// 28 february 2014

package ui

import (
	"unsafe"
)

// #cgo LDFLAGS: -lobjc -framework Foundation
// #include <stdlib.h>
// #include "objc_darwin.h"
// /* cgo doesn't like Nil */
// Class NilClass = Nil;
import "C"

func objc_getClass(class string) C.id {
	cclass := C.CString(class)
	defer C.free(unsafe.Pointer(cclass))

	return C.objc_getClass(cclass)
}

func sel_getUid(sel string) C.SEL {
	csel := C.CString(sel)
	defer C.free(unsafe.Pointer(csel))

	return C.sel_getUid(csel)
}

// Common Objective-C types and selectors.
var (
	_NSObject = objc_getClass("NSObject")
	_NSString = objc_getClass("NSString")

	_alloc = sel_getUid("alloc")
	_new = sel_getUid("new")
	_release = sel_getUid("release")
	_stringWithUTF8String = sel_getUid("stringWithUTF8String:")
	_UTF8String = sel_getUid("UTF8String")
)

func toNSString(str string) C.id {
	cstr := C.CString(str)
	defer C.free(unsafe.Pointer(cstr))

	return C.objc_msgSend_str(_NSString,
		_stringWithUTF8String,
		cstr)
}

func fromNSString(str C.id) string {
	cstr := C.objc_msgSend_noargs(str, _UTF8String)
	return C.GoString((*C.char)(unsafe.Pointer(cstr)))
}

// These consolidate the NSScrollView code (used by listbox_darwin.go and area_darwin.go) into a single place.

var (
	_NSScrollView = objc_getClass("NSScrollView")

	_setHasHorizontalScroller = sel_getUid("setHasHorizontalScroller:")
	_setHasVerticalScroller = sel_getUid("setHasVerticalScroller:")
	_setAutohidesScrollers = sel_getUid("setAutohidesScrollers:")
	_setDocumentView = sel_getUid("setDocumentView:")
	_documentView = sel_getUid("documentView")
)

func newScrollView(content C.id) C.id {
	scrollview := C.objc_msgSend_noargs(_NSScrollView, _alloc)
	scrollview = initWithDummyFrame(scrollview)
	C.objc_msgSend_bool(scrollview, _setHasHorizontalScroller, C.BOOL(C.YES))
	C.objc_msgSend_bool(scrollview, _setHasVerticalScroller, C.BOOL(C.YES))
	C.objc_msgSend_bool(scrollview, _setAutohidesScrollers, C.BOOL(C.YES))
	C.objc_msgSend_id(scrollview, _setDocumentView, content)
	return scrollview
}

func getScrollViewContent(scrollview C.id) C.id {
	return C.objc_msgSend_noargs(scrollview, _documentView)
}