Tree Collapsed with all parent nodes shown

I would like to achieve a functionality where in when I try to collapse the tree , all other level except the first level nodes are closed.


    <item text="A=“a”>

<item text="A1=“a1”>

<item text="A2=“a2”>

<item text="A3=“a3”>

    <item text="B=“b”>

<item text="B1=“b1”>

<item text="B2=“b2”>

<item text="B3=“b3”>

    <item text="C=“c”>

<item text="C1=“c1”>

<item text="C2=“c2”>

<item text="C3=“c3”>

    <item text="D=“d”>

<item text="D1=“d1”>

<item text="D2=“d2”>

<item text="D3=“d3”>

So when I do a collapse all I want my tree to look like

    <item text="A=“a”>

<item text="B=“b”>

<item text="C=“c”>

<item text="D=“d”>

How can I achieve this… when I do closeAllItems() it closes all the nodes.


There is no built in solution, but you can use onOpenStart event to set any custom reaction on item opening|closing
In case of  two-level tree, next code will work

                if (state==-1){
                    if (this._last_open)
                return true;