Improvement: Use frosted glass effect for Navigationbar and Toolbar

[wutschel]

Description

Frosted Glass Effect

Use frosted glass effect ([UIBlurEffect effectWithStyle:UIBlurEffectStyleDark]) for navbar and toolbar. Let the table views extend underneath the frosted glass and adapt contentInset accordingly.

Special care is needed for the following areas:

• To have SVPullToRefresh working as expected it is important to explicitly set contentInset instead of automatic adjustment.
• For iPad it is important to hide the toolbar's effect view buttonsViewEffect while being in fullscreen library view.

Glitch with Sticky Headers for collection view

When changing the layout for the table and collection view to extend underneath the navbar, an issue became visible on some devices (in my case the glitch shows on iPhone 14 Pro iOS 18.5 sim, but not on iPod Touch 7G iOS 15.5 sim). The issue is caused by how the app retrieves contentInset.top, it follows the approach

UIApplication.sharedApplication.statusBarFrame.size.height + navCtrl.navigationBar.frame.size.height

But in fact, the navigation bar ends 1/3 px above, as it is also reported when using

CGRectGetMaxY(navCtrl.navigationBar.frame

Issue (see small visible area between section header and navbar):

Solutions are either to use the CGRectGetMaxY equation, or to increase contentInset.top to slightly overlap with the navigation bar.

Other

In addition, some smaller refactoring, more comments and coding style changes were added.

Screenshots

Screenshots (left = current, right = dark blur): https://ibb.co/zW9r4NRv
Video: link to video

Summary for release notes

Improvement: Use frosted glass effect for Navigationbar and Toolbar

[wutschel]

The solution around CGRectGetMaxY does not have the correct result on e.g. iPod Touch iOS 15.5 simulator. Neverending story...

[wutschel]

While testing I now saw the the bottom inset behaves different (related to UIScrollViewContentInsetAdjustmentNever?). At the same time the impact of scrollIndicatorInsets changed as well. I am a bit lost on how the scroll indicators need to be configured. Until now I thought I set the same insets for them as for the content insets. But this does not seem to be correct.

[wutschel]

Best overall results I achieve when

• Not using UIScrollViewContentInsetAdjustmentNever
• Keep using self.edgesForExtendedLayout = UIRectEdgeNone.
• Programmatically extending maskView (child view of DetailViewController's view) underneath the navbar and status bar. The table view and collection view are child views of maskView and autoscale accordingly.
• Use CGRectGetMaxY(navCtrl.navigationBar.frame) for the extension of maskView and for contentInset.top. But this will result in the table view not extending underneath the status bar in some cases (e.g. iPod Touch 7G, iOS 15.5).
• Keep using the own implementation of sticky headers for collection view (layoutAttributesForElementsInRect). Otherwise keeping support for the sticky section header while active search ("25 results") needs not yet understood changes to maintain visibility.

With above I have

• Proper content inset handling (top and bottom)
• Proper scroll indicators
• Pull-To-Sync works as expected
• Table/collection view not using full screen height in some occasions

Overall, it became difficult as soon as the tables should extend underneath the navigation / status bar. I am quite sure the current path is not correct or desired. This will end up in more trouble, quite unsatisfying.

Force pushed the code now, I hope you have a better idea how this should be done properly.

[kambala-decapitator]

tbh it's rather difficult to track the issue you're facing. Would it be possible to create a minimal reproducible example (a test app I mean)? It'd also be easier to investigate and find solution there.

maybe it's time to start using AutoLayout, it may get the things right automatically.

About the 1/3 px: maybe using value from safe area inset could help?

[wutschel]

With latest rebase this PR only changes behaviour of the navigation bar. All other changes related to coding styles, sticky header implementation and frosted glass toolbars were already merged via dedicated PRs.

[wutschel]

The 1/3 px issue seems to be yet another viewDidLoad vs willLayoutSubviews topic. Currently it is called from viewDidLoad which doesn't result in correct numbers for CGRectGetMaxY(navCtrl.navigationBar.frame) for some simulators and view controllers. Calling it in willLayoutSubviews works, but will require quite some rework and fixing regressions. Might still be the way to go on the long run though ...

Some examples for the 1/3 px issue on iPhone 14 Pro iOS18 simulator:
CGRectGetMaxY(navCtrl.navigationBar.frame) = 97.667 (correct)
UIApplication.sharedApplication.statusBarFrame.size.height + navCtrl.navigationBar.frame.size.height = 98
UIApplication.sharedApplication.keyWindow.safeAreaInsets.top + navCtrl.navigationBar.frame.size.height = 103
navCtrl.navigationBar.frame.size.height = 44

[wutschel]

The fix/workaround for sticky headers does also fix layout problems on bottom toolbar on some devices (screenshot taken from iPhone 18 Pro Max simulator -- left before, right after).