fix #19:

many lines of text inside an Object Box can mess up the GUI viewport
* check when the user types "Enter" in an object or message box, and
  grown the svg viewBox if necessary
This should close the corresponding bug

pd/nw/pd_canvas.js

@@ -166,12 +166,16 @@ var canvas_events = (function() {
         },
         grow_svg_for_element= function(elem) {
             // See if an element overflows the svg bbox, and
-            // enlarge the svg to accommodate it
+            // enlarge the svg to accommodate it.
+            // Note: window.scrollX and window.scrollY might not work
+            // with Android Chrome 43 and IE.
             var svg = document.getElementById("patchsvg"),
                 elem_bbox = elem.getBoundingClientRect(),
                 svg_viewbox = svg.getAttribute("viewBox").split(" "),
-                w = Math.max(elem_bbox.left + elem_bbox.width, svg_viewbox[2]),
-                h = Math.max(elem_bbox.top + elem_bbox.height, svg_viewbox[3]);
+                w = Math.max(elem_bbox.left + elem_bbox.width + window.scrollX,
+                    svg_viewbox[2]),
+                h = Math.max(elem_bbox.top + elem_bbox.height + window.scrollY,
+                    svg_viewbox[3]);
             svg.setAttribute("viewBox",
                 [Math.min(elem_bbox.left, svg_viewbox[0]),
                  Math.min(elem_bbox.top, svg_viewbox[1]),
@@ -433,6 +437,10 @@ var canvas_events = (function() {
             },
             text_keyup: function(evt) {
                 evt.stopPropagation();
+                if (evt.keyCode === 13) {
+                    pdgui.post("growing the svg...");
+                    grow_svg_for_element(textbox());
+                }
                 //evt.preventDefault();
                 return false;
             },