So i have a problem that i know how to solve but not in ann efficient/fast way. Look at this example that i have right now:
So I had made all the outlets before I decided that I need a background image. You can see that I marked them but they are under the UIImage. I can solve this by first removing the image and dragging all the views to another view controller then adding the UIImage and putting the views back on the ImageView but this is time consuming as I have other view controllers. Is there another way to move views up/down?
Think of the views as being listed in the order they are placed on top of others. You start at the top of the list, adding views, and then add the ones next on the list on top, one a time. That's how I remember the ordering.
As Luk2302 says, you can simply drag your views around inside your storyboard to change their order.
Note that there is also an "arrange" sub-menu in the editor menu for IB. You could select your background image, then pick editor>arrange>send to back to move the background view to the back of the stack of views.
P.S.: Don't call them outlets. They are views. Views can be linked to your code using IBOutlets, but they don't have to be. Plus other non-view objects like constraints can also be linked to your code with IBOutlets
Its simple.what you have to do is simply drag you imageview to the top of the view(then it becomes the first IBOutlet you added). I have added some images, then it will easy to understand.
this is your situation
this is the solution(drag it to the top of the view)
then your other IBOutlets come to the front like this
Related
though the elements show, they don't show in the proper location
When I put UI elements in to the storyboard on this app that I'm working on they do not show up in the right location. I can edit them, move them, manipulate them... but all of it shows up lower than where they are actually located. then on this second viewcontroller that I have created, the header from the first viewcontroller is now showing up over there.
Not really sure if there is a way that I can reset the storyboards or get this to clean up at all.
thanks.
delete all your constraints first from the left hand side of the story board.
run the app and see how it looks
now, set contraints for each widget one by one properly and give it a try
The two buttons were in a stack view with constraints that were throwing them off. Once I removed the stack view and laid out the buttons without the extra view they worked perfectly.
So I want to create a Slider on the top of the UI, each item representing a Category (there will be five items). I don't want to switch to another Controller, when sliding to another Category, I just want to load new data into the current controller. So I guess the UIScrollView is the way to go.
See here for what I want to realize:
I have trouble now to show the name of the chosen Category in the middle of the Slider, and by the same time on the left and right its neighbors.
Using a effective AutoLayout is a also necessary.
Is putting Panels into the UIScrollView the right way?
I am new to iOS-Development and would appreciate any help.
Add a scrollview to the top of your controller, in code configure scrollcontentwidth to screenWidth*5 and on each swipe change reload the data of your controller.
Let's say I have a full-screen UIView that overlays the main screen when a button is touched, and then goes away when this overlayed view is touched. This UIView could either be added and removed from the current view using addSubview: and removeFromSuperview, or it could be added when the current view is initialized and then shown and hidden by accessing and setting the hidden property of the UIView. Which is generally faster and better for performance (or are they the same)?
I did try add imageView and try loop 1000000 times to hide and show in each loop and add remove in each loop. Result is hide and show take 1s to do 1000000 loop. And add remove take 3s. I do it in simulator :)
I'd bet show and hide will be faster. The other way requires object creation/destruction, and fiddling with subviews.
More importantly, I think show and hide will be simpler, and the fight against complexity is paramount.
As Clay says, showing hiding will probably be faster, but you would need sensitive instruments to detect the difference. It's going to be single-digit hundredths of a second at the most, and probably much less than that. You won't be able to sense the difference "by eye".
Thus what matters is other things, like what is the easiest to understand and maintain? One problem with making a view exist in the view controller and showing/hiding it at well is that the layout of the view covers the other contents of the view controller and makes it hard to manage.
You can create a second XIB (or an XIB that goes along with your storyboard) that has your view controller's class as it's "File's owner" and link up IBOutlets to the views you want. Then you load the view from an XIB when you need it, install it as a subview of your current view. Then you remove it from the superview when you're done with it. I use that approach a fair amount.
I have 3 different subviews all defined directly in the storyboard, so they have outlets to them as well. All of these subviews are meant to occupy the same coordinates on a screen at different times, with only one occupying the space at any time, so that it looks like some appearance is changing. How do I go about doing this? Say I also have a enumeration that defines what state I'm currently in and thus what subview is shown for that location.
Two basic options:
Just go ahead and add the three subviews to your scene. If you do this, there are a couple of tricks that will make your life much easier in IB:
For each of the views, go to the "identity inspector" tab (the third one) in the far right panel, expand the "Document" section, and give each of the three views unique "labels" (not to be confused with UILabel controls; this is just a label or description that IB will use internally to refer to your view). That way, as you navigate the tree of controls listed in the "Document Outline" (that list of all of your scenes that appears in the left side of the center panel), you'll be able to figure out which is which. As you work with these overlapping views, a strong command of this "document outline" will make your life much easier.
When you have the three views on the scene, you may find that it will be easiest to drag the view you want to work on to the end of the list of the three views (but at the same level as its peers) in that "Document Outline". You can then edit that subview. Repeat that process for the three subviews as you do your IB work on them.
You can make an outlet collection for your three subviews, if you want. This makes it easier when you want to perform some action on all of the subviews. Perhaps not of great utility when dealing with only three, but if you ever had more subviews, the collections can be useful.
You can define unique UIView subclasses for each of the three views, which can be useful to keep your list of IBOutlet references a little more structured. Also any view-specific UI logic can be isolated into the individual UIView subviews.
If you use this technique, if you plan on animating the transition between these three subviews, it's actually quite useful to not just put these three subviews on the top-level view of the scene in question. It's quite useful to have a view on the scene that defines the dimensions of the three subviews, and then put your three subviews inside this new interim subview. This way, when you animate changes, you can constrain the animation to just that portion of the screen. This new, interim UIView is often called a container view, but should not be confused with the iOS 6 container view that you'll see in IB, which is related to the next technique, defined below.
While all of those tricks can make the manipulation and management of the three sets of overlapping views in a single scene a little easier, I actually think that a custom container view controller is the best way to go. One scene for the parent scene/view controller, and a separate view controller and IB scene for each of the three different child views. It takes a little extra code up front (not hard, but a little alien the first time you do it), but then your code and the IB scenes are nicely isolated. Architecturally, this is the most elegant approach, IMHO. If you want to do this, you should refer to:
WWDC 2011 #102 on UIViewController Containment (Apple developer ID required)
the containment section of the View Controller Programming Guide
the containment section of the UIViewController Reference document
I am trying to achieve the following effect:
A UICollectionView displays a grid of cells for a parent type of object, e. g. a photo album. When I tap one of these items, I would like to scroll that element to the top of the screen and open a Springboard like folder from it. Inside that folders area, another collection should be shown, consisting of the detail items, i. e. the individual photos of that album. Tapping in the remaining "parent" view closes the folder again. See this schema:
What I have done so far is a regular collection view for the albums. When I select one, it scrolls to selected item to the top and then uses JWFolders to open an empty folder at that place. Once that is shown, I trigger the surrounding UINavigationController to push my 2nd view controller with the detail items. That one is layed out so it appears to the user as if it were still the same view.
There are several problems with this approach, and I would like to know how to do this better:
JWFolders takes a screenshot and animated two halves of it up/downwards to achieve the opening effect. This is ok, but pretty slow on an iPad3, because it moves a lot of pixels and the iPad3's GPU is not quite up to the task.
The 2nd view needs to be pixel-perfect to match on top of the first one. This is likely to break accidentally.
I am limited as to what animations are possible for the view controller transition. The default UINavigationController's push from the right is not fitting. I override that to do a cross-dissolve, but still it is far from ideal.
I would like to get pointers as to how to approach this problem in a maintainable manner that does not require to much creative hacking against what the frameworks are designed to do. I might be missing something obvious here, so pointers to examples or general advice are appreciated.
Update:
I changed the approach a bit. Now I use a container view controller that has two embedded collection view controllers. One for the "Album" and one for the "Photos" part at the bottom. Using a UIImageView in the middle between the two I can get the triangle pointing upward done. This is also nice from a maintenance point of view, because it makes maintenance easier with the two collections being handled completely separately.
The app uses Auto Layout, so I can change the amount of space each of the two embedded views takes by modifying the constraints. This is way faster than the screenshot based approach with JWFolders and works nicely on an iPad3 as well.
This almost gets me where I want to be. The one thing that remains is to get the opening animation right. I would like to simultaneously scroll the Albums collection, so that the tapped item goes to the top and expand the photos collection with the triangle pointing at the Album cell.
Can I somehow "connect" the lower view to that cell via layout constraints, so that the scrollToItemAtIndexPath:atScrollPosition:animated: call drags the lower view open?
To get around it I would lose the library and cause iOS to move those display elements around without screenshots or other tricks. On the tap, cause the tapped icon to retain its normal appearance while you dim all the others. Find the contents of the collection view from the top to the end of the line where the tapped icon is. Create two new collection views - one which contains the top half, including your tapped icon and one containing the rest, below. Animate those views apart to make room for the folder view.
The folder view is another UICollectionView that appears in the gap created.
In the main view there are either one or three views presented depending on whether the drawer is open or closed. I would probably look at creating a view controller with a collection view, and using view controller containment to manage all three views. You have complete control over how those views are presented, so you could animate top and bottom views up and down simultaneously to reveal the folder view in place, as Springboard does.
When that's all working then you could generalize and start doing things like deciding to make the tapped icon part of the bottom collection with the folder appearing above if the icon was low on the screen.
(I hesitate to answer this because of the large number of upvotes yet no answers, so I may have missed something - but that is how I would begin trying to achieve the Springboard effect.)
To solve this problem in a relatively easy way, you could try to make the folder a simple UICollectionView subclass and then insert that cell when the albums cell is tapped.
In the collection views data source you would have to return different size etc. for the folder cell.
In the folder you would have to create the folders collection view, avoid making the folder cell the data source of the cell folder collection view tho.