Let's say I have a widget that cannot allow a child widget to be displayed on top of it- yet that's the look I need. I'm assuming the only way to accomplish that look would be to make the child widget into its own window.
How can I make that "child" window always on top of the "parent", and position it to always be at the bottom (with a predefined margin) and centered horizontally?
It should respond to resizing of the parent window as well.
A good example would be like a controlbar for video
(in fact- I would guess that in fullscreen mode VLC is essentially doing something like this... is it?)
EDIT: here is my current widgets layout: http://i.imgur.com/NcRLmrd.png
Note that the seekbar is not displaying over the video
The child widget should have Qt::Tool window flag, and parent widget should be set as parent widget of the child as usual. This way it will be a top-level widget and will always be on top of the parent.
You should position the child widget manually. For example, you can install an event filter on the parent widget and react on Move and Resize event types.
Related
I have a Qt parent widget that displays a child widget.
I need to delete the parent widget.
I might (or not) later attach the child to a different parent and display it inside the new container.
I do not have access to the second parent at the time I delete the first parent.
How do I do this?
First hide the child widget using hide() or setVisible(false) methods of QWidget. Then make the child widget have no parent using setParent(nullptr), which makes it a top level window, which is why you needed to hide it first.
To later re-use the widget, add it to appropriate new layout, which also sets it parent. You need to call its show() or setVisible(true) method for it too, or it will stay hidden.
I want to allow a user using my application to be able to drag a boundary between two widgets in my window which will resize the two (i.e. you drag it down and the top one will get bigger while the bottom gets smaller, and vice-versa).
Is there anything in Qt designer that will allow a user to resize an element in the window, within certain constraints?
Thank you
What you're describing is called a QSplitter widget. In Qt Designer, you can create one by selecting 2 or more widgets, and then clicking the splitter button on the toolbar at the top. It's in the same location as the layout buttons. It will place those widgets inside a QSplitter. You still need to place the splitter widget inside another layout. It will create a handle between them to let you resize the portion that each widget gets.
You're looking for the QDockWidget. It can do all that you described above and more. The user can dock the widget to different sides of the window, changing which widget is on the top or bottom. You can customize the minimum and maximum sizes, as well as default sizes.
What I'm trying to accomplish is a very simple and straight forward need, or I thought, but for the life of me, I can't seem to find a way to do it.
In my qt application I want to be able to make a widget or a layout fill the entire space of the parent widget.
For example, let's say I want to have a label with a fixed height and beneath it a stacked widget which occupies the rest of the height of the window.
Here's what I do in the qt-creator designer:
drag a label to the form
drag a stacked widget to the form
select both of them and then right click > lay out > lay out vertically
select the verticalLayout object and in the layoutStretch property have 0,1
Now, how do I make the verticalLayout occupy all of the width/height of the centralWidget?
Nothing seems to work for me.
Thanks.
You've merely put two widgets in a layout, but you also need a layout on their parent widget - on the form. Here's what you should do instead:
Drag any number of widgets to the parent widget (the form). Arrange them roughly the way you want them to be once laid out.
Right click on the form. Select "Lay out >" submenu.
Choose the desired layout from the menu: horizontal, vertical, grid, etc.
I am using Qt to build a view for multipage documents. I'm drawing each page to a separate QLabel widget, like in the ImageViewer example app.
The QLabels are organized vertically using QVBoxLayout. This all works nicely, with a little grey margin between the pages.
What I want now is, when the user does page down, to move the scroll so that the top of a particular QLabel appears right at the top of the window. the "ensure" functions might do that, but I'm not immediately seeing how.
Has anyone done something like this?
If a child widget is taller that the viewport height ensureWidgetVisible scrolls to the middle of the widget.
If you need to scroll to the top of the widget you can do it easily with a little calculation:
//childWidget - QLabel you want to move to
//area - QScrollArea
// calculate childWidget position in coordinates of the viewport
const QPoint p = childWidget->mapTo(area, QPoint(0,0));
// move scroll bar
area->verticalScrollBar()->setValue(p.y() + area->verticalScrollBar()->value());
I am creating a Qt application where I need to display contents in an overlay box(Please refer to the attached image). The box needs to slide up from behind the bottom dock when a button is pressed and slide down by toggling the button. I tried with a QWidget but couldn't achieve what I wanted. Also I don't know how to list the elements in the overlay box. The elements are dynamic or changing.
The widgets stacking order is defined by their order in the QObject hierarchy tree. The first element is the bottom, and every next is on top of the previous. Children are on top of their parents, in widgets confined within their bounds, in QML free.
If you want that sliding element to appear on top of everything else, just put its parent on top of everything else.
After all it is on top of the bottom control bar, which is on top of the playlist, so you have it all worked out for you.
The same applies if you decide to do the wiser thing and use QML instead of QWidget. Animation and states are much easier there. Not to mention more specific designs.