QtQuick approach for developing applications

import QtQuick 2.0
import QtQuick.Controls 1.0

ApplicationWindow {
    color: "#FFFFDF" // we declare rectangle with custom background color
    width:  400;
    height: 300;     // with custom size
    Text {
        anchors.centerIn: parent
        text: "Click me!"         // text in center of window
    }
    MouseArea {
        anchors.fill: parent      // all space in parent Rectangle will be clickable
        onClicked: console.log("clicked")
    }
}

let main () =
  print_endline "Startup initialization"

let () =
    run_with_QQmlApplicationEngine Sys.argv main "Root.qml"

[ {
  "classname": "Controller",
  "methods":
     [ { "name":      "onMouseClicked",
         "signature": ["string", "unit"] }
     ],
  "properties": [],
  "slots": [],
  "signals": []
} ]

class virtual base_Controller cppobj = object(self)
  ...
  method virtual onMouseClicked: string -> unit
end

open QmlContext

let main () =
  let controller_cppobj = Controller.create_Controller () in
  let controller = object(self)
    inherit Controller.base_Controller controller_cppobj as super
    method onMouseClicked msg = Printf.printf "OCaml says: '%s'\n%!" msg
  end in
  set_context_property ~ctx:(get_view_exn ~name:"rootContext") ~name:"controller" controller#handler

ApplicationWindow { // root rectangle
          ....
          MouseArea {
              anchors.fill: parent      // all space in parent Rectangle will be clickable
              onClicked: controller.onMouseClicked("message");
          }
}

ApplicationWindow {
    width: 1366
    height: 768
    menuBar: MenuBar {
        Menu {
            title: "Edit"

            MenuItem {
                text: "Cut";    shortcut: "Ctrl+X";
                onTriggered: console.log("")
            }
            MenuItem {
                text: "Copy";   shortcut: "Ctrl+C"
                onTriggered: console.log("")
            }
            MenuItem {
                text: "Paste";  shortcut: "Ctrl+V"
                onTriggered: console.log("")
            }
        }
    }
    ....
}

    toolBar: ToolBar {
        RowLayout {
            anchors.margins: 8
            anchors.fill: parent
            ToolButton {
                text: "Press me"
                onClicked: console.log("Press me clicked")
            }
        }
    }

    ListModel {
        id: libraryModel
        ListElement{ title: "A Masterpiece" ; author: "Gabriel" }
        ListElement{ title: "Brilliance"    ; author: "Jens" }
        ListElement{ title: "Outstanding"   ; author: "Frederik" }
    }

    TableView {
        model: libraryModel
        anchors.fill: parent

        TableViewColumn { title: "Title";  role: "title"  }
        TableViewColumn { title: "Author"; role: "author" }
    }

{
    "classname": "MainModel",
    "basename":  "QAbstractItemModel",
    "methods": [],
    "properties": [],
    "slots": [],
    "signals": []
}

{
    "classname": "DataItem",
    "methods": [],
    "properties":
      [ { "name":      "author",
          "get":       "author",
          "set":       "setName",
          "notify":    "nameChanged",
          "type":      "string" }
      , { "name":      "title",
          "get":       "title",
          "set":       "setTitle",
          "notify":    "titleChanged",
          "type":      "string" }
      ],
    "slots": [],
    "signals": []
}

  let data =
    [ ("Анна Каренина",           "Лев Толстой")
    ; ("Война и Мир",             "Лев Толстой")
    ; ("Les Misérables",          "Victor Hugo")
    ; ("Les Trois Mousquetaires", "Alexandre Dumas, père")
    ] in

  let dataItems = List.map (fun (title,author) ->
    let cppobj = DataItem.create_DataItem () in
    object
      inherit DataItem.base_DataItem cppobj as super
      method author () = author
      method title () = title
    end
  ) data in

  let model_cppobj = MainModel.create_MainModel () in
  MainModel.add_role model_cppobj 555 "someRoleName";

  let model = object(self)
    inherit MainModel.base_MainModel model_cppobj as super
    method parent _ = QModelIndex.empty
    method columnCount _ = 1
    method index row column parent =
      if (row>=0 && row self#rowCount parent) then QModelIndex.make ~row ~column:0
      else QModelIndex.empty
    method rowCount _ = List.length dataItems
    ...

    ...
    method data index role =
      let r = QModelIndex.row index in
      if (r<0 || r>= List.length data) then QVariant.empty
      else begin
        match role with
          | 0 | 555 -> QVariant.of_object (List.nth dataItems r)#handler
          | _ -> QVariant.empty
      end
  end in
  set_context_property ~ctx:(get_view_exn ~name:"rootContext")
    ~name:"mainModel" model#handler