I've been doing some test with Qt 5 using C++ and I saw a lot of potential! But I came to a big wall which I haven't been able to pass yet.
I want to make a widnow that contains other windows (MDI), and I follow some of the tutorials online but the window is created by code, and I don't know how to "link" it to an UI file that I already design.
I follow the MDI tutorial that comes with Qt Creator, it works fine, but as I said before it doesn't work with custom UIs. And I found this other one that is exactly what I want, I follow it and it doesn't work I also downloaded the source code from the example, run it and still doesn't work. It opens a window with nothing in it.
If some one has an example, a good tutorial or a book that comes with the right info, I'll appreciate it.
Thanks a lot for taking the time to read this.
You should place a QMdiArea widget on your window. It provides an area in which MDI windows are displayed. It can be done via designer.
All your subwindows should inherit QMdiSubWindow which provides a subwindow class for QMdiArea :
class MyWindow : public QMdiSubWindow
{
Q_OBJECT
public:
explicit MyWindow(QWidget *parent = 0);
~MyWindow();
};
After creating a custom subwindow you can add it to the MDI area like:
MyWindow * subWindow = new MyWindow(ui->mdiArea);
MyWindow->show();
You can also add subWindows in designer by right clicking on the MDI area and choosing :
"Add subWindow"
This will add a subwindow which is viewable in designer. You can also add arbitrary widgets to the added subwindows in designer this way.
Related
I'm trying to write a circuit designer software in QT on Linux. I'm using KDE 5 Plasma desktop and QTCreator as an IDE.
I tried to use QFrame paintEvent to paint on it, and it worked, but when im grabbed the window inside QFrame it moved.
I know about QGraphicsView, but i cant make a custom class and promote it based on that(it's not listed).
How can i create a custom class from a container(QFrame, QGraphicsView or anything) where i can override paint event and also it doesn't move window if i grab it?
Sorry for my poor english.
QGraphicsView inherits from QAbstractScrollArea which inherits from QFrame itself.
So you can keep the QFrame in the form, and keep it promoted to your canvas class, but simply make you canvas class inherit QGraphicsView instead.
Although, my Qt has two differences in behavior from the OP (but I don't use KDE):
Clicking on a QFrame and moving the mouse doesn't move the whole window for me. I guess this behavior for the OP could be changed by reimplementing void mousePressEvent ( QMouseEvent * event ) in the canvas class and giving it an empty code instead. (doc)
I can put QGraphicsView in my ui files, and I can right click on them to promote them to another custom-defined class.
Edit: Found the reason why the window moves on KDE!
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);
I'm here because of a problem which remain from a long time >< !
I use Qt to develop an interactive screen using a QMidArea for multiple windows.
I have this configuration :
A class A which inherits from QWidget
A class B which inherits from A and adds some features
Then I add B into a new SubWindow.
But the problem i have is now to detect (maybe with signals and slots) when i drag a subWindow out of the QMainwindow containing all the application.
I tried to implement drag and drop into A but it clearly doesn't work because it's not A which is dragged but the subwindow...
My real aim is to detect when my subwindow hit the left border of the mainwindow.
Anyone has an idea ?
Thanks !
My problem:
I want to customize the way the title bar works and looks for my application.
My idea:
I created a new QWidget form in Qt Designer and added a QWidget to it. I added the following code in constructor:
setAttribute(Qt::WA_TranslucentBackground);
setWindowFlags(Qt::FramelessWindowHint);
QGraphicsDropShadowEffect* effect = new QGraphicsDropShadowEffect();
effect->setBlurRadius(20);
effect->setXOffset(0);
effect->setYOffset(0);
setGraphicsEffect(effect);
which makes the outer widget transparent and adds shadow to my inner widget. From this on I can create a custom title bar widget which I can implement however I want.
This is the result:
My issue
I want to make this usable from the designer as a main window and the QWidget doesn't allow me to add FROM THE DESIGNER tool bars, menu bar and status bar.
What I thought about was adding a QMainWindow widget as a child widget for the outer QWidget(which is transparent and acts as support for my shadow(the shadow is drawn on it)). I did this successfully but only from code:
QMainWindow *centralwidget = new QMainWindow();
centralwidget->setStyleSheet("background-color: lightgray;");
centralwidget->setGeometry(0, 0, 50, 20);
centralwidget->setWindowFlags(Qt::Widget);
this->layout()->addWidget(centralwidget);
QMenuBar *menuBar = new QMenuBar(centralwidget);
menuBar->addAction("Action");
QStatusBar *statusBar = new QStatusBar;
statusBar->showMessage("Status bar here");
centralwidget->addToolBar("tool bar");
centralwidget->setMenuBar(menuBar);
centralwidget->setStatusBar(statusBar);
This is the result:
My question:
How can I achieve this result from Qt Designer? Is it possible to promote a QWidget to QMainWindow? I cannot think to another way of doing it... It is really important for me to make it usable from Qt Designer because I intend to make it a template widget and be able to create e.g. a new QCustomMainWindow form Qt Creator just like you can create a QWidget or a QMainWindow.
Please help!
Here is another SO question similar to yours: Qt4: Placing QMainWindow instance inside other QWidget/QMainWindow
Just adding on to my original comment:
Start with a QMainWindow, and then apply the appropriate flags to it. QMainWindow is a subclass of QWidget. If it can't be done easily in the designer, it is pretty painless to do in code. Do it in your constructor right after the ui->setup() call.
Start with QMainWindow
Customize Window Flags
So in the constructor in mainwindow.cpp, you put
http://qt-project.org/doc/qt-5/qt.html#WindowType-enum
this->setWindowFlags(Qt::Widget);
This is the default type for QWidget. Widgets of this type are child
widgets if they have a parent, and independent windows if they have no
parent. See also Qt::Window and Qt::SubWindow.
// or if you want to apply more than one you, "or" it together, like so:
this->setWindowFlags(Qt::FramelessWindowHint | Qt::WindowStaysOnTopHint | Qt::Tool);
Try out a couple of those and see what you like.
Customize Widget Attributes
There are also Widget Attributes, that give you strong control over how your widgets look like and behave.
http://qt-project.org/doc/qt-5/qt.html#WidgetAttribute-enum
Qt Style Sheets
In addition to all the flags and attributes above, you can also modify a ton of it with stylesheets:
http://qt-project.org/doc/qt-5/stylesheet-reference.html
this->setStyleSheet("background: #000000;");
Qt Designer Custom Widgets
And also if you are interested in making this a reusable thing in Qt Designer, you can make it into a Qt Designer plugin, or custom widgets.
http://qt-project.org/doc/qt-4.8/designer-using-custom-widgets.html
http://qt-project.org/doc/qt-4.8/designer-creating-custom-widgets.html
QMdiArea and QMdiWindow
Another path to look into besides using QMainWindow is QMdiSubWindow
http://qt-project.org/doc/qt-5/QMdiSubWindow.html
I am trying to create a small application using Qt. What I want to do is to display in a dock widget a 3D Interface using DirectX11, other widgets in the QMainWindow will have properties to modify the behavior of what is been displayed in DX11.
The problem I am facing is that when I add a QDockWidget to QMainWindow, the dockWidgetContents function windowHandle returns NULL.
I am using an example from Get HWND on windows with Qt5 (from WId) to get the HWND. But if the function return NULL it will go up and get the HWND of the QMainWindow.
Is there any way to force a QWidget to have its own window handle?
Thanks for any advice!
Yes. You have several options for that. See the topic Native Widgets vs Alien Widgets in the QWidget class documentation.
Use the QT_USE_NATIVE_WINDOWS=1 in your environment.
Set the Qt::AA_NativeWindows attribute on your application. All widgets will be native widgets.
Set the Qt::WA_NativeWindow attribute on widgets: The widget itself and all of its ancestors will become native (unless Qt::WA_DontCreateNativeAncestors is set).
Call QWidget::winId to enforce a native window (this implies 3).
Set the Qt::WA_PaintOnScreen attribute to enforce a native window (this implies 3).