Besides subclassing, is there a simple means to detect double taps on a UIImageView within a UIScrollView?
Thanks
I have created ZoomScrollView class (a drop-in subclass of UIScrollView) that can help you intercept any touches from a scroll view, and also handles double-tap zooming out of the box if that's what you want to do.
Grab it at github.com/andreyvit/ScrollingMadness/ (the README contains a long description of two UIScrollView tricks and the reasoning behind them).
Of course, if you did not want to zoom, and just wanted to intercept a double-tap on some inner image view, then subclassing is your friend. (Another way would be to attach a view controller to that image view or one of its parent views inside UIScrollView, then the controller will be part of the responder chain and will be able to handle the touches.)
Looking at UIImageView.h (within the UIKit framework) there are no public delegate methods or other methods that let you know if the image view has been double-tapped. You'll probably have to subclass.
The answer is NO.
http://developer.apple.com/library/ios/#samplecode/ScrollViewSuite/Introduction/Intro.html
Download the sample code (download link on the top).
See how apple did it.
See you.
Related
I was googling for a while and I found similar problems but when the custom View is inside a ScrollView, but that is not my case.
I have a custom view that consists of a UILabel behind a UITextField, so I can animate that label later.
The problem is that when I add a View in my ViewController and in the Identity Inspector I set the Class as my custom class, when I use the application the UITextField within my custom view does not receive the touches well and it takes time to gain focus and therefore to open the keyboard. The strange thing is that if I move that same arrangement of views to my main ViewController in Storyboard everything works fine. Why doesn't it do it when I place it using the described method?
I plans to reuse this custom view a lot, so putting logic and views in each ViewController is not an option.
Thanks in advance
Well, the problem was in the constraints of the container UIView. That means, the UIView in my main ViewController. The Height of the UIView was a little bit smaller than the space required for my custom view, so although my custom view seemed to draw correctly, it was not receiving the gestures correctly. The solution was simply increase the height to the correct value occupied by my custom View. Thanks a lot!
I want to make the horizontal swipeable page like YouTube. Is there an object in XCode for this? How do I have to do it? I did not find a tutorial about it. Sorry for my English.
Like this
There are tons of components already made for this in the internet, you can try looking at the cocoacontrols site.
If you still want to write your own code for this, one way is writing a custom UIView subclass. The YouTube feature looks very simple and as far as I can guess, they can use two separate UIView subclasses: one for the menu and one for the pages, just as a container.
For the menu you can use UIStackViews or a single UIViews with UIButtons for the page's titles and another view for the selection effect that moves with the UIButton's touch event. This view should provide a delegate or any notification system that fits better to you in order to notify the container that needs to load the right UIViewController's view inside the container.
The container can be a UIView that loads the view property from the UIViewController subclass on demand. Make sure to add the loaded view controller as a child of the parent view controller, otherwise you will loose some important features.
I hope it can help you to start.
I do understand how to go about making the UIKeyboard push up the UIView if the active UITextView is blocked by the UIKeyboard as per this question: How to make a UITextField move up when keyboard is present?.
What I'm wondering is, from a design perspective, how do you go about implementing the keyboardDidShow and keyboardDidHide methods so that all of the views in your app, whether they be a UIView, UITableView, or UIScrollView all have this functionality and so you need to implement these methods only once?
The only way I could think of would be to have the view property of the UIViewController always set to a UIView, and if you have a UIViewController that needs a UIScrollView or UITableView, just attach it as a subview to this. Then if the UITextView is being blocked, just move the parent UIView up so it will move all of the views that are attached to it.
Does this sound like a good plan, or is it even worth it? Anyone else have any other ideas?
This is a little old, but it's a great article about using firstResponder methods to tell views to slide up. I, personally, like to put my UITextField in a parent container and move it all up. However, I do NOT suggest putting everything in there and moving it all up, because the UITextField "feels" better just above the keyboard. But I do like the background or certain items to move up with the UITextField.
See below: http://cocoawithlove.com/2008/10/sliding-uitextfields-around-to-avoid.html
This is a nice implementation that moves the field up based on the section of the screen it's in (upper, middle, lower). Works very well. May need to be updated for newest SDK, but should be pretty easy.
In experimenting with this, I noticed that if you want to make a BaseViewController that implements this functionality to work for everything that inherits from it, you have to attach another view on top of the UIViewController's view property in order to get it to work. Reason is, if you push the UIViewController's view property up when the keyboard appears, then it resets itself if the app comes back from being active and it's messy.
The problem with this however, is now in all of your child classes you have to attach your subviews to this new view property instead of the regular view property. Also, you probably have to make a custom UITableViewController which will inherit from your BaseViewController class so it can inherit the keyboard notification methods.
Ultimately, I've found it's not the worst idea to have another view on top of the UIViewController's property for a bunch of different scenarios. Making a custom UITableViewController isn't that big of a deal either. So if you have a lot of text fields in your app, this might not be the worst way to go.
I have 4 UIViews inside of a main view controller view. All I need to be able to do is drag the views around the "screen". Is UIScrollView the best option for this, or is there a simpler way?
Apple's Touches sample application contains code that does just this, so you might want to check it out.
UIScrollView should be used for scrolling, not dragging. And the 4 scroll views won't work if they're overlapped so don't even think of using UIScrollView in your case.
A dedicate UIView subclass that overrides -touches*****:withEvent: is needed. See http://github.com/erica/iphone-3.0-cookbook-/tree/master/C08-Gestures/01-Direct%20Manipulation/ for example.
I'm looking to have two views which are part of a constituent set. Data in each view would be best represented in a UITableView. I'd like to then add a gesture to flicker the view off screen and have another similar view brought in, with a page indicator control. My fear is that UITableView intercepts touches and becomes the responder to any such 'flickering' which the UIView might be waiting for. This will directly impede on the usability of the application.
So my question to you usability/UI experts is, is putting a UITableView inside of UIPageControl a poor design choice?
A UITableView is a subclass of UIScrollView. The PageControl sample provided with the iPhone SDK explains nicely how to use a UIScrollView with UIPageControl. Any method which belongs to UIScrollViewDelegate will be called inside your view controller if the view controller implements UITableViewDelegate.
To achieve what you are trying to do, the best approach would be to use UITableView with UIPageControl as explained in the PageControl sample.
Hope that helps!