I'd like to have a fixed size QGraphicsView, which I want to add to a layout together with some other widgets. However, the QGraphicsView simply ignores resize(), here is the relevant code:
QGraphicsScene* scene = new QGraphicsScene;
QGraphicsView* view = new QGraphicsView(scene);
view->setBackgroundBrush(QBrush(Qt::black, Qt::SolidPattern));
view->resize(1000, 600);
QVBoxLayout* layout = new QVBoxLayout;
layout->setMargin(0);
layout->addWidget(view);
setLayout(layout);
If I use setFixedSize() instead of resize(), the size is actually being set correctly. However, it seems that the window size is not updated, the window is not centered properly.
How am I supposed to set a fixed size for a QGraphicsView?
I know this is a very old question, but in case anyone else stumbles into it: you can set both minimumSize and maximumSize to the desired target size, and it should work regardless of what layout the QGraphicsView is in.
If I understood you right you want to have QGraphicsView centred inside the window and having fixed size. You need rather then VBoxLayout you should use QGridLayout with spacers, so your form should look like:
<Empty> <VSpacer> <Empty>
<HSpacer> <GraphicsView> <HSpacer>
<Empty> <VSpacer> <Empty>
Related
I have a stacked widget on which I have a QLabel. I display an image on this label. I want to zoom and pan this image and I am trying to use the QGraphicsView technique. However a new window opens.
This is what I am doing.
scene = new QGraphicsScene(this);
view = new QGraphicsView(this);
QPixmap pix("/root/Image);
label->setPixmap(pix);
scene->addWidget(label);
view->setScene(scene);
view->setDragMode(QGraphicsView::scrollHandDrag);
view->show();
Can someone please suggest me what I should do. I want the label to act like the QGraphicsView.
Thank You :)
You create a scene and view and add the label to the scene, then tell the view to show itself with: -
view->show()
If, as you state, you want the QGraphicsView on the label, don't add the label to the scene, but add the QGraphicsView to the label: -
QLabel* pLabel = new QLabel(mainWindow); // setting mainWindow as the parent
QGraphicsView* pView = new QGraphicsView(pLabel) // set the label as the parent of the view.
You do not need to call show, as the label will handle that for you, assuming the label is on a Widget that is already displayed.
Now, instead of setting the pixmap on the label, create a pixmap in the scene with: -
pScene->addPixmap(pixmap);
Making my way up the Qt learning curve, I've seen many questions about dynamic layouts but the solutions aren't working for me or I don't quite understand them.
Reference questions:: Qt Scroll Area does not add in scroll bars, How can i make widgets overflow to make a scrollbar appear in Qt?
Question:: I want to have a dynamic layout of a set of widgets within a QScrollArea. I've been able to do this manually in Qt Creator and now I am trying to do it through code.
How do I prevent the widgets from stretching/force the area to scroll?
How do I have the added widgets start from the top? I have a vertical spacer in my QVBoxLayout but that pushes everything to the bottom.
Simple test code::
void MainWindow::on_pushButton_clicked()
{
ui->myScroll->setWidgetResizable(true); //making sure this is set
QPushButton *b = new QPushButton(this);
b->setText(QString("Hello Button"));
QHBoxLayout *h = new QHBoxLayout();
h->addWidget(b,0);
ui->myVBoxLayout->addLayout(h,0);
}
Result:: Left side squished (dynamic) – Right side Ok (set up manually)
Qt Creator Setup:: Left side: dynamic – Right side set up manually
Properties::
You can set use setMinimumHeight() on your buttons for preventing squished buttons. The layout can be configured with setContentsMargin() for space between item-border and item-content (QtDesigner has all four directions set to 9 IIRC) and setSpacing() for space between items (QtDesigner uses a default of 6). Also setWidgetResizable(true) allows your scrollarea to resize the view widgeth inside the area (this is where your layout and children are being placed).
This works for me:
In constructor or code set scrollArea->widget() to hold the QVBoxLayout:
v = new QVBoxLayout;
ui->scrollArea->widget()->setLayout(v);
In Button Slot:
void MainWindow::pushButtonPressed()
{
ui->scrollArea->setWidgetResizable(true);
QPushButton *b = new QPushButton(this);
b->setText(QString("Hello Button"));
QHBoxLayout *h = new QHBoxLayout();
h->addWidget(b,0);
v->addLayout(h);
}
I am creating a UI in Qt that has a QDockWidget containing a QPushButton and QLineEdit. Please refer to the attached mock-up. I have created the widget components and successfully got them up and running. However they are not positioned the way I want them to. Both the elements should float to the left making the extra space to the right stretch when the window is resized.
The code-
this->searchField = new QLineEdit; //"this" is a QDockWidget subclassed Object
searchField->setFixedWidth(200);
mainMenu = new Menu();
QHBoxLayout *layout= new QHBoxLayout;
QSpacerItem *filler = new QSpacerItem(1000, 10);
layout->addWidget(mainMenu->getMenuBar());
layout->addWidget(this->searchField);
layout->addSpacerItem(filler);
Any suggestion or help would be awesome!
Thanks for your time :)
http://qt-project.org/doc/qt-4.8/layout.html
http://qt-project.org/doc/qt-4.8/qboxlayout.html#addStretch
void QBoxLayout::addStretch ( int stretch = 0 )
Adds a stretchable space (a QSpacerItem) with zero minimum size and stretch factor stretch to the end of this box layout.
So this is what your new code would look like:
this->searchField = new QLineEdit;
searchField->setFixedWidth(200);
mainMenu = new Menu();
QHBoxLayout *layout= new QHBoxLayout;
layout->addWidget(mainMenu->getMenuBar());
layout->addWidget(this->searchField);
layout->addStretch(); // Added this
Hope that helps.
I want to expand QTableViews' size so each QTableView takes the half size of the window! , how can i do it?
screenshot:
http://i.stack.imgur.com/Rh87o.jpg
Add a QHBoxLayout to your widget/window and then add the tables to it.
The following code on a top level widget..
QHBoxLayout *horizontalLayout;
QTableView *tableView;
QTableView *tableView_2;
horizontalLayout = new QHBoxLayout(Widget);
tableView = new QTableView(Widget);
horizontalLayout->addWidget(tableView);
tableView_2 = new QTableView(Widget);
horizontalLayout->addWidget(tableView_2);
Will give you something like..
The two tables share the available space equally and expand and resize with the main window.
I understand how to add a scrollArea to a particular widget. However in my case Qwidget has multiple child widgets and these are all set using QVBoxLayout. Now how can I add a scroll bar in this case? Here QWidget is not the center widget, its one of the pages of the TabWidget. My code looks like:
QTabWIdget *center = new QTabWidget; setCentralWIdget(center);
xTab = new QWidget;
formLayout = new QFormLayout; formLayout->addWidget(...); formLayout->addWidget(...); formLayout->addWidget(...); formLayout->addWidget(...);
xTab->setLayout(formLayout);
Now how can I set the scrollBar to xTab? I tried using
scrollArea = new QScrollArea;
scrollArea->setWidget(xTab);
however, this isn't working.
Any idea/suggestions are helpful and appreciated.
Have you tried using QScrollArea as the tab page?
QTabWIdget *center = new QTabWidget; setCentralWIdget(center);
xTab = new QScrollArea;
formLayout = new QFormLayout; formLay....
xTab->setLayout(formLayout);
center->addTab(xTab, "XXX Tab");
I had success using the following:
scroll=new QScrollArea(mainWindow->centralWidget);
scroll->setGeometry(mainWindow->tabWidget->geometry());
scroll->setWidget(mainWindow->tabWidget);
scroll->show();
The QScrollArea defines where the scrollable widget will appear. If parent is 0, it's a non-modal window. setGeometry sets the QScrollArea instance to the desired dimensions (that of the tab). setWidget defines what widget the QScrollArea will actually be scrolling.