andlabs-ui/redo/common_windows.go

37 lines
971 B
Go

// 12 july 2014
package ui
import (
"fmt"
"syscall"
"unsafe"
)
// #include "winapi_windows.h"
import "C"
//export xpanic
func xpanic(msg *C.char, lasterr C.DWORD) {
panic(fmt.Errorf("%s: %s", C.GoString(msg), syscall.Errno(lasterr)))
}
//export xmissedmsg
func xmissedmsg(purpose *C.char, f *C.char, uMsg C.UINT) {
panic(fmt.Errorf("%s window procedure message %d does not return a value (bug in %s)", C.GoString(purpose), uMsg, C.GoString(f)))
}
func toUTF16(s string) C.LPCWSTR {
return C.LPCWSTR(unsafe.Pointer(syscall.StringToUTF16Ptr(s)))
}
func getWindowText(hwnd C.HWND) string {
// WM_GETTEXTLENGTH and WM_GETTEXT return the count /without/ the terminating null character
// but WM_GETTEXT expects the buffer size handed to it to /include/ the terminating null character
n := C.getWindowTextLen(hwnd)
buf := make([]uint16, int(n + 1))
C.getWindowText(hwnd, C.WPARAM(n),
C.LPCWSTR(unsafe.Pointer(&buf[0])))
return syscall.UTF16ToString(buf)
}