The source code

/** + + + + The source code + + + + +
/*!
+ * Ext JS Library 3.2.1
+ * Copyright(c) 2006-2010 Ext JS, Inc.
+ * licensing@extjs.com
+ * http://www.extjs.com/license
+ */
+/**
  * @class Ext.BoxComponent
  * @extends Ext.Component
  * Base class for any {@link Ext.Component Component} that is to be sized as a box, using width and height.
@@ -36,6 +42,26 @@ var myImage = new Ext.BoxComponent({
  */
 Ext.BoxComponent = Ext.extend(Ext.Component, {
 
+    // Configs below are used for all Components when rendered by BoxLayout.
+    /**
+     * @cfg {Number} flex
+     * Note: this config is only used when this Component is rendered
+     * by a Container which has been configured to use a {@link Ext.layout.BoxLayout BoxLayout}.
+     * Each child Component with a flex property will be flexed either vertically (by a VBoxLayout)
+     * or horizontally (by an HBoxLayout) according to the item's relative flex value
+     * compared to the sum of all Components with flex value specified. Any child items that have
+     * either a flex = 0 or flex = undefined will not be 'flexed' (the initial size will not be changed).
+     */
+    // Configs below are used for all Components when rendered by AnchorLayout.
+    
/**
+     * @cfg {String} anchor Note: this config is only used when this Component is rendered
+     * by a Container which has been configured to use an {@link Ext.layout.AnchorLayout AnchorLayout} (or subclass thereof).
+     * based layout manager, for example:

+     * {@link Ext.form.FormPanel}
+     * specifying layout: 'anchor' // or 'form', or 'absolute'
+     * 

+     * See {@link Ext.layout.AnchorLayout}.{@link Ext.layout.AnchorLayout#anchor anchor} also.
+     */
     // tabTip config is used when a BoxComponent is a child of a TabPanel
     /**
      * @cfg {String} tabTip
@@ -261,7 +287,8 @@ var myPanel = new Ext.Panel({
 
         // support for standard size objects
         if(typeof w == 'object'){
-            h = w.height, w = w.width;
+            h = w.height;
+            w = w.width;
         }
         if (Ext.isDefined(w) && Ext.isDefined(this.boxMinWidth) && (w < this.boxMinWidth)) {
             w = this.boxMinWidth;
@@ -277,7 +304,8 @@ var myPanel = new Ext.Panel({
         }
         // not rendered
         if(!this.boxReady){
-            this.width = w, this.height = h;
+            this.width  = w;
+            this.height = h;
             return this;
         }
 
@@ -300,14 +328,15 @@ var myPanel = new Ext.Panel({
                 rz.setWidth(aw);
             }
             this.onResize(aw, ah, w, h);
+            this.fireEvent('resize', this, aw, ah, w, h);
         }
         return this;
     },
 
     /**
      * Sets the width of the component.  This method fires the {@link #resize} event.
-     * @param {Number} width The new width to setThis may be one of:
-     * A Number specifying the new width in the {@link #getEl Element}'s {@link Ext.Element#defaultUnit}s (by default, pixels).
+     * @param {Mixed} width The new width to set. This may be one of:
+     * A Number specifying the new width in the {@link #getEl Element}'s {@link Ext.Element#defaultUnit defaultUnit}s (by default, pixels).
      * A String used to set the CSS width style.
      * 
      * @return {Ext.BoxComponent} this
@@ -318,8 +347,8 @@ var myPanel = new Ext.Panel({
 
     /**
      * Sets the height of the component.  This method fires the {@link #resize} event.
-     * @param {Number} height The new height to set. This may be one of:
-     * A Number specifying the new height in the {@link #getEl Element}'s {@link Ext.Element#defaultUnit}s (by default, pixels).
+     * @param {Mixed} height The new height to set. This may be one of:
+     * A Number specifying the new height in the {@link #getEl Element}'s {@link Ext.Element#defaultUnit defaultUnit}s (by default, pixels).
      * A String used to set the CSS height style.
      * undefined to leave the height unchanged.
      * 
@@ -498,7 +527,7 @@ var myPanel = new Ext.Panel({
             this.positionEl = Ext.get(this.positionEl);
         }
         this.boxReady = true;
-        this.setAutoScroll(this.autoScroll);
+        Ext.isDefined(this.autoScroll) && this.setAutoScroll(this.autoScroll);
         this.setSize(this.width, this.height);
         if(this.x || this.y){
             this.setPosition(this.x, this.y);
@@ -526,7 +555,6 @@ var myPanel = new Ext.Panel({
      * @param {Number} rawHeight The height that was originally specified
      */
     onResize : function(adjWidth, adjHeight, rawWidth, rawHeight){
-        this.fireEvent('resize', this, adjWidth, adjHeight, rawWidth, rawHeight);
     },
 
     /* // protected
@@ -568,6 +596,6 @@ Ext.reg('box', Ext.BoxComponent);
 Ext.Spacer = Ext.extend(Ext.BoxComponent, {
     autoEl:'div'
 });
-Ext.reg('spacer', Ext.Spacer);
- +Ext.reg('spacer', Ext.Spacer);