I have a custom QWidget subclass that lays out a number of children. In my stylesheet I define a background, which works fine. I also define padding, which doesn't work. I clearly need to provide support for this myself.
To do that, I need to be able to find out what padding is set in the stylesheet for my widget. I do not wish to parse the stylesheet myself, that would not make much sense. How can I access the top, left, bottom and right padding set in the stylesheet?
Thanks in advance,
Your custom widget has to inherit from a widget that supports the "box model" (you can find which widgets do on that page), and then you can use QWidget::contentsRect() to get the... content rectangle :
Related
When I run my program it will display all content properly, and when I resizing the main window, the layout along with all associated widgets remain fixed, rather than resizing with the main window. I used to increase my all widget and listWidget respect to window computer resolution size but still this not one work properly.
I used this one code finding the system height and width.
QWidget widget;
widget.resize(widget.width(), widget.minimumHeight());
QRect rec = QApplication::desktop()->screenGeometry();
int h = rec.height();
int w = rec.width();
// Increasing the listwidget size
ui->listWidget->setFixedHeight(h);
ui->listWidget->setFixedWidth(w);
//increasing the button size
ui->pushButton->setFixedHeight(h0.2);
ui->pushButton->setFixedWidth(w0.2);
At this link you will find two screenshots that illustrate my problem.
Please resolve to solve my problem. Thanks very much in advance.
When defining the layout of your windows and forms in Qt Designer you have to define each element of your form in advance, in order to have a working layout.
This solution is based on the screenshots provided in the comments to the question. Follow these steps:
Add an empty widget to the central area of your form, if there is nothing there. It will be used as a placeholder for the controls you will add later, and of course you can replace it with whatever widget you want. But you need it there to define a proper layout.
In the property panel, set the horizontal QSizePolicy of this widget to MinimumExpanding.
Add an horizontal spacer to the left side of your progress bar.
Define a minimum/maximum width for the white widget on the left (I guess it's a text area). As an example set the maximum width to 200
pixels.
Make the same for the QTabWidget on the right.
Give a minimum height to the Groupbox on top.
Then give the grid layout to the MainWindow.
You should get something similar in the designer view (I use a dark theme, yours will have different colors of course):
If you complete all steps you should have a nicely resizing window.
For the future: remember to integrally define your layouts, also using placeholder widgets when needed, read carefully the documentation about the widgets size policies (there are several, you need to play with them to fully understand each one) and keep in mind that Qt uses a container based approach which is different, as an example from those used by the .Net framework that relies on the concept of anchors.
EDIT : to answer questions in the comments
You will need to add a layout to any widget that contains other widgets, e.g. adding controls to your groupbox will require to give it a grid, horizontal or vertical layout in order to scale nicely on resize. Again use spacers and size policies to make it look the way you want. If you need to add or remove controls, or change their positions, you may need to brake the layout, rearrange and then set it again.
You can also select groups of widgets and give them a layout e.g. vertical, than another group and set them horizontal and so on... then give a grid layout to the container widget to build a compound layout.
There are endless possibilities, you just need to practice and go through trial and error as for everything else...
You can also do it all programmatically, check the Qt widgets documentation for this. But for complex layouts I would not go that way: it's a lot of code... and you have to compile and run to test every modification.
Using the QtCreator, within the designer you can simply right-click on the parent-widget and add a Grid-Layout.
This one resizes it's children to it's dimensions.
I am trying to create a profile menu for my polymer website, something on the lines of github.com
If you notice,there is a triangular tip at the top of the menu.I am trying to create a similar triangle at the top of paper-listbox.
The problem I am facing is that the triangle seems to hide as soon as it gets out of the boundaries of paper-listbox.
I have create a jsbin to demonstrate my problem: http://jsbin.com/samaloqowu/1/edit?html,console,output
If you change the top property of the triangle (say -16px), it hides when it gets out of the listbox region. Please help me solve this CSS issue.
Short answer : No you can't.
Explanation : Because the dropdown content get encapsulated in a slotted element that gets styled inside the shadowRoot of the custom element you try to modify the behavior. And the paper-menu-button doesn't actually gives you a way to directly customize the slotted.
But there is a trick ! You can access the slotted through classic javascript. Just alter your connectedCallback function and add this line :
...
connectedCallback() {
super.connectedCallback();
this.$.profileMenu.$.dropdown.querySelector('.dropdown-content').style.overflow = 'visible';
...
}
...
This should do the trick, I agree this looks totally awful and trying to force and change the initial behavior of an element is not really recommended but well it seems to work, just make some tests when the element gets in a new context to see if anything breaks.
UPDATE (22/09/2017) :
Thinking of that again, I think this is a terrible idea to change this overflow to visible, I guess the polymer team has set the overflow to auto because if the list get long and you force the height of the element, the list will flow and be visible which is not really a dropdown anymore, but more like a full list display and that will mess with the general design purpose of your app. IMO when you start trying to mess with the inner properties of a custom element it means this element doesn't quench your requirement, and that it's time to make your own, especially when you try to modify the design of a custom element that has a design already implemented.
I'm using Dojo GFX to do some simple drawing, but having a problem with IE 7/8 (switching browsers is not an option).
If I create a div, set up a surface and draw some rects, they draw correctly relative to the div, so far so good.
However, what I want to do is create a widget, something with an embedded 'surface' that draws based on some widget-specific data. As such, I have a widget that contains a div, and I draw into this div. When I do that, the rects I create behave as if they are responding to a float:right, appearing in order they are created and ignoring the 'x' parameter.
I assume that this behaviour is something to do with CSS, but I haven't got to the bottom of it yet. Any ideas or solutions gratefully appreciated!
Updates:
I've disabled all stylesheets and I am not using style attributes. No difference to the behaviour.
I've inspected the markup that gets generated using IE8 dev tools. Apart from the different location of the containing div, the only difference I can see is that the v:roundrect elements have no child elements when created against the widget div, but they do have empty elements like stroke when created against the div referenced by ID.
Reading back through the docs, a difference I can see that might be responsible is that the postCreate method where I am doing my drawing is manipulating a div that has not been added to the dom yet, whereas drawing on a hardcoded div is done when it does exist. Maybe the difference in rendering is something to do with this? Is there a specific lifecycle function which is appropriate to draw in for widgets?
It seems that if you are going to use Dojo GFX and draw on DOM elements that are created as part of a widget in IE7/8, you must actually do the drawing in an override of the startup() method.
Drawing in the postCreate() method causes incorrect rendering resembling a float: left.
I have created QLabel *msgLbl. How do I make the msgLbl background semi-transparent?
The easiest way is probably to call setStylesheet(). If you're using Qt Designer you can also set the stylesheet from within the designer window (look in the properties bar on the right.
You want to set the background-color attribute, so something like
msgLbl->setStyleSheet("background-color: rgba(255, 255, 255, 10);");
would be the simplest way to do what you describe.
Having said that, you might also want to think about stylesheet inheritance. For example, you might want to set the background-color for a number of QLabels, all children of a parent widget. You can do that using css-style selectors in a stylesheet set on the parent widget (read this for more information).
What is the best way to change/set a registration point on a Flex 3 display object? I know this isn't really built in to easily change, but does anyone have any suggestions on how I could extend UIComponent to achieve this?
For some reason, the Flash Player API doesn't expose the registration point of DisplayObjects (and the Flash IDE makes them a pain to modify once an object is created). The best solution, as David pointed out, is to add your component as a child of another component (UIComponent would be fine). So, for example, if I had a Button and I wanted its registration point at its center, I'd add it as a child of a UIComponent (not Canvas) and offset the child by setting its position to (-button.width/2, -button.height/2).
Put your DisplayObject inside a sprite and set the DisplayObject's x & y positions to the negitive of your target registration point. Apply all transforms to the Sprite container.
Put it inside a Canvas container, with its clipContent attribute set to false. Within the canvas, you can put your object wherever you like.