I am using a Qt Designer GUI that has some widgets that should appear alternatively. I tried to solve this by simply hiding the unwanted widgets and showing the wanted widgets using setVisible().
This works well and most times the unwanted widgets are optically replaced by the new widgets smoothly. However sometimes I can see a flickering in the layout that sems to happen because an update or something similar takes place while both of the widgets are visible at the same time.
How can this flickering be suppressed?
I tried setUpdatesEnabled() but that wasn't effective.
The (easy) solution is to use QStackedWidget.
Related
This is a screenshot of a QFormLayout holding a series of widgets. Note that the top and bottom input widgets are not horizontally aligned to the middle two rows. Note also that the labels on the left are not vertically aligned to the middle two rows.
The difference is that the top and bottom widgets are plain QLineEdit and QTextEdit widgets, the second row is a QWidget with a QHBoxLayout holding a QSpinBox and QDateTimeEdit, and the third is a QStackedLayout containing QWidgets each with a QHBoxLayout and API-supplied widgets inside those.
It looks like these middle two have extra margins. I can (partially) improve the situation by calling QLayout::setContentsMargins on the plain QWidgets' layouts. In fact, in the image above I already have, without that it's worse.
I haven't interfered with styles in the application, it's all system-default. This seems to affect Qt5 on Ubuntu 15.04, I don't think I saw this back when it was a Qt4 application.
I tried setStyleSheet ("QWidget {margin:0;}") in the top-level widget, that introduced all sorts of problems. I also tried the variation setStyleSheet (".QWidget {margin:0;}") but that had no effect. QLayout::setSpacing also had no effect, and setting padding:0 in the stylesheet doesn't fix it either.
Nothing I've tried seems to bring the spacing around these custom-layout QWidgets in line with the API-supplied widgets.
What have I missed? Thanks.
What you observe is both the struggle of multi-platform ui and the simple fact that some widgets are horrible. Given a limited amount of time and a big task, dev teams will not treat fairly the set of features. Powerful widgets and layouts like standard widgets, QGridLayout, will be maintained day and night to be defect free while legacy widgets like QStackedWidget will be pushed at the bottom of the maintenance queue.
I tried to reproduce your issue using designer alone and here is what I got (Qt 4.8) :
What you can see:
The second line with a widget container has great marging
The third line doesn't even show the combo box (I swear it's there!!).
My two cents :
There is a difference in behavior in the second row. Because I used Qt4 and you Qt5, and we both set the QHBoxLayout margin to zero then it means there is a potential regression at play, either in Qt5 or the linux implementation. So this confirms what you suspected.
QStackedWidget is horrible. It is the usual widget provided to give quick and basic functionality rather implementing the real deal. Here it would be a widget with a QStackedLayout. Like I said I suspect those kind of widgets to receive less love when big development efforts are required.
In these situations, use QGridLayout instead of a QStackedLayout of widgets with layout of widget. It will solve the issue of labels not being aligned. Difficult to set up at first but the result is usually neat.
By the way, I switched to a widget with a stackedlayout and here is the result :
I would like to achieve with QML a menu with a single menu item, like chrome does it. It has this button with those three horizontal bars and when you click it you get a single menu. Recent versions of firefox also follow the same principle. It allows not to waste too much horizontal space in the GUI of the application, unline usual menus which take up the whole width of the window.
I did not manage to reproduce exactly this GUI with QML. From what I saw you can either use a QML ApplicationWindow, and then a MenuBar, but then it takes the whole width of the window... Or have a toggle button to trigger the menu, then use a standalone Menu and its popup() method, but then it pops-up directly under the cursor, not exactly under the button to open the menu, which doesn't look good. That's really more abusing the mechanism for a context menu.
I could make a fake menu which would be a custom widget in my window but then it could not expand beyond my application window. Such a behaviour is almost required because I'll put this button on the far right of the window, as chrome does it.
Is it possible to achieve exactly that behaviour in pure QML (no C++)?
What I did for now is the last option that I mentioned: fake menu in the window. It's drawing using the canvas which enables me to make it a little pointy arrow from the menu to the menu toggle button, as done also by firefox.
The minus as I said is that the menu cannot go out of the window, plus everything is very manual (mouseover effect for menu items...), so I'm still interested in other solutions.
EDIT: ok after some time I realized a big plus of my approach: I can put custom widgets, not only labels in the menu. So I think it's absolutely the right approach now.
I am relatively new to jquery UI. I am able to understand the functionality and making use of the widgets. However I find the widgets quite large and clunky and would like to resize them. Specifically I am using a large number of spinners, sliders and choice buttons. I would like to resize these to fit my page but can't figure out any way to do this. Please help.
There is a css file that comes with the widget, you can edit it, or you can overwrite the rules in you css file.
I'm having a Qt application here where I have a main window with 5 QPushButtons that are aligned vertically.
These buttons work in a radio-group manner.
This means, that they are checkable and auto-exclusive.
Since I need to be able to resize the font size of the button text when the main window resizes, I included my own override of QPushButton and set it as custom widget in designer.
What I don't understand is, that there is a heavy delay when I switch from one button to another via keyboard shortcuts! Same when I click with the mouse.
I would say that this delay is about 0.5 to 1 second.
Have tried it on different machines.
I really need to get rid of this!
Anyone has an idea of what I could do to fix this??
Edit : Just found out that this behavior is the same when I just use normal QPushButtons. It seems that the delay is getting more when the buttons are getting bigger. Any help is strongly appreciated!!!
A shot in the dark: Setting the font might cause another resizeEvent, which in turn causes another one and so on... Try putting the font adjustment code into a method that you explicitly call when you enter/leave full screen mode.
When the menu of a QTabWidget grows beyond its width, the default behaviour is to turn the tab menu into a horizontaly scrollable list. What I'd prefer is to wrap the menu round so you now have two rows of tabs. This style is used on some Windows dialogs. I can't find any way to do this though.
Is anyone aware of a trick or option to allow this kind of layout?
This option is currently not available for QTabWidget. Perhaps you could simulate this behavior using a few QTabBars?
There is an outstanding request for this on Qt's bug tracker but no progress on it yet. Perhaps somebody knows of another component/solution.
Flow layout does what you need, but then you will have to also make your own "tab widget" http://doc.trolltech.com/4.7/layouts-flowlayout.html