Qt5 and bacon

[bigbass]

Qt5 is not an easy thing to use.
but it is very powerful and many professional apps have been made with it en.wikipedia.org/wiki/Qt_(software)


That being said mixing it with bacon can be a mind bending experience
since Qt uses their own way of connecting events with SIGNALS and SLOTS (they don't use the standard callbacks)
and it uses C++

that was my warning label and legal disclaimer you could stop here

there was a first demo of Qt4 as a window with no events posted to bacon
basic-converter.proboards.com/post/10101/thread



Qt5 has changed a lot and getting the signals / slots idea to work in bacon
took me quite a bit of time to get it working


this demo uses the raspberry pi 3
you would need to edit -I/usr/include/arm-linux-gnueabihf/qt5
to the location of your qt5 headers


most code will port from qt4 to qt5 with this


PRAGMA INCLUDE <QtWidgets/QApplication>  <QtWidgets/QLabel>  <QtWidgets/QMainWindow> <QtWidgets/QPushButton>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/arm-linux-gnueabihf/qt5

OPTION PARSE FALSE






PRAGMA INCLUDE <QtWidgets/QApplication>  <QtWidgets/QLabel>  <QtWidgets/QMainWindow> <QtWidgets/QPushButton>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/arm-linux-gnueabihf/qt5

OPTION PARSE FALSE


'--- our signal /slot  from Qt  placed in a  bacon SUB
SUB handleButton()
   PRINT "Qt callback hack working with events"
   '--- change the text
   m_button->setText("Example")
  '--- resize button
   m_button->resize(100,100)
ENDSUB




   DECLARE app TYPE QApplication*
   DECLARE mainWindow TYPE QMainWindow*
   DECLARE m_button  TYPE QPushButton*
   app = new QApplication(argc, argv)




   '--- mainwindow.cpp used in Qt modified and redirected  the signal/slot to a bacon SUB
   '--- Create the button
   m_button = new QPushButton("Qt Button")
   '--- set size and location of the button
   m_button->setGeometry(QRect(QPoint(100, 100), QSize(200, 50)))
 
   '--- Connect button signal to appropriate slot hacked for a BaCon SUB
   '--- had to add the QObject::   to the connect to get this to work in bacon
   QObject::connect(m_button, &QPushButton::released,  handleButton)

 
   m_button->show()
   return app->exec()







[Pjot]

Thanks Bigbass!

Against all odds, I tried your code on my Linux Mint system, but unfortunately it didn't work there. But I'll try to revive my Raspberry VM shortly...

Best regards,
Peter

[bigbass]

Hello Peter


thanks for the test and feedback

I would suspect on mint it should work by changing

RPI 3
-I/usr/include/arm-linux-gnueabihf/qt5

mint 64 amd
-I/usr/include/x86_64-linux-gnu/qt5

and remove or replace the GL line -lGLESv2
with what mint uses



should work for mint 64 amd ( I don't have my mint laptop anymore)


joe

PRAGMA INCLUDE <QtWidgets/QApplication>  <QtWidgets/QLabel>  <QtWidgets/QMainWindow> <QtWidgets/QPushButton>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core  -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/x86_64-linux-gnu/qt5
OPTION PARSE FALSE


[bigbass]

this is the demo in pure qt (scroll down the page for the source code to build the widget)
wiki.qt.io/How_to_Use_QPushButton


Hello

I will include the source files that I used to port the demo to bacon
1.) this way anyone can test the code and their qt is working correctly

2.) it will provide a reference to what to do to port the code to bacon

once confirmed on other systems Will add a step by step detailed list of what to look for
while porting to get all the headers and callbacks working and if any changes need to be made to the class
to get it all public


tips : once you get the official makefile generated from the source code
it makes adding the correct PRAGMA lines easier to port the code

joe

[bigbass]

Good news QT5 can work in the same way as the fltk coding style
except for the connect line

here is another widget a checkbox with the low level events from qt




hope this demo works for everyone
I think that QT5 has the door open now with bacon and events
this is starting to be fun again


PRAGMA INCLUDE <QtWidgets/QApplication>    <QtWidgets/QMainWindow> <QtWidgets/QCheckBox>   <QtWidgets/QHBoxLayout>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/arm-linux-gnueabihf/qt5

OPTION PARSE FALSE


'--- our signal /slot  from Qt  placed in a  bacon SUB
'------------------------------------------------------
SUB showTitle()
'------------------------------------------------------
PRINT "Qt callback hack working with events"
IF (cb->isChecked()) THEN
 w->setWindowTitle("Checked")
ELSE      
  w->setWindowTitle("Unchecked")
ENDIF
 
ENDSUB




DECLARE app TYPE QApplication*
DECLARE window TYPE QMainWindow*
DECLARE hbox  TYPE QHBoxLayout*
DECLARE cb  TYPE QCheckBox*
DECLARE w  TYPE QWidget*
app = new QApplication(argc, argv)


'--- Create a widget instead of a window
w = new QWidget()
hbox = new QHBoxLayout()
 
cb = new QCheckBox("Show Title")
 
hbox->addWidget(cb, 0, Qt::AlignLeft | Qt::AlignTop)

'--- Set the hbox as the layout of the widget
'--- this fixes having a window and a widget that are not joined
w->setLayout(hbox )
 

  QObject::connect(cb, &QCheckBox::stateChanged, showTitle)
 

  cb->show()
  w->resize(350, 150)
  w->setWindowTitle("QCheckBox demo")
  w->show()
  return app->exec()




[bigbass]

one more for fun
just to see if the idea will work for more widgets

the callback is all qt updating the label






PRAGMA INCLUDE <QtWidgets/QApplication>    <QtWidgets/QMainWindow> <QtWidgets/QCheckBox>   <QtWidgets/QHBoxLayout> <QtWidgets/QLabel> <QtWidgets/QSlider>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/arm-linux-gnueabihf/qt5

OPTION PARSE FALSE






DECLARE app TYPE QApplication*
DECLARE window TYPE QMainWindow*
DECLARE hbox  TYPE QHBoxLayout*
DECLARE cb  TYPE QCheckBox*
DECLARE w  TYPE QWidget*
DECLARE slider  TYPE QSlider*
DECLARE label  TYPE QLabel*
app = new QApplication(argc, argv)


'--- Create a widget instead of a window
w = new QWidget()
hbox = new QHBoxLayout()
 
slider = new QSlider(Qt::Horizontal )
hbox->addWidget(slider)

 
hbox->addWidget(slider, 0, Qt::AlignLeft | Qt::AlignTop)
label = new QLabel("0")
hbox->addWidget(label)

'--- Set the hbox as the layout of the widget
'--- this fixes having a window and a widget that are not joined
w->setLayout(hbox )
 
  '---no callback in SUB since the label handels the changes of the slider
QObject::connect(slider, &QSlider::valueChanged, label,qOverload<int>(&QLabel::setNum))


 
  w->resize(350, 150)
  w->setWindowTitle("Qt5 slider demo")
  w->show()
  return app->exec()


[Pjot]

Thanks bigbass,

The below code works for me in Linux Mint 20.3.

BR

Peter

PRAGMA INCLUDE <QtWidgets/QApplication>  <QtWidgets/QLabel>  <QtWidgets/QMainWindow> <QtWidgets/QPushButton>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core  -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/x86_64-linux-gnu/qt5 -fPIC
OPTION PARSE FALSE

'--- our signal /slot  from Qt  placed in a  bacon SUB
SUB handleButton()
PRINT "Qt callback hack working with events"
'--- change the text
m_button->setText("Example")
'--- resize button
m_button->resize(100,100)
ENDSUB

DECLARE app TYPE QApplication*
DECLARE mainWindow TYPE QMainWindow*
DECLARE m_button  TYPE QPushButton*
app = new QApplication(argc, argv)

'--- mainwindow.cpp used in Qt modified and redirected  the signal/slot to a bacon SUB
'--- Create the button
m_button = new QPushButton("Qt Button")
'--- set size and location of the button
m_button->setGeometry(QRect(QPoint(100, 100), QSize(200, 50)))

'--- Connect button signal to appropriate slot hacked for a BaCon SUB
'--- had to add the QObject::   to the connect to get this to work in bacon
QObject::connect(m_button, &QPushButton::released,  handleButton)


m_button->show()
return app->exec()


[bigbass]

Hello Peter

great to hear you got it to compile on mint with your fix

-I/usr/include/x86_64-linux-gnu/qt5 -fPIC


so it seems that with this x86 template it should work with the other demos by adding the correct <QtWidgets/ that were used here >


PRAGMA INCLUDE <QtWidgets/QApplication>  <QtWidgets/QLabel>  <QtWidgets/QMainWindow> <QtWidgets/QPushButton>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core  -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/x86_64-linux-gnu/qt5 -fPIC
OPTION PARSE FALSE

joe

[vovchik]

Dear Joe and Peter,

Works great for me on Mint, using Peter's example. I will now try on my Pi4 and report back.

Thanks!

With kind regards,
vovchik

[bigbass]

Hello vovchik !

First great to hear from you
and that it works on your box too

the -fPIC works on the rpi3 and without it but it is safer to use it
since we are mixing callbacks

here is the slider with a bacon callback





PRAGMA INCLUDE <QtWidgets/QApplication>    <QtWidgets/QMainWindow> <QtWidgets/QCheckBox>   <QtWidgets/QHBoxLayout> <QtWidgets/QLabel> <QtWidgets/QSlider>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/arm-linux-gnueabihf/qt5 -fPIC
OPTION PARSE FALSE

'--- our signal /slot  from Qt  placed in a  bacon SUB
SUB handleslider()
 
   '--- print out to the terminal the sliders value
   '--- this shows that we can use qt5 code in the bacon callback too
 PRINT   slider->value()
 
ENDSUB





DECLARE app TYPE QApplication*
DECLARE window TYPE QMainWindow*
DECLARE hbox  TYPE QHBoxLayout*
DECLARE cb  TYPE QCheckBox*
DECLARE w  TYPE QWidget*
DECLARE slider  TYPE QSlider*
DECLARE label  TYPE QLabel*
app = new QApplication(argc, argv)


'--- Create a widget instead of a window
w = new QWidget()
hbox = new QHBoxLayout()
 
slider = new QSlider(Qt::Horizontal )
hbox->addWidget(slider)

 
hbox->addWidget(slider, 0, Qt::AlignLeft | Qt::AlignTop)
label = new QLabel("0")
hbox->addWidget(label)

'--- Set the hbox as the layout of the widget
'--- this fixes having a window and a widget that are not joined
w->setLayout(hbox )
 
   '---no callback in SUB here since the label handels the changes of the slider
QObject::connect(slider, &QSlider::valueChanged, label,qOverload<int>(&QLabel::setNum))
   
   '--- pass to the bacon SUB then use the sliders value  
   QObject::connect(slider, &QSlider::valueChanged, handleslider)

 
  w->resize(350, 150)
  w->setWindowTitle("Qt5 slider demo")
  w->show()
  return app->exec()





[vovchik]

Dear Joe,

Thanks, and good to see you here too, again, and pushing the envelope. I just tried the qt examples on my Pi4 and everything works perfectly. I also like the binary size I get: < 20k stripped. I think we might want to start thinking about some kind of simplified GUI syntax, like HUG, soon.

With kind regards,
vovchik

[bigbass]

one more for today

start thinking about some kind of simplified GUI syntax

I am always looking for something easier and less things to remember and type
on the bacon side of things we can do much to help with the C++ code
and make it easier to digest



combobox widget





PRAGMA INCLUDE <QtWidgets/QApplication>    <QtWidgets/QMainWindow> <QtWidgets/QComboBox>   <QtWidgets/QHBoxLayout>  <QtWidgets/QLabel>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/arm-linux-gnueabihf/qt5

OPTION PARSE FALSE





DECLARE app TYPE QApplication*
DECLARE window TYPE QMainWindow*
DECLARE hbox  TYPE QHBoxLayout*
DECLARE combo  TYPE QComboBox*
DECLARE label TYPE QLabel*
DECLARE w  TYPE QWidget*
'DECLARE  combotext TYPE QString

app = new QApplication(argc, argv)


DECLARE  distros = { "Arch", "Xubuntu", "Redhat", "Debian","Mandriva" } TYPE QStringList


'--- Create a widget instead of a window
w = new QWidget()
hbox = new QHBoxLayout()
 
combo = new QComboBox()
combo->addItems(distros)

 
hbox->addWidget(combo)
hbox->addSpacing(15)

label = new QLabel("Arch")
hbox->addWidget(label)

'--- Set the hbox as the layout of the widget
'--- this fixes having a window and a widget that are not joined
w->setLayout(hbox )
 

  QObject::connect(combo, qOverload<const QString &>(&QComboBox::activated),label, &QLabel::setText)
 
 
 
  w->resize(350, 150)
  w->setWindowTitle("Qcombox demo")
  w->show()
  return app->exec()


[bigbass]

how about a statusbar widget demo
looks like we will be able to add many widgets
and notice never using the C++ class in the code




had to modify this a lot for bacon use
with any alignment the statusbar wouldn't show




PRAGMA INCLUDE <QtWidgets/QApplication>    <QtWidgets/QMainWindow> <QtWidgets/QComboBox>   <QtWidgets/QHBoxLayout>  <QtWidgets/QLabel>
PRAGMA INCLUDE <QtWidgets/QLabel> <QtWidgets/QPushButton>   <QtWidgets/QStatusBar>   <QtWidgets/QFrame>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/arm-linux-gnueabihf/qt5 -fPIC

OPTION PARSE FALSE

'--------------------------------------
SUB OnOkPressed()
'--------------------------------------
Statusbar->showMessage( "OK button pressed", 4000)
'---note the 4000 is 4 seconds to view the message
PRINT "OK button pressed"
END SUB

'--------------------------------------
SUB OnApplyPressed()
'--------------------------------------
Statusbar->showMessage("Apply button pressed", 4000)
PRINT "Apply button pressed"
END SUB



DECLARE app TYPE QApplication*
DECLARE frame  TYPE QFrame*
DECLARE hbox  TYPE QHBoxLayout*
DECLARE okBtn  TYPE QPushButton*
DECLARE aplBtn TYPE QPushButton*

DECLARE label TYPE QLabel*
DECLARE Statusbar TYPE QStatusBar*
DECLARE w  TYPE QWidget*


app = new QApplication(argc, argv)





 '--- Create a widget instead of a window
 w = new QWidget()
 frame = new QFrame()
 'setCentralWidget(frame)


 hbox = new QHBoxLayout(frame)

 okBtn = new QPushButton("OK", frame)
 hbox->addWidget(okBtn, 0, Qt::AlignLeft | Qt::AlignTop)

 aplBtn = new QPushButton("Apply", frame)
 hbox->addWidget(aplBtn, 1, Qt::AlignLeft | Qt::AlignTop)
 
 Statusbar = new QStatusBar()
 '--- Set the hbox as the layout of the widget
 '--- this fixes having a window and a widget that are not joined
 
 hbox->addWidget(Statusbar, 2)
 w->setLayout(hbox )
 

 QObject::connect(okBtn, &QPushButton::clicked, OnOkPressed)
 QObject::connect(aplBtn, &QPushButton::clicked, OnApplyPressed)

 Statusbar->show()
 w->resize(450, 150)
 w->setWindowTitle("Statusbar demo")
 w->show()
 return app->exec()



[bigbass]

I added a few things to get the output
and a new Qt macro
DEF FN PRINTOUT(x) = qDebug() << (x)

Qt forces you to use debug for terminal out stuff




PRAGMA INCLUDE <QtWidgets/QApplication>    <QtWidgets/QMainWindow> <QtWidgets/QComboBox>   <QtWidgets/QHBoxLayout>  <QtWidgets/QLabel>
PRAGMA INCLUDE <QtWidgets/QPushButton>   <QtWidgets/QStatusBar>   <QtWidgets/QFrame>   <QtWidgets/QVBoxLayout>
PRAGMA INCLUDE <QtWidgets/QListWidget> <QtCore/QDebug>
PRAGMA INCLUDE  <iostream>
PRAGMA LDFLAGS -lQt5Widgets -lQt5Gui -lQt5Core -lGLESv2 -lpthread -latomic
PRAGMA COMPILER g++
PRAGMA OPTIONS -Wno-write-strings -Wno-pointer-arith -I/usr/include/arm-linux-gnueabihf/qt5 -fPIC
OPTION PARSE FALSE


'---must include this <QtCore/QDebug>
'--- a new macro without formatting or casting or c++
DEF FN  PRINTOUT(x) =  qDebug()  << (x)

'--------------------------------------
SUB addPressed()
'--------------------------------------
Statusbar->showMessage( "add", 4000)
'---note the 4000 is 4 seconds to view the message
END SUB

'--------------------------------------
SUB renamePressed()
'--------------------------------------
Statusbar->showMessage("rename ", 4000)
END SUB

'--------------------------------------
SUB removePressed()
'--------------------------------------
Statusbar->showMessage("remove", 4000)
END SUB


'--------------------------------------
SUB removeallPressed()
'--------------------------------------
Statusbar->showMessage("remove all ", 4000)
END SUB



'--------------------------------------
SUB clickedsub()
'--------------------------------------
'--- I figured out how to get the selected from a click
Statusbar->showMessage(lw->currentItem()->text(), 4000)

'--- how to get the terminal out strings of the selected text
PRINTOUT(lw->currentItem()->text())
END SUB


DECLARE app TYPE QApplication*
DECLARE hbox  TYPE QHBoxLayout*
DECLARE vbox  TYPE QVBoxLayout*
DECLARE add  TYPE QPushButton*
DECLARE renamed TYPE QPushButton*
DECLARE removeme TYPE QPushButton*
DECLARE removeall TYPE QPushButton*
DECLARE lw TYPE QListWidget*
DECLARE Statusbar TYPE QStatusBar*
DECLARE w  TYPE QWidget*


app = new QApplication(argc, argv)
'--- Create a widget instead of a window
w = new QWidget()
 
 hbox = new QHBoxLayout()
 vbox = new QVBoxLayout()
 
 lw = new QListWidget()
 lw->addItem("apples")
 lw->addItem("oranges")
 lw->addItem("mangos")
 lw->addItem("bananas")
 lw->addItem("lemons")

 add = new QPushButton("Add")
 renamed = new QPushButton("Rename")
 removeme = new QPushButton("Remove")
 removeall = new QPushButton("Remove All")

 vbox->setSpacing(3)
 vbox->addStretch(1)
 vbox->addWidget(add)
 vbox->addWidget(renamed)
 vbox->addWidget(removeme)
 vbox->addWidget(removeall)
 vbox->addStretch(1)
 hbox->addWidget(lw)
 hbox->addSpacing(15)
 hbox->addLayout(vbox)

 '--- Set the hbox as the layout of the widget
 '--- this fixes having a window and a widget that are not joined
 Statusbar = new QStatusBar()
 
 
 '---add the statusbar widget
 hbox->addWidget(Statusbar, 3, Qt::AlignBottom)
 w->setLayout(hbox )
 

 QObject::connect(add, &QPushButton::clicked, addPressed)
 QObject::connect(renamed, &QPushButton::clicked, renamePressed)
 QObject::connect(removeme, &QPushButton::clicked, removePressed)
 QObject::connect(removeall, &QPushButton::clicked, removeallPressed)
 '--- added a custom callback to get the listwidget
 'QObject::connect(lw, &QListWidget::itemDoubleClicked, doubleclickedsub)
 QObject::connect(lw, &QListWidget::itemClicked, clickedsub)
 
 
 w->resize(500, 200)
 w->setWindowTitle("Listwidget demo")
 w->show()
 return app->exec()





[Pjot]

Thanks bigbass!

It's pretty cool how these widgets work and look like. Your code demonstrates how quickly it can be done

Best regards
Peter