragLeaveEvent dle;
QApplication::sendEvent(object->target(), &dle);
willDrop = false;
global_accepted_action = Qt::IgnoreAction;
updateCursor();
restoreCursor = true;
object->d_func()->target = 0;
}
if (cw && cw->acceptDrops()) {
object->d_func()->target = cw;
QDragEnterEvent dee(cw->mapFromGlobal(me->globalPos()), possible_actions, dropData,
me->buttons(), me->modifiers());
QApplication::sendEvent(object->target(), &dee);
willDrop = dee.isAccepted() && dee.dropAction() != Qt::IgnoreAction;
global_accepted_action = willDrop ? dee.dropAction() : Qt::IgnoreAction;
updateCursor();
restoreCursor = true;
}
} else if (cw) {
QDragMoveEvent dme(cw->mapFromGlobal(me->globalPos()), possible_actions, dropData,
me->buttons(), me->modifiers());
if (global_accepted_action != Qt::IgnoreAction) {
dme.setDropAction(global_accepted_action);
dme.accept();
}
QApplication::sendEvent(cw, &dme);
willDrop = dme.isAccepted();
global_accepted_action = willDrop ? dme.dropAction() : Qt::IgnoreAction;
updatePixmap();
updateCursor();
}
if (global_accepted_action != prevAction)
emitActionChanged(global_accepted_action);
}
return true; // Eat all mouse events
}
case QEvent::MouseButtonRelease:
{
qApp->removeEventFilter(this);
if (restoreCursor) {
willDrop = false;
#ifndef QT_NO_CURSOR
QApplication::restoreOverrideCursor();
#endif
restoreCursor = false;
}
if (object && object->target()) {
QMouseEvent *me = (QMouseEvent *)e;
QDragManager *manager = QDragManager::self();
QMimeData *dropData = manager->object ? manager->dragPrivate()->data : manager->dropData;
QDropEvent de(object->target()->mapFromGlobal(me->globalPos()), possible_actions, dropData,
me->buttons(), me->modifiers());
QApplication::sendEvent(object->target(), &de);
if (de.isAccepted())
global_accepted_action = de.dropAction();
else
global_accepted_action = Qt::IgnoreAction;
if (object)
object->deleteLater();
drag_object = object = 0;
}
#ifndef QT_NO_LOCALEVENTLOOP
eventLoop->exit();
#else
asyncDragFinished();
#endif
return true; // Eat all mouse events
}
default:
break;
}
return false;
}
bool QDragManager::eventFilter(QObject *o, QEvent *e)
{
if (beingCancelled) {
return false;
}
if (!o->isWidgetType())
return false;
switch(e->type()) {
case QEvent::MouseButtonPress:
{
}
case QEvent::MouseMove:
{
if (!object) { //#### this should not happen
qWarning("QDragManager::eventFilter: No object");
return true;
}
QDragManager *manager = QDragManager::self();
QMimeData *dropData = manager->object ? manager->dragPrivate()->data : manager->dropData;
if (manager->object)
possible_actions = manager->dragPrivate()->possible_actions;
else
possible_actions = Qt::IgnoreAction;
QMouseEvent *me = (QMouseEvent *)e;
if (me->buttons()) {
Qt::DropAction prevAction = global_accepted_action;
QWidget *cw = QApplication::widgetAt(me->globalPos());
// map the Coords relative to the window.
if (!cw)
return true;
while (cw && !cw->acceptDrops() && !cw->isWindow())
cw = cw->parentWidget();
bool oldWillDrop = willDrop;
if (object->target() != cw) {
if (object->target()) {
QDragLeaveEvent dle;
QApplication::sendEvent(object->target(), &dle);
willDrop = false;
global_accepted_action = Qt::IgnoreAction;
if (oldWillDrop != willDrop)
updateCursor();
object->d_func()->target = 0;
}
if (cw && cw->acceptDrops()) {
object->d_func()->target = cw;
QDragEnterEvent dee(cw->mapFromGlobal(me->globalPos()), possible_actions, dropData,
me->buttons(), me->modifiers());
QApplication::sendEvent(object->target(), &dee);
willDrop = dee.isAccepted() && dee.dropAction() != Qt::IgnoreAction;
global_accepted_action = willDrop ? dee.dropAction() : Qt::IgnoreAction;
if (oldWillDrop != willDrop)
updateCursor();
}
} else if (cw) {
QDragMoveEvent dme(cw->mapFromGlobal(me->globalPos()), possible_actions, dropData,
me->buttons(), me->modifiers());
if (global_accepted_action != Qt::IgnoreAction) {
dme.setDropAction(global_accepted_action);
dme.accept();
}
QApplication::sendEvent(cw, &dme);
willDrop = dme.isAccepted();
global_accepted_action = willDrop ? dme.dropAction() : Qt::IgnoreAction;
if (oldWillDrop != willDrop) {
updatePixmap();
updateCursor();
}
}
if (global_accepted_action != prevAction)
emitActionChanged(global_accepted_action);
}
return true; // Eat all mouse events
}
case QEvent::MouseButtonRelease:
{
qApp->removeEventFilter(this);
#ifndef QT_NO_CURSOR
if (restoreCursor) {
QApplication::restoreOverrideCursor();
willDrop = false;
restoreCursor = false;
}
#endif
if (object && object->target()) {
QMouseEvent *me = (QMouseEvent *)e;
QDragManager *manager = QDragManager::self();
QMimeData *dropData = manager->object ? manager->dragPrivate()->data : manager->dropData;
QDropEvent de(object->target()->mapFromGlobal(me->globalPos()), possible_actions, dropData,
me->buttons(), me->modifiers());
QApplication::sendEvent(object->target(), &de);
if (de.isAccepted())
global_accepted_action = de.dropAction();
else
global_accepted_action = Qt::IgnoreAction;
if (object)
object->deleteLater();
drag_object = object = 0;
}
eventLoop->exit();
return true; // Eat all mouse events
}
default:
break;
}
return false;
}
