MDL-46860 filepicker: iframe context aware

The filepicker now checks if it's within an iframe when
creating the dialogue, if so it will set the dialogue width
to fit within the iframe and disable dragging.

repository/filepicker.js

@@ -1299,17 +1299,25 @@ M.core_filepicker.init = function(Y, options) {
             var client_id = this.options.client_id;
             var fpid = "filepicker-"+ client_id;
             var labelid = 'fp-dialog-label_'+ client_id;
+            var width = 873;
+            var draggable = true;
             this.fpnode = Y.Node.createWithFilesSkin(M.core_filepicker.templates.generallayout).
                 set('id', 'filepicker-'+client_id).set('aria-labelledby', labelid);
+
+            if (this.in_iframe()) {
+                width = Math.floor(window.innerWidth * 0.95);
+                draggable = false;
+            }
+
             this.mainui = new M.core.dialogue({
                 extraClasses : ['filepicker'],
-                draggable    : true,
+                draggable    : draggable,
                 bodyContent  : this.fpnode,
                 headerContent: '<h3 id="'+ labelid +'">'+ M.util.get_string('filepicker', 'repository') +'</h3>',
                 centered     : true,
                 modal        : true,
                 visible      : false,
-                width        : '873px',
+                width        : width+'px',
                 responsiveWidth : 873,
                 height       : '558px',
                 zIndex       : this.options.zIndex
@@ -1947,6 +1955,10 @@ M.core_filepicker.init = function(Y, options) {
                 M.util.set_user_preference('filepicker_' + name, value);
                 this.options.userprefs[name] = value;
             }
+        },
+        in_iframe: function () {
+            // If we're not the top window then we're in an iFrame
+            return window.self !== window.top;
         }
     });
     var loading = Y.one('#filepicker-loading-'+options.client_id);