** MyWindow ** the one that gets rendered fixed outside the viewport. When constrain=true, it is overlayed over the viewport, but the window is not draggable.

Ext.define('MyApp.view.MyWindow', {
    extend: 'Ext.window.Window',

    height: 185,
    width: 334,
    layout: {
        type: 'absolute'
    },
    title: 'My Window',

    initComponent: function() {
        var me = this;

        Ext.applyIf(me, {
            items: [
                {
                    xtype: 'textfield',
                    x: 20,
                    y: 20,
                    itemId: 'edName',
                    width: 280,
                    fieldLabel: 'Name'
                },
                {
                    xtype: 'textfield',
                    x: 20,
                    y: 50,
                    itemId: 'edAddress',
                    width: 280,
                    fieldLabel: 'Address'
                },
                {
                    xtype: 'button',
                    anchor: 'right',
                    x: 280,
                    y: 120,
                    itemId: 'btnOK',
                    text: 'OK',
                    listeners: {
                        click: {
                            fn: me.onBtnOKClick,
                            scope: me
                        }
                    }
                },
                {
                    xtype: 'button',
                    x: 220,
                    y: 120,
                    itemId: 'btnCancel',
                    text: 'Cancel',
                    listeners: {
                        click: {
                            fn: me.onBtnCancelClick,
                            scope: me
                        }
                    }
                }
            ]
        });

        me.callParent(arguments);
    },

    onBtnOKClick: function(button, e, eOpts) {
        //var name = edName.Text;

        //alert("Hello, "+name);
    },

    onBtnCancelClick: function(button, e, eOpts) {
        this.close();
    }

});