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

<syntaxhighlight lang="cpp-qt" line>

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

<syntaxhighlight lang="cpp-qt" line>

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

<syntaxhighlight lang="cpp-qt" line>

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 the heap. After creating document() and view(), the GUI definitions are loaded from editorui.rc. The call guiFactory()->addClient(m_view) adds the kate parts menue and toolbar definitions to MainWindow. After that a full featured texteditor with syntax highlighting etc. is available for your application.

MainWindow::setupAction() defines three additional actions.

editorui.rc

<!DOCTYPE kpartgui SYSTEM "kpartgui.dtd"> <kpartgui name="editor" version="1">

<MenuBar>

 <Menu name="file" noMerge="1"><text>&File</text>

   <Action name="file_open" />
   <DefineGroup name="save_merge" append="save_merge" />
   <Separator/>

   <DefineGroup name="revert_merge" append="revert_merge"/>
   <DefineGroup name="print_merge" append="print_merge"/>
   <Separator/>

   <Action name="file_quit"/>
 </Menu>
 <Merge />

</MenuBar>

<ToolBar name="mainToolBar" noMerge="1"><text>Main Toolbar</text>

 <Action name="file_open" />
 <DefineGroup name="file_operations" />
 <Separator />
 <DefineGroup name="print_merge" />
 <Separator />
 <Action name="file_close" />
 <Separator />
 <DefineGroup name="edit_operations" />
 <Separator />
 <DefineGroup name="find_operations" />
 <Separator />
 <DefineGroup name="zoom_operations" />

</ToolBar>

<Menu name="ktexteditor_popup" noMerge="1">

 <DefineGroup name="popup_operations" />

</Menu>

</kpartgui>

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)