navigation MDL-25596 Improvements for the navigation blocks JS

The biggest change is that the navigation block has been converted to a proper YUI module.
The following are the other changes made at the same time:
 * A loading icon is displayed when a branch is being loaded by AJAX.
 * Fixed a bug where you could trigger multiple AJAX requests by rapidly clicking an unloaded branch.
 * Fixed a bug where empty branches weren't being marked as such after a successful AJAX load.
 * When docked the width of the blocks dock panel is now inspected an increased if required to try avoid horizontal scrolling.
 * Removed the no longer needed inclusion of the YUI2 dom library from the navigation and settings block.
 * Expandable nodes are now passed as JS data allowing the navigation JS to be initialised through block_navigation::get_required_javascript.
 * AJAX is now focused around the branch in question rather than the tree in general.
 * Expansion of branches is now delegated to the tree rather than being an individual event on all branches.
 * Tidied up the code in general removing unneeded-unused parameters.

blocks/dock.js

@@ -268,6 +268,43 @@ M.core_dock.getPanel = function() {
                 }
                 return;
             };
+            /**
+             * Increases the width of the panel to avoid horizontal scrolling
+             * if possible.
+             */
+            dockpanel.correctWidth = function() {
+                var bd = this.one('.dockeditempanel_bd');
+
+                // Width of content
+                var w = bd.get('clientWidth');
+                // Scrollable width of content
+                var s = bd.get('scrollWidth');
+                // Width of content container with overflow
+                var ow = this.get('offsetWidth');
+                // The new width
+                var nw = w;
+                // The max width (80% of screen)
+                var mw = Math.round(this.get('winWidth') * 0.8);
+
+                // If the scrollable width is more than the visible width
+                if (s > w) {
+                    //   Content width
+                    // + the difference
+                    // + any rendering difference (borders, padding)
+                    // + 10px to make it look nice.
+                    nw = w + (s-w) + ((ow-w)*2) + 10;
+                }
+
+                // Make sure its not more then the maxwidth
+                if (nw > mw) {
+                    nw = mw;
+                }
+
+                // Set the new width if its more than the old width.
+                if (nw > ow) {
+                    this.setStyle('width', nw+'px');
+                }
+            }
             // Put the dockpanel in the body
             parent.append(dockpanel);
             // Return it
@@ -520,7 +557,7 @@ M.core_dock.init_genericblock = function(Y, id) {
     if (!this.initialised) {
         this.init(Y);
     }
-    new this.genericblock(id).init(Y, Y.one('#inst'+id));
+    new this.genericblock(id).initialise_block(Y, Y.one('#inst'+id));
 };
 /**
  * Removes the node at the given index and puts it back into conventional page sturcture
@@ -700,7 +737,7 @@ M.core_dock.genericblock.prototype = {
      * @param {YUI.Node} node The node that contains all of the block's content
      * @return {M.core_dock.genericblock}
      */
-    init : function(Y, node) {
+    initialise_block : function(Y, node) {
         M.core_dock.init(Y);
 
         this.Y = Y;
@@ -939,6 +976,7 @@ M.core_dock.item.prototype = {
         panel.setHeader(this.titlestring, this.commands);
         panel.setBody(Y.Node.create('<div class="'+this.blockclass+' block_docked"></div>').append(this.contents));
         panel.show();
+        panel.correctWidth();
 
         this.active = true;
         // Add active item class first up

blocks/navigation/block_navigation.php

@@ -102,6 +102,13 @@ function instance_can_be_docked() {
     function get_required_javascript() {
         global $CFG;
         user_preference_allow_ajax_update('docked_block_instance_'.$this->instance->id, PARAM_INT);
+        $this->page->requires->js_module('core_dock');
+        $limit = 20;
+        if (!empty($CFG->navcourselimit)) {
+            $limit = $CFG->navcourselimit;
+    }
+        $arguments = array('id'=>$this->instance->id, 'instance'=>$this->instance->id, 'candock'=>$this->instance_can_be_docked(), 'courselimit'=>$limit);
+        $this->page->requires->yui_module(array('core_dock', 'moodle-block_navigation-navigation'), 'M.block_navigation.init_add_tree', array($arguments));
     }
 
     /**
@@ -113,7 +120,6 @@ function get_content() {
         if ($this->contentgenerated === true) {
             return $this->content;
         }
-        $this->page->requires->yui2_lib('dom');
         // JS for navigation moved to the standard theme, the code will probably have to depend on the actual page structure
         // $this->page->requires->js('/lib/javascript-navigation.js');
         // Navcount is used to allow us to have multiple trees although I dont' know why
@@ -171,14 +177,7 @@ function get_content() {
             }
         }
 
-        // Initialise the JS tree object
-        $module = array('name'=>'block_navigation', 'fullpath'=>'/blocks/navigation/navigation.js', 'requires'=>array('core_dock', 'io', 'node', 'dom', 'event-custom', 'json-parse'), 'strings'=>array(array('viewallcourses','moodle')));
-        $limit = 20;
-        if (!empty($CFG->navcourselimit)) {
-            $limit = $CFG->navcourselimit;
-        }
-        $arguments = array($this->instance->id, array('expansions'=>$expandable, 'instance'=>$this->instance->id, 'candock'=>$this->instance_can_be_docked(), 'courselimit'=>$limit));
-        $this->page->requires->js_init_call('M.block_navigation.init_add_tree', $arguments, false, $module);
+        $this->page->requires->data_for_js('navtreeexpansions'.$this->instance->id, $expandable);
 
         $options = array();
         $options['linkcategories'] = (!empty($this->config->linkcategories) && $this->config->linkcategories == 'yes');