size of backgroundView is too small depending on the number of items

[karmeye]

When the number of items in the grid does not fill the last row exactly the backgroundView's height is to small (960 in my case).

fixed it by changing

self.backgroundView.frame = backgroundRect;

in layoutSubviews to

self.backgroundView.frame = CGRectMake(backgroundRect.origin.x, backgroundRect.origin.y, self.contentSize.width, self.contentSize.height);

This was just a fast fix, I do not know if its a good one. This is the develop branch.

[evadne]

Thanks! That sounds like a bug, and the line of code you mentioned is probably good. We should fix the underlying issue that causes backgroundRect to contain an invalid value.

On Nov 5, 2012, at 10:29 AM, rassol [email protected] wrote:

When the number of items in the grid does not fill the last row exactly the backgroundView's height is to small (960 in my case).

fixed it by changing

self.backgroundView.frame = backgroundRect;

to

self.backgroundView.frame = CGRectMake(backgroundRect.origin.x, backgroundRect.origin.y, self.contentSize.width, self.contentSize.height);

This was just a fast fix, I do not know if its a good one. This is the develop branch.

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177

[karmeye]

In the future it would be gread to implement a recycling model for the background view. Now if there are several hundred items the scrolling becomes hacky, even more in landscape mode.

thanks for good work.

[evadne]

View tiling / recycling is something that can be trivially done from the calling class. You’ll observe -scrollViewDidScroll: and tile your background views, using contentOffset and the bounds to determine how much to tile.

We are not tiling the background view in AQGridView, at least as of the version I know. :)

Slow is not good. Post a project somewhere under a new issue, slap PERFORMANCE on the title and we’ll work a way out.

On Nov 6, 2012, at 4:46 AM, rassol [email protected] wrote:

In the future it would be gread to implement a recycling model for the background view. Now if there are several hundred items the scrolling becomes hacky, even more in landscape mode.

thanks for good work.

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10104434

[AlanQuatermain]

I've got code for a tiling background view that I've been meaning to clean up & commit — we've been doing that at Kobo for a while now to avoid the memory footprint of the layer backing store in a large background view.

On 2012-11-06, at 10:35 AM, Evadne Wu [email protected] wrote:

View tiling / recycling is something that can be trivially done from the calling class. You’ll observe -scrollViewDidScroll: and tile your background views, using contentOffset and the bounds to determine how much to tile.

We are not tiling the background view in AQGridView, at least as of the version I know. :)

Slow is not good. Post a project somewhere under a new issue, slap PERFORMANCE on the title and we’ll work a way out.

On Nov 6, 2012, at 4:46 AM, rassol [email protected] wrote:

In the future it would be gread to implement a recycling model for the background view. Now if there are several hundred items the scrolling becomes hacky, even more in landscape mode.

thanks for good work.

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10104434 — Reply to this email directly or view it on GitHub.

Cheers, -Jim

jimdovey@(mac|gmail).com http://twitter.com/alanQuatermain http://github.com/alanQuatermain http://stackoverflow.com/users/103900/jim-dovey http://ca.linkedin.com/pub/jim-dovey/2/24b/883

[evadne]

Can it be made into a magic view that automatically works when put into any UIScrollView? I’d push for that, on a separate repository.

On Nov 6, 2012, at 10:37 AM, Jim Dovey [email protected] wrote:

I've got code for a tiling background view that I've been meaning to clean up & commit — we've been doing that at Kobo for a while now to avoid the memory footprint of the layer backing store in a large background view.

On 2012-11-06, at 10:35 AM, Evadne Wu [email protected] wrote:

View tiling / recycling is something that can be trivially done from the calling class. You’ll observe -scrollViewDidScroll: and tile your background views, using contentOffset and the bounds to determine how much to tile.

We are not tiling the background view in AQGridView, at least as of the version I know. :)

Slow is not good. Post a project somewhere under a new issue, slap PERFORMANCE on the title and we’ll work a way out.

On Nov 6, 2012, at 4:46 AM, rassol [email protected] wrote:

In the future it would be gread to implement a recycling model for the background view. Now if there are several hundred items the scrolling becomes hacky, even more in landscape mode.

thanks for good work.

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10104434 — Reply to this email directly or view it on GitHub.

Cheers, -Jim

jimdovey@(mac|gmail).com http://twitter.com/alanQuatermain http://github.com/alanQuatermain http://stackoverflow.com/users/103900/jim-dovey http://ca.linkedin.com/pub/jim-dovey/2/24b/883

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10114870

[AlanQuatermain]

Probably. Maybe. I'd have to check & see if there's any glue in there— we wouldn't want to eat the scroll view delegate property by requiring this background always be the delegate…

On 2012-11-06, at 10:43 AM, Evadne Wu [email protected] wrote:

Can it be made into a magic view that automatically works when put into any UIScrollView? I’d push for that, on a separate repository.

On Nov 6, 2012, at 10:37 AM, Jim Dovey [email protected] wrote:

I've got code for a tiling background view that I've been meaning to clean up & commit — we've been doing that at Kobo for a while now to avoid the memory footprint of the layer backing store in a large background view.

On 2012-11-06, at 10:35 AM, Evadne Wu [email protected] wrote:

View tiling / recycling is something that can be trivially done from the calling class. You’ll observe -scrollViewDidScroll: and tile your background views, using contentOffset and the bounds to determine how much to tile.

We are not tiling the background view in AQGridView, at least as of the version I know. :)

Slow is not good. Post a project somewhere under a new issue, slap PERFORMANCE on the title and we’ll work a way out.

On Nov 6, 2012, at 4:46 AM, rassol [email protected] wrote:

In the future it would be gread to implement a recycling model for the background view. Now if there are several hundred items the scrolling becomes hacky, even more in landscape mode.

thanks for good work.

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10104434 — Reply to this email directly or view it on GitHub.

Cheers, -Jim

jimdovey@(mac|gmail).com http://twitter.com/alanQuatermain http://github.com/alanQuatermain http://stackoverflow.com/users/103900/jim-dovey http://ca.linkedin.com/pub/jim-dovey/2/24b/883

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10114870 — Reply to this email directly or view it on GitHub.

Cheers, -Jim

jimdovey@(mac|gmail).com http://twitter.com/alanQuatermain http://github.com/alanQuatermain http://stackoverflow.com/users/103900/jim-dovey http://ca.linkedin.com/pub/jim-dovey/2/24b/883

[evadne]

Guess we can use -didMoveToSuperview:, then KVO the contentOffset and bounds or worse use CADisplayLink and poll the presentationLayer.

On Nov 6, 2012, at 10:45 AM, Jim Dovey [email protected] wrote:

Probably. Maybe. I'd have to check & see if there's any glue in there— we wouldn't want to eat the scroll view delegate property by requiring this background always be the delegate…

On 2012-11-06, at 10:43 AM, Evadne Wu [email protected] wrote:

Can it be made into a magic view that automatically works when put into any UIScrollView? I’d push for that, on a separate repository.

On Nov 6, 2012, at 10:37 AM, Jim Dovey [email protected] wrote:

I've got code for a tiling background view that I've been meaning to clean up & commit — we've been doing that at Kobo for a while now to avoid the memory footprint of the layer backing store in a large background view.

On 2012-11-06, at 10:35 AM, Evadne Wu [email protected] wrote:

View tiling / recycling is something that can be trivially done from the calling class. You’ll observe -scrollViewDidScroll: and tile your background views, using contentOffset and the bounds to determine how much to tile.

We are not tiling the background view in AQGridView, at least as of the version I know. :)

Slow is not good. Post a project somewhere under a new issue, slap PERFORMANCE on the title and we’ll work a way out.

On Nov 6, 2012, at 4:46 AM, rassol [email protected] wrote:

In the future it would be gread to implement a recycling model for the background view. Now if there are several hundred items the scrolling becomes hacky, even more in landscape mode.

thanks for good work.

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10104434 — Reply to this email directly or view it on GitHub.

Cheers, -Jim

jimdovey@(mac|gmail).com http://twitter.com/alanQuatermain http://github.com/alanQuatermain http://stackoverflow.com/users/103900/jim-dovey http://ca.linkedin.com/pub/jim-dovey/2/24b/883

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10114870 — Reply to this email directly or view it on GitHub.

Cheers, -Jim

jimdovey@(mac|gmail).com http://twitter.com/alanQuatermain http://github.com/alanQuatermain http://stackoverflow.com/users/103900/jim-dovey http://ca.linkedin.com/pub/jim-dovey/2/24b/883

---

Reply to this email directly or view it on GitHub: https://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10115173

[evadne]

I wrote it. Tested a few combinations, view dequeueing, reusing, and stretching all seem to work well.

Code: https://github.com/evadne/RATilingBackgroundView Sample app: https://github.com/evadne/RATilingBackgroundView-Sample

[karmeye]

Cool. I've added it to the gridView:

In my ViewController viewDidLoad

    _gridView.backgroundView = [[UIView alloc] initWithFrame:CGRectZero];    
    [_gridView insertSubview:self.tilingBackgroundView belowSubview:_gridView.backgroundView];

In AQGridView layoutSubviews

self.backgroundView.frame = CGRectZero;

Changed the property

- (RATilingBackgroundView *) tilingBackgroundView {

    if (_tilingBackgroundView)
        return _tilingBackgroundView;

    //if ([self isViewLoaded]) {
        RATilingBackgroundView *tilingBackgroundView = [RATilingBackgroundView new];
        tilingBackgroundView.delegate = self;
        tilingBackgroundView.layer.borderColor = [[UIColor blueColor] colorWithAlphaComponent:0.5f].CGColor;
        tilingBackgroundView.layer.borderWidth = 8.0f;
        //[_gridView addSubview:tilingBackgroundView];
        _tilingBackgroundView = tilingBackgroundView;
    //}

    return _tilingBackgroundView;
}

Works fine now with 3000 grid items which did not work at all before.

I am looking into adding the headerView now and also being able to drag the gridview beyond its contentSize to see the contents of its superview (now the tiles continue even tough contentoffset is negative).

[evadne]

Probably need a way to tell the tiling background view if it should continue tiling outside the bounds! It should be a single flag…. Up for grabs?

On Nov 12, 2012, at 6:49, rassol [email protected] wrote:

Cool. I've added it to the gridView:

In my ViewController viewDidLoad

_gridView.backgroundView = [[UIView alloc] initWithFrame:CGRectZero];
[_gridView insertSubview:self.tilingBackgroundView

belowSubview:_gridView.backgroundView];

In AQGridView layoutSubviews

self.backgroundView.frame = CGRectZero;

Changed the property

• (RATilingBackgroundView *) tilingBackgroundView {

  if (_tilingBackgroundView) return _tilingBackgroundView;

  //if ([self isViewLoaded]) { RATilingBackgroundView *tilingBackgroundView = [RATilingBackgroundView new]; tilingBackgroundView.delegate = self; tilingBackgroundView.layer.borderColor = [[UIColor blueColor] colorWithAlphaComponent:0.5f].CGColor; tilingBackgroundView.layer.borderWidth = 8.0f; //[_gridView addSubview:tilingBackgroundView]; _tilingBackgroundView = tilingBackgroundView; //}

  return _tilingBackgroundView;}

Works fine now with 3000 grid items which did not work at all before.

I am looking into adding the headerView now and also being able to drag the gridview beound its contentSize to see the contents of its superview, now the tiles continue even tough contentoffset is negative.

— Reply to this email directly or view it on GitHubhttps://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10284646.

[karmeye]

Added a local variable to keep track of the contentOffset. Also added a public UIEdgeInsets property which top value I set to the same height as the gridViews header.

if ([keyPath isEqualToString:contentOffsetKey])
        {            
            _curContentOffset = [change[NSKeyValueChangeNewKey] CGPointValue];
            const CGSize tileSize = [self tileSize];

            self.offset = (CGPoint)
            {
                fmodf(-1 * _curContentOffset.x, tileSize.width) - (self.horizontalStretchingEnabled ? 0.0f : ceilf(CGRectGetWidth(self.bounds) / tileSize.width) * tileSize.width),
                fmodf(-1 * _curContentOffset.y, tileSize.height) - (self.verticalStretchingEnabled ? 0.0f : ceilf(CGRectGetHeight(self.bounds) / tileSize.height) * tileSize.height)
            };

        }
        else if ([keyPath isEqualToString:boundsKey])
        {
            self.frame = CGRectOffset(self.superview.bounds, 0.f, _edgeInsets.top);// self.superview.bounds;
        }

In layoutSubviews added

tile.frame = rect;

        if (_curContentOffset.y < _edgeInsets.top && tile.frame.origin.y < _curContentOffset.y * -1.f) {
            tile.hidden = YES;
        }
        else {
            tile.hidden = NO;
        }

Also added a if (self.superview) in didMoveToSuperView.

[evadne]

Thanks a bunch. That is interesting: I expected that overriding the method which gives you tile rects might suffice — if you hide something, there is still a small performance penalty for keeping it around. Will pull into project. Thanks again!

On Nov 12, 2012, at 10:20, rassol [email protected] wrote:

Added a local variable to keep track of the contentOffset. Also added a public UIEdgeInsets property which top value I set to the same height as the gridViews header.

if ([keyPath isEqualToString:contentOffsetKey]) { _curContentOffset = [change[NSKeyValueChangeNewKey] CGPointValue]; const CGSize tileSize = [self tileSize];

        self.offset = (CGPoint)
        {
            fmodf(-1 * _curContentOffset.x, tileSize.width) -

(self.horizontalStretchingEnabled ? 0.0f : ceilf(CGRectGetWidth(self.bounds) / tileSize.width) * tileSize.width), fmodf(-1 * _curContentOffset.y, tileSize.height) - (self.verticalStretchingEnabled ? 0.0f : ceilf(CGRectGetHeight(self.bounds) / tileSize.height) * tileSize.height) };

    }
    else if ([keyPath isEqualToString:boundsKey])
    {
        self.frame = CGRectOffset(self.superview.bounds, 0.f,

_edgeInsets.top);// self.superview.bounds; }

In layoutSubviews added

tile.frame = rect;

    if (_curContentOffset.y < _edgeInsets.top &&

tile.frame.origin.y < _curContentOffset.y * -1.f) { tile.hidden = YES; } else { tile.hidden = NO; }

Also added a if (self.superview) in didMoveToSuperView.

— Reply to this email directly or view it on GitHubhttps://github.com/AlanQuatermain/AQGridView/issues/177#issuecomment-10291246.

[karmeye]

I hid it only because I was lazy. But I do not think it's a performance penalty. It ought to be at least as slow as when all tiles are visible.

[karmeye]

How come you call setNeedsLayout first in observeValueForKeyPath and not last? I call them last in each if case. Seems to work.

Hmm, maybe it doesn't matter since setNeedsLayout is async.