Basic question: Including headers with INCLUDEPATH doesn't work

[mrjj]

@Binary91
Well anything seems possible with your setup. :)
Q_OBJECT should not bork anything.

Im out of ideas :)

[Binary91]

Well, I'll post the whole project file, its headers and sources and maybe you can copy/paste it and try to run it with?

If it works, then it is a setting problem. If not, something with my include logic doesn't work.

project file:

#-------------------------------------------------
#
# Project created by QtCreator 2016-11-17T15:45:17
#
#-------------------------------------------------

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = CourseCalculator
TEMPLATE = app

INCLUDEPATH += C:/Qt/lib/headers

HEADERS  += main.h

SOURCES += main.cpp
           C:/Qt/lib/sources/myQString.cpp \
           C:/Qt/lib/sources/myQLineEdit.cpp \
           C:/Qt/lib/sources/myQPushButton.cpp

main.cpp:

// main.cpp

#include "main.h"

int main(int argc, char *argv[])
{
  QApplication applicationApp(argc, argv);
  clsWindowMain windowMain;

  QTimer::singleShot(0, &windowMain, SLOT(slotStart()));
  int ret = applicationApp.exec();
  return ret;
}

main.h:

// main.h

#ifndef MAIN_H
#define MAIN_H

#include <QApplication>
#include <QTimer>
#include <QWidget>
#include <QDialog>

#endif // MAIN_H

myQLineEdit.h:

// myQLineEdit.h

#ifndef MYQLINEEDIT_H
#define MYQLINEEDIT_H

#include <QDebug>
#include <QLineEdit>
#include <QMessageBox>
#include <QDir>


// forward declaration

class myQLineEdit;


// declaration

class myQLineEdit : public QLineEdit
{
  Q_OBJECT

  // .. properties

  public:
    myQLineEdit(QWidget* widgetParent = 0);
    ~myQLineEdit();

    // .. more methods
};

#endif

myQLineEdit.cpp:

// myQLineEdit.cpp

#include <myQLineEdit.h> // absolute path or absolute path with whitespaces also doesn't work


// ----- constructors -----

myQLineEdit::myQLineEdit(QWidget* widgetParent) : QLineEdit(widgetParent)
{
   // stuff
}

Is that compilable for you?

[mrjj]

@Binary91
would be very much easier if you zipped folder and shared via dropbox or g drive as
copy paste to real files again is very error prone and time consuming :)

[Binary91]

Good idea. But my dropbox accout has no free memory left :-D

Have to create a new account first, maybe on g drive...

[mrjj]

@Binary91
well a zipped project is ultra small. so delete/remove something for a moment and it should have space :)

btw: G Drive is 15 GB but the client is nowhere near as nice as dropbox.

[jsulm]

@Binary91 If you derive from Qt classes which are derived from QObject then you need to include the generated moc_ files.
For example in myQLineEdit.cpp add

#include "moc_myQLineEdit.cpp"

[Binary91]

but from where do I get this moc file?
If I try to include, compiler gives me an error that it can not find such file or directory

btw:
https://www.dropbox.com/s/whqdkcat767224t/test.zip?dl=0

[jsulm]

@Binary91 You should read the Qt documentation. The moc_ files are generated for you using moc tool. Take a look at the build directory.

[jsulm]

@Binary91 Why do you have a main.h? This is quite unusual.

[jsulm]

@Binary91 For QApplication you need QT += gui, else you should use QCoreApplication.

[Buckwheat]

@jsulm , why would you include the MOC files? I "never" include the MOC files in my source because they get generated, compiled, and linked after the normal build. The only generated file I would include is the ui_NameOfForm.h file created when using the form designer. And, only in the CPP for the UI class.

@Binary91 , I am sure it was explained that INCLUDEPATH tells qmake where to find common include files. I use it for 3rd party libraries or pre-built packages I developed for Qt (I treat them like 3rd party libraries). And, as I know you know... always run qmake after changing a PRO file.

There is one curious item I have found about QtCreator though... if you are using static libraries (even if your dependencies are setup) and make a change to a CPP file in the library... Press build-all and it will build the library and NOT re-link the application or shared library that depends on that static library. Kind of annoying but I just get around it!

[Binary91]

I know what moc files are, but they were not permanently created by QtCreator (not in my build folder).
But can you tell me why I should have to generate them and manually include them when it works to simply add the headers to the project?
I mean, I wanted to reduce work by using INCLUDEPATH and NOT adding all the included headers.
Generating moc files and manually adding them is not reducing but increasing work.

Also I do not understand why I should include them when I don't need it if I add the headers directly...

[jsulm]

@Binary91 Where is myudp.cpp ?

[jsulm]

@jsulm With some fixes I can build your project.
pro file:

QT       += core network

QT       -= gui

TARGET = test
CONFIG   += console
CONFIG   -= app_bundle

TEMPLATE = app

INCLUDES += lib/headers/myQLineEdit.h

SOURCES += main.cpp \
    #myudp.cpp

#HEADERS += \
#    myudp.h

main.cpp

#include <QCoreApplication>

int main(int argc, char *argv[])
{
  QCoreApplication applicationApp(argc, argv);
  //clsWindowMain windowMain;

  //QTimer::singleShot(0, &windowMain, SLOT(slotStart()));
  int ret = applicationApp.exec();
  return ret;
}

[jsulm]

@Binary91 Where I did say you have to create moc_ files manually?
They are generated for you. And they are completely unrelated to your problem!

[Binary91]

It's getting strange now :-D

What is a myudp.cpp ?? I didn't ever used this...

@jsulm
But you are including the header directly now. That is exaclty what I tried to avoid...

Why is main.h unusual? I think using headers as a bundle of #include directives for my purposes is the correct way, so in the source file, there only exists one #include directive to its corresponding header file. Not good?

[jsulm]

@Binary91 That is what you uploaded:

SOURCES += main.cpp \
    myudp.cpp

main.h is unusual because there is no need for it. You only need a header file if you need to include some functionality provided in one source code file in another one. Where do you want to include main.h and why (and please do not say in main.cpp, because there is no need to do it this way)?
I will try to change your project to use INCLUDEPATH.

[jsulm]

@Binary91 It builds here if I do:

QT       += core network

QT       -= gui

TARGET = test
CONFIG   += console
CONFIG   -= app_bundle

TEMPLATE = app

#INCLUDES += lib/headers/myQLineEdit.h
INCLUDEPATH += lib/headers

SOURCES += main.cpp

[Binary91]

I really don't know from where this "myudp.cpp" comes. Maybe a de-zipping error. That should mean "lib/sources/myQLineEdit.cpp"

Yeah this way its getting built on my computer as well, but there you manually added the header file to the project:
INCLUDES += ...
or
HEADERS +=...

That is what I try to avoid by using INCLUDEPATH. That was what the discussion is all about...

[jsulm]

@Binary91 Where did I add the header file manually?
I commented out the old line, please take a look again:

QT       += core network

QT       -= gui

TARGET = test
CONFIG   += console
CONFIG   -= app_bundle

TEMPLATE = app

#INCLUDES += lib/headers/myQLineEdit.h <-- this line is commented out
INCLUDEPATH += lib/headers

SOURCES += main.cpp