addEventListener in a dockable panel

[RobWomack]

I wrote a question earlier about this and received no response, but without a script example. Now, I have one. Basically, I have a script that I want to display all the current comp's layers in a list item. When the user changes to a new comp, I want the list to repopulate with the active comp's layers. This would require rebuilding the list item when the window gets focus. I've written a script that does this, but here's the rub: if you make it a dockable panel, it doesn't work, until you click the control itself. Here's the code for the NON-dockable window:

{
// WIN
// ===
var win = new Window("window"); 
    win.text = "addEventListener Test"; 
    win.orientation = "column"; 
    win.alignChildren = ["center","top"]; 
    win.spacing = 10; 
    win.margins = 16; 

// COL1
// ====
var col1 = win.add("group", undefined, {name: "col1"}); 
    col1.orientation = "row"; 
    col1.alignChildren = ["left","center"]; 
    col1.spacing = 10; 
    col1.margins = 0; 

// LISTBOX_GROUP
// =============
var listbox_group = col1.add("group", undefined, {name: "listbox_group"}); 
    listbox_group.orientation = "row"; 
    listbox_group.alignChildren = ["left","center"]; 
    listbox_group.spacing = 10; 
    listbox_group.margins = 0; 

var listbox1_array = ["Item 1","Item 2"]; 
var listbox1 = listbox_group.add("listbox", undefined, undefined, {name: "listbox1", items: listbox1_array}); 
    listbox1.preferredSize.width = 120; 

// COL2
// ====
var col2 = col1.add("group", undefined, {name: "col2"}); 
    col2.orientation = "column"; 
    col2.alignChildren = ["left","top"]; 
    col2.spacing = 10; 
    col2.margins = 0; 

// GROUP1
// ======
var group1 = col2.add("group", undefined, {name: "group1"}); 
    group1.orientation = "row"; 
    group1.alignChildren = ["left","center"]; 
    group1.spacing = 10; 
    group1.margins = 0; 

var statictext1 = group1.add("statictext", undefined, undefined, {name: "statictext1"}); 
    statictext1.text = "Position"; 

var edittext1 = group1.add('edittext {properties: {name: "edittext1"}}'); 
    edittext1.preferredSize.width = 70; 

// GROUP2
// ======
var group2 = col2.add("group", undefined, {name: "group2"}); 
    group2.orientation = "row"; 
    group2.alignChildren = ["left","center"]; 
    group2.spacing = 10; 
    group2.margins = 0; 

var button2 = group2.add("button", undefined, undefined, {name: "button2"}); 
    button2.text = "OK"; 

    button2.onClick = function() {
        win.close();
    };

listbox1.onChange = function(){

}    

var set_focus = true;
var populate_listbox = function(){
    var myComp = app.project.activeItem;
    var myLayers = myComp.layers;
    var mySelectedLayers = myComp.selectedLayers;
    listbox_group.remove(listbox1);
    for (i=1; i<myComp.numLayers; i++) {
        var tab_name = myLayers[i].index + ". " + myLayers[i].name;
        listbox1_array.push(tab_name);
    }
    listbox1 = listbox_group.add("listbox", undefined, undefined, {name: "listbox1", items: listbox1_array});
    listbox1.preferredSize.width = 120; 
    listbox1_array = []; // clear the array
    //refresh(listbox1);
    set_focus = false;
    win.layout.layout(true); 
    win.layout.resize(); 
}
win.addEventListener ("focus", function(){ 
    if (set_focus == true) { populate_listbox(); }
});

win.addEventListener("blur", function(){
    set_focus = true;
});

win.show();

}

Is there any way to replicate this in a dockable window? 

[Mathias Moehl]

I don't think it is possible, since there is no event for this.

A dirty hack is do check say once a second if the comp changed using app.scheduleTask(), but this really affects Ae's performance and therefore you should definitely not do it that way. I think the usual workaround is to offer a refresh button (yes, not ideal UX)

[Tomas Sinkunas]

I second what Mathias has said - there's no native way of doing what you want, apart from re-reading AE DOM every couple of seconds, and this approach really bogs down the system and isn't recommended.

The best way is to keep it simple and reload data by clicking on a button in your script.

[RobWomack]

That’s what I figured. The odd thing is, if you make the panel a non-dockable window, it works. Plus, the manual says that focus is an event for the window object, so it must be something specifically to do with the interface that blocks events from dockable windows. At least, that’s my non-expert opinion. 

[Mathias Moehl]

I guess technically a panel is not really its own Window and that's why you don't get the event.