I'm using GUI form editor in qt creator, I have set the background
(right_click -> change_stylesheet->Add Resource -> background_image)
Then I added a few buttons, the buttons are colored like the background, instead of being normal - default. I was trying this with properties->palette but with poor results. I'm new to qt, so I am asking for your help.
Like in CSS, Qt Style Sheet will apply your styling rules to any item that matches them.
If you just write:
background-image: url(:/my_background.png);
it will change the background of all the widgets in your application.
If you want to change the background of the main window only, you should write:
QMainWindow {
background-image: url(:/my_background.png);
}
That will apply the background image only to the QMainWindow object.
For an detailed explanation of Qt Style Sheet, I invite you to read the official documentation here.
Related
I need to create a toggle button in qt and it should look like the below image. It should show the ON image when it is turned on and remain at this state until it is toggled again. It should show the OFF image in the off case. Please help me on this.
You can use images as an icon (sadly, it won't scale with button by default), create a class which would paint those images in the handler for paint event, or you can use those images in QSS stylesheet. QSS is CSS 2.0 analog for Qt's GUI elements.
Note that after using stylesheet all changes to visuals of said element should be done through changes to stylesheet as well.
THose styles can be set through form editor by right-clicking a widget and choosing "Change stylesheet" or through code directly by calling setStyleSheet, depending which workflow you prefer.
button->setStyleSheet(
"QPushButton { border-image: url(:/Resources/chbUnchecked.png); }"
"QPushButton::checked { border-image: url(:/Resources/chbChecked.png); }" );
border-image Scales image to border limits, replacing standard border.There is also a background-image which fills widget's surface with regular repeats.
To limit this change only for checkable buttons:
button->setStyleSheet(
"QPushButton[checkable="true"] { border-image: url(:/Resources/chbUnchecked.png); }"
"QPushButton::checked[checkable="true"] { border-image: url(:/Resources/chbChecked.png); }" );
:/Resources/ is a path within app's resources.
QSS syntax: https://doc.qt.io/Qt-5/stylesheet-syntax.html
Note that QSS have selectors, so it's it have same "Cascading" ability as CSS. You can assign styles bulk based on hierarchical location on GUI, class-inheritances, class names, quasi-states and names.
If you set style above to a window, all instances of QPushButton within that window would have said style. If you define a new class for such Button, you can use its name instead of standard button class, although QSS for base class would apply to it.
the easiest way is to add the on-off images to your project as resources
then set the button as checkable and in its properties set the images to be rendered when is selected or not..(under icon -> selected on and selected off)
of course you have create images with a properly geometry... in the screenshot they look pretty small because I borrow them from your post..
:)
I'm new to Qt and the difference between QPushButton and QToolButton is not so clear to me.
I know that a QToolButton is usually used in a QToolBar and it usually shows only an icon, without text, but I don't quite understand the main difference between both.
Does it have any bigger difference?
When should I use QPushButton and when should I use QToolButton?
I would like to know this to use the most appropriate button, and I need to perform some GUI tests and maybe it can be relevant.
QPushButton is simply a button. QToolButton is part of a group of widgets in the QtWidgets module that operate on QActions: QMenu and QToolBar are other examples. As a result, QToolButton is much more complex under the hood than QPushButton.
Some examples of how they are different in practice:
QToolButton is tightly integrated with QAction. Changing the icon, text, or other properties of a tool button's default action is reflected on the button.
You can change the layout of the tool button contents (icon only, text only, text beside icon, text below icon). This is not possible for a QPushButton.
QToolButton supports a "split" button type: a sidebar hot zone opens a menu instead of triggering the default action.
Tool buttons can be created directly in a QToolBar by adding an action. Other widgets must be explicitly added to the toolbar.
A tool button is meant to be displayed in a grid, so it has smaller default internal margins than a push button.
QPushButton is more for "Ok"/"Close" type buttons that contain text with an optional icon.
A QToolButton should generally have an icon.
A QPushButton should always have text.
From Qt doc: http://doc.qt.io/qt-5/qtoolbutton.html#details
"A tool button is a special button that provides quick-access to specific commands or options. As opposed to a normal command button, a tool button usually doesn't show a text label, but shows an icon instead."
When i want a button in the GUI simple with only an icon, I use QToolButton. But when i want a classic button, i use QPushButton.
No big differences,
I'm setting up a small code editor using QT and following this example. However, i'm curious on how to create windows within windows or widgets within widgets. I'm trying to achieve something similar to these:
http://i.stack.imgur.com/Vn8Ut.png
http://www.hanselman.com/blog/content/binary/Windows-Live-Writer/Download-Visual-Studio-2013-while-your-f_1431E/image_4eb5427c-1ae7-4464-9c26-2282fe8d06c3.png
Is there an example of overlaying widgets like this?
Any alternative soloution for QMessagebox for IOS development (QWidget application only)?
I gave an example of getting another QWidget to be embedded and painted on top of another one. Let me know if you have any questions about how it was done.
The PopUp flag and Qt::Tool options are also relevant.
Be sure to check out: the ToolTip property of a QWidget and the WhatsThis property of QWidget.
http://qt-project.org/doc/qt-5/qwidget.html#toolTip-prop
http://qt-project.org/doc/qt-5/qwidget.html#whatsThis-prop
There are also other ways to make borderless, focusless windows that hover and disappear quickly on command. The Window Flags and Widget Attributes in Qt are very powerful when you are looking to modify Qt Widgets.
When you parent a Widget to another widget, it will draw itself on top of the other. Then you just need to resize and position it properly.
Also subclassing existing widgets can give you more options.
Draw text on scrollbar
Also common Qt::Tools that you will find are QDockWidgets. They are awesome!
Hope that helps.
Take a look at Qt Namespace especially Qt::WA_LayoutOnEntireRect and Qt::WA_StyleSheet. Pass it as a widget attrybutes. The second option looks promising but you have to create style sheet for QWidget.
How to put an image on the GUI created by Qt?
The south west part of the screen is empty so I want a picture to be put there on a click of a button but I am unable to use QPixmap and setPixmap. Please help me with this !
Use QLabel in Qt Creator
Then Go to Properties of QLabel
Go to Pixmap
Select the file
Its done.
You can create a QWidget or a QFrame at the place you want to add an image. You can then use the style sheet to set a background-image on that picture. You might want to add your image to your ressources (.qrc).
Using QtDesigner is a good idea for this kind of task.
EDIT :
Here is an easy way to do that without bothering with QPixMap.
QWidget *frame = new QWidget(this);
frame->setGeometry(x, y, width, height);
frame->setStyleSheet("background-image: url(:/path/to/image.png)");
The : specifies that you want to use the path in your Qt resources. The first two lines are not needed if you define this QWidget using QtDesigner.
Also, don't forget to import your resources.qrc (however you called it) file (including your resources) and add this to your .pro :
RESOURCES = resources.qrc
You should use a label (QLabel). You can add a label to your form and edit its pixmap property in Qt Designer (you will be able to choose one of images you've added to project resources). Also you can set an image on QLabel programmatically using setPixmap().
I have created some QLabel type of widgets in QT, and added that to a QToolbar. I want to highlight the particular widget which is under the cursor. I am unable to understand how do I do that. Can somebody please help ? I need this information on QT 4.
Thanks.
You have several possibilities.
First, as you subclass QLabel, you can handle mouse events directly in your class.
Make sure to use QWidget::setMouseTracking() to enable this.
In such scenario you can do whatever you want with your control but you will have to
override paint routine so that your class can draw itself in some specific way.
Unfortunately QLabel does not support "hover" style sheet state so that you cannot
do it easily with styles sheets. However, if you consider subclassing from QPushButton you can have this wonderful feature
so that with the help of CSS you get nice highliting effect.
For more info on style sheets in QT look here.
If subclassing QPushButton is fine for you, then look here.
Just make sure you also use hover state like in this simple example:
QPushButton:hover {
background-color: black;
}
QPushButton:hover {
background-color: white;
}
Example for the mouse events handling can be found here