init {
	screenTemplates := {
				"000": {"widgets": {"001": {"type": "textInput", "text": "", "visible": true}, 
									"002": {"type": "button", "text": "Next", "visible": true}}, 
						"layout": true},
				"001": {"widgets": {"003": {"type": "label", "text": "label", "visible": true}, 
									"004": {"type": "button", "text": "Back", "visible": true}}, 
						"layout": true}
				}
}

native channel ScreenUpdate {
	in screen(curSc: Json, update(curSc, nextSc)) = nextSc
}

native channel SetLayout {
	in screen.layout(curLayout: Bool, setLayout(nextLayout)) = nextLayout
}

native channel SetVisible(wid: Str) {
	in screen.widgets.{wid}.visible(curVisible: Bool, setVisible(nextVisible)) = nextVisible
}

native channel SetText(wid: Str) {
	in screen.widgets.{wid}.text(curText: Str, setText(nextText)) = nextText
}

native channel SetX(wid: Str) {
	in screen.widgets.{wid}.x(curX: Int, setX(nextX)) = nextX
}

native channel SetY(wid: Str) {
	in screen.widgets.{wid}.y(curY: Int, setY(nextY)) = nextY
}

native channel SetWidth(wid: Str) {
	in screen.widgets.{wid}.width(curWidth: Int, setWidth(nextWidth)) = nextWidth
}

native channel SetHeight(wid: Str) {
	in screen.widgets.{wid}.height(curHeight: Int, setHeight(nextHeight)) = nextHeight
}

native channel MouseEvent(wid: Str) {
	out screen.widgets.{wid}.state(curState: Int, mouseEvent(nextState)) = nextState
}

native channel TextEvent(wid: Str) {
	out screen.widgets.{wid}.text(curText: Str, textEvent(nextText)) = nextText
}

channel ChangeCurScreen {
	out curScreen(curScId: Str, changeCurScreen(nextScId)) = nextScId
}

channel ScreenTransition {
	in curScreen(curScId: Str, transScreen(nextScId, screen)) = nextScId
	ref screenTemplates.{nextScId}(screen, transScreen(nextScId, screen))
	out screen(curS, transScreen(nextScId, screen)) = screen
}

channel EventHandler1(wid: Str) {
	in screen.widgets.{wid="002"}.state(curState: Int, handleEvent1(nextState)) = nextState
	out curScreen(curScId: Str, handleEvent1(nextState)) = if((curScId == "000") && (nextState == 0), "001", curScId)
}

channel EventHandler2(wid: Str) {
	in screen.widgets.{wid="004"}.state(curState: Int, handleEvent2(nextState)) = nextState
	out curScreen(curScId: Str, handleEvent2(nextState)) = if((curScId == "001") && (nextState == 0), "000", curScId)
}

channel ChangeLayout {
	out screen.layout(curLayout: Bool, changeLayout(layout)) = layout
}

channel ChangeX(wid: Str) {
	out screen.widgets.{wid}.x(curX: Int, changeX(x)) = x
}

channel ChangeY(wid: Str) {
	out screen.widgets.{wid}.y(curY: Int, changeY(y)) = y
}

channel AddButton {
	out screen.widgets(widgets: Map, addButton(wid: Str, text: Str)) = insert(widgets, wid, {"type": "button", "text": text, "state": 0})
}

channel AddLabel {
	out screen.widgets(widgets: Map, addLabel(wid: Str, text: Str)) = insert(widgets, wid, {"type": "label", "text": text, "state": 0})
}

channel AddTextInput {
	out screen.widgets(widgets: Map, addTextInput(wid: Str)) = insert(widgets, wid, {"type": "textInput", "text": "", "state": 0})
}

channel AddMovableButton {
	out screen.widgets(widgets: Map, addMovableButton(wid: Str, text: Str, x: Int, y: Int, width: Int, height: Int)) = insert(widgets, wid, {"type": "button", "text": text, "x": x, "y": y, "width": width, "height": height, "state": 0})
}

channel AddMovableLabel {
	out screen.widgets(widgets: Map, addMovableLabel(wid: Str, text: Str, x: Int, y: Int, width: Int, height: Int)) = insert(widgets, wid, {"type": "label", "text": text, "x": x, "y": y, "width": width, "height": height, "state": 0})
}

channel AddMovableTextInput {
	out screen.widgets(widgets: Map, addMovableTextInput(wid: Str, x: Int, y: Int, width: Int, height: Int)) = insert(widgets, wid, {"type": "textInput", "text": "", "x": x, "y": y, "width": width, "height": height, "state": 0})
}