andlabs-ui/redo/common_windows.go

73 lines
1.9 KiB
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 toUINT16(s string) C.LPCWSTR {
return C.LPCWSTR(unsafe.Pointer(syscall.StringToUTF16(s)))
}
func getWindowText(hwnd uintptr) 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 := f_SendMessageW(hwnd, c_WM_GETTEXTLENGTH, 0, 0)
buf := make([]uint16, int(n + 1))
if f_SendMessageW(hwnd, c_WM_GETTEXT,
t_WPARAM(n + 1), t_LPARAM(uintptr(unsafe.Pointer(&buf[0])))) != n {
panic(fmt.Errorf("WM_GETTEXT did not copy exactly %d characters out", n))
}
return syscall.UTF16ToString(buf)
}
func setWindowText(hwnd uintptr, text string, errors []t_LRESULT) {
res := f_SendMessageW(hwnd, c_WM_SETTEXT,
0, t_LPARAM(uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(text)))))
for _, err := range errors {
if res == err {
panic(fmt.Errorf("WM_SETTEXT failed; error code %d", res))
}
}
}
func updateWindow(hwnd uintptr, caller string) {
res, err := f_UpdateWindow(hwnd)
if res == 0 {
panic(fmt.Errorf("error calling UpdateWindow() from %s: %v", caller, err))
}
}
func storelpParam(hwnd uintptr, lParam t_LPARAM) {
var cs *s_CREATESTRUCTW
cs = (*s_CREATESTRUCTW)(unsafe.Pointer(uintptr(lParam)))
f_SetWindowLongPtrW(hwnd, c_GWLP_USERDATA, cs.lpCreateParams)
}
func (w t_WPARAM) HIWORD() uint16 {
u := uintptr(w) & 0xFFFF0000
return uint16(u >> 16)
}
func (w t_WPARAM) LOWORD() uint16 {
u := uintptr(w) & 0x0000FFFF
return uint16(u)
}