QAction with icon displays checkbox on top - c++

I have a menu with checkable QActions in it: (ed: these calls are within a QWidget subclass, so 'this' points to the associated widget).
QAction* action = new QAction(icon, actionName, this);
action->setCheckable(true);
action->setActionGroup(m_actionGroup);
menu->addAction(action);
This menu is attached to a tool button, which is in a QWidget with a few other tool buttons. Previously, it was part of a larger widget, but I've been refactoring to confine some things together.
When it was previously part of the larger widget, these actions and their icons displayed fine. Now, however, the icons are drawn in a dotted pattern and a box for a check box is drawn on top. When I hover over an action, the dotted action goes away entirely, and it's just the check box. When I select an action, the icon appears normally.
I've tried doing the same in a little toy program, and the menu displays correctly then, so I'm having trouble reproducing the issue outside of my rather large program. Has anyone seen behaviour like this before, or know how to fix it?
Qt 5.5 on Ubuntu 16.04 is the platform information.
Edit: It gets even stranger. The original implementation created the QMenus without parents. Which I would have avoided because of memory leak concerns. But if you create the menu with the widget holding the button as a parent, then you get this behaviour. It's something about the QMenu being constructed with a parent that is creating issues, not the QAction.

Related

Is there a way to attach or anchor two QWidgets together?

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.

Difference between QPushButton and QToolButton

I'm new to Qt and the difference between QPushButton and QToolButton is not so clear to me.
I know that a QToolButton is usually used in a QToolBar and it usually shows only an icon, without text, but I don't quite understand the main difference between both.
Does it have any bigger difference?
When should I use QPushButton and when should I use QToolButton?
I would like to know this to use the most appropriate button, and I need to perform some GUI tests and maybe it can be relevant.
QPushButton is simply a button. QToolButton is part of a group of widgets in the QtWidgets module that operate on QActions: QMenu and QToolBar are other examples. As a result, QToolButton is much more complex under the hood than QPushButton.
Some examples of how they are different in practice:
QToolButton is tightly integrated with QAction. Changing the icon, text, or other properties of a tool button's default action is reflected on the button.
You can change the layout of the tool button contents (icon only, text only, text beside icon, text below icon). This is not possible for a QPushButton.
QToolButton supports a "split" button type: a sidebar hot zone opens a menu instead of triggering the default action.
Tool buttons can be created directly in a QToolBar by adding an action. Other widgets must be explicitly added to the toolbar.
A tool button is meant to be displayed in a grid, so it has smaller default internal margins than a push button.
QPushButton is more for "Ok"/"Close" type buttons that contain text with an optional icon.
A QToolButton should generally have an icon.
A QPushButton should always have text.
From Qt doc: http://doc.qt.io/qt-5/qtoolbutton.html#details
"A tool button is a special button that provides quick-access to specific commands or options. As opposed to a normal command button, a tool button usually doesn't show a text label, but shows an icon instead."
When i want a button in the GUI simple with only an icon, I use QToolButton. But when i want a classic button, i use QPushButton.
No big differences,

Qt/C++ Technique To Show Inline Dialog

I have QtCreator 5.5 for the Mac, using C++, and I'm new at this. I have a MainForm window. I want to show a dialog inside that but draw it separately in its own UI designer. Then, at runtime, my code will pull that other UI and show it inside that window.
Imagine for instance a main application window. You click a button and you need to see a confirmation dialog. Normally you could do that with a separate window. Instead, I want it to be inline at runtime, to show it like a widget on the main window.
Sure, I could draw my dialog on top my existing window in a widget, but that defeats the point where I want to be able to adjust it in its own designer window, and just load it as necessary in the main window when I need it.
What's the technique in QtCreator and C++ to do this?
Open QtCreator. This task can only be done through there.
Assuming you have a regular Qt Widget Application, you need to just add a QWidget control on the MainWindow's centralWidget in the UI Designer.
Next, click Edit in the UI Designer and then rightclick Forms. Choose Add New...
In the dialog that opens up, choose Qt > Qt Designer Form Class, and click Choose...
Select Widget and then go with the defaults on the rest. This creates a widget called Form, and the form.h and form.cpp will also be added to your project.
Now find the form.ui and open it in Qt Designer. Add a Stacked Widget Control on the QWidget form. Size it to the same size as the parent widget. Next, stick a Label Control on the Stacked Widget Control's first page. This label will be temporary just to prove that this works. You'll set it to the text of "Testing". Now close the designer.
Flipping back to your UI File of your Main Window, find that QWidget you added and rightclick it. Choose Promote... and a dialog box appears. In that dialog, set Promoted Class Name to Form and then set Header File to form.h. Leave everything else on defaults and click Add and then Promote.
You may be expecting to see an immediate change in your Main Window in that QWidget that you added previously. However, that's not how this works unfortunately. You only see the change at runtime. So, now you should Run your application in Qt Creator. You'll see when it runs that your widget now contains the contents of that form.ui component you created.
Now, here's where it gets interesting. You can now draw all your inline modal dialogs on that form.ui, just putting them on different pages of your Stacked Widget control. You can also set the properties of your widget so that the background of the QWidget container is opaque and dark (creating a background dimmer) and then, at runtime, resize the QWidget to the size of your Main Window. When you need to switch to a different dialog, you can use setCurrentWidget() or setCurrentIndex() on that StackedWidget item like so:
QStackedWidget *w = ui->widget->findChild<QStackedWidget *>("stackedWidget");
w->setCurrentIndex(1);
In that example, I had a QWidget control on my MainWindow named simply widget. I then found the control on it called stackedWidget. Once I had it, I used the setCurrentIndex(x) method on it to change the page of that widget to show the one I needed. Remember that this is a zero-based index. So, (1) would be page 2.
QMainWindow::setCentralWidget
Inside your QMainWindow constructor add:
MyDialogClass myDialog = new MyDialogClass();
setCentralWidget(myDialog);

How to manage QSplitter in Qt Designer

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.

QPushButton is inactive till MainWindow gets focus

I have a QMainWindow with three QPushButtons (arranged in a QVBoxLayout in a QWidget). All have the same properties, except objectName, icon and iconSize. All are enabled and have two icons, one for normal and one for disabled.
When I start my application, always the top most icon shows the disabled icon (but is working, so it is enabled) the other two are fine. As soon as a focusable control in that window gets the focus, the icon changes to the active one and everything is fine.
Calling update or repaint in the showEvent of the window doesn't help either.
I'm using gcc 4.8.1 and qt 5.1.0.
Any ideas how to handle this glitch?
Update: It gets more strange: Starting the program, the icon shows disabled, getting another application the focus, the icon shows enabled, bringing the window on top again without giving it the focus (e.g. by using the task bar) changes the icon back to diabled. Clicking a control in the window, which can have focus will fix it again.
Well, well I finally got it. I just set the focus manually in the code and realized, that the icons were set in a wrong way. If a button was currently focussed it displayed the disabled icon. I had messed up the different button states and too many states got the disabled icon.