qt - why QdoublespixBox can't show big numbers correctly -

i have problem qdoublespinxbox

i'm using qdoublespinxbox delegate in col2,

but when have big numbes 99999999999999999999999999999999

he can't show correctly , shows me 1e+19

i have used

    #include "customtableselldelegate.h" #include <qdoublespinbox> #include <qcombobox> #include <qdebug> #include <databasemananger.h> #include <qlocale> customtableselldelegate::customtableselldelegate(qobject *parent) :     qstyleditemdelegate(parent) { }  qwidget *customtableselldelegate::createeditor(qwidget *parent, const qstyleoptionviewitem &option, const qmodelindex &index) const {     if(!index.isvalid())         return qstyleditemdelegate::createeditor(parent,option,index);      int col= index.column();      if(col == 0)     {         databasemananger dbmgr;          qsqlquerymodel *querymodel = new qsqlquerymodel(parent);          querymodel->setquery("select articledesignation articles");          qcombobox *comboboxeditor = new qcombobox(parent);          comboboxeditor->setmodel(querymodel);         //comboboxeditor->seteditable(true);           return comboboxeditor;      }     else if(col ==1 || col ==2 || col ==3 ||  col == 5 || col == 6 || col == 7)     {         qdoublespinbox *doublespinboxeditor = new qdoublespinbox(parent);         doublespinboxeditor->setrange(-999999999999999.99,999999999999999999.99);         //doublespinboxeditor->setsuffix(" d.a");         doublespinboxeditor->setdecimals(2);         doublespinboxeditor->setbuttonsymbols(qdoublespinbox::plusminus);         doublespinboxeditor->setframe(false);         return doublespinboxeditor;         }else{         return qstyleditemdelegate::createeditor(parent,option,index);     }  }  void customtableselldelegate::seteditordata(qwidget *editor, const qmodelindex &index) const {     if(!index.isvalid())         return qstyleditemdelegate::seteditordata(editor,index);      int col= index.column();      if(col == 0)     {         qstring data = index.model()->data(index,qt::displayrole).tostring();         qcombobox *comboboxeditor = qobject_cast<qcombobox*>(editor);          comboboxeditor->setitemtext(comboboxeditor->currentindex(),data);     }      else if(col ==1 || col ==2 || col ==3 ||  col == 5 || col == 6 || col == 7)     {         double data = index.model()->data(index,qt::displayrole).todouble();         qdoublespinbox *doublespinboxeditor = qobject_cast<qdoublespinbox*>(editor);         doublespinboxeditor->setvalue(data);      }else{         qstyleditemdelegate::seteditordata(editor,index);     }   }  void customtableselldelegate::setmodeldata(qwidget *editor, qabstractitemmodel *model, const qmodelindex &index) const {     if(!index.isvalid())         return qstyleditemdelegate::setmodeldata(editor,model,index);      int col= index.column();      if(col == 0)     {         qcombobox *comboboxeditor = qobject_cast<qcombobox*>(editor);          model->setdata(index,comboboxeditor->currenttext(),qt::editrole);          emit unlockrow(index);       }      else if(col ==1 ||col ==2 || col ==3 ||  col == 5 || col == 6 || col == 7)     {         qdoublespinbox *doublespinboxeditor = qobject_cast<qdoublespinbox*>(editor);         model->setdata(index,doublespinboxeditor->value(),qt::editrole);          if(col == 1 || col == 2)         {             emit qtypricedatachanged(index);         }        }else{         qstyleditemdelegate::setmodeldata(editor,model,index);}    }  void customtableselldelegate::updateeditorgeometry(qwidget *editor, const qstyleoptionviewitem &option, const qmodelindex &index) const {     editor->setgeometry(option.rect);  }  void customtableselldelegate::emitunlockrow(qstring str, qmodelindex index) {     emit unlockrow(index);  }   #include "customtableselldelegate.h" #include <qdoublespinbox> #include <qcombobox> #include <qdebug> #include <databasemananger.h> #include <qlocale> customtableselldelegate::customtableselldelegate(qobject *parent) :     qstyleditemdelegate(parent) { }  qwidget *customtableselldelegate::createeditor(qwidget *parent, const qstyleoptionviewitem &option, const qmodelindex &index) const {     if(!index.isvalid())         return qstyleditemdelegate::createeditor(parent,option,index);      int col= index.column();      if(col == 0)     {         databasemananger dbmgr;          qsqlquerymodel *querymodel = new qsqlquerymodel(parent);          querymodel->setquery("select articledesignation articles");          qcombobox *comboboxeditor = new qcombobox(parent);          comboboxeditor->setmodel(querymodel);         //comboboxeditor->seteditable(true);           return comboboxeditor;      }     else if(col ==1 || col ==2 || col ==3 ||  col == 5 || col == 6 || col == 7)     {         qdoublespinbox *doublespinboxeditor = new qdoublespinbox(parent);         doublespinboxeditor->setrange(-999999999999999.99,999999999999999999.99);         //doublespinboxeditor->setsuffix(" d.a");         doublespinboxeditor->setdecimals(2);         doublespinboxeditor->setbuttonsymbols(qdoublespinbox::plusminus);         doublespinboxeditor->setframe(false);         return doublespinboxeditor;         }else{         return qstyleditemdelegate::createeditor(parent,option,index);     }  }  void customtableselldelegate::seteditordata(qwidget *editor, const qmodelindex &index) const {     if(!index.isvalid())         return qstyleditemdelegate::seteditordata(editor,index);      int col= index.column();      if(col == 0)     {         qstring data = index.model()->data(index,qt::displayrole).tostring();         qcombobox *comboboxeditor = qobject_cast<qcombobox*>(editor);          comboboxeditor->setitemtext(comboboxeditor->currentindex(),data);     }      else if(col ==1 || col ==2 || col ==3 ||  col == 5 || col == 6 || col == 7)     {         double data = index.model()->data(index,qt::displayrole).todouble();         qdoublespinbox *doublespinboxeditor = qobject_cast<qdoublespinbox*>(editor);         doublespinboxeditor->setvalue(data);      }else{         qstyleditemdelegate::seteditordata(editor,index);     }   }  void customtableselldelegate::setmodeldata(qwidget *editor, qabstractitemmodel *model, const qmodelindex &index) const {     if(!index.isvalid())         return qstyleditemdelegate::setmodeldata(editor,model,index);      int col= index.column();      if(col == 0)     {         qcombobox *comboboxeditor = qobject_cast<qcombobox*>(editor);          model->setdata(index,comboboxeditor->currenttext(),qt::editrole);          emit unlockrow(index);       }      else if(col ==1 ||col ==2 || col ==3 ||  col == 5 || col == 6 || col == 7)     {         qdoublespinbox *doublespinboxeditor = qobject_cast<qdoublespinbox*>(editor);         model->setdata(index,doublespinboxeditor->value(),qt::editrole);          if(col == 1 || col == 2)         {             emit qtypricedatachanged(index);         }        }else{         qstyleditemdelegate::setmodeldata(editor,model,index);}    }  void customtableselldelegate::updateeditorgeometry(qwidget *editor, const qstyleoptionviewitem &option, const qmodelindex &index) const {     editor->setgeometry(option.rect);  }  void customtableselldelegate::emitunlockrow(qstring str, qmodelindex index) {     emit unlockrow(index);  } 

but nothing makes diffrent

the default implementation of qdoublespinbox::textfromvalue(double) returns string containing value printed using

locale().tostring(value, 'f', decimals()); 

this never supposed return floating point representation. testing out separately, works , produces correct output:

#include <qtextstream> #include <qlocale int main(int, char **) {     qtextstream out(stdout);     qlocale sysloc = qlocale::system();     double value = 99999999999999999999999999999999.;     double max = 999999999999999999.99;     int decimals = 2;     //q_assert(value < max);     qstring str = sysloc.tostring(value, 'f', decimals);     str.remove(sysloc.groupseparator());     out << str << endl;     return 0; } 

100000000000000005366162204393472.00

the output above correct, way, merely illustrates limited length of mantissa.

alas, maximum value not large enough show either 1e19 or 99999999999999999999999999999999., may problem (the commented-out assert trigger), still should not switch scientific format.

most you're not applying settings correctly spinbox, or system locale messed up. make sure test code above works correctly.