×
Namespaces

Variants
Actions
Revision as of 04:17, 11 October 2012 by hamishwillee (Talk | contribs)

Launching a native application from Qt

From Nokia Developer Wiki
Jump to: navigation, search
Article Metadata
Tested with
SDK: Qt SDK
Devices(s): Nokia 5800 XpressMusic
Compatibility
Platform(s): S60 3rd Edition, FP1, FP2
S60 5th Edition
Symbian
Article
Keywords: QProcess
Created: tepaa (29 Apr 2009)
Last edited: hamishwillee (11 Oct 2012)

Contents

Overview

This code snippet shows how to launch a native application from Qt. The example has been tested launching the Symbian camera application on the Symbian platform, but the code should work generically.

Header

The ProcessHandler starts the process and listens for its states.

#include <QObject>
#include <QProcess>
 
class ProcessHandler : public QObject
{
Q_OBJECT
 
public:
ProcessHandler(QObject *parent = 0);
~ProcessHandler();
 
public:
void StartCameraApp();
 
public Q_SLOTS:
void stateChanged(QProcess::ProcessState state);
void error(QProcess::ProcessError error);
 
private:
QProcess* process;
};


Source

Create QProcess and start listening for process state changes.

ProcessHandler::ProcessHandler(QObject *parent)
: QObject(parent)
{
process = new QProcess(this);
QObject::connect(process, SIGNAL(stateChanged(QProcess::ProcessState)),
this, SLOT(stateChanged(QProcess::ProcessState)));
}

Class descruction:

ProcessHandler::~ProcessHandler()
{
if (process->state() != QProcess::NotRunning)
{
// Close process if it is running
process->close();
}
}


Start the Symbian native camera Cameraapp.exe:

void ProcessHandler::StartCameraApp()
{
QString program = "Cameraapp.exe";
process->start(program);
}

QProcess signals the error to the error slot:

void ProcessHandler::error(QProcess::ProcessError error)
{
switch (error)
{
case QProcess::FailedToStart:
case QProcess::Crashed:
case QProcess::Timedout:
case QProcess::ReadError:
case QProcess::WriteError:
case QProcess::UnknownError:
{
// TODO: Handle error
break;
}
default:
{
break;
}
};
}

QProcess signals the process state changes to the stateChanged slot.

void ProcessHandler::stateChanged(QProcess::ProcessState state)
{
switch (state)
{
case QProcess::NotRunning:
case QProcess::Starting:
case QProcess::Running:
{
// TODO: do what you want with
// different states
break;
}
default:
{
break;
}
};
}


Postconditions

The Symbian native camera is started.

72 page views in the last 30 days.
×