Development/Tutorials/Kate/KTextEditor Example

Abstract

We build a small application using KTexteditor. This example supports syntax highlighting and other useful features. We see how to use KTextEditor.

The Code

main.cpp

1. include <KApplication>
2. include <KAboutData>
3. include <KCmdLineArgs>

1. include "mainwindow.h"

int main (int argc, char *argv[]) {

 KAboutData aboutData( "editor", "editor",
     ki18n("Editor"), "1.0",
     ki18n("A simple text area which can load and save."),
     KAboutData::License_GPL,
     ki18n("Copyright (c) 2007 Developer") );
 KCmdLineArgs::init( argc, argv, &aboutData );
 KApplication app;

 MainWindow* window = new MainWindow();
 window->show();
 return app.exec();

}

In main.cpp just defines aboutData and app and shows Mainwindow.

mainwindow.h

1. ifndef MAINWINDOW_H
2. define MAINWINDOW_H

1. include <KParts/MainWindow>
2. include <QtGui/QKeyEvent>

namespace KTextEditor {

 class Document;
 class View;

}

class MainWindow : public KParts::MainWindow {

 Q_OBJECT
 
 public:
   MainWindow(QWidget *parent=0);
 
 private slots:
   void clear();
   void openFile();

 private:
   void setupActions();
   KTextEditor::View *m_view;
   KTextEditor::Document *m_doc;

};

1. endif

Class MainWindow is a successor of KXmlGuiWindow and contains KTextEditor (document and view) as a private Variable. There are also some useful methods defined.

mainwindow.cpp

1. include "mainwindow.h"

1. include <KApplication>
2. include <KAction>
3. include <KLocale>
4. include <KActionCollection>
5. include <KStandardAction>
6. include <KFileDialog>
7. include <KMessageBox>
8. include <KIO/NetAccess>
9. include <KSaveFile>
10. include <QTextStream>
11. include <KXMLGUIFactory>

1. include <KTextEditor/Document>
2. include <KTextEditor/View>
3. include <KTextEditor/Editor>
4. include <KTextEditor/EditorChooser>

MainWindow::MainWindow(QWidget *) {

 KTextEditor::Editor *editor = KTextEditor::EditorChooser::editor();

 if (!editor) {
   KMessageBox::error(this, i18n("A KDE text-editor component could not be found;\n"

"please check your KDE installation."));

   kapp->exit(1);
 }

 m_doc = editor->createDocument(0);
 m_view = qobject_cast<KTextEditor::View*>(m_doc->createView(this));

 setCentralWidget(m_view);
 setupActions();

 setXMLFile("editorui.rc");
 createShellGUI(true);

 guiFactory()->addClient(m_view);

 show ();

}

void MainWindow::setupActions() {

 KStandardAction::quit(kapp, SLOT(quit()), actionCollection());
 KStandardAction::open(this, SLOT(openFile()), actionCollection());
 KStandardAction::clear(this, SLOT(clear()), actionCollection());

}

void MainWindow::clear() {

 m_doc->clear();

}

void MainWindow::openFile() {

 m_view->document()->openUrl(KFileDialog::getOpenFileName());

}

The implementation is straight forward and self-explanatory. Some remarks

MainWindow::Mainwindow() First the editor component is created on heap. After creating document() and view() MainWindows GUI definition is loaded from editorui.rc. Call guiFactory()->addClient(m_view) adds kate parts menue and toolbar definitions to MainWindow. After that a full featured texteditor with syntax highlighting etc. is available in your application.

MainWindow::setupAction() Defines three additional actions.

editorui.rc

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE kpartgui SYSTEM "kpartgui.dtd"> <gui name="editor" version="1">

 <ToolBar name="mainToolBar" >
   <text>Main Toolbar</text>
   <Action name="clear" />
 </ToolBar>
 <MenuBar>
   <Menu name="file" >
     <Action name="clear" />
   </Menu>
 </MenuBar>

</gui>

CMakeLists.txt

project(editor)

find_package(KDE4 REQUIRED) include_directories(${KDE4_INCLUDES})

set(editor_SRCS

 main.cpp
 mainwindow.cpp

)

kde4_add_executable(editor ${editor_SRCS})

target_link_libraries(editor ${KDE4_KDEUI_LIBS}

                            ${KDE4_KIO_LIBS}
                            ${KDE4_KTEXTEDITOR_LIBS})

install(TARGETS editor DESTINATION ${BIN_INSTALL_DIR}) install(FILES editorui.rc

       DESTINATION ${DATA_INSTALL_DIR}/editor)