I want to know is it possible to make application fully skinned/styled in Qt I mean by that not only controls inside the application window but the mainwindow itself! like close button/maximize button/minimize button and the bar, and the mainwindow border!, is it possible to do that in Qt? and how to?
Yes it is possible. The best method in Qt is to use Qt style sheets. The Qt documentation has plenty of examples and you can style all the widgets, either by specifying a whole class such as QPushButton, or a single, named widget.
As for the items on the title bar, I'm not sure if that's possible directly, but you could certainly turn off the main tool bar that contains the minimise / maximise buttons and then implement and style your own widgets while replicating their functionality.
The second argument to the QWidget constructor is Qt::WindowFlags. You can use the flags to control the properties of a window. For example, pass the flag Qt::FramelessWindowHint to create a borderless window.
There are a few ways to do this in code. You can use the setWindowsFlag method from within your widgets constructor:
setWindowFlags(Qt::FramelessWindowHint);
If you are creating a custom widget, you can pass the flag to QWidget's constructor:
YourWidget::YourWidget(QWidget *parent) : QWidget(parent, Qt::FramelessWindowHint)
{
// ....
}
Or you can pass the flag when you create a widget:
QWidget *your_widget = new QWidget(parent, Qt::FramelessWindowHint);
There are also flags for the minimize button (Qt::WindowMinimizeButtonHint), maximize button (Qt::WindowMaximizeButtonHint), close button (Qt::WindowCloseButtonHint), and title bar (Qt::WindowTitleHint). With these flags, you must also set Qt::CustomizeWindowHint to disable the defaults as described in the documentation.
See the flags documentation for a full list and additional details.
As #Merlin069 stated, style sheets allow you to control the look and feel of the widgets within your application.
Related
I have a graphical application written in C++ using Qt for an embedded device, which uses a QStackedWidget holding a number of UI widgets. The UI is all designed in Qt Creator's designer tool. When the user navigates through the device's application the display to be shown at that menu option is selected from the QStackedWidget and this all works great.
I'm now wanting to pass in a pointer to some configuration which is read from file when the application starts, but I can't seem to find a way to pass this pointer as an argument into the constructor of a widget on the QStackedWidget. Can anyone help?
My current approach is to call a function I've written within the class of a widget on the QStackedWidget, which works but doesn't feel the best way to do it.
To my knowledge if you want to use custom constructors - with other kinds of arguments than just the QWidget * parent - you have to create the ui programmatically:
create your custom StackedWidget with a special constructor,
prepare the global interface using the designer,
then add the StackedWidget in the constructor of the class after the setupUi method.
The other way is to use an initialization method after the construction of the item, like you did.
I got a external library, which includes a derived class from QGLWidget, very similar to that one here. In that library I have a class:
class PictureGLWidget : public QGLWidget { //.. }
This extends Qt's native QGLWidget and personalizes it. But it was not written by me, I just got it, via a *.dll. So then, I bind that Widget manually in my code to a layout like:
QGridLayout* layout = new QGridLayout;
layout->addWidget(myPictureGLWidget, 0, 1);
ui->verticalLayout_5->addLayout(layout);
since I designed my MainWindowWidget with the integrated QtDesigner, which is by the way very comfortable, I would like to handle my myPictureGLWidget also in the QtDesigner, since I am currently redesigning the MainWindow.
Is there a way doing that? Thnx in advance!
Qt Designer supports any foreign widget class without needing to provide plugins for that. You only have to accept that the widget's properties and appearance won't be available within Designer.
Insert a dummy QWidget into the layout.
Right click on the widget, select "Promote to...".
Add PictureGLWidget as a new class promoted from QWidget. Specify appropriate header files etc.
Promote your widget to PictureGLWidget.
When this is done, the code generated by uic will instantiate a PictureGLWidget where you need it, instead of a dummy QWidget.
If you want to use the PictureGLWidget in the designer instead of a dummy widget, you can write a designer plugin that wraps the widget and exposes it in the widget pallette, provides property support, etc.
I might have misunderstood your question but don't you just add a QGLWidget to your design in Designer. Right click the widget and select Promote to... ?
Using Qt 5.2.1
Is it possible to set a QSlider (doesn't matter if it's horizontal or vertical) to read-only that is user cannot change the value of the slider but only use it as an indicator of some sort? I was unable to find anything in the Qt documentation or the Qt Designer.
Example for application: displaying a binary state of some sort in the GUI (in my case is the emergency stop on or off).
AFAIK such feature is not available in the QSlider implementation.
However, you can create your own class deriving from QSlider and implement the desired behavior by overwriting mousePressEvent, mouseReleaseEvent, mouseMoveEvent, keyPressEvent and keyReleaseEvent and only call the respective parent implementation if the readOnly property is set to false.
Luckily, such an implementation is already available in kalarm, so have a look at it: http://api.kde.org/4.6-api/kdepim-apidocs/kalarm/lib/html/slider_8cpp_source.html
Maybe a QProgressBar would be more suitable since users know it as "read only" and "shows how much has been done".
Following kuba ubar's second approach -
Suppose the object name of your slider is horizontalSlider. Then the code should be
// getting the palette of the slider
QPalette _sliderPalette = ui->horizontalSlider->palette();
// changing the colorGroup of that palette
_sliderPalette.setCurrentColorGroup(QPalette::Active);
// setting the changed palette to the slider
ui->horizontalSlider->setPalette(_sliderPalette);
One simple solution would be to install an event filter on the slider that consumes all mouse, focus and keyboard events. You'd also need to make the slider have a Qt::NoFocus policy. Such an event filter would be universal and could be used with any control widget.
An alternative would be to disable the widget, and style it so that the disabled and enabled palette are the same. This might not work with some of the platform styles, though, and would need experimental verification before you commit to it.
I've recently been studying Qt, and have the following questions:
What is the difference between QAction and QToolButton?
How do I know when to override QPushButton? For example, should I override in order to be informed when the mouse enters a QPushButton's bounds? I don't need to in order to get the signal click().
Question 1:
QActions are used to define tasks performed by an application in a way which can be understood by a number of different user interface objects. Using an example from the Qt docs for context:
A QAction is defined; it is given an icon image, a text description, a keyboard shortcut and a longer tooltip description, as well as being linked to a user defined function.
newAct = new QAction(QIcon(":/images/new.png"), tr("&New"), this);
newAct->setShortcuts(QKeySequence::New);
newAct->setStatusTip(tr("Create a new file"));
connect(newAct, SIGNAL(triggered()), this, SLOT(newFile()));
Later in the implementation, the QAction is added both to a textual menu bar...
fileMenu->addAction(newAct);
... and an icon-based tool bar:
fileToolBar->addAction(newAct);
The menu bar uses the text description to create an entry in the menu corresponding to the action. Similarly the toolbar uses the icon set on the QAction to create an icon in the toolbar which corresponds to the action. Selecting the menu item, clicking the toolbar icon or pressing the keyboard shortcut will all result in the same effect: that defined by the linking of QAction::triggered() to newFile().
So to directly answer your question: a QAction is an abstract way of defining the various parameters and behaviour of a particular task performed by the application. A QToolbarButton is a UI object (derived from QWidget) created by a QToolbar in response to QToolbar::addAction()
Question 2:
Yes, QPushButton has a clicked() signal inherited from QAbstractButton, but it does indeed lack a way to inform when the mouse has entered its bounds. You have a couple of options in order achieve this, but first you need to first set the mouseTracking property to be enabled. This will allow you to receive mouse move events on the QPushButton even if no mouse buttons are pressed. With that done you need to explore one of the following options:
As you suggest, you could subclass QPushButton and reimplement mousePressEvent in order to respond to the mouse position.
You could install another widget as an eventFilter on the QPushButton, and watch for events of type (QEvent::MouseMove).
I've subclassed qt's pushbutton and now I would like to use it in my project (instead of qpushbutton) - the problem I have is that even if I add #include "mybutton.h" in ui_class it gets overwritten and I don't know what else can I do it.
Is there a way to have this button within designer on a panel just like the ordinary qpushbutton is?
Never modify the ui_Class file yourself. Any change you make there will be overwritten when the .ui gets compiled. Instead use the promote to functionality within QtDesigner.
If some forms must be designed, but certain custom widgets are
unavailble to the designer, we can substitute similar widgets to
represent the missing widgets. For example, we might represent
instances of a custom push button class, MyPushButton, with instances
of QPushButton and promote these to MyPushButton so that uic generates
suitable code for this missing class.