changing objectName in design view does not update names in mainwindow.cpp

arif_sohaib · wrote on 25 May 2018, 14:35

I recently started learning Qt using the book Computer Vision With Qt 5 and OpenCV 3. I am also newish to C++ after having left it for C# and Python.
I am having issues with changing the objectNames. I changed the name in Design view but when I access it in the mainwindow.cpp using ui-> , it does not show the new names in the intellisense/autocomplete.
Concretely, I change lineEdit to inputLineEdit in design view and then try to use setText on ui->inputLineEdit->setText.
the name inputLineEdit does not show up and instead shows lineEdit and lineEdit2 and all the other default names of the ui widgits.

mrjj · wrote on 25 May 2018, 16:40

Hi and welcome to the forums
try to delete the build folder and run qmake and rebuild all.
( you can find build folder in "Projects" (left side ) and simply right click the path and show it and delete it)

It sounds its stalling.
Normally its renamed at once and a new ui_xxx file is generated.

Also, you are using a .PRO file ?

arif_sohaib · 26 May 2018, 08:16

Thanks for the response and sorry for the late reply.
Yes, I am using a .pro file as well as a .pri file to include OpenCV.

I agree about the stalling thing, it should have renamed it immediately. I have used Visual Studio in the past and it does this with its UI tools.

Another interesting thing I found is, the names are the default ones in the ui_mainwindow.h file and changing them manually does not work.
i.e. I still see lines like:
lineEdit->setObjectName(QStringLiteral("lineEdit"));
lineEdit_2->setObjectName(QStringLiteral("lineEdit_2"));
and try to change it manually but the new names are still not recognized.

mrjj · wrote on 26 May 2018, 08:16

@arif_sohaib
hi
Ok, could it be possible you have copied files around at some point
and have 2 ui_mainwindow.h ?

if you delete ui_mainwindow.h , is it generated again ?

If you manually change the names in ui_mainwindow.h and its not changed back when you compile and
its not seen in .cpp , it must be another one being linked to project or there is 2 of them or something like that.

arif_sohaib · 26 May 2018, 18:54

I just made another project starting from scratch and it now works.
Thanks for the help

arif_sohaib · 26 May 2018, 19:12

I had run into one more problem that others looking at this thread might want a solution to.
After building and running the program, I added a checkBox widgit and it was not showing up in code. This was the same thing as was happening before. I deleted the ui_mainwindow.h file and then it started working.
So it looks like the problem was that qmake was not rebuilding the ui_mainwindow.h file after updates to the display unless its old version is deleted. I am not sure if this is the intended behavior or if it is my settings but if it is the normal behavior, this could turn a lot of people away from using Qt and needs to be fixed.

mrjj · 26 May 2018, 23:58

@arif_sohaib
Hi
Its not normal at all.
I use Designer all day and renaming anything is available at once
via UI-> with no action on my part.

Did you change/use shadow build folder or did anything special with the ui_xxx files ?

Also check that you dont have a virus scanner blocking the files in the build folder.
Especially if you are using Avast.

aha_1980 · 27 May 2018, 00:01

@arif_sohaib,

as @mrjj said, this usually works out of the box.

one more idea: usually you don't open the generated ui_*.h files. if you do, you may be hit by a Clang bug that forbids updating the file.

so if you have Clang Code Model enabled, you could check if it works if you don't open the generated files.

arif_sohaib · M mrjj 26 May 2018, 19:12

@mrjj said in changing objectName in design view does not update names in mainwindow.cpp:

Did you change/use shadow build folder or did anything special with the ui_xxx files ?
Also check that you dont have a vir

I tried with both Shadow Build on and off. I also changed the build folder because under the default settings, it wasn't able to find the .exe file when I hit run so I changed it to "project folder/build" and it started working.
As for virus scanner, I only have the default Windows Defender.

arif_sohaib · wrote on 27 May 2018, 00:01

@aha_1980 said in changing objectName in design view does not update names in mainwindow.cpp:

one more idea: usually you don't open the generated ui_*.h files. if you do, you may be hit by a Clang bug that forbids updating the file.

I know not to touch generated files, and I don't for anything important, but I was just experimenting with getting it to work.
I am not sure about Clang, I am not sure. I am using the Visual Studio 2017 15 C++ compiler. Most things that I didn't mention are on their default settings.
And thanks for the reply.

aha_1980 · wrote on 27 May 2018, 07:08

@arif_sohaib

sorry for being so unspecific, I had QTCREATORBUG-15449 in mind.

you can check with Help > About Plugins if Clang Code Model is enabled.

Regards

mrjj · wrote on 27 May 2018, 07:29

Hi
That is very strange.
if you manually delete the ui_ file and compile it works every time ?

if you are using qmake, it normally call the UI tool correctly
http://doc.qt.io/qt-5/uic.html

Its just Creator + visual studio compiler and nothing special extra?

arif_sohaib · 27 May 2018, 16:33

After the application compiled the first time alone with allowing adding more ui widgits, adding more widgits and compiling isn't causing any more problems.
Now any ui elements I add immediately show up in the mainwindow.cpp file without any additional steps.

mrjj · wrote on 27 May 2018, 16:33

@arif_sohaib
Ok super. Not sure what was up with it :)