I want to set dock widget at place below a widget as in figure
But when I am setting geometry as start point of Y to equivalent the gap size but it is not working.
I think position of QDockWidget should be handled different way, then setting its geometry.
This example shows how QDockWidgets are positioned as you want + one more dock widget tabbed together with another one.
#include <QtGui>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
// Main window
QMainWindow *window = new QMainWindow;
window->setDockNestingEnabled(true);
// Anything to add as central widget
QWidget *widget = new QWidget;
window->setCentralWidget(widget);
// First dock in the left top corner
QDockWidget *dockWidget = new QDockWidget("--- 1 ---");
window->addDockWidget(Qt::LeftDockWidgetArea, dockWidget);
// Second dock below first one
QDockWidget *dockWidget2 = new QDockWidget("--- 2 ---");
window->addDockWidget(Qt::LeftDockWidgetArea, dockWidget2);
// Third in tab with second one
QDockWidget *dockWidget3 = new QDockWidget("--- 3 ---");
window->tabifyDockWidget(dockWidget2, dockWidget3);
window->show();
return a.exec();
}
QMainWindow Has several functions how to handle spliting, moving or tabbing QDockWidgets
Related
I want to have a QHBoxLayout where one QLabel is on the far left, the one QLabel is on the far right.
My Google-fu fails me. :( I cannot find the solution.
Here is a screenshot of the QHBoxLayout with two QLabel widgets:
Whatever I try, I cannot get the second QLabel widget aligned on the far right.
Roughly speaking, I tried something like this:
QHBoxLayout* const hboxLayout = new QHBoxLayout{};
hboxLayout->addWidget(m_leftLabel, 1);
hboxLayout->addStretch(1);
hboxLayout->addWidget(m_rightLabel, 0, Qt::AlignmentFlag::AlignRight);
I tried various large stretch values for the first addWidget() call and addStretch().
I also tried:
m_rightLabel->setAlignment(Qt::AlignmentFlag::AlignRight)
None of these solutions works. I am sure the solution is very simple ( ! ), but I cannot find it.
How can I do this?
My solution is to set a stretch in the middle:
#include <QtWidgets>
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QWidget w;
QHBoxLayout *lay = new QHBoxLayout(&w);
lay->addWidget(new QLabel("Left"));
lay->addStretch();
lay->addWidget(new QLabel("Right"));
w.show();
return a.exec();
}
I'm beginning with Qt and I do not understand something. Here is my code:
#include <QApplication>
#include <QtWebKitWidgets/QWebView>
#include <QMainWindow>
#include <QPushButton>
QApplication a(argc, argv);
QMainWindow *mWin = new QMainWindow();
QPushButton *button = new QPushButton("Button");
button->setGeometry(0,0,128,56);
button->show();
mWin->setGeometry(QRect(300,300,1024,640));
mWin->setWindowFlags(Qt::CustomizeWindowHint | Qt::WindowMinimizeButtonHint | Qt::WindowCloseButtonHint);
mWin->show();
return a.exec();
When I launch the program, it makes a pushbutton, but not on the main GUI. It instead makes it in the upper lefthand corner of my scoeen. How do I make the pushbutton part of the main GUI?
Both QMainWindow and QPushButton derive from QWidget and generally, QWidgets can display themselves independently, so don't need to be attached to a parent, though it's likely you'll want to group and organise the widgets you're presenting to the user.
For a beginner, I think that QMainWindow is a bit misleading as you don't actually need it to display widgets. If, for example, you wanted to just display the button, you only need create the QPushButton and call show: -
QPushButton pButton = new QPushButton("Test");
pButton->show();
Though it's rare that you'll actually want to do this. In actuality, though it appears pointless, you can even just create a QWidget and display that: -
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
QWidget w;
w.show();
return a.exec();
}
The QWidget can now be the parent to all other widgets, still without you defining a QMainWindow.
It is likely that you will want other widgets to display and Qt uses a parent / child hierarchy system of linking them together. Amongst other things, an advantage here is that you don't need to keep track of the different widgets in order to release their memory. When you're finished, you just delete the top level item, which may be a QMainWidget, or QDialog or other QWidget based object. In the case of Windows, all you need to do is close them and their children are cleaned up too.
Adding Widgets to a QMainWindow can be done in different ways, depending upon what you're trying to achieve. Eventually, you'll likely want to use layouts that allow grouping of widgets in logical arrangements, but to start with, if you look at the constructor of the QPushButton, you'll see that it takes an optional parameter of QWidget* : -
QPushButton(QWidget * parent = 0)
This allows you to attach the widget you're creating (QPushButton in this case) to a parent. Therefore, create the QMainWindow and then pass its pointer to the QPushButton.
QMainWindow* pWindow = new QMainWindow; // create the main window
QPushButton pButton = new QPushButton(pWindow); // create the push button
pWindow->show(); // Display the main window and its children.
You're creating a button and a window, but you're not associating them together. Therefore, the button is not part of the main UI. In order to add the button to the main window, you should add the following line-
mWin->setCentralWidget(button);
When creating user interfaces with Qt, it's better to avoid setting the geometry explicitly. Here is a nice page which describes the layouting in Qt.
Also, you seem to be missing a main function.
You are not setting parent child relationship, you need QPushbutton as a child of QMainwindow. Then you can see QPushbutton on QMainwindow.
Please try this, I am not sure what exactly you want to achive..but below code will give some hind about how to proceed..
QApplication a(argc, argv);
QMainWindow *mWin = new QMainWindow();
QPushButton *button = new QPushButton(mWin); // setting parent as QMainwindow
button->setGeometry(0,0,128,56);
// button->show();
//mWin->setCentralWidget( button );
mWin->setGeometry(QRect(300,300,1024,640));
mWin->setWindowFlags(Qt::CustomizeWindowHint | Qt::WindowMinimizeButtonHint | Qt::WindowCloseButtonHint);
mWin->show()
;
Create a central widget for the main window and then use a layout to place the push button on the central widget. For example:
QMainWindow *mWin = new QMainWindow();
// Place the button in a layout
QHBoxLayout *layout = new QHBoxLayout;
QPushButton *button = new QPushButton("Button");
layout->addWidget(button);
// Set up a central widget for the main window
QWidget *centralWidget = new QWidget();
centralWidget->setLayout(layout);
mWin->setCentralWidget(centralWidget);
If you've placed your button into a layout this way (or as a central widget itself, as one of the other answers has indicated), you don't need to set the geometry on the button, nor do you need to call setVisible or show on the button explicitly (but you still need to on the main window).
Consider looking through some of Qt's examples, such as the application example for more information.
Ok, so basically I have a simple table with a QWidget and two buttons as shown below:
QGridLayout *layout = new QGridLayout;
layout->addWidget(viewcontainer,0,0,1,2);
layout->addWidget(reset,1,0);
layout->addWidget(done,1,1);
This is basically what I want, where "reset" and "done" are buttons. Essentially it's a QWidget, viewcontainer, which resizes as the window size is changed by the user while the buttons' heights remains the same. But, the default for the gridlayout is to align the contents to the left. If I change this with:
layout->addWidget(viewcontainer,0,0,1,2, Qt::AlignCenter);
It does sort of what I want, but the graphicsscene no longer resizes (remains a small constant size). I'd like to retain the resizing while just aligning the widget to the center. Thanks.
I think the easiest solution which provides a clean solution is to nest 2 layouts.
Your 'outer' (parent) layout should be a QHBoxLayout and you can add your QGridLayout into it as an 'inner' (child) layout with addLayout().
Based on my experience you should avoid to set Qt::Alignment every time you can. It can really mess up your layout. For simple layouts it can work but for more complex ones you should avoid it. And you never know that you should extend your layout in the future or not so my suggestion is to use nested layouts.
Of course you can create a QWidget for the 'outer' layout and for the 'innser' layout as well but most of the times it should be fine to just nest 2 layouts.
Also you can use QSpacerItem to fine-tune your layout.
Have a look at this example code, I think it does what you want:
#include <QApplication>
#include <QPushButton>
#include <QGraphicsView>
#include <QGridLayout>
#include <QPalette>
class MyWidget : public QWidget
{
public:
MyWidget()
{
QGridLayout * layout = new QGridLayout(this);
QGraphicsView * gv = new QGraphicsView;
layout->addWidget(gv, 0,0, 1,2);
layout->setRowStretch(0, 1); // make the top row get more space than the second row
layout->addWidget(new QPushButton("reset"), 1,0);
layout->addWidget(new QPushButton("done"), 1,1);
}
};
int main(int argc, char ** argv)
{
QApplication app(argc, argv);
MyWidget w;
w.show();
return app.exec();
}
I use a QLabel and QPLineEdit within a QStackedWidget , the QLable should be nearly the size of the window holding this widget.
But when I set a extra long text to QLabel , it's expanding too much , and I'm not able to reduce the window size horizontally , the minimum width was too much.
I set the size policy of these three widgets to Minimum already , it just won't work for me.
UPDATE
maybe it's better saying like this: how to let QLabel display part of the text , when there's not enough space
SAMPLE CODE
#include <QtGui>
int main ( int argc , char **argv )
{
QApplication app (argc , argv);
QWidget w;
QLabel *label = new QLabel ("Very very very long text");
label->setSizePolicy (QSizePolicy::Minimum , QSizePolicy::Fixed);
QVBoxLayout layout (&w);
layout.addWidget ( label );
w.show();
return app.exec();
}
If I understand you correctly, the simplest thing to do is simply to ignore that label's horizontal size hint.
As long as you have other widgets in there (or force a minimum width manually to the container), this should do what you want:
#include <QtGui>
int main(int argc, char **argv)
{
QApplication app(argc, argv);
QLabel *l1 = new QLabel("This very long text doesn't influence "
"the width of the parent widget");
l1->setSizePolicy(QSizePolicy::Ignored, QSizePolicy::Fixed);
// Style just to make it clear that the widget is
// being resized to fit the parent, it doesn't "overflow"
l1->setFrameShape(QFrame::Box);
l1->setFrameShadow(QFrame::Raised);
l1->setAlignment(Qt::AlignHCenter);
QLabel *l2 = new QLabel("This influences the width");
l2->setFrameShape(QFrame::Box);
l2->setFrameShadow(QFrame::Raised);
QWidget w;
QVBoxLayout layout(&w);
layout.addWidget(l1);
layout.addWidget(l2);
w.show();
return app.exec();
}
I am new to Qt and I am trying to create a DockWidget that docks on the right of the window. I set a maximum and minimum width for the dock (as you will see in the code below). This works if the dock widget is added with Qt::LeftDockWidgetArea, but when it is added with Qt::RightDockWidgetArea, The dock is "padded" out to the center of the window, like this:
I am probably not sizing the dock in the correct way.. Here is the code for this window:
int main(int argv, char** args)
{
QApplication app(argv, args);
QMainWindow window;
QDesktopWidget* desktop = QApplication::desktop();
//Docks
QDockWidget* propertyDock = new QDockWidget("",&window);
QWidget* propertyDockContents = new QWidget;
//This sets the window in the center of the screen.
int wWidth = 800; int wHeight = 600;
window.setGeometry(QRect( (desktop->width()-wWidth)/2 , (desktop->height()-wHeight)/2 ,wWidth,wHeight));
propertyDock->setAllowedAreas(Qt::RightDockWidgetArea);
propertyDockContents->setMaximumWidth(200);
propertyDockContents->setMinimumWidth(20);
propertyDock->setWidget(propertyDockContents);
window.addDockWidget(Qt::RightDockWidgetArea,propertyDock);
window.show();
return app.exec();
}
Is there a "correct" way to do this?
As stated in the documentation:
Note: Creating a main window without a central widget is not supported. You must have a central widget even if it is just a placeholder.
Yes! You can't creating a main window without a central widget, But you can set central widget's height to zero.
MainWindow.cpp
centralWidget()->setMaximumHeight(0);