menu.go

/*
与菜单有关的函数

AppendMenu
CheckMenuItem
CheckMenuRadioItem
CreateMenu
CreatePopupMenu
DeleteMenu
DestroyMenu
DrawMenuBar
EnableMenuItem
EndMenu
GetMenu
GetMenuBarInfo
GetMenuCheckMarkDimensions
GetMenuDefaultItem
GetMenuInfo
GetMenuItemCount
GetMenuItemID
GetMenuItemInfo
GetMenuItemRect
GetMenuState
GetMenuString
GetSubMenu
GetSystemMenu
HiliteMenuItem
InsertMenu
InsertMenuItem
IsMenu
LoadMenu
LoadMenuIndirect
MenuItemFromPoint
ModifyMenu
RemoveMenu
SetMenu
SetMenuDefaultItem
SetMenuInfo
SetMenuItemBitmaps
SetMenuItemInfo
TrackPopupMenu
TrackPopupMenuEx

*/

package winapi

import (
	"errors"
	"syscall"
	"unsafe"
)

const (
	MF_INSERT = 0x00000000
	MF_CHANGE = 0x00000080
	MF_APPEND = 0x00000100
	MF_DELETE = 0x00000200
	MF_REMOVE = 0x00001000

	MF_BYCOMMAND  = 0x00000000
	MF_BYPOSITION = 0x00000400

	MF_SEPARATOR = 0x00000800

	MF_ENABLED  = 0x00000000
	MF_GRAYED   = 0x00000001
	MF_DISABLED = 0x00000002

	MF_UNCHECKED       = 0x00000000
	MF_CHECKED         = 0x00000008
	MF_USECHECKBITMAPS = 0x00000200

	MF_STRING    = 0x00000000
	MF_BITMAP    = 0x00000004
	MF_OWNERDRAW = 0x00000100

	MF_POPUP        = 0x00000010
	MF_MENUBARBREAK = 0x00000020
	MF_MENUBREAK    = 0x00000040

	MF_UNHILITE = 0x00000000
	MF_HILITE   = 0x00000080

	MF_DEFAULT = 0x00001000

	MF_SYSMENU      = 0x00002000
	MF_HELP         = 0x00004000
	MF_RIGHTJUSTIFY = 0x00004000

	MF_MOUSESELECT = 0x00008000
	MF_END         = 0x00000080 // Obsolete -- only used by old RES files
)

func AppendMenu(hMenu HMENU, Flags uint32, IdNewItem uintptr, NewItem string) error {
	var err error
	var pNewItem *uint16

	if NewItem != "" {
		pNewItem, err = syscall.UTF16PtrFromString(NewItem)
		if err != nil {
			return err
		}
	}

	return _AppendMenu(hMenu, Flags, IdNewItem, pNewItem)
}

func _AppendMenu(hMenu HMENU, Flags uint32, IdNewItem uintptr, NewItem *uint16) (err error) {
	r1, _, e1 := syscall.Syscall6(procAppendMenu.Addr(), 4,
		uintptr(hMenu), uintptr(Flags), IdNewItem, uintptr(unsafe.Pointer(NewItem)),
		0, 0)
	if r1 == 0 {
		wec := WinErrorCode(e1)
		if wec != 0 {
			err = wec
		} else {
			err = errors.New("winapi: AppendMenu failed.")
		}
	}
	return
}

func CreateMenu() (hMenu HMENU, err error) {
	r1, _, e1 := syscall.Syscall(procCreateMenu.Addr(), 0, 0, 0, 0)
	if r1 == 0 {
		wec := WinErrorCode(e1)
		if wec != 0 {
			err = wec
		} else {
			err = errors.New("winapi: CreateMenu failed.")
		}
	} else {
		hMenu = HMENU(r1)
	}
	return
}

func CreatePopupMenu() (hMenu HMENU, err error) {
	r1, _, e1 := syscall.Syscall(procCreatePopupMenu.Addr(), 0, 0, 0, 0)
	if r1 == 0 {
		wec := WinErrorCode(e1)
		if wec != 0 {
			err = wec
		} else {
			err = errors.New("winapi: CreatePopupMenu failed.")
		}
	} else {
		hMenu = HMENU(r1)
	}
	return
}

func DestroyMenu(hMenu HMENU) (err error) {
	r1, _, e1 := syscall.Syscall(procDestroyMenu.Addr(), 1, uintptr(hMenu), 0, 0)
	if r1 == 0 {
		wec := WinErrorCode(e1)
		if wec != 0 {
			err = wec
		} else {
			err = errors.New("winapi: DestroyMenu failed.")
		}
	}
	return
}