Why GUI (form) header file placed in .cpp file ?

Vinoth Rajendran 4

Hi all,
When a new Qt Designer Form Class is created , 1 header file , 1 cpp file and 1 form is added.
for eg: dialog.h , dialog.cpp and dialog.ui files...

My doubt is why ui_dialog.h is included in dialog.cpp file, rather than in dialog.h file...Is there any design consideration followed for this implementation ???

Any suggestion/view is appreciable....

Regards,
Vinoth R

mrjj

@Vinoth-Rajendran-4
This is because its best to limit includes in the .h file ( for compile speed)
and you do not need
ui_dialog.h there as .h should be for definition and .CPP for the implementation.

So in .h you do not need to know anything ui_xxx declares. only in the
.cpp where you might use ui->xxxx in some of your functions.

Hope it makes sense :)

Its mostly only something you will notice when you try to declare the full function in the .H file.

class MainWindow : public QMainWindow {
  Q_OBJECT
 protected:
  virtual void mouseMoveEvent(QMouseEvent* event) override {
   // this code belongs to the .cpp
  };
};

instead of

class MainWindow : public QMainWindow {
  Q_OBJECT
 protected:
  virtual void mouseMoveEvent(QMouseEvent* event) override;
};

and in cpp file
void MainWindow::mouseMoveEvent(QMouseEvent *event)
{
ui->xxxxx
}

Note that creator can move it for you. ( from .h -> cpp)
Simple right click function and choose Refactor.