iPhone: How to create title bar like in Google+ stream? - iphone

I'm about to create an app with the same technology like the Google+ app. I want to reproduce the "stream"-viewcontroller.
Currently i've set up a scrollview with paging and pagecontrol, but I can't get how the bar under the navigationbar in the Google+-app is created. It shows the titles of the current page and the pages to the left and right. It also has a zoom-effect that zoom in at the current visible pagetitle.
Anyone has any ideas?

One way to do it would be to create your VC, throw a scrollview in it whose x, y and width are the same as your backing view, but whose height is the height of your backing view minus however high you want your titlebar to be. Create a separate view for that. Your paging scrollview will work fine for the content area.
For your titlebar, you'll probably just set up some CABasicAnimations and keep some images off screen, sliding them around as you see fit, or what-have-you. This is one approach you can use.

Related

How to get the visible view size in iOS13 when presenting a view controller

In iOS13, the default way when presenting a view controller was changed to the "sheets/cards" view. As I’m not using auto layout (why not, is not really important and relevant), I rely on getting position of elements based on the frame of the view.
Now, the problem with the new method is, that the view frame doesn’t really reflect the actual content size visible on the screen anymore. E.g. if I have positioned a UIButton at the bottom on the view controller based on the view.frame bottom coordinate, it will be now cut off, as the view is actually moved down in the amount of the nice "sheets/cards" visual indication at the top. The same problem is even more evident in an iPad, where centring another view in the view controllers view will be offset, due to the fact that the default presentation style is now a "sheet" in the middle of the screen.
I’ve currently changed everything to force the full screen version, but it would be nice to use the new fancy design.
Anybody has any idea how to get the actual visible rect/coordinates in the new style without changing things to auto layout?
Here are how they look. The "flower" is centered in the view and the X button should not be so close to the bottom or missing completely in the iPad version.
Finally figured it out. As I was setting the positions of items in viewDidLoad, the frame was not calculated correctly, thus resulting things being laid out incorrectly. When resetting the frame and positions in viewDidLoadSubviews, the positions were placed correctly.

Unable to get the correct frame for UIViewControllerAnimatedTransitioning to UIPageViewController

I have been battling this transition animation and I am pretty much out of ideas. I am attempting something similar to going from the collection to the individual photos in the Photos app on iOS.
It all works to my satisfaction with the exception that the frame for the "big" detail view of the image is not correct. It is the right size but it is about 87 points closer to the top of the screen compared to the actual position of the image in the final state. This is pretty much the same height as what is above the "safe area" (iPhone X titles + navItem) and irritatingly close to what is also below the safe area (toolbar and iPhone X home area).
I have Googled (and "SO'd") a bunch of different solutions to similar sounding problems. E.g: UIViewControllerAnimatedTransitioning with Safe Area Insets on iPhone X
I have downloaded and perused example code from Github. E.g: https://github.com/SamStone92/CustomTransitions
It seems to me that I have something in my view (controller) hierarchy which is complicating this more than most. I would love some hints as to what might be causing the problem and how I might go about fixing it.
My hierarchy is:
NavigationController containing the root VC with a UICollectionView.
Tapping a cell transitions to a UIPageViewController for a "detail view" where I can page between items in the collection.
UIPageViewController has a bottom toolbar in addition to the navigation bar.
The content ViewController has a ScrollView with a UIImageView in it to get some zooming.
Seems like the common approach is to add the destination view to the container, force a layout pass and then get the frame. I have tried many variants of this with and without converting the coordinates. (they appear to always remain the same before and after conversion)
My Theory
I am leaning towards the UIPageViewController being the complicating factor. But I have not been able to untangle how to get the correct coordinates.
The destination view (in the animation) is not the content view but the PageVC view which in turn may or may not have added the content view, adapted it to the navigation item or the toolbar.
Seems like viewWillAppear on the content VC does not have the right coordinates. I can tell that the detail content view is getting a call to viewWillLayoutSubviews after that and also after all the animation delegation stuff has had its turn.
This is a color overlay of my main views. Grey is the top and bottom areas outside the safe area. Blue is where the transition animates to before revealing the green, underlying actual position it should have animated to.

Why do my UIImageviews get resized/dimmed when using UINavigation/UITabbar controller

I have an app with a primary view that has a UITabBarController with 5 tabs. Each tab is a UINavigationController.
In interface builder, I'm customizing the background of each page by dragging a UIImageView and setting it fullscreen. The image I'm setting to the view is 640x960. I am setting it to be Aspect Fill.
However, what I've noticed is that it is not where I would expect it to be. When navigating between by tabs, the image seems to be shifted down from where it should be.
Also, when pushing a new view to the navigation controller, the background of this new view isn't offset in the same way as the tabbar one, and it is also slightly dimmed.
How can I set my UIImageViews on each page to be aspect correct and fill the screen 1:1? Also, how does one disable the dimming when pushing a view to the navigation controller?
Thanks for any tips, and apologies if this is covered in another thread, I couldn't find an answer searching the site.
Assuming that you are using the IB to setup your views, you should select navbar/tabbar options to reflect what will be on the actual page. That should place your image correctly. I would also recommend that you make both a low res and hi res version of your background images -- 320x480 and 640x960. Of course, your size may need to be adjusted (reduced) for the navbar and/or tabbar which will leave less than 960 px of vertical height -- probably more like 920px if you are in portrait mode. Then you add #2x to the base name of the hi res version, this would account for older iPhone screens.
Once you have the image placed correctly, resizing should be unnecessary. You can have the image automatically resize width and height using the little arrows on the layout page -- that's a bit hard to describe. It can also be done in code -- if you still need that I can provide a sample.
Maybe you need to set all AutoresizingMask in order to resize the UIImageView properly on each view. And to main aspect ratio u should use either AspectFill or AspectFit on the contentMode.

Correct approach for implementing vertical scrolling with UIScrollView

I know that I asked a question a few minutes ago, but I want to make a few points clearer before asking for the community's help. I'm new to iOS development, close to finishing my first app. The only thing standing in my way is this UIScrollView. I simply do not understand it, and could use your help.
This is in the detail view controller of a drill-down app with a tab bar. I have approximately 8 fields (for things like phone numbers and such) drawing from a .plist. Obviously, those take up enough room that I could use a little extra real estate. I would guess that it needs to be about the size of two views vertically, but I do not understand how to allocate that sort of space to a UIScrollView. Some tutorials I have read say that you don't even need to define it in the header, which I doubt and do not understand. Additionally, I do not understand how to simply get the app to smoothly scroll up-and down only. Apple's examples have constant move cycles that flip between horizontal pictures.
I doubt it makes very much a difference, but I have an image that is in the background. I'm going to load the view on top of that.
My question is broad, so I don't expect you to take the time to sit down and write out all of the code for me (and I wouldn't ask you to). Just an outline of quick, helpful tips would help me understand how to get this view to load in the context of my project.
Many thanks!
It's fairly simple. Add a UIScrollView to your view. Add your fields and such to the scrollview. In viewDidLoad or somewhere similar, you need to set the contentSize on your scrollview. This is the "virtual" area that will be scrollable. This will generally be larger than the frame of the scrollview. In your case, you indicated it should be roughly double the width.
For instance, if you had a scrollview with a view inside, and you wanted to make sure the entire view is visible via scrolling:
self.scrollView.contentSize = self.contentView.frame.size;
//setting scrollview zoom level
self._scrollview.minimumZoomScale=0.5;
self._scrollview.maximumZoomScale=6.0;
self._scrollview.contentSize=CGSizeMake(320,500 );
you have to outlet scroll view in .h class and #property #synthesis this scroll view.then you can able to scroll up and down,if u want only vertical scrolling ,then u have to go to interface builder and uncheck the horizontal scrolling.
You can set a few settings for your scrollview to limit the scrolling to horizontal or vertical. A few important ones are:
// pseudcode here, start typing "[scrollView " then press escape to get a intelli-sense of all // the things you can set for the scrollview.
// values could be YES/NO or TRUE/FALSE, I can't remember which one but
// I think it's YES/NO. Once you start scrolling, the phone will determine
// which way you're scrolling then lock it to that direction
[scrollView setDirectionalLockEnabled:YES];
// when you slide the view, if enough of the next part of the view is visible,
// the scrollview will snap or bounce the scrollview to fit this new "page".
// think of swiping feature to navigate the iPhone home screens
// to show different "pages" of iphone apps
[scrollView setPagingEnabled:YES];
// as a safe guard, make sure the width of your scrollview fits snuggly with the content
// it is trying to display. If the width is more than necessary to display your table of
// data vertically, sometimes the scrollview will cause the
// horizontal scrolling that you don't want to happen and you get bi-directional scrolling
Just set the content size of UIScrollView after adding all the controls/button/textfields etc. for example you add 10 textfields in UIScrollview then content size of UIScrollView will be
lastTextField.frame.origin.y+lastTextField.frame.size.height+20; 20 is for margin.
That's it let me know if you want to know something more related to your app.

how do i work on a taller view in interface builder?

OK, so I am learning to use UIScrollView in interface builder. since the scrollView itself does not have any content, I created another view, the contentView, to hold my controls and scrollable content. into this view I place controls, labels, etc and then in my code i set the contentSize of the scrollView to the size of this contentView.
My question seems stunningly simple and so obvious that I must have missed something somewhere. when I created this XIB in IB I got your standard empty iPhone interface window. I dropped a scrollView on top of it, it took up the whole window. I dropped a view on top of that, it took up the whole scrollview. I added some controls, which so far I can still see inside the contentView rectangle in IB.
My question is how do I work on/add controls which lie outside of the visible part of the contentView in IB? LOL. it seems so simple, but i just don't get it. I can set the height of the content view or drag the rectangle to whatever I like (and indeed this is the whole point of having a scrollview) but the fixed UI window from IB won't expand so i can see the "offscreen" part of the contentView to add more controls. It's like it's just fixed at that size because that's the size of one iPhone screen and it won't let me make it any bigger/taller.
what did I do wrong?
-a
You need to turn off all simulated user interface elements (like the status bar) to be "undefined" except for size, which you select to be "Freeform" from the drop-down, and then you can set the view height using the Ruler tab to be whatever you like.
For example, here I've selected a photo view controller, and set the size in the right side bar to be "iPad Full Screen" - but I could also change that to "freeform" to set any height I wished.
First add a ViewController by any which way you prefer. Then in interface builder, click on the view controller Icon (on left). In the connections inspector click on the ruler icon "Show the size inspector". There will be option list for simulated size, change to "Freeform" and increase the height to any size you want. Hope this helps.
neeever mind. you drag the content view up so that some controls are offscreen and then add more controls/expand to the part you just made visible by moving the top stuff off the top. in effect, you physically scroll the contentView in IB by dragging it with the mouse. seems a smidge counterintuitive, but whatever.
Set simulated size to freeform for the the view controller to a large enough size that you can add in your controls
You don't have to create a view to place inside the scrollview if you don't want. In your case, it sounds like it doesn't make much sense.
As for the second part of your question, you can place items directly on the scrollview (it is a view afterall), as subviews. If you want them to be off screen, then just set their frame up to be at those particular x, y coordinates you want it to be at. You will have to ensure your scrollview's contentSize property is large enough though to house your entire content, this is what allows scrolling horizontally/vertically.
You probably want to do the offscreen elements programmaticly instead of using xibs.