instance of an application is running or not????

hi all,
The application is being developed in Linux and to explain the problem in more detail..application has 2 dialog windows(D1 & D2).Note that D2 is dynamically created based on an event taking place on D1.I come across a situation where I have to update the content displayed on D2 that is already running.I would like to know how to identify whether an instance of D2 is already runnin.The caption on each of the D2(s) that is generated are different.
Any help would be appreciated...

thanx and rgards,
sinche

You will have to maintain a pointer to the D2 and use it to update the Contents of D2

Code:

---

if ( ! pointerToD2 ) {
    // D2 is not yet created !
   // May be U can create it here 
}
 
pointerToD2->updateTheContents( params );

---

ok....how to access the pointer to D2 from main.cpp.

Could u please explain what do intend to Do ?

Since accessing a pointer to a Form Created within Another is very Rare :confused:

Any way

Code:

---

int main() {
   D1 d1;
   d1.d2->updateContents()
}

---

Please recheck the Design before u decide to do this !!

If you need interaction between two dialogs use the singleton pattern :

mydialog.h

Code:

---

#include <QtCore>
#include <QtGui>
 
class mydialog : public QDialog
{
   Q_OBJECT
 
   public:
   static mydialog* Instance()
 
   // your stuffs here
 
  private:
    static mydialog *inst;
}

---

mydialog.cpp

Code:

---

mydialog mydialog:: *inst = 0;
 
mydialog* mydialog::Instance()
{
if (inst == 0)
  inst = new mydialog;
return inst;
}

---

constructors and destructors are declared private

Check the code
pm me if you have any doubts :)