I'm learning qt by working on given examples. I've started to play a bit with keyboard shortcuts. To assign them I've used QtDesigner which is very handy, for example using "return" key to click a research QPushButton.
Here my main class is a Widget called TextFinder, which has a pointer on a Ui::TextFinder class, which is automatically built from QtCreator, which is the standard procedure to encapsulate user interface attributs and methods.
By assigning a shortcut using QtDesigner, the following lines are generated in the Ui::TextFinder class:
#ifndef QT_NO_SHORTCUT
findButton->setShortcut(QApplication::translate("TextFinder", "Return", nullptr));
#endif // QT_NO_SHORTCUT
where findButton is an alias for my QPushButton. So far so good.
Suppose now, in a large program, I want to implement many shortcuts to trigger many kinds of signal and I use QtDesigner to do so, it will generate these lines of code, possibly in different header files corresponding to different widgets. It will become quickly difficult to manage them and have a global vision of the "shortcuts state" of the program.
What would be a good method to manage all the shortcuts in the program at one place? Is it possible to make some config file to perform this task?
Typically in this case you go one level up from the shortcuts and look into Actions.
A QAction is a somewhat global (e.g. on the level of a QMainWindow) vehicle for something that the user can trigger (or toggle) through various ways. To name the most prominent ones,
Menu entries
(Toolbar) buttons
Shortcuts
You can manage your actions through Qt Designer (if you have a QMainWindow), or at a central place in your code. Note that the action encompasses not only the shortcut, but also title, icon etc.
You can arrange a toolbar in Qt Designer by dragging actions onto it, but you can also manually assign an action to any button in code.
Related
I am just beginning to learn some programming with QT, and would like to start with the designer portion of QT Creator, before diving into the .cpp, and .h files. I would like to do simple tasks like change the color of a box based on a condition, or perform some arithmetic. But everything I read describes how to the change the code, not do it in the UI editor. Even the QT Designer manual gives no demonstration of how to create a simple calculator in Designer. They only show the code (http://doc.qt.io/qt-5/designer-using-a-ui-file.html). I've loaded the project from the links at the bottom of this page: http://doc.qt.io/qt-5/qtdesigner-calculatorform-example.html, but I'm still stumped as to how it does the arithmetic from looking at the UI editor. I don't see any signals/slots indication an addition on the numbers in the spin boxes. Nor, do I see anything in the properties of the Output QLabel that makes it the sum of Input1 and Input2.
And just to add another level to this simple example, how could I change the color of the output box if a condition is met? Let's just say if the output is larger than 10, make the box blue. I see the palette in the Properties box, but how do I make it conditional, staying within the Designer portion of the Creator application?
Thanks!
You're searching for a way to execute simple code/actions directly from within qt-designer, without using any code behind.
That's not possible, if you use qt-designer and .ui files.
You can connect slots to signals directly from the designer, but you have to implement those slots in your *.cpp file.
If you want to mix the UI design with your application logic take a look at QML.
I would like to know if anybody knows if it is possible to drag a QDockWidget from one window to another.
I am developping an application that has a lot of windows. Each of these windows has a specific usage. I want to use QDockWidget because of the automatic rescaling when docking a widget in the main window. But I would also like to have the possibility to have a new dock area in a new window so that I can put together all the widgets related one to each other.
Does anyone have a suggestion?
As far as I know, you cannot drag a QDockWidget from one application to another if they are developed separately.
On the other hand, I think that you can reparent a QDockWidget to another QMainWindow, only if it's part of the same application.
...aaaaand you can always try to intercept the drap/drop events and pass information between the two windows with a protocol of your own: define a new mime type for the drag and define the syntax of the data associated to the QDockWidget. Then, implement the code to analyze the data and reconstruct the contents of the QDockWidget in the target window... not an easy task!
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.
I would like to know what the established procedure is for initializing the controls within a Qt custom dialog box. In the code I am writing, the dialog would present a QListView containing directories from an object passed (by reference) to the dialog class during construction. When the dialog is displayed, I obviously want the list to display the directories currently configured in the object.
Where should this be done though? Perhaps in the overridden showEvent() method?
Background: I used to do a lot of MFC programming back in the day, and would have done this sort of stuff in the OnCreate method, or some such, once the window object had been created.
Thankfully Qt doesn't require you to do any hooking to find the moment to create things (unless you want to). If you look over the Qt examples for dialogs, most do all the constructing in the constructor:
http://doc.qt.io/archives/qt-4.7/examples-dialogs.html
The tab dialog example--for instance--doesn't do "on-demand" initializing of tabs. Although you could wire something up via the currentChanged signal:
http://doc.qt.io/archives/qt-4.7/qtabwidget.html#currentChanged
Wizard-style dialogs have initializePage and cleanupPage methods:
http://doc.qt.io/archives/qt-4.7/qwizardpage.html#initializePage
http://doc.qt.io/archives/qt-4.7/qwizardpage.html#cleanupPage
But by and large, you can just use the constructor. I guess the main exception would be if find yourself allocating the dialog at a much earlier time from when you actually display it (via exec), and you don't want to bear the performance burden for some part of that until it's actually shown. Such cases should be rare and probably the easiest thing to do is just add your own function that you call (like finalizeCreationBeforeExec).
I want a widget like the properties window in Visual Studio or NetBeans. It basically has two columns: the name of the property on the left, and the value on the right. The value needs to be able to be restricted to certain types, like 'bool' or 'float' (with valid ranges), but should also support more complex types (perhaps requiring a popup dialog when clicked, and then it can just display a toString() version in the window. I'm sure I can add most of those features myself, but what's the best base widget to start with?
Oh... grouping of properties is good too (like a tree I guess). And property editing should invoke a callback (send a signal).
Qt designer has properties exactly like you want. They are most likely implemented with QTreeView. You can always look at the source code.
QTreeView or QTableView. Do all (ok, most) of the heavy lifting with a specialized model that handles all of your type restrictions and what-not. Check out delegates as well.
Here's a link led to github, it might be useful.
another userful link