ensureVisible ? about angular-winjs

[jayrenn]

@sensiblearts Can you provide a repro of your code? You should be able to use the indexOfFirstVisible property to get the first visible item (or set, if you wish to jump to a particular item).

[sensiblearts]

@jayrenn , @AmazingJaze , Basically, I'm loading listview data in $scope.init and trying to time when to scroll to the right object.

   $scope.backToTab = function() {
           // code omitted here, switches to the tab with the listview
           if (item_index) {  // e.g., 7 to scroll to 7th item
                   var list_v = document.getElementsByClassName("win-listview");
                   if (list_v.length) {
                       list_v = list_v[0].winControl;
                       if (list_v) {
                           //not working:
                           list_v.indexOfFirstVisible = item_index;
                           console.log(list_v.indexOfFirstVisible); //  -1 or 0, regardless of what I set it to
  
                           // or if I add another timeout delay here, I get error as in my previous post
 
                        }
                    }
               }
           }
        };
        $scope.init = function () {
             $http.get('api/mygroups',{broadcastError:true}).
                  success(function(data, status, headers, config) {
                    $scope.groups = data.groups || [];   // data for listview
                    //...
                    $timeout( $scope.backToTab, 100);  // see above
                  }).
                  error(function(data, status, headers, config) {
                  });
         };
  

[AmazingJaze]

Hi @sensiblearts , thanks for the additional information. Just to clarify, are you only seeing this problem when trying to navigate back to a ListView that was already rendered? Or do you see this problem the first time a ListView is constructed and are unable to get ensureVisible() to work correctly even then?

When the problem occurs, does the ListView element have proper dimensions when you are setting the data or trying to call ensureVisible() ? If the ListView element can not accurately measure itself and its items, for example. due to a parent element having display:none; , then you might find that calling ListView.forceLayout() or the less expensive ListView.recalculateItemPosition(), once the element once again has proper dimensions, may rectify this problem for you.

Finally, I see that you are using document.getElementsByClassName("win-listview")[0] to get a hold of the listview element, is it possible that the element at index 0 is not actually the correct listview element? Out of curiosity what is the length of the array that getElementsByClassName is returning when that code is executed?

If none of the above addresses your issue, can you share a page or app that repros the bug? If you want to send us files, you can use OneDrive as described in our described in our wiki.

[AmazingJaze]

Edited my previous response for extra clarification.

[sensiblearts]

Thank you so much for the detailed reply.

I built a test app by stripping out unrelated code, and (probably no
surprise to you), indexOfFirstVisible works as it is supposed to!

I will figure out what in my full app is causing the side effect, and I
will pass along the information just in case it is relevant to your efforts.

D. Alm

On Wed, Jul 29, 2015 at 7:56 PM, AmazingJaze [email protected]
wrote:

Hi @sensiblearts https://github.com/sensiblearts , thanks for the
additional information. Just to clarify, are you only seeing this problem
when trying to navigate back to a ListView that was already rendered? Or do
you see this problem the first time a ListView is constructed and are
unable to get ensureVisible() to work correctly?

When the problem occurs, does the ListView element have proper dimensions
when you are setting the data or trying to call ensureVisible() ? If the
ListView element can not accurately measure itself and its items, for
example. due to a parent element having display:none; , then you might find
that calling ListView.forceLayout() or the less expensive
ListView.recalculateItemPosition may rectify this problem for you.

Finally, I see that you are using
document.getElementsByClassName("win-listview")[0] to get a hold of the
listview element, is it possible that the element at index 0 is not
actually the correct listview element? Out of curiosity what is the length
of the array that getElementsByClassName is returning when that code is
executed?

If none of the above addresses your issue, can you share a page or app
that repros the bug? If you want to send us files, you can use OneDrive as
described in our described in our wiki
https://github.com/winjs/winjs/wiki/How-to-share-repros-of-issues-with-WinJS
.

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Reply to this email directly or view it on GitHub
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David Alm