There's a particular control which I'm trying to build properly. I refer to it as an ImageTile. It's basically a little square box, which, when the user taps it, will present the user (via an action sheet in a popover) the option of selecting an image from the library, or taking a photo. Depending on the response, I then either present the UIImagePickerController inside a popover (for selecting an image) or modally (for taking a new picture). Once they take/select the image, I have a modal view which appears and allows them to edit the picture in a few simple ways. When they finish editing, the modal dismisses, and the original ImageTile, rather than being a blank square box, gets filled up with the user's edited image.
The issue is that this ImageTile control is going to be used profusely throughout several different parts of the application, across numerous View Controller hierarchies, and so on... and I really want it to be a basically totally self-contained unit, such that whenever I stick an ImageTile inside a UIView onscreen, all the above functionality is handled by the ImageTile itself.
Initially, I made it a UIViewController subclass (so it could present modals etc), and just added its view as a subview of a "holder" view onscreen. I know this isn't recommended, as the controller isn't part of the VC hierarchy then... and also, I wound up with some really weird behavior regarding things like autorotation, especially when the camera was involved.
What's the "right" way to implement something like this?
I think what you've done by making it a UIViewController subclass is correct. You should just use the methods that UIViewController exposes for adding child view controllers, such as - addChildViewController:.
You will also note that Interface Builder has a Container View object designed specifically for holding a place in the hierarchy for a child View Controller:
Related
Apologies if this seems a straightforward question! I'm using AVFoundation to build a custom camera app that allows the user to draw on the image after it's taken (similar to snapchat).
I have the camera functionality working. Currently, after the shutter button is pressed I add (as a subview) a standard UIImageView to display the photo taken. Seeing as I want there to be custom options at this stage (including drawing on the image), I proceeded to create my own subclass of UIImageView. I am designing this view in Interface Builder (xib file).
Say for instance I have a button on this custom view, that when pressed, simply deletes the image and takes me back to the camera view to take another image. Can I handle the IBActions for this custom view within the ViewController for my camera view? Is this bad practice?
Any guidance on how best to implement this would be really appreciated! Thanks.
I would not suggest putting the button on your custom view.
I would have the UIViewController display the custom view and also give display a button for your action. Most likely the UIViewController will want to display a UIToolBar at the bottom of the screen which will allow for multiple buttons/actions, but that's up to you.
But why do I say this? Compartmentalization. Your custom view has no need or use for the button. It's meaningless to what your doing... displaying the image. Your custom view will also probably be used in many locations, several of which won't want this button displayed. Even if your custom view had the button it wouldn't know what to do if someone tapped it. It would then have to pass that interaction off the view controller which cares about the action and and handle it. Your custom view will mostly likely have public methods allowing other code to give it directions (like clear or undo).
Depending on the say things go, you may decide you want a custom UIViewController which handles interactions on your custom view. Then any other view controllers could just add it in as a containerized view controller and you could have the same functionality with no code duplication at several places in your applications.
I am creating a simple little popup view, similar to the popup that appears when you push the volume buttons. I would like to display an instance of that popup view in different view controllers. I have been pondering a couple approaches, but I would like to know what is the best approach, taking into account MVC, complexity, and otherwise 'good' practices.
Currently, I am creating and displaying this UIView from within my UIViewController. I justified that approach since it's really a small view and I do a lot of work with it to modify its behavior in that VC, so that code was already going to be in the VC. Essentially, I make a frame, set the background, apply corner radius, add text to it, apply motion effects, then make it fade in then later fade out. I could copy and paste the code into my other VCs but that's obviously a bad approach.
I could create a subclass of UIView and I'm sure I could use drawRect to draw it, but I'm not sure exactly how to add that view to the VC exactly in the middle, unless I drag out a view to my VCs and change its class. But if I do that I can do most everything in Interface Builder anyways, which would be preferred especially if I can use Auto Layout to always keep it centered. But, I'd need to copy and paste that UIView into each VC and hide it - that doesn't sound good.
I could create a subclass of UIView and instead of drawing with drawRect, implement a method that creates the UIView and returns it. Then in the VCs I just call that method and add the view it returns as a subview. I've never done this, and I'm not sure if that's an appropriate approach.
What is a plausible approach to implementing such a view that can be thrown on screen from any of my VCs? Thanks!
Note that this view should always be the same size, in the center of the screen, not tied to any specific VC. It should remain on screen unaffected by transitions and such. It closely mimics the Volume popup.
I would like to display that same popup in multiple view controllers.
I expect that you mean you'd like to have separate instances of that same class in multiple view controllers. A given view can have only one superview, so it can't exist in more than one view at a time.
I'm not sure exactly how to add that view to the VC exactly in the middle
It's easy to center a view in its superview. To center horizontally, subtract the width of the view from the width of the parent. Divide the result by 2. That's your X coordinate. Same goes for the Y coordinate, except that you'd obviously use the heights.
An even easier method is to create a point by dividing the superview's width and height each by 2. Set your view's center property to that point.
What is a plausible approach to implementing such a view that can be thrown on screen from any of my VCs?
Don't try to reuse the same view. There's no need for that, and trying to pass it around between controllers will really complicate your code. Just have any controller that needs to display your popup create its own copy.
Remember, views are the interface to the data that's stored in your model -- they can display that data or let you interact with the model, but they shouldn't store app state themselves. Given that, there's no reason that you'd need to use the very same view in more than one view controller. As long as your pop up gets its data from the right place, you can have as many instances of it as you like.
If your popup really is separate from the content of any of your view controllers, another possible strategy is to use view controller containment. You can create one view controller that handles just the "app-wide" stuff, like this popup, and have it load and unload the various other view controllers as it's children. I'd caution against trying this, though -- it's probably more complicated than you need and surely more complicated than you should attempt right now given that you seem to still be getting your sea legs.
It sounds like MBProgressHUD is what you're looking for. FFCircularProgressView might also help.
Note: I'm not talking about custom view controller transition effects which can be done by using a custom view controllers it's the iOS 5+ API.
I'm talking about transitioning to another view controller, where a view from the presently displayed view controller is animated to the view controller to be presented's view.
EXAMPLE
-you have friendsViewController which displays a list of the current users friends. Each table view cell has a profile picture and name.
-click on a cell, all other cells fade away and the name and picture animate to the top. At this point, UserProfileViewComtroller is displayed.
THEORIES
-I could easily do this by combining the two view controllers, but UserProfileViewComtroller can be launched from other parts of the app.
-if the UserProfileViewControllers view is instantiated, I could convert the coordinates using UIViews methods
I feel like there is a more appropriate/cleaner solution here which is why I'm asking the community for help :)
It seems to me that what you want is exactly about view controllers transition, since you want to do 'something' that would look to the user as if you took a view from old VC and moved it to the new VC.
Then you're in luck, as you're allowed to move a UIView from one view controller to another using [superview addSubview:view] as part of the transition you want to do.
This can be done on any iOS version, although it's easier now as in iOS 7 there's a delegate you write (see <UIViewControllerAnimatedTransitioning> reference) which has access to both VC's view hierarchies and can change them at will (move one view, fade other views) during transition period.
Also, making your new view controller during the transition transparent (or using old controller's snapshot) will help you hide the fact that VC changed.
Not so much an answer but a technique that might inspire a solution. I did an app that had need for a custom transition like this. The original app arranged itself then took a snapshot, so at the last moment the user is looking at an image. The second viewController was created, given coordinates etc, and the image, then shown immediately. It put the image into its view (subview with same bounds).
At this point the second vc has complete control, and can fade in some other content etc. the reverse was more or less as the start - the image is used, swapped, used removed to uncover the real view content.
Note that this took a bit of time to get it working with no glitches etc.
EDIT: if you are concerned in turning the whole original view into an image, then modify the technique. For instance, in the original view, fade all other content to black but the cell, then snapshot the one cell. The second view will start with an all black background, and place the cell image over top it, then go from there.
EDIT2: As mentioned in the comments, you of course push the second view with no animation, so it happens instantaneously. By setting a small image on the second vc, with an agreed upon background, you can quickly "pass the baton" so to speak and let the second controller go to work quickly and seamlessly.
I apologize in advance for not being able to efficiently describe my problem statement. But, I shall include a link to an image to better describe what I'm looking for. Basically I have a Viewcontroller with a TableView inside it and I have a toolbar on top with three bar button items on it. Now what, I want is to be able to have a functionality whereby the user taps on any of these buttons and we go to different views. Now, I would like a design where if possible I stay on the same screen and render the information in the tableview below depending on which button has been pressed. Visually, I'm trying to go for an effect where the button that is pressed is shown as being depressed and information is rendered and on pressing a different button a different view is rendered. I'm familiar with attaching different view controllers to all the buttons and then segueing into those viewers. However, I would like to know if there's a way in which I can stay on the same view controller and just use sub views. If there is, how can I do this from storyboards? Again,, I apologize for being verbose, my picture should hopefully be able to tell you what I'm trying to do.
The link to what I'm trying to achieve: http://imgur.com/GM5eH
Well, one basic solution is simply to add these other views in your controller. Now that subview is set to hidden on viewDidLoad:. Then just create an action, and show the subView. You can size that view however you want, and play around with the other view as well.
Now, there might be a better way to do this, but that is how I would do it.
EDIT - Concerning Apple's method on Calender
Now, I have never tried anything like this, so this is all theory.
First, you create three classes. Each with it's own custom view. This view should be the size you need it on the other (Main View). You can set the size to freeform in the Interface Builder.
Once you have that done, you head to your main view. That view will have the three buttons. Set an IBAction for each of those that creates an instance of each view and places it on the screen. (I am not sure how to accomplish this, but I am sure there is a way. Take a look here: Objective-c Adding subViews in my controller
You should dealloc each view after you head to another view as well for memory management.
I'm building a custom view with an xib file that contains various subcontrols. I've got some container control that needs to hold my custom view. I'm kind of unclear on whether I need to make a View that somehow loads itself from the xib file, or a ViewController that does this.
However it's done, I'd like my custom view to be reusable, and something that appears in the toolbox in Xcode, along side buttons and textboxes and such, so I can visually design other views containing my custom view.
What is the right way to do this?
Does your component manages other view controllers (like UITabBarViewController does for example)? If yes, make it a subclass of view controller, if not, and it's just a control, like a switch or a fancy button, scroll wheel etc, then make it a subclass of UIView.