I have a UIView which is essentially doing two things. The first mode lets the user control things that they've inputted. The second mode lets them input new values to interact with.
To switch between modes it animates the alpha of most of the components of the view to 0.0 and the new ones to 1.0 and it looks really nice. So far the only downside is that my nib in IB is kind of messy for editing.
I was just wondering if this was the best practice for doing this type of thing or if I should be loading a new view. The components are all just UIKit objects like buttons, sliders, labels, etc.
I would recommend add a second View to your xib which holds the editing elements. Then create an IBOutlet for the second view so you can access it in your view controller. When you are ready to switch between, the code that does the alpha animation can also quickly add that editing view as a subview of your main view starting with a 0.0 alpha. Then your alpha animation will bring it into view. It will look the same to you, but it'll be easier to edit in IB. I set up a simple example and took a screenshot to show you what I mean.
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I'm writing an iPhone app (which will be my first ios app) that has about 50 screens, each of which has the same background - where the background is an image covering the entire screen real estate and another image at the top as a banner.
Each screen will have some text along with 0, 1, 2 or 3 buttons appearing beneath the banner image.
What is the best design for putting this together?
The options I could think of were (in every each I was planning on having a root controller which is responsible for displaying each view as appropriate).
1) Have 50 separate screens as xibs (and associated view controllers), each of which contains the two background images plus however many buttons each particular screen needs.
2) Have 4 superclasses as xibs - (representing no buttons, 1 button, 2 button, 3 buttons) and have each of those contain the background images and as many buttons as appropriate. Then have 50 subclasses which simply just set the text and button content as appropriate using the superclasses instance variable outlets.
3) Have the root controller have a view which contains the two background images which is there permanently, and each of the 50 views displays its text and buttons on top of that.
4) (If this is possible, I need to check if a window can have images). Same as 3, except the root controller doesn't have a view, the main window displays the background images and each class displays its text and buttons on the top of this. So each view controller would have to load and display the text and button objects using code (in which case there's not much point to have xibs for them).
Is there another solution? Is one of these the "best" solution?
If I went with 3 would it not be possible to define the position text and buttons in a xib? (because in order to do so they would need a parent view in order to position them in interface builder, but if that were the case then when the view is drawn the background wouldn't be visible).
If 4 is possible, then the root controller has no view, therefore does it still need to be descended from UIViewController, or could it simply be descended from NSObject?
I think at the moment I am leaning towards option 2) as that way I can design all the views visually as xibs, but there are only 4 of them. Unless there is a better more elegant solution.
TIA
What you can do, is one XIB with all the buttons and then you would set then hidden accordingly. Although it would tie you up a bit. The 2) option is more flexible. The 3) is ok too. You could have one rootViewController, just to hold the images and then you could something like this:
[rootViewController.spaceForMyChildView addSubview: myNewViewController.view];
The "spaceForMyChildView" would be a view that would hold your child views.
I would do fusion between 2) and 3) probably.
UIWindow inherits from UIView, so can have anything within it. So (4) is feasible, though you're starting to get into tricky water if you want to support any sort of view rotation.
I'd think an inverted (2) would be the easiest thing — have a single superclass that upon viewDidLoad adds the background and top banner programmatically. Have your specific controllers inherit from that and design them graphically to contain whatever you want, mindful that the image and banner will subsequently be added.
That said, if your views are really as simple as a single text area and up to three buttons, always with fixed positions, then it sounds like a single view that repopulates its fields from a data source, as Jacky Boy suggests, is probably the smartest thing.
I've understood that I need to subclass a UIView t be able to draw inside it.
The thing I don't understand yet, is the philosophy of the way i must be done...
Let's say I have a view controller, and depending on context, I may want to draw a line into one of the subviews it manages, or a circle, or a rect, or a processed graphic. Or lets say two points that are moving inside a view into a defined rect and that display a bigger point when they are close.
How may I subclass and define the subview to make it able to do this only into its drawRect method ?
How does the controller, that manages more than this simple UIView (let's imagine you have a view controller that manages a view inside which there are many other view, and you want to make some drawings in two of them), and that knows what is needed to be drawn into the correct view (it's a controller, isn't it ?), may interact with the views ? And when the drawing is done, how may the views interact with the controller ?
I've read many doc about drawings (apple, web, forums, tutorials, ...), but I still can't touch the philosophy of the way this must be done.
it's very simple. Make a new class, OliverView, which is a UIView. (ie, it is a subclass of UIView.) In that view, make it draw stuff in a fancy way, inside drawRect.
Now make a UIViewController, called OliverVC. In storyboard put an OliverView inside OliverVC. (beginner explanation of how to do that).
In the OliverView, have properties "hours", "minutes", "seconds".
Now, in OliverView - in the drawRect - have a fancy way to display those values. (Pie chart, glowing letters, animation - whatever you want.)
Now, up in OliverVC, do some calculations to determine the time in Zimbabwe, for example.
Once you want a time displayed, simply set those properties in OliverView - - and you are done.
Your colleague could be programming the OliverView. You need know nothing about how she is going to display the time. Conversely, your colleague need know nothing about your calculations in OliverVC..
So, it's simpleL One part has the job of displaying the data. One part has the job of coming up with the data (doing whatever sort of calculation is relevant in the app).
It's the only architecture possible in a "real time" screen device where the views can and do change at any time.
In answer to your question below: you've forgotten that quite simply, if you have a button that would be a whole separate element. (Perhaps sitting "on top of" the OliverView.) So, it's easy!
The -drawRect method in your UIView subclass defines the onscreen appearance of the view. All drawing is done in -drawRect. Your UIViewController calls methods on its UIView to tell it to draw something differently or to perform some other action.
The UIViewController manages everything to do with the view that is not inherently associated with the drawing of the content. Data associated with the view is often stored in the controller.
Need help with the following. I am creating two different combinations of view/controllers that allow me to add/edit a set of information , think tasks or some type of to-do. I have all the data capture/store functionality working.
I decided that it would be nice to have an icon associated to these tasks. So the icon would show up in the UITableview. I commissioned 18 customer 44x44 icons that would be added tot he table.
But there is where I'm stuck:
I was to add/edit views to have the capability to select an icon to attach to the tasks. In order to do so, i added a 44x44 round-rect button with one of the images as a default. I wanted to have that button trigger another view with the 18 icons so the user selects one and it passes control back to the main view and updates de selected icon appropriately.
I created this little 18 icon view together with the main view, which is based on a scroll view. I configured the little icon view to be hidden.
But I have no idea if the little view should be a subview of the main view, who should be the file owner, how do I make it appear hidden as the main view is displayed and toggle t as needed...
I am stumped. Anyone done something like this? Ideas? Things I completely messing up, you can think of?
Thanks in advance
Probably the easiest way to hide and show the view is to adjust the "alpha" property on the view. If you set the alpha of the little view to 0 it will be hidden, and when you set it to 1 it will be showing. So in your awakeFromNib function (or wherever you are doing initialization) you can add the littleView and set the alpha to 0 so it starts hidden. I suggest adding the littleview to your mainview unless for some reason the little view will have any part of it outside of the mainview. Then, when the user selects the icon to change it, you can set the alpha to 1. Finally, when the user chooses from the view, you would set the alpha back to 0.
Note:
This is not the most efficient use of memory because the view is technically always around. So if you think that you will be low on memory I would suggest creating the view programmatically when needed and removing it from mainview when the user is done. (But only do this if you think it will be an uncommon task because creating the view with a bunch of images will probably be a relatively expensive operation).
I've made a ViewBased app, in the app delegate i've set a UITabBarCotntroller, in the app i have different view Controller two of them displays text in a UITextView and labels, the other one is my "ShakeController" a UIViewController in which i've set a UIAcelerometerDelegate, in it i create a instance of UIAccelerometer, in the method which manages the shake everything works fine, in this controller i have also set a UIImageView to make a simple animation, in the view Did Load method i set my imageView.animation to an array of UIImage.
My problem is : when the app is launched i use the ViewControllers and everything work fine, but when i tap the ShakeController item in the tab bar and then when i come back to the other controllers the label looks like : label and textView like : Lorem ipsum..... the text of UItextView in IB.
I have noticed thaht if i comment the initialisation of my imageView to the array of image i can navigate the items (from a view controller to another) without the label change and stay what i want them to be.
Notice that the two controllers are in a UINavigationController.
(i use #proprety (nonnatomic, retain) then #synthesize ... then releqse in the dealloc for the labels textview and my uiimageView)
Do not know what to do thanks to all
Quite hard to understand what you're asking here... I re-read it three times and I'm still not sure!
Since you find the problem (the data in the other view being "released") goes away when you comment out your imageView animation initialisation, I would conclude that you are using up a large amount of the iPhone's memory which means that it is automatically unloading any un-seen view controllers. It will do this quite quickly to preserve memory.
You don't say how many images are in your animation, but just 10 medium-large images can be enough to trigger memory issues; if you are wanting to use 20/30+ you have to look for another way.
You can try just loading a few frames into your image first and then swapping them out on a recurring timer. But if it's anything more than very basic animation you'll need to get stuck in to core animation instead: http://developer.apple.com/iphone/library/documentation/Cocoa/Conceptual/CoreAnimation_guide/Articles/WhatisCoreAnimation.html#//apple_ref/doc/uid/TP40004689
I have an iPhone app that displays a modal view controller. The modal view controller shows two instances of a custom subclass of UITextView called RoundedTextView, an MKMapView, and a UIToolbar. I construct the viewController only once, and reset its data and present it each time the user summons it.
When showing this view controller with presentModalViewController, I noticed that the animation to show the view was choppy on the 3G. So, to speed it up, I set the alpha of the MKMapView and the two RoundedTextView objects to 0 on viewWillDisappear and back to 1 on viewDidAppear. This made it nice and fast. I also presume that I could remove the views from the superview to speed it up as well.
Does anyone else jump through these kind of hoops on the iPhone. Is there something else I should be doing to avoid this hack?
It's not a hack to simplify drawing during animation in order to make the animation more smooth. It is indeed a very valid technique.
You may be able to achieve similar performance improvements by setting all UI elements to Opaque, a technique also used to fix table view cell performance issues. You just have to make sure background colors match.
The main problem I had was I subclassed UIButton to make gradient buttons and I had the boundary mask enabled. This made the performance terrible. I removed that option and made my buttons square and it's blazin now.