Discovery of printers in the network?

[surwassu]

Hey Guys !!
i am new to qt4.7.2 and i got task to discover no of printers available in your network?
I have read qt docs and got qprinterinfo class having availableprinter() function but can anyone give me idea about how to use it ? i am working on unix platform.

Thanks...
regards ,
Sumit

[high_flyer]

can anyone give me idea about how to use it ?

You just call it!
What is there to explain?
If you know how to call a function, you know how to use it!

[surwassu]

hi wiseguy,
I have searched for programs based on printer but nobody has explain these things properly.I went to Qt
website but no examples are there.If you have any examples please let us know..
regards,
Sumit

[high_flyer]

(my username is high_flyer)
Again - example for what?
you have found the correct function to solve your problem, just use it.
What is your question?

[surwassu]

Hi high_flyer,

I have written code to show one of the available printer name ,I have used QLineText to show printer name
but getting error in following part of code:

void qprint::give_name_of_printer()
 
{   
    QPrinterInfo PrinterInfo;
    QPrinter *printer=new QPrinter(QPrinter::ScreenResolution);
 //line no 33
  QList<QPrinterInfo> pinfo;
//line 34  
QString str;
  pinfo= PrinterInfo.availablePrinters(); // transferring QList into temp list pinfo   
  str=pinfo.value(1).printerName();//value function will return Qprinterinfo object at 2nd location & that object 
                                                  // is used get printer name & stored in CString object
  Name_edit->setText(str);//This is used to set text to printer name
 
}

void qprint::give_name_of_printer()

{   
    QPrinterInfo PrinterInfo;
    QPrinter *printer=new QPrinter(QPrinter::ScreenResolution);
 //line no 33
  QList<QPrinterInfo> pinfo;
//line 34  
QString str;
  pinfo= PrinterInfo.availablePrinters(); // transferring QList into temp list pinfo   
  str=pinfo.value(1).printerName();//value function will return Qprinterinfo object at 2nd location & that object 
                                                  // is used get printer name & stored in CString object
  Name_edit->setText(str);//This is used to set text to printer name

}

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I am getting error as incomplete type and cannot be defined 'class QList<QPrinterInfo>' at line no 33
can you please help me out...

Thanks
Regards,
Sumit

[wysota]

Did you remember to #include the proper header file?

[Santosh Reddy]

You code is fine, it will work, may be you missed to include <QList> file, just add it and any other file which is required, you should have it running.

Tip:
when you read the printer name, make sure the list contains the printers on the first hand, else your program will crash

...
    str=pinfo.value(1).printerName(); // this is not suggersted;
...
    if(pinfo.count() > n)
        str=pinfo.value(n).printerName();// get nth printer name
...

...
    str=pinfo.value(1).printerName(); // this is not suggersted;
...
    if(pinfo.count() > n)
        str=pinfo.value(n).printerName();// get nth printer name
...

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remember to post the code in code tags

[surwassu]

thanks alot........

[ChrisW67]

You also don't need to create an instance of QPrinterInfo (line 4) in order to use the static method QPrinterInfo::availablePrinters().

[surwassu]

Hi Guys,

Thanks alot for ur soln it really works.but m getting one problem ,when i put
int n as value it should show me printer's name to which m currently connected in the network.My printer
name is SJM_TESTER in windows. , but it shows me following values


for
n=0 printer
n=1 epr
n=2: ipr
n=3: pdf
n=4: null string

what must be problem ?How should I go ahead?M attaching source file below

m running my Qt on unix..

please help me.

main.cpp:

//**********************************
 
 
#include "print.h"
#include <QDesktopWidget>
#include <QApplication>
 
 
 
 
int main(int argc, char *argv[])
{
  QApplication app(argc, argv);
 
  qprint window;
QFont font("Arial");
     app.setFont(font);
  //window.setWindowTitle("printer info");
  window.showFullScreen();
  //center(window);
 
  return app.exec();
}
 
//***************************

//**********************************


#include "print.h"
#include <QDesktopWidget>
#include <QApplication>




int main(int argc, char *argv[])
{
  QApplication app(argc, argv);

  qprint window;
QFont font("Arial");
     app.setFont(font);
  //window.setWindowTitle("printer info");
  window.showFullScreen();
  //center(window);

  return app.exec();
}

//***************************

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print.cpp:

//*****************************
 
#include "print.h"
 
 
 
qprint::qprint()
{
  sumit=new QPrinter(QPrinter::ScreenResolution);
  grid = new QGridLayout(this);
  grid->setSpacing(80);
 
  Name= new QLabel("printer name", this);
  grid->addWidget(Name, 0, 0, 1, 1);
 
   Name_edit= new QLineEdit(this);
   grid->addWidget(Name_edit, 0, 1, 1, 1);
 
Name->setBuddy(Name_edit);
 
 
   setLayout(grid);
  give_no_of_printer();
}
 
 
void qprint::give_no_of_printer()
 
{   int n=5;
	QPrinterInfo PrinterInfo;
    info= PrinterInfo.availablePrinters();
  if(info.count() > n)
	  str=info.value(n).printerName();
  //defaultPrinter(); 
  Name_edit->setText(str);
 
}
 
//***********************************

//*****************************

#include "print.h"



qprint::qprint()
{
  sumit=new QPrinter(QPrinter::ScreenResolution);
  grid = new QGridLayout(this);
  grid->setSpacing(80);

  Name= new QLabel("printer name", this);
  grid->addWidget(Name, 0, 0, 1, 1);

   Name_edit= new QLineEdit(this);
   grid->addWidget(Name_edit, 0, 1, 1, 1);

Name->setBuddy(Name_edit);


   setLayout(grid);
  give_no_of_printer();
}


void qprint::give_no_of_printer()

{   int n=5;
	QPrinterInfo PrinterInfo;
    info= PrinterInfo.availablePrinters();
  if(info.count() > n)
	  str=info.value(n).printerName();
  //defaultPrinter(); 
  Name_edit->setText(str);

}

//***********************************

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print.h

//***********************************
#include <QtGui>
 
 
class QPrinterInfo;
class CString;
class QLabel;
class QLineEdit;
class QPrinter;
class QGridLayout;
#include<QList>;
class qprint : public QMainWindow
 
 
{
 
 
 
	Q_OBJECT
 QString str;
QList<QPrinterInfo> info;
  QPrinter *sumit;
  QLabel *Name;
  QLineEdit *Name_edit;
QGridLayout *grid;
 public:
		qprint();
	    void give_no_of_printer();
 
};
//****************************

//***********************************
#include <QtGui>


class QPrinterInfo;
class CString;
class QLabel;
class QLineEdit;
class QPrinter;
class QGridLayout;
#include<QList>;
class qprint : public QMainWindow


{
	
	
	
	Q_OBJECT
 QString str;
QList<QPrinterInfo> info;
  QPrinter *sumit;
  QLabel *Name;
  QLineEdit *Name_edit;
QGridLayout *grid;
 public:
		qprint();
	    void give_no_of_printer();

};
//****************************

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thanks
regards,
Sumit

---

Added after 4 minutes:

You also don't need to create an instance of QPrinterInfo (line 4) in order to use the static method QPrinterInfo::availablePrinters().

hi
if i dont create an instance of QPrinterInfo as per u how qt will call availablePrinters function.coz this function comes under QPrinterinfoM I correct or not?
Plz guide me.


hi guys,
I have used lpstat -a in unix and i got previously mention printrers .that means code my is working properly..
I would like to ask you if i create QPrintdialog's instance then, is that class directly adds available printers in the system to its dialog box's printer list or we have to write code for that ..

plz guide me..
regards,
Sumit

[Santosh Reddy]

if i dont create an instance of QPrinterInfo as per u how qt will call availablePrinters function.coz this function comes under QPrinterinfo
M I correct or not?
Plz guide me.

Qt does't do anything, its plain C++ which will call QPrinterInfo::availablePrinters(), as this is static call it need not have a instance to call (you can also call with instance if you have on)

refer http://www.cplusplus.com/doc/tutorial/classes2/ for Static members

I have used lpstat -a in unix and i got previously mention printrers .that means code my is working properly..
I would like to ask you if i create QPrintdialog's instance then, is that class directly adds available printers in the system to its dialog box's printer list or we have to write code for that ..

Controls are already provided to enable users to choose from the printers available, including any configured network printers. Make sure your network printer (hosted on windows) is configured in unix.

[surwassu]

Qt does't do anything, its plain C++ which will call QPrinterInfo::availablePrinters(), as this is static call it need not have a instance to call (you can also call with instance if you have on)

refer http://www.cplusplus.com/doc/tutorial/classes2/ for Static members


Controls are already provided to enable users to choose from the printers available, including any configured network printers. Make sure your network printer (hosted on windows) is configured in unix.

thanks alot buddy.

[ChrisW67]

Edit your post to use [code][/code] tags around your code before someone loses their eyesight trying to read that mess.

hi
if i dont create an instance of QPrinterInfo as per u how qt will call availablePrinters function.coz this function comes under QPrinterinfo
M I correct or not?
Plz guide me.

You can call it directly. As a static member method it does not need an object instance to function.

QList<QPrinterInfo> printers = QPrinterInfo::availablePrinters();

QList<QPrinterInfo> printers = QPrinterInfo::availablePrinters();

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If you use the standard Qt print dialogs then this is done for you anyway.

[surwassu]

Edit your post to use [code][/code] tags around your code before someone loses their eyesight trying to read that mess.


You can call it directly. As a static member method it does not need an object instance to function.

QList<QPrinterInfo> printers = QPrinterInfo::availablePrinters();

QList<QPrinterInfo> printers = QPrinterInfo::availablePrinters();

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If you use the standard Qt print dialogs then this is done for you anyway.

Thanks buddy,

from next time onwords , I will remember what said ...n sorry for mess .
I got your point & I tried using QPrintDialog it works fine ..thanks

[surwassu]

Hi Guys,

Is there any API in Qt which will communicate with my print server to discover all printer present in the network???

The function availablePrinters() is giving me locally configured printer details,But I want list of all printer present in the network on my machine..

Plz guide me..
Thank you
Regards,
Sumit

[wysota]

You need to perform the process of service discovery. It differs based on the protocols the printers implement. You can try using zeroonf (http://doc.qt.nokia.com/qq/qq23-bonjour.html)

[surwassu]

Hi guys,

Can you guys please provide some direction on how I can use Bonjour service in Qt app to discover printer devices on the dedicated printer network?
I have used http://doc.qt.nokia.com/qq/qq23-bonjour.html link but can't able to understand properly how to proceed...

can anyone give me good n simple example for this..
please give me somw guidence ..

Thank you
Regards,
Sumit

[wysota]

Please stop multiposting!

What exactly are you having problems with?

[surwassu]

Please stop multiposting!

What exactly are you having problems with?

Extreme apologies my friend ! i should not supposed create another thread for same problem ..sorry
i have already mention my problem in my previous post
regards,
sumit

[squidge]

There are examples included in the link. If you do not understand the examples, which part are you having problems with? Saying "can't able to understand" is too vague.