I have a C++ model that is used in QML. It's working fine, but I have problems showing decoration. How can I display icons in QML? I have searched the documentation and the web, no success. Image doesn't work either.
You have two options:
provide the icon as a string with a path to the icon file and use an Image element in QML to load the icon from the path string.
provide the icon as a QImage and use a custom image provider to use the QImage as a source for a QML Image.
The second approach is overkill in your case, but still, image interop between C++ and QML is possible if you need it in future.
Related
I have couple .png files and I need to create icons for the button.
Initially it will be a first image and when button is clicked and action is successful, the image shall be replaced with the second one.
What I can see, you can create only predetermined Vaadin icons. Documentation does not even provide images of these icons, only names, therefore I can't even decide if any of those icon will be suitable for me.
If anyone knows how to do it, I will appreciate the tip.
The setIcon method of the Button component actually accepts any component as a parameter. Thus if you want to use png-file as a icon, you can just create Image component using png as a resource for it.
Image image = new Image(png);
Button button = new Button("Button");
button.setIcon(image);
The font-icons from Vaadin Icons collection are naturally more light weight, and you can find visual map of the icons here if you use them instead: https://vaadin.com/docs/latest/components/icons
In Qt Designer 4.7, I am trying to add custom icons to a UI.
When editing the QPushButton or QLabel properties, I'll go to Icon -> Choose File and select my PNG.
I then get this popup error: "The pixmap file 'custom/icon.png' cannot be read."
I have no idea why it won't accept my PNGs. What's weird is there are other PNGs in our database that are accepted by Qt Designer, and I can't tell what properties they have that make them readable. Like, when I select my PNGs in the file browser, the working PNGs have an accurate thumbnail, but the one that doesn't work just has a blank file thumbnail.
What would cause a pixmap PNG to be unreadable by Qt Designer? The icon I'm trying to use is a 4KB 80×80 image made in Paint...
Is there a simple ready solution to just #include <icon.xpm> and get it as your app icon?
See example code answers to this question - you need to upload rgba data to server-side pixmap and assign _NET_WM_ICON value to pixmap id.
Unfortunately this won't work for ubuntu/unity - there you set icon in the desktop file and associate your window with desktop file using by setting _NET_WM_DESKTOP_FILE property ( see my related answer )
I'm working on a Qt UI that will run on a touchscreen. At some point it will be useful to select files, in (probably) a QFileDialog.
But little icons on a QFileDialog leads to a terrible touch-user experience, I'd like them to be bigger, so the user doesn't get crazy trying to navigate in the filesystem.
Actually, I'm searching documentation to see if there is a way through css, but haven't seen yet which target/propery to use.
Given the doc of QFileDialog class:
QFileDialog::Detail 0 Displays an icon, a name, and details for each item in the directory.
QFileDialog::List 1 Displays only an icon and a name for each item in the directory.
You can't set icon size this way. I recommend you to set a custom icon provider on the QFileDialog.
I'm trying to display a "warning" icon next to a QLineEdit if it contains invalid data. I was trying to use QStyle::standardIcon(QStyle::SP_MessageBoxWarning) to get a standard pixmap and place it inside a QLabel, and in some cases this seems to work. When running Gnome the icon is displayed correctly, but when running under KDE no icon is shown. I assume that the warning icon is simply not included in the style used under KDE.
What is the preferred way to display a "standard" warning icon in Qt? Does there exist some list which shows which icons are included in every style? How can I get an icon from a style that I know includes the warning icon?
The last time I had a similar problem, I found this Qt labs discussion useful. It informed me that QIcon now (since 4.6 I believe) has a QIcon::fromTheme function that allows you to load an icon based on the Freedesktop.org Icon Naming Specification, and in addition provide a fallback icon to be used if the current theme does not have the icon in question.
What I did was then to include some very basic icons for use as fallback, and in general specify icons only by their Freedesktop names. This gave a theme-consistent look almost always, and the program still worked in cases where people were missing icons.
As for the warning icon, I'm guessing/hoping that every theme must have the one named "dialog-warning", and that it's what you're looking for.
I hope this helps.
Edit: Oh and, in case you don't know, it can be useful to look at for example the Tango icon set to get a rough idea of what the Freedesktop names correspond to (although it is of course theme-dependent).
Qt does bundle a number of images that are resources that you can use in your own code. These images are a superset of those available via standardIcon() You may want to verify that the particular image is included in the versions of Qt you're targeting.
The end result could look like the following:
QPixmap pixmap(":/trolltech/styles/commonstyle/images/up-128.png");
// use pixmap as needed
For anyone who wants to know how to do this in a Windows environment you can:
Create a qLabel in your custom class, and then in the constructor of that class create a QIcon with the style you want, convert it into a pixmap and use the QLabel::setPixmap() function to apply it to the one you created:
QIcon icon = style()->standardIcon(QStyle::SP_MessageBoxWarning); //or
//whatever icon you choose
QPixmap pixmap = icon.pixmap(QSize(60, 60));
ui->iconLabel->setPixmap(pixmap);
ui->iconLabel->setScaledContents(true); //you can set this to fill the
//dimensions of your qLabel if you wish.