I did not find a "CommandColumn", and i add an "ext-widgetColumn" with buttons as alternative, but now i need to hide some buttons, and add events using the rows values, how can I do it?

<ext-treePanel id="MyTree" flex="4" title="Example" scrollable="true" frame="true" margin="5">
    <root>
        <ext-treeNode text="Composers" expanded="true">
            <children>
                <ext-treeNode text="Mozart" iconCls="x-md md-icon-person">
                    <children>
                        <ext-treeNode text="Concertos">
                            <children>
                                <ext-treeNode text="Piano Concerto No. 12" iconCls="x-md md-icon-music-note" leaf="true" />
                                <ext-treeNode text="Piano Concerto No. 17" iconCls="x-md md-icon-music-note" leaf="true" />
                                <ext-treeNode text="Clarinet Concerto" iconCls="x-md md-icon-music-note" leaf="true" />
                                <ext-treeNode text="Violin Concerto No. 5" iconCls="x-md md-icon-music-note" leaf="true" />
                                <ext-treeNode text="Violin Concerto No. 4" iconCls="x-md md-icon-music-note" leaf="true" />
                            </children>
                        </ext-treeNode>
                    </children>
                </ext-treeNode>
            </children>
        </ext-treeNode>
    </root>
    <columns>
        <ext-treeColumn Flex="1" DataIndex="text" />
        <ext-widgetColumn width="100">
            <widget>
                <ext-button iconCls="x-md md-icon-menu-book" width="40" />
            </widget>
        </ext-widgetColumn>
    </columns>
</ext-treePanel>