static size_t nextrunetext(const char *text, size_t position, int inc){	ssize_t n; 	/* return location of next utf8 rune in the given direction (+1 or -1) */	for (n = position + inc; n + inc >= 0 && (text[n] & 0xc0) == 0x80; n += inc)		;	return n;} /* return bytes from beginning of text to nth utf8 rune to the right */static size_t runebytes(const char *text, size_t n){	size_t ret; 	ret = 0;	while (n-- > 0)		ret += nextrunetext(text + ret, 0, 1);	return ret;} /* return number of characters from beginning of text to nth byte to the right */static size_t runechars(const char *text, size_t n){	size_t ret, i; 	ret = i = 0;	while (i < n) {		i += nextrunetext(text + i, 0, 1);		ret++;	}	return ret;} /* move caret on pre-edit text */static void preeditcaret(XIC xic, XPointer clientdata, XPointer calldata){	XIMPreeditCaretCallbackStruct *pcaret; 	(void)xic;	pcaret = (XIMPreeditCaretCallbackStruct *)calldata;	if (!pcaret)		return;	switch (pcaret->direction) {	case XIMForwardChar:		cursor = nextrune(+1);		break;	case XIMBackwardChar:		cursor = nextrune(-1);		break;	case XIMForwardWord:		movewordedge(+1);		break;	case XIMBackwardWord:		movewordedge(-1);		break;	case XIMLineStart:		cursor = 0;		break;	case XIMLineEnd:		if (preview[cursor] != '\0')			cursor = strlen(preview);		break;	case XIMAbsolutePosition:		cursor = runebytes(text, pcaret->position);		break;	case XIMDontChange:		/* do nothing */		break;	case XIMCaretUp:	case XIMCaretDown:	case XIMNextLine:	case XIMPreviousLine:		/* not implemented */		break;	}	pcaret->position = runechars(preview, cursor);} /* start input method pre-editing */static int preeditstart(XIC xic, XPointer clientdata, XPointer calldata){	(void)xic;	(void)calldata;	(void)clientdata;	composing = 1;	printf("PREEDIT\n");	return BUFSIZ;} /* end input method pre-editing */static void preeditdone(XIC xic, XPointer clientdata, XPointer calldata){	(void)xic;	(void)clientdata;	(void)calldata;	printf("DONE\n"); 	composing = 0;} /* draw input method pre-edit text */static void preeditdraw(XIC xic, XPointer clientdata, XPointer calldata){	XIMPreeditDrawCallbackStruct *pdraw;	size_t beg, dellen, inslen, endlen; 	printf("DRAW\n"); 	(void)xic;	pdraw = (XIMPreeditDrawCallbackStruct *)calldata;	if (!pdraw)		return; 	/* we do not support wide characters */	if (pdraw->text && pdraw->text->encoding_is_wchar == True) {		fputs("warning: wchar is not supportecd; use utf8", stderr);		return;	} 	beg = runebytes(text, pdraw->chg_first);	dellen = runebytes(preview + beg, pdraw->chg_length);	inslen = pdraw->text ? runebytes(pdraw->text->string.multi_byte, pdraw->text->length) : 0;	endlen = 0;	if (beg + dellen < strlen(preview))		endlen = strlen(preview + beg + dellen); 	/* we cannot change text past the end of our pre-edit string */ 	if (beg + dellen >= BUFSIZ || beg + inslen >= BUFSIZ)		return; 	/* get space for text to be copied, and copy it */	memmove(preview + beg + inslen, preview + beg + dellen, endlen + 1);	if (pdraw->text && pdraw->text->length)		memcpy(preview + beg, pdraw->text->string.multi_byte, inslen);	(preview + beg + inslen + endlen)[0] = '\0'; 	/* get caret position */	cursor = runebytes(text, pdraw->caret);} static void init_input_method(XIM xim){	XVaNestedList preedit = NULL;	XICCallback start, done, draw, caret;	XIMStyle preeditstyle;	XIMStyle statusstyle;	XIMStyles *imstyles;	int i; 	/* get styles supported by input method */	if (XGetIMValues(xim, XNQueryInputStyle, &imstyles, NULL) != NULL)		fputs("XGetIMValues: could not obtain input method values", stderr); 	/* check whether input method support on-the-spot pre-editing */	preeditstyle = XIMPreeditNothing;	statusstyle = XIMStatusNothing;	for (i = 0; i < imstyles->count_styles; i++) {		if (imstyles->supported_styles[i] & XIMPreeditCallbacks) {			preeditstyle = XIMPreeditCallbacks;			break;		}	} 	/* create callbacks for the input context */	start.client_data = NULL;	done.client_data = NULL;	draw.client_data = (XPointer)text;	caret.client_data = (XPointer)text;	start.callback = (XICProc)preeditstart;	done.callback = (XICProc)preeditdone;	draw.callback = (XICProc)preeditdraw;	caret.callback = (XICProc)preeditcaret; 	/* create list of values for input context */	preedit = XVaCreateNestedList(0, XNPreeditStartCallback, &start, XNPreeditDoneCallback,				      &done, XNPreeditDrawCallback, &draw, XNPreeditCaretCallback,				      &caret, NULL);	if (preedit == NULL)		fputs("XVaCreateNestedList: could not create nested list", stderr); 	xic = XCreateIC(xim, XNInputStyle, preeditstyle | statusstyle, XNPreeditAttributes, preedit,			XNClientWindow, win, XNFocusWindow, win, NULL);	XFree(preedit); 	long eventmask;	/* get events the input method is interested in */	if (XGetICValues(xic, XNFilterEvents, &eventmask, NULL))		fputs("XGetICValues: could not obtain input context values", stderr); 	XSelectInput(dpy, win,		     ExposureMask | KeyPressMask | VisibilityChangeMask | ButtonPressMask |			     PointerMotionMask | eventmask);}