I'm trying to recreate a text editor I've made but using the MVC design pattern; I'm not totally sure about certain parts of it.
For example, I have a tree view displaying my project directory, and a text editor showing the contents of a file, along with this i have output from compilation of files being displayed as well as a tabbed interface.
Would this be split into a few different models or under one big model? If it's under 1 big model how would I go about using the Qt model classes for such a thing?
Open up Qt Designer and drag and drop all the stuff you need. It should get you pretty far.
I think the only model/view you should worry about is the QFileSystemModel and pairing it up with a QTreeView. Everything else Qt has some nice examples showing how to do it.
If you are showing multiple files at once in separate tabs, then you might want to look into the Tabbed Browser Example to see how its done.
http://doc.qt.io/qt-5/examples-mainwindow.html
http://doc.qt.io/qt-5/qtwidgets-richtext-syntaxhighlighter-example.html
http://doc.qt.io/qt-5/qtwidgets-widgets-codeeditor-example.html
http://doc.qt.io/qt-5/qtwebkitexamples-webkitwidgets-browser-example.html
I like QDockWidgets and using QActions and putting them on the QToolbar in a QMainWindow.
http://doc.qt.io/qt-5/model-view-programming.html
http://doc.qt.io/qt-5/qfilesystemmodel.html#details
http://doc.qt.io/qt-5/qmdiarea.html#details
http://doc.qt.io/qt-5/qtextedit.html
For the compilation part you will just need to create a QProcess and connect its output to a QTextEdit.
Hope that helps.
Related
The project I'm working on calls for workspace layouts for a large section of it, by which I mean that users can move around panes, resize them, close them, etc., like in VSCode (but more like Emacs since VSCode does not currently support both vertical and horizontal splitting).
The current methodology I'm considering to create a custom LayoutManager that has a json object and injects views into recursive Row and Column objects in a binary-tree-like structure. Before I start this undertaking, I'm wondering if there is a library or set of QtQuick (QML) elements that would let me do this a lot more easily or if there is a better approach to this problem. Or, please just tell me why I'm wrong in doing it this way.
Note: The technologies I'm using are C++ with Qt 5 (currently 5.10).
If you want highly customizable GUI, with the option of persisting UI configuration, it is best to design the whole thing model driven.
QML already has the necessary stuff - list views, repeaters and so on. QML is a little at odds with tree models, but you can essentially fake a tree by using lists of lists.
The model provided here will do the trick, with the added benefit it also supports declarative instantiation. So you can easily set up an initial GUI state declaratively, like you would with normal QML, but then allow the user to make modifications to that initial state which can then be saved and recalled.
Then all you have to do is bind the desired GUI elements to the underlying model data source objects.
I'm new to Qt and it's quite a learning curve!
I've been search/reading/hacking and learning for most of the day on this one.
I'm working on an app that will have a image in a scroll area as it's main purpose. The image viewer example is where I started. This example appears to be "laid out by hand" if you will - i.e. there are no .ui form files for it (it's trivial so why not).
So here is the rub - I want to use designer to build a much more sophisticated app. If I start fresh with a new project and use designer the resizing doesn't work unless I add layout (used vertical, all appear to fix the resize issue) to the .ui form.
Designer creates a lot more code to do the same thing - I don't care, it is after all an IDE / code generation tool.
However it's not clear to me why the layout is required when I use designer and not if I code it by hand. I searched the code for the image viewer example and there doesn't seem to be ANY layout involved at all, just 3 or 4 nested widgits (Main/Scroll/Label).
Is the default layout basically built in?
The example you linked to uses a QMainWindow. This widget has its own layout because it has built-in support for menubars, toolbars, dock widgets and a statusbar:
Main Window Framework:
Normally, the widget set as the central-widget would need to have a layout explicitly set on it in order to layout its own child widgets. However, in your linked example, the central-widget is a QScrollArea, which also happens to have a built-in layout. This is all just coincidental, though. The large majority of widgets don't have a built-in layout, so most GUIs will need to explictly add at least one layout, and several will usually be needed for more complex applications.
I would say Qt Designer is absolutely essential when it comes to experimenting with layouts (especially when you start learning Qt). Even if you don't actually use the ui file, it's still very helpful to just view the code that would be generated from it.
I have found a really neat custom widget for Qt and managed to incorporate it into Qt Designer. I would now like to create a customer widget in designer by placing 32 of these LEDs into a new widget in Designer, then add some functions to it such as giving it address and passing data into it that will then illuminate patterns in colours according to the passed data.
My questions are:
Can I do this? I have placed 32 LEDs on to a new QFrame widget in designer and named the LEDs 0-31, but am at a loss as to know what to do next.
Is there a tutorial anywhere for this? I have found loads of hits on google for creating custom widgets for designer, but not using designer.
Please bear in mind I am not a good Qt programmer, I write embedded code for micros in C and am really not good at object orientated code; I can just hack together relatively simple programs for test and measurement. I need something that will hand hold me through this.
http://doc.qt.io/qt-5/qtdesigner-worldtimeclockplugin-example.html
This seemed to be the kind of thing I wanted, it seemed to look like someone has placed widgets on a screen to create a new widget, but it seems to keep referring back to Creator.
Maybe I am trying to do something impossible. Maybe I have to place this new LED in creator with code?
Many thanks for any pointers.
Yes, it is. A Designer plugin basically consists of 2 Parts:
The Widget that you want to add to the designer
The plugin itself that provides information about the widget usw.
You can simply create the widget with the designer, add the QDESIGNER_WIDGET_EXPORT macro and thats it. Create your designer plugin to load this widget and it should work.
Note: Since you mentioned your not very experienced, you should try to follow the Custom Widget Plugin Example. Once you understood that one, it's only a small step to your designed plugin.
When it comes to designing a GUI in Qt, I am hesitating between using the designer in Qt Creator, or doing everything in source code. I'm using Qt widgets and not QML.
If I use the designer I can easily create a GUI using qt standard widgets. But as soon as I need to subclass a widget to extend its functionality I have to build a Designer plugin to support my new widget. Is that correct? Or is there another way to it?
You can build all the GUI in Designer including custom widgets, and you can also build your custom widgets in Designer.
Designer does not need to interpret your custom widgets. Just use the promote functionality. With promote, you start with a plain widget within Designer and then tell the "real" class of it (your custom one) and the header file where it is decleared. The only drawback is that within Designer, it will stay looking like an empty widget.
In my experience, it is much better to use Designer for the GUI than writing source code yourself. You can easily change all the properties afterwards etc., and it is helpful even if you rely on custom widgets. Source code is not a good declarative language for GUI objects, with all the properties etc. Also you cannot play around, you would need to compile all the time just to tell "Is it better to have this text label in bold font?".
Sometimes I edit the XML files that are created by Designer by hand. For example, if I want to put a widget somewhere else in the object tree. If you don't mess up the XML, Designer will still read it and not destroy your changes. The only reason I see for writing GUI in source code is when you have repetitive elements, or dynamic changes based on data input, e.g. a for()-loop that produces elements. In my project I have some Selector Boxes that are filled with options in the source code.
And btw: If you prefer to write your GUI in code instead of using Designer, maybe you are not the right person to craft the GUI. Most programmers don't understand that while they are technically able to design a GUI, they are not always also competent in doing it.
http://hallofshame.gp.co.at/index.php?file=shame.htm&mode=original
It is a bit of a shortcut, but I often use a simple QWidget as a container for my custom widget. This way, I can setup sizing policies, put the whole thing in the layout I want before my custom widget is even in. Then, in C++, I add the custom widget as a child of the container widget.
edit: As ypnos mentioned you can promote the placeholder directly. You can find guidelines here
In general, is the order in which I add my widgets into each other, the same order I access them back?
Example:
If I have a bunch of QPushButton in a QHBoxLayout, and this layout in a Window::ui,
can I access those button by simply ui->button_name? or Do I must do ui->layout->itemAt(idx)?
EDIT: My question aims to find an easy way to access elements that are deep into the hierarchy, like a label in a frame, inside a layout, inside a frame, inside the window etc...
PS: Also, I would really appreciate any documentations about good practices of GUI architecture!
Use ui->object_name you don;t need to worry about the layout!
It's possible to redesign the layout, eg. for different platforms, without changing any of the C++ code.
There are a couple of good books on Qt and the sample code is very good.
C++ GUI Programming with Qt 4
Advanced Qt Programming