Xcode: How can I slide left/right between UIViews? - uiview

I want the easiest way to implement a sliding right/left gesture between multiple UIViews like AngryBirds levels as in the below screenshot

Your best bet is probably to not use a slide gesture, instead use a UIScrollView with a contentSize.width smaller than its frame.size.width (to show the previous/next pages), with pagingEnabled = YES and clipsToBounds = NO.

Related

UIScrollView over MKMapView

I'm trying to create a specific layout in an iOS App, where the "background" is a MKMapView and the overlay is a UIScrollView. The idea is that there are two screens, one with a map, and another with some additional information on. The user can scroll down to see this general information, and this view covers up the map and has a blurred background to create some depth.
Here's an image showing the layout:
As you can see, the map is fixed in its position. It will always be behind the content, even if you scroll. I want the map to respond to gestures, but only when used directly on the map. When the user "scrolls" over the bottom bar, I want the content to scroll up, revealing the second page which then covers the map.
I'm lost at what to do to achieve this. I tried putting the map on the original UIView and then covering it up with a scrollview, but this causes the map not to respond to gestures. I only want the UIScrollView to respond to gestures when it's on either the bottom bar, or the second page (each is its own separate view). Otherwise I want the Map to respond to the gestures.
I hope I managed to explain it well, if not, please do not hesitate to ask questions. I appreciate all help!
It sounds like you are adding a full screen UIScrollView on top of a MKMapView and the scrollview is picking up all the touches.
What you are asking about is not necessarily standard so there are multiple ways to implement it and you have to decide what works best for your use case.
Here is what I would do:
Use constraints on the scrollview to ensure that it is only covering the bottom bar area.
Make sure you can toggle the constant of the constraint controlling the scroll view's height (hook up an IBOutlet if you're using storyboard).
Add both a swipe gesture recognizer and a tap gesture recognizer that will fire toggleScrollViewFullScreen if recognized. Ensure that these recognizers can only be recognized while the scrollView is the bottom bar.
Have an X-out button display in the top corner while the scrollview is in full screen. This button can call toggleScrollViewFullScreen to dismiss the view back down.
Example toggleScrollViewFullScreen method:
//Toggle size of scroll view
- (void) toggleScrollViewFullScreen {
CGFloat bottomBarHeight = 100;
if (self.scrollViewHeightConstraint.constant > bottomBarHeight){
self.scrollViewHeightConstraint.constant = bottomBarHeight
}else {
self.scrollViewHeightConstraint.constant = self.view.bounds.size.height;
}
//Animate constraint change:
[UIView animateWithDuration:1 animations:^{
[self.view setNeedsUpdateConstraints];
[self.view setNeedsLayout];
}];
}

iOS: How do I allow scrolling only when the user drags the scrollbar?

I have been trying to create a scrollable view using UIScrollView. I want this view to be a scratchpad where I can do rough work with touch gestures.
But, doing a drag gesture makes the UIScrollView move the page.
This is why I want to disable scrolling on gesture and enable scrolling only when I drag the scroll bars on the screen.
I have tried Googling, but haven't found any result so far.
It would be great if you could guide me to a solution or help me with some pointers.
Not sure you can or that it would be usable.
How about enabling scrolling only with 2 fingers? By setting the scroll view pan gesture minimumNumberOfTouches To 2.
Otherwise, think about acting as the delegate of the scroll view pan gesture, specifically for gestureRecognizer:shouldReceiveTouch: so that you can examine the touch position and only allow the gesture to start of significantly close to the edge of the view.
I world recommend using this library: https://github.com/BasheerSience/BRScrollBar
1- Use instance method to add the scrollBar
2- in your UIViewController add these lines of code
// First intit by using the instance method
_brScrollBarController = [BRScrollBarController initForScrollView:self.scrollView
inPosition:kIntBRScrollBarPositionRight
delegate:self];
// show the scrollBar always, do not hide
_brScrollBarController.scrollBar.hideScrollBar = NO;
// disable scrolling for your scrollView
self.scrollView.scrollEnabled = NO;
3- now your scrollView will not respond to gestures, and you will use BRScrollView to scroll by dragging the bar
let me know if you have any questions

iOS UIScrollView with multiple pages visible

I'm having a little issue with scrollview pagination.
My intention is to have 3 pages visible on screen and when I scroll right only on page is scrolled, following the example below, scrolling right will display page 2, 3 and 4 on screen:
However I don't know how to display mutiple pages at the same time, at the moment I have it like this:
Obviously like this is not what I want.
To achieve the desired functionality I tried making the scrollview's frame the size of the page I want (1/3 of the screen width) and setting the clipToBound to NO so the other pages are visible. This indeed shows 3 pages in the screen; however since the scrollview frame is only 1/3 of the screen I can only swipe in that area, I would like the swipe area to be the whole screen width.
You're on the right path. Now you can try manipulating UIPanGestureRecognizer of your scrollView, say, re-attaching it to scrollView's superview.
Alternatively, take a look at iCarousel, it can be perfectly customized to suit your needs.
My solution in the end was the following:
I took my initial approach.
I disabled the scrollview's scrollEnabled property.
Added swipe gesture recognisers to the scrollview.
When the gesture is made I modify the scrollview's contentOffset to move 320/3 pixels to the right or left.

What control should I use when doing this in objective-C

Below is my snapshot. In this snapshot I have to make the boot control like images when I click image#1 then image#1 show on the upper side UIImageView I also define on the image... image#1 .. image#1000
so what controls should I use? I think I should use UIScrollView but I don't know what is the height and width I should take for that because UIScrollView has only game of height and width and also how to define click control on them.
I want some slider look like .. I slide the below images.
Yes you will want to use a UIScrollView for this. The width and height will have to be calculated dynamically based off how many images you have and their dimensions.
To perform actions on touches, you will have to either encapsulate each image into a subclass view and handle the touches, or use gesture recognizers.
See this document for more info.
I would use UIButton for the bottom images and UIImageView for the top view.

How can I let UIScrollView (pagingEnabled) to move 1.2 page each time?

Ok. here is the story:
I have a UIWebView in full screen, width = 768
It loads several images and those images are in one line, which means the UIWebView will scroll only horizontally.
Now, I set the UIScrollView inside the UIWebView to pagingEnabled = YES. So the scroll on the UIWebView will move page by page.
The problem is that every image's width is about 900. I won't scale them down and if I scroll the UIWebView, from the 2nd page on, always 132points of previous image will show. This is not good for me.
So how can I manipulate the UIWebView or the UIScrollView inside the UIWebView so that each scroll will move a page of 900 points, if the view's frame width is 768?
The constraints are:
I can't change its contentSize
I can't change its bounds or frame
I say these constraints because UIWebView will change them on its own purpose when it loads contents.
Anyone would like to join this brain storming?
Thanks
I'm thinking you're going to need to set a UIScrollView delegate that tracks touches beginning and ending. More specifically, scrollViewDidEndDragging:willDecelerate is what I'm thinking you'll need to use, as it fires the instant a user lifts their hand from the device.
First, pagingEnabled=NO seems obvious, we're going to have to control our own paging. Which, I don't feel is too tough. Track the direction of the scrolling in scrollViewDidScroll:, so that we have some global set:
BOOL isGoingRight = YES or NO (NO means the last movement was to the left)
float PAGESIZE = 900.0;
Here's how my scrollview delegate method would look like that handles paging.
- (void) scrollViewDidEndDragging:(UIScrollView*)_scrollView willDecelerate:(BOOL)willDecelerate {
float offsetProportion = _scrollView.contentOffset.x/_scrollView.frame.size.width;
//depending upon our direction, round up or down
int page = isGoingRight? ceilf(offsetProportion): floorf(offsetProportion);
//manually finish the scroll
[_scrollView scrollRectToVisible:CGRectMake(page*PAGESIZE, 0, _scrollView.frame.size.width, _scrollView.frame.size.height) animated:YES];
}
I didn't test this, you may or may not need to disable touches at points.

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