Function InsertChars

micropolis-activity/src/tk/tkentry.c:1021–1073

(entryPtr, index, string)

 *
 * Side effects:
 *	New information gets added to entryPtr;  it will be redisplayed
 *	soon, but not necessarily immediately.
 *
 *----------------------------------------------------------------------
 */

static void
InsertChars(entryPtr, index, string)
    register Entry *entryPtr;	/* Entry that is to get the new
				 * elements. */
    int index;			/* Add the new elements before this
				 * element. */
    char *string;		/* New characters to add (NULL-terminated
				 * string). */
{
    int length;
    char *new;

    length = strlen(string);
    if (length == 0) {
	return;
    }
    new = (char *) ckalloc((unsigned) (entryPtr->numChars + length + 1));
    strncpy(new, entryPtr->string, index);
    strcpy(new+index, string);
    strcpy(new+index+length, entryPtr->string+index);
    ckfree(entryPtr->string);
    entryPtr->string = new;
    entryPtr->numChars += length;

    /*
     * Inserting characters invalidates all indexes into the string.
     * Touch up the indexes so that they still refer to the same
     * characters (at new positions).
     */

    if (entryPtr->selectFirst >= index) {
	entryPtr->selectFirst += length;
    }
    if (entryPtr->selectLast >= index) {
	entryPtr->selectLast += length;
    }
    if (entryPtr->selectAnchor >= index) {
	entryPtr->selectAnchor += length;
    }
    if (entryPtr->leftIndex > index) {
	entryPtr->leftIndex += length;
    }
    if (entryPtr->cursorPos >= index) {
	entryPtr->cursorPos += length;
    }

    if (entryPtr->textVarName != NULL) {
	Tcl_SetVar(entryPtr->interp, entryPtr->textVarName, entryPtr->string,
		TCL_GLOBAL_ONLY);
    }