[TIMOB-3572] Updating views on a ScrollableView does not release previously set views from memory..

Expectation:

var scrollable = Ti.UI.createScrollableView();

scrollable.views = [set of views]; // initial

scrollable.views = [new set of views]; // further in flow; release previous set of views

Steps to recreate:

1) Run on device and load Instruments (all processes)
2) Tap 'Generate Section' button to confirm memory is being released on recreation.
3) Tap 'Update Views' button to confirm memory is not being released. Application will send memory notifications and eventually crash on approx. 15-20 attempts.

var win = Ti.UI.createWindow({ backgroundColor:'#fff', top:0, right:0, bottom:0, left:0 });

var contentContainer = Ti.UI.createView({ backgroundColor:'#000' });
var sectionContainer = Ti.UI.createView({ backgroundColor:'#f00' });

var scrollable = Ti.UI.createScrollableView({ top:0, right:0, left:0, bottom:50, backgroundColor:'#ff0' });
var button1 = Ti.UI.createButton({ bottom:0, left:0, width:'40%', height:50, title:'GENERATE SECTION' });
var button2 = Ti.UI.createButton({ bottom:0, right:0, width:'40%', height:50, title:'UPDATE VIEWS' });

var sectionState = false;

var currentImages = [];

function createButton() {
    var button = Ti.UI.createButton({ left:0, right:0, height:30, bottom:0, title:'Button' });
    
    button.addEventListener('click', function() {
        Ti.API.info('Tapped button.');
    });
    
    return button;
}

// ### Border Radius Performance - toImage improves this - larger memory footprint
function generateItem(img) {
    var itemContainer = Ti.UI.createView({ width:200, height:200, top:5, left:5, bottom:5, right:5, backgroundColor:'#0f0' });
    var image = Ti.UI.createImageView({ width:200, height:100, image:img, borderRadius:5 }); // slow performance
    var comp = Ti.UI.createImageView({ width:200, height:100 });
    var title = Ti.UI.createLabel({ touchEnabled:'false', text:'Title', textAlign:'center', top:0, height:'auto' });
    var button = createButton();
    
    itemContainer.add(image);
    itemContainer.add(title);
    itemContainer.add(button);
    
    itemContainer.addEventListener('singletap', function() {
        Ti.API.info('Tapped view.');
    });

    image.addEventListener('load', function() {
        comp.image = image.toImage();
        itemContainer.remove(image);
        itemContainer.add(comp);
    });
    
    return itemContainer;
}

function createCustomView(images) {
    var view = Ti.UI.createView({ top:0, left:0, right:0, bottom:0, layout:'horizontal', backgroundColor:'#f00' });
    
    var item;
            
    for (var i = 0; i < 12; i++) {
        item = generateItem(images[i]);
        view.add(item);
    }
    
    item.addEventListener('singletap', function() {
        Ti.API.info('Tapped view.');
    });
    
    return view;
}

// SUCCESS ON RELEASE FROM MEMORY
function generateSection() {    
    if (sectionState) {
        contentContainer.remove(sectionContainer);
    }
    
    setTimeout(function() {
        var images = [];
        
        for (var i = 0; i < 12; i++) {
            images.push('image.png');
        }
        
        currentImages = images;             
        
        sectionContainer = Ti.UI.createView({ backgroundColor:'#f00' });
        contentContainer.add(sectionContainer);

        scrollable = Ti.UI.createScrollableView({ top:0, right:0, left:0, bottom:50, backgroundColor:'#ff0' });

        scrollable.views = [
            createCustomView(images),
            createCustomView(images),
            createCustomView(images),
            createCustomView(images)
        ];

        sectionContainer.add(scrollable);

        sectionState = true;
    }, 500);
}

// MEMORY ISSUES
function refreshViews() {   
    // works on simulator, crash on device (log below) - perhaps this should be done in a reverse order (remove last, first)
    // for (var i = 0, sl = scrollable.views.length; i < sl; i++) {
    //      scrollable.removeView(scrollable.views[i]);
    //  }
    // [ERROR] The application has crashed with an unhandled exception. Stack trace:
    // 
    // 0   CoreFoundation                      0x3173463d __exceptionPreprocess + 96
    // 1   libobjc.A.dylib                     0x3642dc5d objc_exception_throw + 24
    // 2   CoreFoundation                      0x31734491 +[NSException raise:format:arguments:] + 68
    // 3   CoreFoundation                      0x317344cb +[NSException raise:format:] + 34
    // 4   QuartzCore                          0x309ed61d _ZL18CALayerSetPositionP7CALayerRKN2CA4Vec2IdEEb + 140
    // 5   QuartzCore                          0x309ed58b -[CALayer setPosition:] + 38
    // 6   UIKit                               0x32e1136b -[UIView(Geometry) setCenter:] + 22
    // 7   scrollabletest2                     0x00043115 -[TiViewProxy relayout] + 632
    // 8   scrollabletest2                     0x00042673 -[TiViewProxy refreshView:] + 362
    // 9   scrollabletest2                     0x00043445 -[TiViewProxy layoutChildrenIfNeeded] + 136
    // 10  scrollabletest2                     0x0009d459 performLayoutRefresh + 344
    // 11  CoreFoundation                      0x3170ba47 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 14
    // 12  CoreFoundation                      0x3170decb __CFRunLoopDoTimer + 850
    // 13  CoreFoundation                      0x3170e845 __CFRunLoopRun + 1088
    // 14  CoreFoundation                      0x3169eec3 CFRunLoopRunSpecific + 230
    // 15  CoreFoundation                      0x3169edcb CFRunLoopRunInMode + 58
    // 16  GraphicsServices                    0x3288741f GSEventRunModal + 114
    // 17  GraphicsServices                    0x328874cb GSEventRun + 62
    // 18  UIKit                               0x32e07d69 -[UIApplication _run] + 404
    // 19  UIKit                               0x32e05807 UIApplicationMain + 670
    // 20  scrollabletest2                     0x00003bb3 main + 70
    // 21  scrollabletest2                     0x000036a8 start + 40
    // 
    // 
    // 2011-04-13 09:19:00.904 scrollabletest2[8820:707] *** Terminating app due to uncaught exception 'CALayerInvalidGeometry', reason: 'CALayer position contains NaN: [nan 4.0726e-10]'
    // *** Call stack at first throw:
    // (
    //  0   CoreFoundation                      0x3173464f __exceptionPreprocess + 114
    //  1   libobjc.A.dylib                     0x3642dc5d objc_exception_throw + 24
    //  2   CoreFoundation                      0x31734491 +[NSException raise:format:arguments:] + 68
    //  3   CoreFoundation                      0x317344cb +[NSException raise:format:] + 34
    //  4   QuartzCore                          0x309ed61d _ZL18CALayerSetPositionP7CALayerRKN2CA4Vec2IdEEb + 140
    //  5   QuartzCore                          0x309ed58b -[CALayer setPosition:] + 38
    //  6   UIKit                               0x32e1136b -[UIView(Geometry) setCenter:] + 22
    //  7   scrollabletest2                     0x00043115 -[TiViewProxy relayout] + 632
    //  8   scrollabletest2                     0x00042673 -[TiViewProxy refreshView:] + 362
    //  9   scrollabletest2                     0x00043445 -[TiViewProxy layoutChildrenIfNeeded] + 136
    //  10  scrollabletest2                     0x0009d459 performLayoutRefresh + 344
    //  11  CoreFoundation                      0x3170ba47 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__ + 14
    //  12  CoreFoundation                      0x3170decb __CFRunLoopDoTimer + 850
    //  13  CoreFoundation                      0x3170e845 __CFRunLoopRun + 1088
    //  14  CoreFoundation                      0x3169eec3 CFRunLoopRunSpecific + 230
    //  15  CoreFoundation                      0x3169edcb CFRunLoopRunInMode + 58
    //  16  GraphicsServices                    0x3288741f GSEventRunModal + 114
    //  17  GraphicsServices                    0x328874cb GSEventRun + 62
    //  18  UIKit                               0x32e07d69 -[UIApplication _run] + 404
    //  19  UIKit                               0x32e05807 UIApplicationMain + 670
    //  20  scrollabletest2                     0x00003bb3 main + 70
    //  21  scrollabletest2                     0x000036a8 start + 40
    // )
    // terminate called after throwing an instance of 'NSException'
    
    // this seems to work, but memory jumps on regenerating section
    // for (var i = 0, sl = scrollable.views.length; i < sl; i++) {
    //      scrollable.views[i] = createCustomView(currentImages);
    // }
    
    // previous views do not seem to be released from memory
    scrollable.views = [
        createCustomView(currentImages),
        createCustomView(currentImages),
        createCustomView(currentImages),
        createCustomView(currentImages)
    ];
}

button1.addEventListener('click', function(e) {
    generateSection();
});

button2.addEventListener('click', function(e) {
    refreshViews();
});

win.add(contentContainer);
win.add(button1);
win.add(button2);

win.open();

generateSection();