I am new to PyQt and Qt Designer and I'm trying to create an easy method for relating qWidgets with the tables and columns in an SQLite database. My idea was to tag each qWidget in designer with two custom properties, one with the table name and one with the column name. Later, I would use the info provided by designer to build my own class which creates a relationship between the qwidets and SQLite database.
Adding the custom properties in Designer seems to work fine however, the code for these custom properties do not get generated when converting the xml of designer into python (using UIC). Has anyone done this successfully? Perhaps there is a better way to do this?
Thanks,
Eric
If you added a property in Designer called "myproperty", fetch it with...
mywidget.property("myproperty")
This works fine in pyqt 4.8.3, perhaps it did not work in previous versions.
Check out this article Eric. Particularly look at the section titled "Producing a Plugin." River Bank Computing has another great PyQt reference.
EDIT:
I've been doing some more reading and I can't find a way to have this done automatically for you. If you are ok with with adding dynamic properties at run-time instead of design time you could accomplish the same end result. Here is an explanation of the setProperty() method in QObject, from which QWidget inherits.
If that doesn't work for you then it seems you might be better off going with a less generic approach. Instead of using a generic QWidget, you might be able to use a custom class derived from QSqlTableModel to keep track of your connection info. Another way would be to just use a QTableView and do the queries yourself to populate the data. Here and here are articles on databases in Qt. You might some inspiration for a new design from one of them.
I have not had great luck with using the Designer tool -- usually I end up doing a few rough layout, using pyuic and then editing and adding other stuff by hand.
It sounds like you could easily accomplish your task by creating your own custom class that inherits from QWidget and has the additional properties that you described. With my experiences trying to use custom widgets in the designer, I think the 'easier' way is to just write the class yourself and then set the layout by hand.
I know this doesn't exactly answer your question, but maybe you will try some of my suggestions.
Related
I have extended a class by one method, using the Enhancement Framework.
Now, my problem is that I want to add ABAPDoc to it but cannot find any way to do it!
The code in the Enhancement Include section seems to be editable in no way.
Is there any way to do it at all? I tried also from ADT in Eclipse but this calls the SAP GUI anyway.
What are you trying to do is indeed impossible.
The enhancement include is a technical object and it cannot be edited from the tab you highlighted, it is auto-generated as you changing pre- and post-methods.
What this tab shows is not an include itself, but the placement of the enh. include within the parent object
If you want to change the method comment from enhancement, you should go to Technical details tab and click on changed object, or just go to the class in SE24 and press to pre/post exit button, and you will end up in the same include:
You can write the ABAPDoc-syntaxed comment, but for me it didn't work, and Eclipse didn't recognized my comment written in SAPGui, maybe you will be luckier.
ABAPDoc team describes this piece in a fuzzy manner, it may be an expected behavior:
This ABAPDoc is only available to ADT and not SE80? I can not use it in SAP GUI development?
You can also write it in the source code and you will get also warnings when you execute a check, but there is no dedicated tools support like source code element information or quick assist (Ctrl+1)
To your principal question, ABAPDoc is a two-way road when viewing: the ABAPDocs can be viewed both from the Eclipse and SE80, and they are automatically showed in SE80 description fields (but only if they are declared synchronized).
But it seems to be a one-way road for edit: they can be created only in ADT Eclipse to be fully compatible. If the object cannot be opened in Eclipse natively like your enhancement you are out of the luck.
I put seems because I am not 100% sure. Maybe on later systems it was fixed, but on my 750 they are not recognized by Eclipse for enhanced methods.
The only reliable way of "editing" via SE80 is writing the comments to descriptions and then importing these SE80 descriptions into ABAPDoc in Eclipse
which is ridiculous in context of your question, so there is no way for you.
Currently, I am "forced" to develop my reports with SE80 / SE24, etc. and I can't use eclipse. There I've seen that if you have the "Source Code-Based" view in Z-Classes, above every method the signature is shown as a comment. See in the following picture:
Well, I know that those comments are not really in the source code, but shown anyway (generated somehow).
Do you know a way how to disable those "comments"?
I find them unnecessary and I am losing the overview over the class. And instead of a 27-row implementation part of a class I've got an 88-row-long implementation part.
These signature comments are automatically generated by the SAP GUI based class editor reached through transactions SE24 and SE80.
Use the ABAP Development Tools to avoid them.
There's no way to disable those comments. I genereally prefer the form editor when forced to use SE80, I think it gives a better overview. The best would be if you were allowed to use Eclipse, but politics can be difficult to change.
I have certain Modules that I would like to setup to be referencable by multiple solutions, as the code always behaves in basically the same manner (ex. code for logging errors). They make no sense as classes, so it seems like a class library is out; and I haven't seen any other suggestions for sharing code between solutions.
So I'm left wondering what would be the best way to create one thing that I can just use across multiple solutions to avoid having to rewrite the same code?
It sounds like a class library is exactly what you want. Build it, reference it within each solution, and code against it. One source, multiple solutions running off that code.
You could also implement the functionality into a separate piece such as an API. This is dependent on the function of the code obviously, but logging errors is a good use case.
I'm trying to make a new UI to visualize my Alloy instances. I've got an A4Solution and have been successful in extracting atoms, relations, checking atom signatures BUT I can't seem to understand how to project the instance on some sig.
I've noticed that I can try to use the edu.mit.csail.sdg.alloy4viz.AlloyInstance, I've got options to project there, but that'd imply in starting over, from a different angle.
Would that be the way to go? I'd prefer to extract that from the A4Solution object.
Thanks
You might want to look at the edu.mit.csail.sdg.alloy4viz.StaticProjector class and its project methods---that's how the Alloy Visualizer implements projections. If your visualization uses the edu.mit.csail.sdg.alloy4viz.AlloyModel class, you should be able to reuse the existing code in StaticProjector; from your post it seems, however, that you'd prefer not use any of the alloy4viz classes, in which case it should not be too difficult to understand how StaticProjector works and reapply the same ideas to your project. Or you could convert an A4Solution object to an AlloyInstance[1] and build your visualizer around the alloy4viz classes, which, in my opinion, would be a good way to go about your project.
[1] something like:
a4sol.writeXML("instance.xml")
AlloyInstance inst = StaticInstanceReader.parseInstance(new File("instance.xml"));
I'm creating a plugin in Quantum GIS that is using Postgres as the back end and QT Designer to make the GUI. I'm using psycopg2 to run scripts in the database and even fetch results of queries to set the values of labels in the GUI. This stuff is working fine for me.
What I would like to do now after some queries are run by clicking a 'calculate' button is for the resulting table to be shown in the plugin as a TableView. I know there widget exists expressly for the purpose of viewing tables but I can't quite figure out how to go about it. I'm not sure if I should be using psycopg2 or PySide, since most examples I have seen online use the latter.
I am wondering if someone can tell me which between psycopg2 and PySide should be used to create the TableView. Second, I am wondering what the 'signal' should be to the TableView widget to display the results of a query in Postgres. Lastly, is anyone can offer some instruction as to how to set up the code it would be hugely appreciated!
Cheers,
Roman
I've gone ahead and tried following the PyQt documentation, but as it's provided in C++ and I'm only a beginner programmer using Python I'm not sure if I've caught all the necessary amendments to the code syntax. Anyways, this is what I have so far:
db = QSqlDatabase.addDatabase("database")
db.setHostName("localhost")
db.setUserName("postgres")
db.setPassword("password")
#Not sure what to do to set the connection. The C++ documentation says to put "bool ok = db.open();"
model = QSqlQueryModel()
model.setQuery("SELECT name, density, deveff FROM public." +str(filename)+ "_rezoning ORDER BY gid;")
model.setHeaderData(0, Qt.Horizontal, "Name")
model.setHeaderData(1, Qt.Horizontal, "Density")
model.setHeaderData(2, Qt.Horizontal, "DevEff")
view = QTableView()
view.setModel(model)
view.show()
What happens when I click the button in my GUI to run the calculations, a small blank QGIS window briefly flashes and goes away. At least I'm not getting an error, but it's obviously not complete. I assume part of the issue is the connection to the database that is missing and that I do not know how to set. The other issue is that I would like this to show in the tableView widget in the GUI, but I'm not sure how to specify this...
Any further tips? I really appreciate it.
Roman
If you're planning to use Qt widgets and models, PySide (PyQt, or plain Qt/C++) is the way to go.
With bare psycopg2 you'll have a lot more work to do, and you'll need to implement your own model in order to leverage Qt's model/view classes. This is simply not the Qt way of doing things. PySide (and PyQt) has it own means to connect to a supported database, there's no need for pure Python database adapters like psycopg2. It uses the underlying libqt4-sql library (C++) and the installed plugins (QPSQL, QMYSQL, QSQLITE, etc).
Essentially you need to:
Connect to a database.
Instantiate a model (QSqlQueryModel, QSqlTableModel or a custom QAbstractTableModel derived class)
Attach that model to a view (ie. QTableView).
Take a look at the PySide QtSql Documentation and the PyQt documentation to get an idea. They're mostly compatible/interchangeable, but at a glance I see that the PyQt documentation looks more complete.
EDIT (after your edit):
A Qt GUI application requires an event loop to run, and that's provided by a QApplication instance. Before going any further with the specifics of your app, take the time to understand a few basic concepts first. Here's a nice Getting Started with PyQt Guide.