User:Dipesh/Kross-Tutorial

Warning

This section needs improvements: Please help us to

cleanup confusing sections and fix sections which contain a todo

• Kross Overview
• Kross Homepage

Intro

The purpose of this tutorial is to offer a step-by-step introduction how to integrate Kross into your application. While you can integrate Kross also in non-kpartified applications, it's easier to do with the KPart system. This tutorial will assume that you have a kpart application and what we will do is to go step by step through the process of creating a KPart plugin that integrates into your application and provides all the scripting. The scripting functionality is strictly separated from the application. The plugin that implements scripting is optional and the application does not need to know any details about what the plugin does.

This tutorial needs kdelibs4 based on Qt 4.2. While Kross and the KDE Javascript backend are included in kdelibs4, it is needed to compile the KOffice2 libraries to install the Ruby and Python support (will be moved to kdebindings soon).

The whole sourcecode we will produce within this tutorial could also be downloaded as kross2tutorial.tar.gz and contains all files needed to build a simple example that demonstrates how Kross could be used. Download and extract the tarball. Compile, install and run the kross2tutorialapp application and its kross2tutorial KPart plugin now with;

cd src && mkdir _build && cd _build
cmake -DCMAKE_INSTALL_PREFIX=`kde4-config --prefix` ..
make
sudo make install
./kross2tutorialapp

For additional examples where Kross is used you may also like to look at;

• KWord Scripting
• KSpread Scripting
• Krita Scripting

The application

This section deals with the question how to integrate Kross into a KPart-application to be able to extend your application with scripting.

For testing purposes we first create a simple KPart application. If you already have an application you may like to skip this section and continue with the KPart Plugin.

Relevant files within the kross2tutorial.tar.gz are;

• src directory
  • CMakeLists.txt for the cmake build system
  • main.cpp create the KApplication and show the MainWindow
  • mainwindow.h and mainwindow.cpp contains the top-level KParts::MainWindow implementation.
  • plugin directory
    • CMakeLists.txt for the cmake build system
    • module.h and module.cpp implements the "KrossModuleTutorial" module
    • part.h and part.cpp implements a KParts::ReadWritePart

The CMake build system

The src/CMakeLists.txt file;

project(kross2tutorial)

find_package(KDE4 REQUIRED)
include(KDE4Defaults)
find_package(Perl REQUIRED)
add_definitions(${QT_DEFINITIONS}
  ${KDE4_DEFINITIONS} -DHAVE_CONFIG_H=1)
link_directories(${KDE4_LIB_DIR})
set(CMAKE_REQUIRED_DEFINITIONS
  ${_KDE4_PLATFORM_DEFINITIONS})
include_directories(${CMAKE_SOURCE_DIR}
  ${KDE4_KDECORE_INCLUDES} ${KDE4_INCLUDES}
  ${KDE4_KDEUI_INCLUDES}
  ${KDE4_KPARTS_INCLUDES})

add_subdirectory( plugin )

set(kross2tutorialapp_SRCS
  mainwindow.cpp main.cpp)
kde4_automoc(${kross2tutorialapp_SRCS})
kde4_add_executable(kross2tutorialapp
  ${kross2tutorialapp_SRCS})
target_link_libraries(kross2tutorialapp
  ${KDE4_KDECORE_LIBS} ${KDE4_KDEUI_LIBS}
  kparts krosscore )

The src/plugin/CMakeLists.txt file;

include_directories(${CMAKE_SOURCE_DIR}
  ${KROSS_INCLUDES})
set(krossmoduletutorial_PART_SRCS
  module.cpp part.cpp)
kde4_automoc(${krossmoduletutorial_PART_SRCS})
kde4_add_plugin(krossmoduletutorial
  ${krossmoduletutorial_PART_SRCS})
target_link_libraries(krossmoduletutorial
  ${KDE4_KDECORE_LIBS} ${KDE4_KROSSCORE_LIBS}
  kparts )
install(TARGETS krossmoduletutorial
  DESTINATION ${PLUGIN_INSTALL_DIR})
install(FILES krossmoduletutorial.desktop
  DESTINATION ${SERVICES_INSTALL_DIR})

The KApplication

The main function (main.cpp) creates the KApplication and shows the MainWindow.

int main(int argc, char **argv) {
  KAboutData about();
  KCmdLineArgs::init(argc,argv,&about);
  KApplication app();
  MainWindow *mainWin = new MainWindow();
  mainWin->show();
  return app.exec();
}

The KPart main window

The MainWindow class (mainwindow.h mainwindow.cpp) contains the top-level KParts::MainWindow implementation.

class MainWindow
    : public KParts::MainWindow
{
  public:
    MainWindow()
      : KParts::MainWindow()
    {
      KLibFactory* factory =
        KLibLoader::self()->factory(
          "krossmoduletutorial");
      KParts::ReadWritePart* part =
        dynamic_cast<KParts::ReadWritePart*>
          ( factory->create(this) );
      part->openUrl(
        KUrl("file:///path/myscript.py"));
    }
    virtual ~MainWindow() {}
};

The plugin

The KPart plugin

The Part class (part.h part.cpp) implements a KParts::ReadWritePart.

class Part
  : public KParts::ReadWritePart
{
  public:
    Part(QWidget*, QObject* parent,
      const QStringList&)
      : KParts::ReadWritePart(parent)
      , m_guiclient(
          new Kross::GUIClient(this,this))
      , m_action(0) {}
    virtual ~Part() { delete m_action; }
    virtual bool openFile() {
      delete m_action;
      m_action = new Kross::Action(m_file);
      m_action->trigger();
    }
    virtual bool saveFile() {return false;}
  private:
    Kross::GUIClient* m_guiclient;
    Kross::Action* m_action;
};

The Module

The Module class (module.h module.cpp) implements the "KrossModuleTutorial" module.

class Module : public QObject {
  Q_OBJECT
  public:
    Module(Part* part=0)
      : QObject(part), m_widget(0) {}
    virtual ~Module() {}
  public slots:
    QWidget* widget() {
      if(m_widget) return m_widget;
      Part* part = 
        dynamic_cast<Part*>(parent());
      m_widget = new QWidget(
        part ? part->widget() : 0 );
      m_widget->setLayout(
        new QVBoxLayout(m_widget) );
      QWidget* w = 
        part ? part->widget() : 0;
      if(w && w->layout())
        w->layout()->addWidget(m_widget);
      m_widget->show();
      return m_widget;
    }
  private:
    QWidget* m_widget;
};

Samples

Following sample scripts are also included in the kross2tutorial.tar.gz and should be executed using the "kross2tutorialapp" application.

Python forms script

The sample_forms.py Python script demonstrates usage of into an application embedded Kross forms.

#!/usr/bin/env kross
import Kross
import KrossModuleTutorial
forms = Kross.module("forms")
w = KrossModuleTutorial.widget()
l = forms.createWidget(w,"QLabel")
l.wordWrap = True
l.text = "The labels text."
b = forms.createWidget(w,"QPushButton")
def buttonClicked():
  global forms
  forms.showMessageBox("Information",
    "Caption", "the message text")
b.connect("clicked()", buttonClicked)
b.text = "Show messagebox"

Python Tkinter script

The sample_tkinter.py Python script uses the Tkinter to show a modal dialog.

#!/usr/bin/env kross
class TkTest:
  def __init__(self):
    import Tkinter
    self.root = Tkinter.Tk()
    self.root.title("TkTest")
    self.root.deiconify()
    self.mainframe =
      Tkinter.Frame(self.root)
    self.mainframe.pack()
    self.button1 = Tkinter.Button(
      self.mainframe,
      text="Button1",
      command=self.callback1)
    self.button1.pack(side=Tkinter.LEFT)
    self.root.mainloop()
  def callback1(self):
    import tkMessageBox
    tkMessageBox.showinfo(
      "Callback1", "Callback1 called.")
TkTest()

Ruby forms script

The sample_forms.rb Ruby script uses the Kross forms module to create and embedded a QLabel instance.

#!/usr/bin/env kross
require 'Kross'
require 'KrossModuleTutorial'
forms = Kross.module("forms")
w = KrossModuleTutorial.widget()
l = forms.createWidget(w,"QLabel")
l.wordWrap = true
l.text = "Some labels text"

JavaScript with KjsEmbed script

The sample_kjsembed.js JavaScript script creates and embeddes a QFrame using KjsEmbed.

#!/usr/bin/env kross
w = KrossModuleTutorial.widget()
var f = new Widget("QFrame", w);
f.frameShape = f.StyledPanel;
f.frameShadow = f.Sunken;
f.lineWidth = 4;
f.show();