QCompleter popup position - qt

I'm having trouble trying to move the QCompleter popup view position.
I tried the QCompeter:complete and it's pops the completer view in the position as I wanted.
But if I start typing it close it, and open the completer in the 'default' position.
I also tried the QCompleter:setPopup() function.
I create a QListView and I tried to moved to different position.
And still the QCompleter popup view remains in the same position.
In my project I'm using a QFrame that wrap QLineEdit.
And I want that the completer view will get the QFrame position.
I succeed to set the completer view width via setFixedWidth() function.
but not to move the position.
Any suggestions ?
Thanks.

I suggest setting the CompletionMode to InlineCompletion, so there will be no popup. Then make your QListView indepedant of the QLineEdit; just react to signals that indicate when a view types some text, leaves the QLineEdit, etc (hint: subclass QListView) and sets the text in QLineEdit when a user selects a value from the list.
I think it will be difficult to override the placement since QCompleter takes ownership of your QListView. (Personally I think it does not make much sense to place the completion list somewhere else than next to the input field, but alas...)

Related

Buttons in vertical layout in QDialog with return value

I want to create a QDialog with Qt that looks somewhat like this:
The desired properties here are:
I can add a text to the dialog explaining the question behind it
I can add several buttons that are in a vertical layout
I can retrieve the value of the clicked button, i.e. I know if the user cancelled or clicked 1, 2 or 3 - ideally I can emit a signal with the corresponding value as parameter.
The dialog has a certain minimum height and width.
I have used a QMessageBox before for this purpose, but I can't get it to use a vertical layout. I have experimented with a QDialogButtonBox and a QDialog, but I can't really figure out how to get my desired return value easily.
A piece of code creating this dialog with code how to retrieve the clicked value would be great!
Did you try a QDialog widget? you can add QDialog without buttons to your project. In UI designer, add Vertical layout, label, and buttons.
In your class define your signals and emit it when the user clicked on buttons.

qt qcombobox shows no scroll bar

I have a QComboBox with an underlying model. Sometimes the model gets a couple of hundred of items, which makes it very difficult to scroll through the combobox. Is it somehow possible to add a scroll bar to the QComboBox? This would help a lot because my items are sorted.
I have read that QComboBox should come with a scroll bar by default, but this is not true in my case on my linux system. Is this the case with windows?
Best regards
QComboBox uses an QAbstractItemView (by default a QListView I think) for its popup. It's possible to call view() to get that widget. Since QAbstractItemView descends from QAbstractScrollArea, you can use all features from that class to modify how you want the scrollbars to show up.
As an extra, you can change this view to another type. For instance I have used a QTreeView in the past since it fit better with the data.

How to set cursor when it is in some area?

I have some rectangle link area on my widget. What is the best way to make cursor Qt::PointingHandCursor when it is in this area?
The QWidget class has a cursor property that you can set with the cursor you wish displayed when the mouse is above it.
EDIT:
Without more detail on what you are trying to achieve, I can only assume you're making your life much more difficult than it needs to be. You can create a QLabel widget to handle the link and then place the label on the menubar automatically.
QLabel *link = new QLabel("<a href='http://doc.qt.io'>Qt Documentation</a>");
menuBar()->setCornerWidget(link);
All the text formatting, cursor display and user interactions are handled by existing code in the Qt classes. The only thing you need to do yourself is to handle what happens when the user clicks on the link, that you can do by connecting a slot to the QLabel::linkActivated(const QString &) signal.

Qt: display qgraphicsitem in a widget

I got a QGraphicsScene that contains QGraphicsItems. On clicking such an item I open a dialog. I now want the item to be displayed in an area of the dialog.
I tried a QGraphicsView (in the dialog) and "pointed" it to the item which works allmost perfectly. The problem is, that it is possible to click the item in the dialog which would open a new dialog.
So my question: is there a easy way to tell QGraphicsView to ignore any input events? If not, is there a easy way to display a QGraphicsItem within a widget?
I am feeling so stupid...
QGraphicsView::setInteractive(false) did the trick.
I am still able to move the icon with the mouse wheel but this can probably be avoided by restricting the scene rect with setSceneRect()
You can install an event filter, on the QGraphicsView, which ignores input events. The Qt documentation states:
In your reimplementation of this function, if you want to filter the event out, i.e. stop it being handled further, return true; otherwise return false.

How to remove focus from a QLineEdit when anyplace else on the window is clicked

I'm working on a custom Qt button that allows you to edit the text on the button if you double click it. When the button is double clicked, a QLineEdit appears where the text on the button is allowing the user to edit the text on the button. My requirement is that if the user clicks anywhere in the application window, the QLineEdit should disappear and cancel the edit operation. This works in some cases. Specifically, it works if I click on anything that is capable of text entry. Other portions of the window don't work as expected. I'll click on a blank portion of the application window, and the QLineEdit retains its focus. How can I remove its focus in these cases?
I've found a solution that seems to work, though I'm still open to other options if there are any. I'm using PyQt4, so my example is in python:
Create a subclass of QLineEdit just so I have a new type. I don't want or need this behavior on all QLineEdit instances; just these specific ones.
class MyLineEdit(QtGui.QLineEdit):
pass
Now, in my QMainWindow subclass, I override the mousePressEvent() implementation. It gets the currently focused widget. If that widget is of type MyLineEdit, clear the focus.
class MyMainWindow(QtGui.QMainWindow):
def ...
def mousePressEvent(self, event):
focused_widget = QtGui.QApplication.focusWidget()
if isinstance(focused_widget, MyLineEdit):
focused_widget.clearFocus()
QtGui.QMainWindow.mousePressEvent(self, event)
def ...
This gets me the behavior I'm looking for so that if the user clicks anywhere on the application's window, the focus is cleared.
Edit: I did find one caveat to this. I have a QTreeView in the main window. If the user clicks on the tree view, focus is not removed from the text edit field.
Catch the clicked() signal of your parent widget and call yourLabel->clearFocus() (that unfortunatelly happens to not be a slot, making things more complicated) there.
I followed Grant Limberg instruction here but figured out that, in my case, a simple:
QApplication.focusWidget().clearFocus()
would fix the problem.
I'm not sure if this also works in Qt4 (I'm using PyQt5) but you can change the FocusPolicy of the QMainWindow or parent widget to clear the focus in the QLineEdit. As per https://doc.qt.io/qt-5/qwidget.html#focusPolicy-prop
I've changed the policy of my QMainWindow to Qt.StrongFocus and it worked like the functionality described in the question.
If done in C++ I would do something along the lines of:
connect(myWidgets->MyLineEdit, SIGNAL(returnPressed()), this, SLOT(onLineEditDone());
void onLineEditDone()
{
myWidgets->MyLineEdit->clearFocus();
}
For this particular case I would use editingFinished() instead of returnPressed(), probably, but I would NOT use textChanged(QString).

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