// 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 xpanichresult func xpanichresult(msg *C.char, hresult C.HRESULT) { panic(fmt.Errorf("%s; HRESULT: 0x%X", C.GoString(msg), hresult)) } //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.LPWSTR { return C.LPWSTR(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.LPWSTR(unsafe.Pointer(&buf[0]))) return syscall.UTF16ToString(buf) }