I have a QTreeView class with a context menu installed as follows:
m_ui.tree->setContextMenuPolicy(Qt::CustomContextMenu);
connect(m_ui.tree, SIGNAL(customContextMenuRequested(const QPoint&)),
this, SLOT(ShowTreeContextMenu(const QPoint&)));
...
void ShowTreeContextMenu(const QPoint& point)
{
m_treeContextMenu->exec(m_ui.tree->viewport()->mapToGlobal(point));
}
However when the context menu is being displayed the QTreeView will no longer respond to mouse clicks. Clicking on an item in the QTreeView while the context menu is displayed will remove the context menu but does not select the clicked item.
This is especially disorientating when right clicking on a new item, as the context menu pops up over the new item, but as the item was not selected the contents of the context menu are referring to the previously selected item.
A possible solution which I haven't verified would be to capture the click event of the right click, manually make the selection in the tree view and then invoking the parent click event which will in turn activate the context menu.
You don't say which version of Qt you are using, but we found the same problem in Qt4.4.0, it worked in 4.3. We reported this to Trolltech as a bug 225615
This is still marked as pending, so in the meantime I would follow Shy's suggestion of intercepting the right click and making the selection yourself.
Subclass the QTreeView and add the protected method void contextMenuEvent(QContextMenuEvent *event); In this method you execute a QMenu:
class TreeView : public QTreeView{
Q_OBJECT
public:
TreeView(QWidget *parent);
~TreeView();
protected:
void contextMenuEvent(QContextMenuEvent *event);
};
void TreeView::contextMenuEvent(QContextMenuEvent *event){
QMenu menu(this);
menu.addAction(action1);
menu.addAction(action2);
//...
menu.addAction(actionN);
menu.exec(event->globalPos());
}
Related
I would like to intercept the paste action of a QLineEdit context menu that is created by default in any QLineEdit widget (see picture below)
Is there a way to redirect the Paste action of the context menu by any means?
One can fiddle with the actions in the context menu by overloading the contextMenuEvent of the QLineEdit widget.
Edit:
The code of the link above:
void LineEdit::contextMenuEvent(QContextMenuEvent *event)
{
QMenu *menu = createStandardContextMenu();
menu->addAction(tr("My Menu Item"));
//...
menu->exec(event->globalPos());
delete menu;
}
And the code that I actually used for my purposes:
menu = self.createStandardContextMenu()
menu.actions()[5].connect(self.paste) # The hard ref to the 6th item is not ideal but what can you do...
menu.exec_(event.globalPos())
I have pretty specific situation. I want to place a QAction into QToolbar and reach following behaviour:
Checkable QAction with icon.
Classic arrow on the right side which is used for showing menu
By pressing this arrow my QDialog should appears on screen instead of QMenu-like one
Now I'm a bit confused with implementing all this things together.
For now I've created QAction added it to toolbar and also created an empty QMenubecause I didn't get the idea of how to add the "dropdown" arrow another way.
So, I also connected my slot to QMenu aboutToShow() signal and now, I can create my dialog and exec() it just before QMenu shows. But here's the main problem appears: after I did everything with my dialog an click OK button QMenu trying to appear, but as it is empty it shows nothing and further actions become available only after I left-click somwhere to "close" this menu.
Is there any way to force QMenu not to show or can inherit from QMenu and reimplemnt its behaviour (I've tried to do such trick with exec() show() popup() methods of QMenu after subclassing from it, but none of them are being called when menu appears on the screen) ?
Here's the solution, which worked for me.
class QCustomMenu : public QMenu
{
Q_OBJECT
public:
QCustomMenu(QObject *parent = 0):QMenu(parent){};
};
In code:
QAction* myActionWithMenu = new QAction ( "ActionText", toolbar);
QCustomMenu* myMenu = new QCustomMenu(toolbar);
connect(myMenu, SIGNAL(aboutToShow()), this, SLOT(execMyMenu()));
execMyMenu() implementation:
void execMyMenu(){
m_activeMenu = (QCustomMenu*)sender(); // m_activeMenu -- private member of your head class, needs to point to active custom menu
QMyDialog* dlg = new QMyDialog();
// setup your dialog with needed information
dlg->exec();
// handle return information
m_myTimer = startTimer(10); // m_myTimer -- private member of your head(MainWindow or smth like that) class
}
Now we have to handle timerEvent and close our menu:
void MyHeadClass::timerEvent(QTimerEvent *event)
{
// Check if it is our "empty"-menu timer
if ( event->timerId()==m_myTimer )
{
m_activeMenu->close(); // closing empty menu
killTimer(m_myTimer); // deactivating timer
m_myTimer = 0; // seting timer identifier to zero
m_activeMenu = NULL; // as well as active menu pointer to NULL
}
}
It works great on every platform and does what I wanted.
Hope, this would help someone. I've spent week trying to find this solution.
I want to have a line edit field in a popup menu I've got. I'm basically letting the user pick from one of several common sizes for something, but I want them to be able to enter a custom size as the last entry in the menu.
So I've got something like this (snipped from larger code, new_menu is the menu of interest):
QWidget *widget = new QWidget(new_menu);
QHBoxLayout *layout = new QHBoxLayout;
QLineEdit* le = new QLineEdit;
le->setPlaceholderText("Custom");
le->setFixedWidth(100);
ayout->addWidget(le);
widget->setLayout(layout);
QWidgetAction* wa = new QWidgetAction(new_menu);
wa->setActionGroup(group);
wa->setDefaultWidget(widget);
new_menu->addAction(wa);
connect(le, SIGNAL(returnPressed()), this, SLOT(leslot()));
Which works great, the LineEdit shows up nice and centered in the menu, it's got the placeholder text, I can click it and edit, everything. However, when I hit enter on the textBox, it emits the returnPressed signal and the menu emits a triggered signal with one of the other actions on the list, so at best I'm changing my configuration twice and at worst things break.
Additionally, when I click off the edge of the LineEdit (still in the menu though, but not in the editable area), the menu emits a triggered signal with the QWidgetAction associated with it, which isn't what I want.
So two questions:
1) Can I get the return to work the way I want. It's fine if the menu closes when it's hit, but it can't emit another action too.
2) Can I get it to not emit an action at all when the lineEdit is clicked?
Here's what I ended up doing for anyone that follows. I subclassed QLineEdit thusly:
class EnterLineEdit : public QLineEdit {
Q_OBJECT
public:
void keyPressEvent(QKeyEvent *evt) {
if (evt->key() == Qt::Key_Enter || evt->key() == Qt::Key_Return) {
emit returnPressed();
} else {
QLineEdit::keyPressEvent(evt);
}
}
};
This lets me manually emit the returnPressed signal when enter/return is hit and not pass it up the widget hierarchy, so the menu never sees it when enter is hit over the lineedit. I connected the returnPressed signal to the hide() slot of the menu so that the menu will still close, but without triggering an action.
Is there a way to show a popup when the user right clicks on an empty portion of the scene?
I'm new at Qt and I've tried slots and subclassing, but to no avail.
No such slot and, respectively:
"error: 'QMouseEvent' has not been declared"
when trying to implement the onMouseRelease event.
QGraphicsView is the widget used for displaying the contents of the QGraphicsScene. So the correct place to implement the context menu (popup menu) is the QGraphicsView.
You need to reimplement the contextMenuEvent function is your own class inherited from QGraphicsView:
void YourGraphicsView::contextMenuEvent(QContextMenuEvent *event)
{
QMenu menu(this);
menu.addAction(...);
menu.addAction(...);
...
menu.exec(event->globalPos());
}
See also the Qt's Menus Example.
You can re-implement the contextMenuEvent method of the QGraphicsScene class, which will give you access to the scene coordinates as well as the screen coordinates (as opposed to QGraphicsView, which also works but doesn't have this information):
void YourGraphicsScene::contextMenuEvent(QGraphicsSceneContextMenuEvent *event)
{
// event->scenePos() is available
QMenu menu(this);
menu.addAction(...);
menu.addAction(...);
...
menu.exec(event->screenPos());
}
I have a few combo-boxes and double spin boxes on my Qt Dialog. Now I need a "ResetToDefault" item on a menu that comes up when you right click on the widget (spin box or combo box).
How do i get it. Is there some way I can have a custom menu that comes up on right click or Is there a way i can add items to the menu that comes on right click.
First, for Qt4, the simplest way is to create an action to reset the data, and add it the the widget using the addAction method (or use the designer). Then, set the contextMenuPolicy attribute to Qt::ActionsContextMenu. The context menu will appear and the action will be triggered.
Code example:
QAction *reset_act = new QAction("Reset to default");
mywidget->addAction(reset_act);
mywidget->setContextMenuPolicy(Qt::ActionsContextMenu);
// here connect the 'triggered' signal to some slot
For Qt3, you might have to intercept the context menu event, and thus inherit the QSpinBox and others. Or maybe you can intercept the context menu event from the main window, detect if it occurred above the widget supposed to have a context menu (using the QWidget::childAt method) and show it there. But you'll have to test.
For Qt4, you can do this for an editable QComboBox by using your own QLineEdit. Create a derived QLineEdit class which implements the contextMenuEvent
class MyLineEdit : public QLineEdit
{
Q_OBJECT
public:
MyLineEdit(QWidget* parent = 0) : QLineEdit(parent){}
void contextMenuEvent(QContextMenuEvent *event)
{
QPointer<QMenu> menu = createStandardContextMenu();
//add your actions here
menu->exec(event->globalPos());
delete menu;
}
};
Then, use the setLineEdit function of QComboBox to set the line edit
MyLineEdit* edit = new MyLineEdit();
comboBox->setLineEdit(edit);
The combo box will now use your line edit class. The createStandardContextMenu function creates the normal context menu and you can add any new actions to it that you like in the contextMenuEvent handler before it is shown.
If the QComboBox is not editable then it doesn't have a default context menu so using the Qt::ActionsContextMenu method is much simpler.
QAbstractSpinBox also has a setLineEdit function so you can use a similar technique. Although, for some reason the setLineEdit function is protected on QAbstractSpinBox but public on QLineEdit.