Get Display information using Qt

Article Metadata

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Tested with

Devices(s): Nokia 5800 and Nokia N97.

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Compatibility

Platform(s): S60 3rd Edition, FP1, FP2
S60 5th Edition

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Article

Keywords: QSystemDisplayInfo, QListWidget, QScrollArea

Created: (30 Mar 2010)

Last edited: Yashu (30 Mar 2010)

Under Construction: This article is under construction and it may have outstanding issues. If you have any comments please use the comments tab.

Overview

This code example shows how to access display information from the system. For example to get color depth and display brightness of the device. Code example use QSystemDisplayInfo API from QtMobility APIs.

This snippet requires ReadDeviceData capabilities. Self-signing is not possible, a Developer certificate is needed to sign application for testing.

Prerequisite

• Install Qt for Symbian:Installing Qt on Symbian
• Install QtMobility APIs:Setting up environment for Qt Mobility API

Headers required

#include <qsysteminfo.h>

.pro file

Modify your .pro file as follows.

QT += core \
    gui \
    network
INCLUDEPATH += d:/qtmobility/src/systeminfo
INCLUDEPATH += D:/QtMobility/src/global
 
CONFIG += mobility
MOBILITY = systeminfo
symbian:TARGET.CAPABILITY = ReadDeviceData

Header file

/* GetDisplayInfo.h */
 
#ifndef GETDISPLAYINFO_H
#define GETDISPLAYINFO_H
 
#include <QtGui/QMainWindow>
#include <qsysteminfo.h>
 
QTM_USE_NAMESPACE;
 
class QListWidget;
class QScrollArea;
 
class GetDisplayInfo : public QMainWindow
{
    Q_OBJECT
 
public:
	GetDisplayInfo(QWidget *parent = 0);
    ~GetDisplayInfo();
 
private:
	void setWidgetGeometry(QSize* screenSize);
    void getDisplayInformation();
 
private:
    QSystemDisplayInfo* sysInfo;
	QListWidget     *listWidget;
	QScrollArea     *scrollArea;
};
 
#endif // GETDISPLAYINFO_H

Source file

/* GetDisplayInfo.cpp */
 
#include "GetDisplayInfo.h"
#include <QListWidget>
#include <QScrollArea>
 
GetDisplayInfo::GetDisplayInfo(QWidget *parent)
    : QMainWindow(parent)
{
	setWindowTitle("Get display information");
 
	/*The sysInfo becomes a child of the GetDisplayInfo, and will be destroyed when the GetDisplayInfo is deleted */
	sysInfo = new QSystemDisplayInfo(this);
 
	/* To show items in list view */
	listWidget = new QListWidget();
	listWidget->setObjectName(QString::fromUtf8("listWidget"));
 
	/* To make UI scrollable */
	scrollArea = new QScrollArea();
	setWidgetGeometry(&(size()));
 
	/* scrollArea takes ownership of the listWidget, so no need to delete it */
	scrollArea->setWidget(listWidget);
	scrollArea->setAlignment(Qt::AlignLeft);
	scrollArea->setWidgetResizable(true);
 
	/* QMainWindow takes ownership of the scrollArea, so no need to delete it */
	setCentralWidget(scrollArea);
	getDisplayInformation();
 
}
 
GetDisplayInfo::~GetDisplayInfo()
{
}
 
void GetDisplayInfo::setWidgetGeometry(QSize* screenSize)
{
	resize(*screenSize);
	QRect rect(0,0,screenSize->width(), screenSize->height());
	listWidget->setGeometry(rect);
}
 
void GetDisplayInfo::getDisplayInformation()
{
	QString infoStr;
 
	/* get color depth of screen */
	infoStr.setNum(sysInfo->colorDepth(0));
	infoStr.prepend("Color depth: ");
	listWidget->addItem(infoStr);
 
	/* get display brightness of screen */
	infoStr.clear();
	infoStr.setNum(sysInfo->displayBrightness(0));
	infoStr.prepend("Display brightness: ");
	listWidget->addItem(infoStr);
}

Postconditions

The code snippet is expected to read display information from device and show it on screen.

Download Code Example

• Working Code Example is available to download from here.

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