Development/Tutorials/Programming Tutorial KDE 4/Using KConfig

 

Warning
The subject matter that I was going to cover in this tutorial is already covered in Development/Tutorials/KConfig and so this tutorial will probably be removed.

Abstract

Author: Fabian Korak

Author: Matt Williams(presets)

In this tutorial, we're going to be showing you how to utilise KConfig XT in an application. It is recommended that you read Development/Tutorials/Using KConfig XT before continuing in order to familiarise yourself with the framework.

Prerequisites

• Tutorial 3 - KActions

• Development/Tutorials/Using_KConfig_XT

KConfig XT

At first we make new File called tutorial4.kcfg within the source directory of your project.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE kcfg SYSTEM "http://www.kde.org/standards/kcfg/1.0/kcfg.xsd">
<kcfg>
	<kcfgfile name="kjotsrc"/>
	<include>kglobalsettings.h</include>
	<group name="kjots">
		<entry name="showAction" type="Bool">
			<label>Whether setupAction is called</label>
			<default>true</default>
		</entry>
	</group>
</kcfg> 
</code>
 
This code makes a setting of the type bool, which determines whether we want to do something. Then we set the default value to be true.
 
'''Always start the value of <entry name=""> in lower case since KConfig XT sets them to lower case within the generated headers either way. If you don't this could give you some nearly untraceable errors'''
 
Now we make a new File called tutorial4.kcfgc.
 
<syntaxhighlight lang="ini">
File=tutorial4.kcfg
ClassName=tutorial4
Singleton=true
Mutators=true
</code>
 
This should set up your configuration for now.
 
==The Code==
===mainwindow.h===
<syntaxhighlight lang="cpp-qt" line>
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
 
#include <KXmlGuiWindow>
#include <KTextEdit>
 
 
class MainWindow : public KXmlGuiWindow
{
 
	public:
		MainWindow(QWidget *parent=0);
	private:
		KTextEdit* textArea;
		void setupActions();
		void setupConfig();
		void readConfig();
		void saveSettings();
		int m_showAction;
 
};
 
#endif
 
 
</code>
 
There are some new voids in here, as well as m_showAction witch determines the value stored in KConfig XT. Despite that value being a bool we can actually use an integer here, since the type is converted either way.
 
===mainwindow.cpp===
<syntaxhighlight lang="cpp-qt" line>
#include "mainwindow.h"
#include "tutorial4.h"
 
#include <KApplication>
#include <KAction>
#include <KLocale>
#include <KActionCollection>
#include <KStandardAction>
#include <KConfigDialog>
 
MainWindow::MainWindow(QWidget *parent) : KXmlGuiWindow(parent)
{
 
	textArea = new KTextEdit;
	setCentralWidget(textArea);
	setupConfig();
}
 
void MainWindow::setupActions()
{
 
	QAction* clearAction = actionCollection()->addAction( "clear" );
 
	clearAction->setText(i18n("Clear"));
	clearAction->setIcon(KIcon("filenew"));
	clearAction->setShortcut(Qt::CTRL+ Qt::Key_W);
 
	connect(clearAction, SIGNAL(triggered(bool)), textArea, SLOT(clear()));
 
	KStandardAction::quit(kapp, SLOT(quit()), actionCollection());
 
	setupGUI();
 
}
 
void MainWindow::setupConfig()
{
	readConfig();	
 
 
}
 
void MainWindow::readConfig() {
	m_showAction    = tutorial4::showAction();
	if(m_showAction = (true)) 
		setupActions();
 
}
 
void MainWindow::saveSettings() { 
	tutorial4::setShowAction(m_showAction);
	tutorial4::self()->writeConfig();
}
 
 
 
</code>
 
At first we import "tutorial4.h", which should be auto-generated at runtime by KConfig XT every time you compile this. MainWindow and SetupActions are copied from the tutorials before. The only thing new is that we now call a new void called setupConfig. This then calls readConfig. We '''could''' also call saveSettings(but only after we called readConfig), but since we don't change any values there this is more of a "proof of concept".
 
Within readConfig we assign m_showAction the value of the setting showAction. If this returns true setupsActions makes buttons and all that. When false it doesn't.
 
The setShowActions() in saveSettings() overwrites showAction with a value of your choice, in this case with itself. Then you need to call writeConfig() to apply the changes you made.
 
===main.cpp===
<syntaxhighlight lang="cpp-qt" line>
 
#include "mainwindow.h"
 
 
#include <KApplication>
#include <KAboutData>
#include <KCmdLineArgs>
 
int main (int argc, char *argv[])
{
	KAboutData aboutData( "tutorial4", "tutorial4",
			      "0.4", "KMessageBox popup",
	 KAboutData::License_GPL, "(c) 2007" );
	KCmdLineArgs::init( argc, argv, &aboutData );
 
	KApplication app;
 
	MainWindow* window = new MainWindow();
	window->show();
 
	return app.exec();
 
}
</code>
 
No news in here
 
===tutorial4ui.rc===
<code xml n>
<?xml version="1.0" encoding="UTF-8"?>
<gui name="tutorial4"
     version="1"
     xmlns="http://www.kde.org/standards/kxmlgui/1.0"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://www.kde.org/standards/kxmlgui/1.0
                         http://www.kde.org/standards/kxmlgui/1.0/kxmlgui.xsd" >
 
  <MenuBar>
    <Menu name="file" >
      <text>&amp;File</text>
      <Action name="clear" />
    </Menu>
  </MenuBar>
 
  <ToolBar name="mainToolBar" >
    <text>Main Toolbar</text>
    <Action name="clear" />
  </ToolBar>
 
</gui>
 
</code>
 
==CMake==
===CMakeLists.txt===
<code ini n>
PROJECT(tutorial4)
 
FIND_PACKAGE(KDE4 REQUIRED)
INCLUDE_DIRECTORIES( ${KDE4_INCLUDES} ${CMAKE_CURRENT_BINARY_DIR})
 
SET(tutorial4_SRCS 
  main.cpp
  mainwindow.cpp
)
 
KDE4_ADD_KCFG_FILES(tutorial4_SRCS settings.kcfgc)
 
KDE4_ADD_EXECUTABLE(tutorial4 ${tutorial4_SRCS})
 
TARGET_LINK_LIBRARIES( tutorial4 ${KDE4_KDEUI_LIBS})
 
install( TARGETS tutorial4 DESTINATION ${BIN_INSTALL_DIR})
install( FILES tutorial4ui.rc DESTINATION  ${DATA_INSTALL_DIR}/tutorial4)
install( FILES tutorial4.kcfg  DESTINATION  ${KCFG_INSTALL_DIR} )
</code>
 
==Moving On==
 
For a better understanding of the XML used in KConfig XT you could try 
[[Development/Tutorials/Programming_Tutorial_KDE_4/How_to_write_an_XML_parser|to write an Xml Parser]]