Merge lp:~methanal-developers/methanal/812032-better-scroll-to into lp:methanal

[Jonathan Jacobs]

[Tristan Seligmann (mithrandi)]

review: Approve

=== modified file 'methanal/js/Methanal/Util.js'
--- methanal/js/Methanal/Util.js	2011-07-13 15:51:04 +0000
+++ methanal/js/Methanal/Util.js	2011-07-17 22:21:49 +0000
@@ -1419,3 +1419,44 @@
     pluralForm = pluralForm || word + 's';
     return n == 1 ? word : pluralForm;
 };
+
+
+
+/**
+ * Scroll a node into view.
+ *
+ * @type  node: I{DOM element}
+ *
+ * @type  scrollPosition: C{String}
+ * @param scrollPosition: Name of the position to scroll C{node} to. Available
+ *     options are:
+ *
+ *     - C{'top'}: Scroll the element to the top of the screen.
+ *
+ *     - C{'bottom'}: Scroll the element to the bottom of the screen.
+ *
+ *     - C{'middle'}: Scroll the element to the middle of the screen.
+ *
+ *     - C{null}: Perform no scrolling.
+ */
+Methanal.Util.scrollTo = function scrollTo(node, scrollPosition) {
+    if (scrollPosition === null || !node.scrollIntoView) {
+        return;
+    }
+
+    if (scrollPosition === 'bottom') {
+        node.scrollIntoView(false);
+    } else if (scrollPosition === 'middle') {
+        node.scrollIntoView(true);
+        var innerHeight = window.innerHeight;
+        // For IE < 9.
+        if (innerHeight === undefined) {
+            innerHeight = node.ownerDocument.documentElement.clientHeight;
+        }
+        // Scroll the view up by half its size, after scrolling the node to the
+        // top of it, to centre the node.
+        window.scrollBy(0, -innerHeight / 2);
+    } else {
+        node.scrollIntoView(true);
+    }
+};

=== modified file 'methanal/js/Methanal/View.js'
--- methanal/js/Methanal/View.js	2011-07-13 12:59:13 +0000
+++ methanal/js/Methanal/View.js	2011-07-17 22:21:49 +0000
@@ -1252,7 +1252,7 @@
 
         function focusControl(control) {
             return function () {
-                control.focus(true);
+                control.focus();
                 return false;
             }
         }
@@ -1596,20 +1596,28 @@
 
     /**
      * Give keyboard focus to the form input.
+     *
+     * @type  scrollPosition: C{String}
+     * @param scrollPosition: Scroll the input into a view position, defaults
+     *     to C{'middle'}.
+     *
+     * @see: L{Methanal.Util.scrollTo}
      */
-    function focus(self, scrollIntoView/*=true*/) {
+    function focus(self, scrollPosition/*='middle'*/) {
         if (!self.inputNode) {
             return;
         }
 
         if (self.inputNode.focus !== undefined) {
-            self.inputNode.focus();
-        }
-        if (scrollIntoView === undefined || scrollIntoView) {
-            if (self.inputNode.scrollIntoView) {
-                self.inputNode.scrollIntoView(true);
+            try {
+                self.inputNode.focus();
+            } catch (e) {
+                // Internet Explorer throws an exception when it can't focus
+                // things.
             }
         }
+
+        Methanal.Util.scrollTo(self.inputNode, scrollPosition || 'middle');
     },