QListWidget . First attempts

blackbelt

I start using QListWidget. The snippet the follow, shows no item inside the QListWidget. What's wrong?

@
QListWidget* list= new QListWidget;
list->addItem(new QListWidgetItem("Banana"));
list->addItem(new QListWidgetItem("Apple"));
list->addItem(new QListWidgetItem("Orange"));
list->addItem(new QListWidgetItem("Grapes"));
list->addItem(new QListWidgetItem("Jayesh"));
list->show();
@

Peppy

Did you set up parent/size of QListWidget?

blackbelt

actually no. Should I ? The snippet runs inside a QGraphicsView. Is there anything wrong with this

Peppy

with this snippet? No, there is nothing wrong. But if you want to show anything inside QGraphicsView, I think, you will have to show us more...

blackbelt

the snipet I post in the first post:

@ QListWidget* list= new QListWidget;
list->addItem(new QListWidgetItem("Banana"));
list->addItem(new QListWidgetItem("Apple"));
list->addItem(new QListWidgetItem("Orange"));
list->addItem(new QListWidgetItem("Grapes"));
list->addItem(new QListWidgetItem("Jayesh"));
list->show();@

Peppy

set up parent for QListWidget. Just to make sure.
show us more code... I promise, I don't say it to your mom... :)

blackbelt

@class MyView : public QGraphicsView
{
Q_OBJECT

public:
MyView(QGraphicsView *parent = 0) {

            QListWidget* list= new QListWidget(this);
            list->addItem(new QListWidgetItem("Banana"));
            list->addItem(new QListWidgetItem("Apple"));
            list->addItem(new QListWidgetItem("Orange"));
            list->addItem(new QListWidgetItem("Grapes"));
            list->addItem(new QListWidgetItem("Jayesh"));
            list->show();
   }

}@

andre

So... is MyView created anywhere?

Note that it is not a good idea to put widget inside a QGraphicsView. It is possible, but chances are you'll run into issues.

blackbelt

[quote author="Andre" date="1343143131"]So... is MyView created anywhere?

Note that it is not a good idea to put widget inside a QGraphicsView. It is possible, but chances are you'll run into issues.[/quote]

yes, in the main I had also a class that extends a QMainWindow and, inside it I create the MyView. If it is not a good idea how can I create a multi widget application?

andre

Multi-widget is fine, but putting widgets inside a QGraphicsView is a source of problems. You're not actually doing that (yet), but based where you create your QListWidget (in the constructor of a QGraphicsView derived class), it seemed likely you'd like to do that.

Peppy

without GraphicsView...
well, look at demos & examples:http://qt-project.org/doc/qt-4.8/examples-mainwindow.html

blackbelt

So create a QWidget inside a QGraphicsView does not add it to QGraphicsView itself?

andre

That's the point: try to avoid doing that in the first place.

Anyway, for your first steps with the item view framework (including QListWidget), it would be good if you spare yourself the complications and just use the widget in a normal form to see how to work with it.

blackbelt

So this rule is valid for every kind of QWidget? The QPushButton for istance? is It safe to add a QWidget to the QMainWindow (does it make sense)?

andre

I am only referring to putting widgets (any widget) in a QGraphicsView (so, using [[doc:QGrapicsProxyWidget]]). Putting a QpushBotton on a QmainWindow makes perfect sense, and has no issues.