I am writing a little program in C++ with Qt.
I have a QGridLayout with 3*3 QWidget. In each QWidget, I have a QVBoxLayout.
Within that QVBoxLayout I need to put a certain number of black and white rectangles.
For now, I use QWidgets for these rectangle and I apply a background-color to get the white and the black ones.
I saw in the documentation something about a Rectangle class that is linked with QtQuick and I don't really want to go into that.
Thanks for your answers,
I wouldn't bother with the layout and widgets unless you actually need interactive objects for each square. Just overload the paintEvent member of the widget you are using that contains the grid layout and use the QPainter object and call fillRect.
To get an outline around a widget, use a QFrame. Also QLabel subclasses QFrame. There are a lot of examples of using QFrame in the documentation.
Hope that helps.
Related
I would like to create a Qt window that
can be scrolled/panned by dragging its background (scrollbars should not be shown)
contains multiple sub-widgets at defined locations (which scroll with the background)
the sub-widgets can be resized by pulling their border
What I managed so far is to create a QGraphicsView with setDragMode(QGraphicsView::ScrollHandDrag) http://doc.qt.io/qt-5/qgraphicsview.html#dragMode-prop. I then placed the sub-widgets on a QGraphicsScene, however, this didn't allow the sub-widgets to be resized by pulling their border.
I also tried to inherit my custom sub-widget class from QDialog, which allows setSizeGripEnabled(true). However, this doesn't resize their content, and QDialog is probably not meant to be part of a QGraphicsView.
Any suggestions? It would also be ok if the sub-widgets behave like sub-windows that can also be dragged at their title bar, as long as they cannot be closed and they move when the background is dragged.
You can look aside QMdiArea class (Qt documentation: QMdiArea). By problem description it is what you need.
Of course, you can use Graphics View Framework, but, i think, it will be more difficult. If you choose such approach, very useful will be class QGraphicsWidget (Qt documentation: QGraphicsWidget).
I am working on a hide/show feature for my console in my Qt GUI application. The console consists of 2 widgets; QLabel and QTextEdit. Do I need to add the QLabel and QTextEdit to a QWidget in order to show/hide them, or is there a better way?
So basically I am looking for a container such as 'JPanel' in Java...
Do I need to add the QLabel and QTextEdit to a QWidget in order to show/hide them, or is there a better way?
Multiple methods are possible here. You can, as you suggest, create a parent QWidget and add the QLabel and QTextEdit to a QWidget. Calling show and hide on the parent widget will affect its children.
Another method would be to have a slot function, which when an action is called, the slot calls show / hide on the 2 widgets.
Neither is right or wrong and depends upon the overall design of your application.
Ok, I think you need to use a layout (horizontal / vertical):
The simplest way to arrange objects on a form is to place them in a
horizontal or vertical layout. Horizontal layouts ensure that the
widgets within are aligned horizontally; vertical layouts ensure that
they are aligned vertically.
Horizontal and vertical layouts can be combined and nested to any
depth. However, if you need more control over the placement of
objects, consider using the grid layout.
How can I create a triangular pushbutton in Qt? What is the most simplest way of executing this? I use the designer to create buttons and not code.
Also, I read somewhere that shapes may be changed as long as the frame of the button is still rectangular but I want the frame to adjust according to the shape as well. How can I achieve this?
More detail: I want to place lots of small triangular buttons next to each other with every other triangle flipped. Each triangle button has it's own function, etc (no overlapping borders accepted). Can anyone give me a descriptive explanation for how I might go about this?
The geometry on a QWidget is always a rectangle.
It would be possible to create a QPushButton derivative, override its paintevent and do some nasty painting considering its neighborhood etc. but it would be really a pain...
it is much easier to use a QGraphicsView, QGraphicsScene and add appropriate QGraphicsItem (maybe the QGraphicsPolygonItem?), add them and use their signals/slots or create a derived class for your purposes.
It is not that hard to override the mouseevents to recognize clicks and you can even use the QStyleSheets to let the "button" look like it gets pressed.
I've a class that extends QWidget and contains a QLabel (lblBackground). I've overriden paintEvent function too.
I want to draw something on top of lblBackground however paintEvent method is called before the QLabel is drawn. Thus my custom drawings are overwritten.
Is there a way to change drawing order?
Painting the children on top of their parent is the common thing to do. That being said you could try one of the following options:
extend QLabel itself to paint whatever you want
try to set the Qt::WA_TranslucentBackground flag on the QLabel and having an alpha channel, so that the underlying parent (QWidget) would shine through
if you are only using the QLabel to paint some background, maybe you can get rid of it and paint the desired background first thing in the QWidget's paintEvent()?
If you want to use label as a background then just create your custom widget as a child of your label. May be split some window frame related tasks if any (to be implemented as a parent of the label) and drawing/controls/etc (to be child of the label).
Using Qt Creator, I have set a QWidget's background property to black. However, some parts of the QWidget, more specifically, between QFrames/QGroupBoxes are still in its system's default color.
Now, I thought that the QFrames and QGroupBoxes need to have its background property set to black too, but it did not work. I have also tried setting the border-color to black, but it does not work, since by default borders, margins are set to 0.
QWidget { background: black; }
Any advice on this issue?
EDIT
The QWidgets are placed in QMdiArea. However, if I make it a QWindow, it works. However, I want the QWidgets to be in the QMdiArea. Also, if I just show the QWidgets as it is, the spaces that I have mentioned above are transparent.
It sounds like you have some widgets within another widget, and are setting the contained widgets to be black, but then the space between them is not black. If that is the case, it is likely because you have a layout in the containing widget, which allocates space between each contained widget. The empty space between widgets will be drawn with the containing widget's background color.
Found out the solution. It seems that you need to set the background color at the QMdiSubWindow, not at QWidget. Don't know why, but it seems logical.