I have an application written in C++/QT5 with a QListView widget within a QHBoxLayout within a QGroupBox. There is also a QTabWidget in the main window. I would like the user to be able to resize the QListView widget by clicking and dragging and for the other items to automatically resize themselves accordingly.
I feel like this should be something that is easily done within the framework of QT5, but I can't for the life of me find a way. Even having a border on the list view that I can resize within the code of my application would be a start.
Thanks to jhnnslschnr I was able to solve this via the QSplitter widget. If you're using QtCreator as I was, you can use QSplitter simply by Ctrl-clicking the widgets you want in the splitter and then selecting "Lay out horizontally (vertically) in splitter". The user can now select the partitioning at run-time.
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I'm getting started with Qt and decided to build a full-screen text editor. I want to have a button (button with arrow in screenshot) attached to a QDockWidget which opens and closes it so the button is always visible to the right side of the screen and stay anchored to it when dock is visible or resized.
My current app is a simple fullscreen textEdit set to centeralwidget in Mainwindow.
I haven't found a way to do this yet with layouts or existing addAnchor() functions so any help or direction is appreciated.
You can achieve what you want by using a container for your text edit and the button. A QWidget instance can be used as an "invisible"*** container for other widgets.
So in Qt Designer you add a widget as a central widget of the main-window, inside this widget you add the text edit and the button, then you set a vertical layout for this container widget.
Don't forget to restrict the docking widget to only dock to the right side, you can do that with: dock->setAllowedAreas(Qt::DockWidgetArea::RightDockWidgetArea); //assuming dock is the pointer to your QDockWidget.
In case you want the dockWidget to be able to dock to any side and the button to follow, you can do that too, but it get a little bit more complicated. Basically you need to connect a slot to dockLocationChanged of your dockWidget and based on where it's docked you need to set-up a new layout for the container widget to be vertical or horizontal and the order of the textEdit and the button based on the side the dock happened.
LE:*** you will most likely need to set the margins you want, since both the widget and it's layout can have them and the actual content might have higher spacing than you want.
I am new to Qt and I need to implement a monitoring interface with the following considerations:
I have a main window, on which I should put multiple screens, qsplitter appears to be the best solution.
The interface provides user with the option of changing the number of cameras, so QSplitter should be created/re-created during run time.
The problem is that I have too many cameras to pre-define widgets for them, so I need to create QSplitter UI instances dynamically.
The problem is that I can't find QSplitter classes when using Qt Designer and creating QSplitter class programatically is not working as MainWindow has been created through Qt Designer (.ui).
I would like to hear any suggestions regarding this issue, if there are better approaches, please let me know.
In Qt Designer, the QSplitter is not a widget, but a Layout.
Select the widgets you want to include in the two splitter areas, then select Layout from the context menu (right mouse button) - you will find two entries Layout Horizontally in splitter and Layout Vertically in splitter to group the widgets in a vertical or in a horizontal splitter.
QSplitter isn't a strict UI element, it's essentially a parent element that controls child elements. If you want to do it through Designer you'd probably run into headaches, but the basic gist is you select a number of widgets to be controlled by it, and click the Layout Horizontally/Vertically in splitter button which is in the layout buttons group.
What you might be best doing is creating your child elements programmatically, creating your splitter programmatically, adding the child widgets with someSplitter->addWidget(...). In the Qt docs there's some sample code for this:
QSplitter *splitter = new QSplitter(parent);
QListView *listview = new QListView;
QTreeView *treeview = new QTreeView;
QTextEdit *textedit = new QTextEdit;
splitter->addWidget(listview);
splitter->addWidget(treeview);
splitter->addWidget(textedit);
http://doc.qt.io/qt-5/qsplitter.html#details
And if you really want to do it in Designer there's a guide here: http://www.bogotobogo.com/Qt/Qt5_Splitter.php
Although QSplitter is a widget, you can't create one directly in Qt Designer. It is only available for laying out pre-existing widgets - which does not fit your use-case, since you need to create child widgets dynamically.
However, you can work around this limitation by using widget promotion. This is a simple mechanism that allows you to add substitute classes to represent widgets that are not directly available in Qt Designer. The idea is that you add a widget that is most similar to the one you actually want (e.g. a QFrame is most similar to QSplitter) and then promote that to the substitute class which you have defined in your own header file. When uic finally generates the code, it will use your substitute class instead of the class of the widget added in Qt Designer (which just acts as a placeholder).
Note that when you create your substitute class in the Promoted Widgets dialog, the base class should be a QFrame, not a QSplitter. This is because you are extending a QFrame (i.e. your placeholder widget), rather than a QSplitter. Of course, you can define your substitute class to be anything you like.
Image is easier to understand.
I have two Qt widgets in the window. One of them is QDockWidget, and another one is just QWidget.
When I drag the QDockWidget, the default behaviour of the another widget is moving without changing its size. And I want it to fill the whole window except dock widget, and to change its size programmatically when I drag QDockWidget. Hwo to do it better?
The solution was to set container horizontal policy as "fixed"
When I press a button, I bring up a dialog where user select things and press 'Ok' at the end. I want a splitter in this dialog. Left pane will show tree and right will show something else. How do I do that right?
From Qt example itself:
QSplitter *splitter = new QSplitter(parent);
QListView *listview = new QListView;
QTreeView *treeview = new QTreeView;
QTextEdit *textedit = new QTextEdit;
splitter->addWidget(listview);
splitter->addWidget(treeview);
splitter->addWidget(textedit);
So in this example, splitter is created without any dialog resource. If I have to create this way, that would mean I have to create all my controls in the code as well rather than Qt Creator.
What is the right way to do this when I need other controls on the screen?
You can simply create splitter containing items in Qt Designer :
First place your widgets on your dialog or widget in designer (They should not be in a layout)
Select the widgets that you want to be in a splitter (By holding CTL and clicking on them)
Right click on a selected widget and from Layout menu select Lay Out Horizontally in Splitter or Lay Out Vertically in Splitter.
Now apply a grid layout to the dialog and everything should be OK. You would see something like this in Object Inspector View :
Okay, I know this is ancient, but here's the complete answer.
First, within some sort of widget container, plop your pieces in. For the window I just did, I have a Widget as my window. I put two widgets inside that labeled something like topContainer and bottomContainer. I then put all the widgets they each need into them, and gave them their own layouts.
Then do NOT select the main container. Select the two widgets you want to split. You're in effect putting a splitter on them, not on the main container. So I went to the widget list window and selected both together, then right-click for the dialog window, scroll down to the Layout option, and "Lay Out Vertically in a Splitter" is NOT greyed out. Select it.
You still need a layout on the main container. A splitter is not a layout. So at that point, I just put a vertical layout on the main container.
To repeat: you are NOT setting a layout on the container holding the pieces you're trying to split. You are selecting the two widgets to split and adding a QSplitter around them. That's the trick to get it to work.
You can still create your controls in a .ui file using Qt Designer (integrated in Qt Creator). Within Qt Designer, add a QWidget object to your dialog. Then, from QDialog derived class you'll write, directly in your constructor, create your QSplitter using the QWidget object as a parent.
This way, you can create all but the splitter object from Qt Designer.
I think it's also possible to create the QSplitter (as you can create a QButton, QCheckBox...) item directly from Qt Designer.
I have a form written with Qt Designer, which contains a QWidget promoted to a custom widget I have. The custom widget contains several combo boxes. I want the form to have a reasonable tab order, with focus moving from the widget immediately before the custom widget, then going through the combo boxes in the custom widget, and proceeding to the widget after the custom widget. So I set the QWidget to have tab focus in Designer, but the custom widget doesn't handle having focus properly.
I could solve this problem using QWidget::setTabOrder, but that would be messy because I would have to reach into the custom widget from the outside. Alternatively I could give the custom widget a member function to set the tab order. Ideally there should be a simpler way. Is there?