added OBJ_GetChildAt

avr/modules/lcd2/gui2/base/object.asm

@@ -271,6 +271,39 @@ OBJ_GetLastChild_ret:
 
 
 
+; ---------------------------------------------------------------------------
+; @routine OBJ_GetChildAt @global
+;
+; @param Y   address of object
+; @param R16 idx of child to get (starting at 0)
+; @return CFLAG set, if found, cleared otherwise
+; @return r19:r18 resulting object
+; @clobbers none
+
+OBJ_GetChildAt:
+  push yl
+    push yh
+      rcall OBJ_GetFirstChild     ; R19:R18=obj (none)
+      brcc OBJ_GetChildAt_ret
+
+OBJ_GetChildAt_loop:
+        tst r16
+        breq OBJ_GetChildAt_secRet
+        mov yl, r18
+        mov yh, r19
+        rcall OBJ_GetNext         ; R19:R18=obj (none)
+      brcs OBJ_GetChildAt_loop
+      rjmp OBJ_GetChildAt_ret     ; idx too high, not found
+OBJ_GetChildAt_secRet:
+      sec
+OBJ_GetChildAt_ret:
+    pop yh
+  pop yl
+  ret
+; @end
+
+
+
 ; ---------------------------------------------------------------------------
 ; @routine OBJ_AddChild @global
 ;