compiled successfully but form is not displayed

[zubair]

I am a newbie for c++ as well as qt. I am trying some example, which i pasted it for
easy understanding. I am trying to compile it through qmake and make command line tool. It compiles successfully but when i try to execute it no form is displayed.
please look into the code help me where i am doing mistake....

//finddialog.h file
 
#ifndef FINDDIALOG_H
#define FINDDIALOG_H
 
#include<QDialog>
 
class QLineEdit;
class QCheckBox;
class QLabel;
class QPushButton;
 
class FindDialog:public QDialog
{
  Q_OBJECT
public:
  FindDialog(QWidget *parent=0);
 
signals:
  void findNext(const QString &str,Qt::CaseSensitivity cs);
  void findPrevious(const QString &str,Qt::CaseSensitivity cs);
 
public slots:
  void findClicked();
  void enableFindButton(const QString &text);
 
private:
  QLabel *label;
  QLineEdit *lineEdit;
  QCheckBox *caseCheckBox;
  QCheckBox *backwardCheckBox;
  QPushButton *findButton;
  QPushButton *closeButton;
};
#endif
//************************************************
//finddialog.cpp
#include<QtGui>
#include "finddialog.h"
 
FindDialog::FindDialog(QWidget *parent):QDialog(parent)
{
  label=new QLabel("Find &what: ");
  lineEdit=new QLineEdit;
  label->setBuddy(lineEdit);
 
  caseCheckBox=new QCheckBox("Match &case");
  backwardCheckBox=new QCheckBox("Search &backward");
 
  findButton=new QPushButton("&Find");
  findButton->setDefault(true);
  findButton->setEnabled(false);
 
  closeButton=new QPushButton("Close");
 
  connect(lineEdit,SIGNAL(textChanged(const QString &)),
	  this,SLOT(enableFindButton(const QString &)));
  connect(findButton,SIGNAL(clicked()),
	  this,SLOT(findClicked()));
  connect(closeButton,SIGNAL(clicked()),
	  this,SLOT(close()));
 
  QHBoxLayout *topleftLayout=new QHBoxLayout;
  topleftLayout->addWidget(label);
  topleftLayout->addWidget(lineEdit);
 
  QVBoxLayout *leftLayout=new QVBoxLayout;
  leftLayout->addLayout(topleftLayout);
  leftLayout->addWidget(caseCheckBox);
  leftLayout->addWidget(backwardCheckBox);
 
  QVBoxLayout *rightLayout=new QVBoxLayout;
  rightLayout->addWidget(findButton);
  rightLayout->addWidget(closeButton);
  rightLayout->addStretch();
 
  QHBoxLayout *mainLayout=new QHBoxLayout;
  rightLayout->addLayout(leftLayout);
  rightLayout->addLayout(rightLayout);
  setLayout(mainLayout);
 
  setWindowTitle("Find");
  setFixedHeight(sizeHint().height());
}
 
void FindDialog::findClicked()
{
  QString text=lineEdit->text();
  Qt::CaseSensitivity cs=caseCheckBox->isChecked()?
    Qt::CaseSensitive:Qt::CaseInsensitive;
 
  if(backwardCheckBox->isChecked())
  {
    emit findPrevious(text,cs);
  }
  else
  {
    emit findNext(text,cs);
  }
}
 
void FindDialog::enableFindButton(const QString &text)
{
  findButton->setEnabled(!text.isEmpty());
}
//*****************************************************
//main.cpp file
 
#include<QApplication>
#include "finddialog.h"
 
int main(int argc,char *argv[])
{
  QApplication app(argc,argv);
  FindDialog *dialog=new FindDialog;
  dialog->show();
  return app.exec();
}
//****************************
 
//subdialog.pro file
 
######################################################################
# Automatically generated by qmake (2.01a) Sat Oct 16 23:27:20 2010
######################################################################
 
TEMPLATE = app
TARGET = 
DEPENDPATH += .
INCLUDEPATH += .
 
# Input
HEADERS += finddialog.h
SOURCES += finddialog.cpp main.cpp
//*********************

//finddialog.h file

#ifndef FINDDIALOG_H
#define FINDDIALOG_H

#include<QDialog>

class QLineEdit;
class QCheckBox;
class QLabel;
class QPushButton;

class FindDialog:public QDialog
{
  Q_OBJECT
public:
  FindDialog(QWidget *parent=0);

signals:
  void findNext(const QString &str,Qt::CaseSensitivity cs);
  void findPrevious(const QString &str,Qt::CaseSensitivity cs);

public slots:
  void findClicked();
  void enableFindButton(const QString &text);

private:
  QLabel *label;
  QLineEdit *lineEdit;
  QCheckBox *caseCheckBox;
  QCheckBox *backwardCheckBox;
  QPushButton *findButton;
  QPushButton *closeButton;
};
#endif
//************************************************
//finddialog.cpp
#include<QtGui>
#include "finddialog.h"

FindDialog::FindDialog(QWidget *parent):QDialog(parent)
{
  label=new QLabel("Find &what: ");
  lineEdit=new QLineEdit;
  label->setBuddy(lineEdit);

  caseCheckBox=new QCheckBox("Match &case");
  backwardCheckBox=new QCheckBox("Search &backward");

  findButton=new QPushButton("&Find");
  findButton->setDefault(true);
  findButton->setEnabled(false);

  closeButton=new QPushButton("Close");

  connect(lineEdit,SIGNAL(textChanged(const QString &)),
	  this,SLOT(enableFindButton(const QString &)));
  connect(findButton,SIGNAL(clicked()),
	  this,SLOT(findClicked()));
  connect(closeButton,SIGNAL(clicked()),
	  this,SLOT(close()));

  QHBoxLayout *topleftLayout=new QHBoxLayout;
  topleftLayout->addWidget(label);
  topleftLayout->addWidget(lineEdit);

  QVBoxLayout *leftLayout=new QVBoxLayout;
  leftLayout->addLayout(topleftLayout);
  leftLayout->addWidget(caseCheckBox);
  leftLayout->addWidget(backwardCheckBox);

  QVBoxLayout *rightLayout=new QVBoxLayout;
  rightLayout->addWidget(findButton);
  rightLayout->addWidget(closeButton);
  rightLayout->addStretch();

  QHBoxLayout *mainLayout=new QHBoxLayout;
  rightLayout->addLayout(leftLayout);
  rightLayout->addLayout(rightLayout);
  setLayout(mainLayout);

  setWindowTitle("Find");
  setFixedHeight(sizeHint().height());
}

void FindDialog::findClicked()
{
  QString text=lineEdit->text();
  Qt::CaseSensitivity cs=caseCheckBox->isChecked()?
    Qt::CaseSensitive:Qt::CaseInsensitive;

  if(backwardCheckBox->isChecked())
  {
    emit findPrevious(text,cs);
  }
  else
  {
    emit findNext(text,cs);
  }
}

void FindDialog::enableFindButton(const QString &text)
{
  findButton->setEnabled(!text.isEmpty());
}
//*****************************************************
//main.cpp file

#include<QApplication>
#include "finddialog.h"

int main(int argc,char *argv[])
{
  QApplication app(argc,argv);
  FindDialog *dialog=new FindDialog;
  dialog->show();
  return app.exec();
}
//****************************

//subdialog.pro file

######################################################################
# Automatically generated by qmake (2.01a) Sat Oct 16 23:27:20 2010
######################################################################

TEMPLATE = app
TARGET = 
DEPENDPATH += .
INCLUDEPATH += .

# Input
HEADERS += finddialog.h
SOURCES += finddialog.cpp main.cpp
//*********************

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[tbscope]

Here's your problem:

setFixedHeight(sizeHint().height());

setFixedHeight(sizeHint().height());

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Print out the value of sizeHint().height() and see why it fails.

[faldzip]

I compiled your project and it shows nothing because it crashes!
And I think that this might be because of this line:

rightLayout->addLayout(rightLayout);

rightLayout->addLayout(rightLayout);

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I can't imagine what it might do :P

[gboelter]

Change this

rightLayout->addLayout(leftLayout);
rightLayout->addLayout(rightLayout);

to this

mainLayout->addLayout ( leftLayout );
mainLayout->addLayout ( rightLayout );

and it should work ...

[zubair]

thanks a lot..... faldzip !!
now i know it was a silly mistake and nothing......