I have a small window where inside is horizontal QSplitter, on one side there is control widget (labels, buttons, list widget etc), on another side there is empty widget (where stuff will be painted).
But because of empty widget splitter resizes control widget to maximum and view widget to minimum. I tried to set horizontal size policy to "Minimum" for control widget and to "Expanding" for view widget and layouts, that didn't helped.
What would be right (or easiest) way to set size for controll widget to be as small as possible and view widget expand?
Looks like it was enough to set Horizontal Stretch to factor 2 for view widget size policy.
Related
I have a custom QDialog comprised of a QStackedWidget with QScrollArea widgets for each page of the stacked widget.
I want to set the size hint for the QDialog such that the dialog is just large enough that the scroll bars for the scroll area are not visible when the dialog is first shown (i.e. ensure size of QScrollArea viewport = size hint of child widget in scroll area). Currently, the default sizeHint() implementation for the QDialog has insufficient height, which causes the vertical scroll bar to be shown when first loaded.
I thought this could be achieved by re-implementing sizeHint() for the QDialog, whereby the size hint of the dialog would be adjusted by the amount required for the size of QScrollArea viewport to equal the size hint for child widget in the scroll area (for the first page of the stacked layout). Unfortunately, in sizeHint(), the size of the QScrollArea viewport is set to the default size of QStackedWidget (640x480), and only updates to the correct size once the QDialog is shown.
Is there some way to get the correct size of the QScrollArea viewport before it is shown, or another way to achieve the desired effect of adjusting the size hint of the dialog to prevent scroll bars from being shown when it is first displayed (aside from hard-coding the dialog size).
With the composition of your dialog as:
I have a custom QDialog comprised of a QStackedWidget with QScrollArea
widgets for each page of the stacked widget.
The tricky part is to answer:
Is there some way to get the correct size of the QScrollArea viewport
before it is shown?
Well, before switching to certain page you can estimate the scroll area viewport if it is either correctly set or you can just measure the content going inside the scrollarea. I usually force the widget to demand certain height from the scroll area like that:
wdgetInScrollArea->setMinimumSize( widgetInScrollArea->sizeHint() );
wdgetInScrollArea->adjustSize(); // sometimes it is needed
The the scroll area viewport hint is then more 'adequate':
qDebug() << scrollArea->viewPortSizeHint(); // report
I don't see the code but usually it is not even required to do any custom event handling here, just prepare all the nested widgets like that.
I have two Qt widgets in the window. One of them is QDockWidget, and another one is just QWidget.
When I drag the QDockWidget, the default behaviour of the another widget is moving without changing its size. And I want it to fill the whole window except dock widget, and to change its size programmatically when I drag QDockWidget. Hwo to do it better?
The solution was to set container horizontal policy as "fixed"
How do I place a widget next to a QScrollbar like here seen:
I use a QScrollArea and overwrite the Horizontal-QScrollBar. First I thought, I could use the paintEvent to draw a text like the "100 %" next to the bar. But I can only overwrite the existing painting.
Now I think, the only opportunity would be to implement the hole QScorllBarPrivate from the source code... anyone any idea?
The main idea is to create an overlay obscuring default horizontal scroll bar and displaing your own bottom line instead.
Create a widget representing the bottom line, i.e. a widget with labels displaying some information and a horizontal QScrollBar, all together put in a hbox layout.
Put this widget in the scroll area without adding it to a layout by making QScrollArea direct parent widget of this widget.
Use move() and resize() on the bottom line widget to position it properly on initialization. Also resize and reposition it on scroll area resize (you can use event filters or inheritance to get to resize events).
Make sure that scroll area's horizontalScrollBarPolicy is Qt::ScrollBarAlwaysOn so that scroll area's internal layout always keeps space enough for bottom line widget to fit in.
Also make sure that bottom line widget has the same height as default scroll bar. It should be easy as long as you remove spacing and margins in the hbox layout and labels (or other widgets) don't require more vertical space than a scroll bar.
Use horizontalScrollBar() to get scroll area's internal QScrollBar and syncronize it with your own bar. QScrollBar has rangeChanged() and valueChanged() signals so you can connect to them and update your bar properly. When user changes value of your scroll bar and triggers its valueChanged() signal, you should set the same value for the internal scrollbar. You can protect from infinite recursion in there by using a flag that indicates that this is your own change.
I want to make a QToolBar have 3 columns of buttons when docked on the left side of the QMainWindow, but have 1 row when docked on the top of the main window. Is this possible?
I have a tried using a QToolBar with a custom layout, but the normal re-size behavior of the QToolBar doesn’t work (doesn’t hide widgets behind an expand button when its too small). The non-working expand button isn’t that big of a deal, but the bigger problem is that the custom layout prevents the main window from being smaller than the toolbar.
I was able to get my desired behavior by putting each row of Tool Buttons in a QHBoxLayout, putting that layout in a empty QWidget, and calling toolBar->addWidget( widget ) for each row. This gives me a grid toolbar when the toolbar is mounted on the left, and single horizontal bar when mounted on the top.
I have a ui with a QScrollArea Widget. The QScrollArea uses a Flowlayout. My problem is when I add widgets to my layout the scroll area begins to scroll and does not expand when it has room to expand. I want the scroll area to expand to its limit before the scroll bar appears first.
How can I get the scroll area to expand before the scroll bar appears?
can you try doing setWidgetResizable(true) for your QScrollArea
ScrollArea->setWidgetResizable(true);
A couple of suggestions:
Ensure that the size policy of the scroll area itself is Expanding.
Set the "stretch" values of the size policy of the scroll area to a value greater than that of the other widgets in the same layout. Ie:
QSizePolicy policy = pScrollArea->sizePolicy()
policy.setVerticalStretch(1);
policy.setHorizontalStretch(1);
This assumes that the siblings of the scroll area (if any) have a stretch value of 0 (the default).
Subclass the scroll area and override the sizeHint() method.