How to update iOS PhotoScroller sample code - ios

I'm using altered sample code from PhotoScroller within my app. I have a table view of image thumbnails, and I can pass the array of images that populate that table to PhotoViewController. Currently, PhotoViewController starts with the first image in my array and I can scroll back and forth. This works properly as Apple's sample code.
Now What I want to do is tap a table cell with thumbnail, and start scrolling images beginning with the image in my array at that index. Ex: if I have 5 images in a table and I tap image #3, I want the first image in PhotoViewController to be that third image, and able to scroll left or right to #2 or #4. Hope this makes sense.
I see in PhotoViewController that sub views are being added per image. Any way I can tell it "jump to view #3" without destroying the other views or their overall order of appearance? Any ideas or advice is welcome. Code can be found on the iOS developer site for PhotoScroller sample code.
Ok, I'm rambling... Thanks in advance for your help!

The way I do this is to have a variable called startingPage which gets set in the initialiser of the photo view controller. Then when the pages are being created, first set the correct offset for the scroll view.
So in the PhotoScroller case that would be in loadView. Like so:
- (void)loadView
{
// Step 1: make the outer paging scroll view
CGRect pagingScrollViewFrame = [self frameForPagingScrollView];
pagingScrollView = [[UIScrollView alloc] initWithFrame:pagingScrollViewFrame];
pagingScrollView.pagingEnabled = YES;
pagingScrollView.backgroundColor = [UIColor blackColor];
pagingScrollView.showsVerticalScrollIndicator = NO;
pagingScrollView.showsHorizontalScrollIndicator = NO;
pagingScrollView.contentSize = [self contentSizeForPagingScrollView];
pagingScrollView.delegate = self;
self.view = pagingScrollView;
// Set the content offset of the scrollview
CGRect bounds = pagingScrollView.bounds;
CGPoint contentOffset = CGPointMake(bounds.size.width * startingPage, 0.0f);
[pagingScrollView setContentOffset:contentOffset animated:NO];
// Step 2: prepare to tile content
recycledPages = [[NSMutableSet alloc] init];
visiblePages = [[NSMutableSet alloc] init];
[self tilePages];
}

Related

Should I use GIF file or animation code on iOS?

I intend to make a splash screen on iOS consists of a person, a chair objects. Each of these objects has seperated aspects like the hands, head, body and feets that animated together. I wonder which is better way to go? Importing a GIF file or coding CALayer objects then adding animation?
You can't use GIF files or any code for animation for your launchscreen (splash screen), you can only use a static image, a PNG or JPG (if the launchscreen is a storyboard).
So, if you want your app's startup with some animation then you should manage it in your first view controller.
You can animate imageview with image sets like,
UIImageView* myImageViewForAnimation = [[UIImageView alloc] initWithFrame:self.view.bounds];
myImageViewForAnimation.animationImages = [NSArray arrayWithObjects:
[UIImage imageNamed:#"image1"],
[UIImage imageNamed:#"image2"],
[UIImage imageNamed:#"image3"],
[UIImage imageNamed:#"image4"], nil];
myImageViewForAnimation.animationDuration = 1.0f;
myImageViewForAnimation.animationRepeatCount = 0;
[myImageViewForAnimation startAnimating];
[self.view addSubview: myImageViewForAnimation];
Update (as asked in comment) :
You can get your view on which you have added gesture recognizer in your action method or you can set tag to every imageview and handle it in action method.
For example,
-(void)tapOnProfileImage : (UITapGestureRecognizer*)recog{
UIImageView *tempView = (UIImageView *)recog.view;
// or
if (recog.view.tag == 1) {
// image 1
}
if (recog.view.tag == 2) {
//image 2
}
}
So, on every image view, you should add target with selector - tapOnProfileImage and you can differentiate it as mentioned in above code snippet!
You can use gif image but not directly on launch xib. You create one view controller and load gif image on that view controller, once animation is completed then remove this controller from navigation stack. https://github.com/Flipboard/FLAnimatedImage use this gif image view control.

iOS Image Viewer: Set Zoomed Image Back when Scrolling

I have a gallery view that I use to, surprise, view images. :) I wanted it to be very similar to the standard iOS photo app with the same basic functionality: scrolling through images that are zoomable. To do this, I use a regular scroll view which I then populate with other scroll views that contain the images. The basic idea is something like this:
And, I do the populating the following way:
for (int i = 0; i < [imageGalleryArray count]; i++)
{
UIScrollView *imageContainer = [[UIScrollView alloc] initWithFrame:CGRectMake((windowSize.width * i), 0.0f, windowSize.width, windowSize.height)];
imageContainer.contentSize = CGSizeMake(windowSize.width, windowSize.height);
imageContainer.showsHorizontalScrollIndicator = NO;
imageContainer.showsVerticalScrollIndicator = NO;
imageContainer.bouncesZoom = YES;
imageContainer.delegate = self;
imageContainer.minimumZoomScale = 1.0f;
imageContainer.maximumZoomScale = 3.0f;
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0.0f, 0.0f, windowSize.width, windowSize.height)];
imageView.image = [[imageGalleryArray objectAtIndex:i] objectForKey:#"image"];
imageView.contentMode = UIViewContentModeScaleAspectFit;
imageView.tag = IMAGEZOOMVIEW;
imageView.opaque = YES;
[imageContainer addSubview:imageView];
[galleryScrollView addSubview:imageContainer];
// Add it to array for proper removal later
[contentScrollViewSubviewList addObject:imageContainer];
}
Quite simple and it works fine. The only problem arises when I am zoomed into an image and want to scroll to another. The expected behavior in this case would be to set the zoom level of all images back to their original size. I do this in the scrollViewDidEndDecelerating delegate method like so:
if (scrollView.tag == GALLERYSCROLLVIEW)
{
for (int i = 0; i < [contentScrollViewSubviewList count]; i++)
{
[[contentScrollViewSubviewList objectAtIndex:i] setZoomScale:1.0f animated:YES];
}
}
Unfortunately, it does not work (or rather not as intended). I did some poking around and found out that the image does indeed animate back to its original size when it is the active slide. To elaborate: if I zoom into an image and scroll to another, the image stays zoomed in. When I scroll back to it, that is when it zooms back to its original size. I, however, need the image to scale back as soon as I move away from it ().
just like in the iOS image viewer).
Frankly, I do not understand the whole zoom mechanic enough to find out how to do this properly, and the UIScrollView documentation is of no help either. Could someone show me how to solve my problem?

Key-Frame Animation appears fuzzy when moving Frames?

I use JazzHands to create a key frame based animation in a UIScrollView.
Here is an example. Look at the view at the top. When you move from page to page. While the animation is running the view at the top is slightly moving from left to right. The animation appears a bit fuzzy.
Here is the code taken from the example here:
IFTTTFrameAnimation *titleView1FrameAnimation = [IFTTTFrameAnimation new];
titleView1FrameAnimation.view = self.titleView1;
[self.animator addAnimation:titleView1FrameAnimation];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(1)
andFrame:self.titleView1.frame]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(2)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(2), 0)]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(3)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(3), 0)]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(4)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(4), 0)]];
When running the demo take a look at the part marked with red in the following screenshot:
Edit: Here is the code containing this problem: https://github.com/steffimueller/Intro-Guide-View-for-Talk.ai
How can I make the animation running smooth and less fuzzy?
This is due to the frame rate in the JazzHands IFTTTAnimatedScrollViewController being set for non-retina displays. You need to double the number in timeForPage, and also use double the number of the contentOffset in animate, but use the original non-doubled values of timeForPage in places where you were using that for laying out the positions of views instead of using it for the animation time.
Here's a Gist of the changes you'd have to make to your example to get it working. Fixed Demo Gist
You need this method for setting the animation times:
#define timeForPage(page) (NSInteger)(self.view.frame.size.width * (page - 1) * 2.0)
And this one for setting the centers of your views based on the page dimensions:
#define centerForPage(page) (NSInteger)(self.view.frame.size.width * (page - 1))
Then you need to override the scrollViewDidScroll: method in IFTTTAnimatedScrollViewController to use double the numbers it's currently using.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
[self.animator animate:(NSInteger)(scrollView.contentOffset.x * 2)];
}
We'll work on getting the JazzHands demo updated!
Before you start your animation call:
view.layer.shouldRasterize = YES; (seems that you are using objective-c so I put YES here, for swift should be true)
As soon as the animation is finished call
view.layer.shouldRasterize = NO; (seems that you are using objective-c so I put NO here, for swift should be false)
You should always use it when you animating a view
You can see more details about it in the WWDC 2012 Polishing Your Interface Rotations video (paid developer subscription needed)
I hope that helps you!
[EDIT]
Every Time you call the method animate set shouldRasterize to YES before it, like in the example bellow:
titleView1FrameAnimation.view.layer.shouldRasterize = YES;
[self. titleView1FrameAnimation animate:scrollView.contentOffset.x];
I've messed around a bit with the code and it seems that keeping those top views in place while the scrollview is scrolling made it jiggle left and right.
What I did is take out the title view from the scroll view and add it to the view controller view.
You can see it in action here
Later edit:
To actually see what I've changed you can check the file differences in Git. Basically I moved your titleViews (titleView1, titleView2, etc) from the scrollView to the view controller's view (so basically I've replaced all the lines that were like this:
[self.scrollView addSubView:self.titleView1]
to something like this:
[self.view addSubView:self.titleView1]
After that I've also took out the keyframe animations that were keeping your title views in place since they were not moving with the scrollview anymore. Practically I've deleted all the lines that were adding a frame animation to your titleviews from each configurePageXAnimation.
2nd question answer:
Say your screenshot view is called screenshotView. You can go ahead and create it like this:
UIImageView *screenshotView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"ScreenshotImage"]];
[self.view addSubview:screenshotView];
self.screenshotView = screenshotView;
[self.screenshotView setCenter:CGPointMake(self.view.center.x + self.view.bounds.size.width, <#yourDesiredY#>)];
And animate it like this:
//screenshotView frame animation
IFTTTFrameAnimation *screenshotViewFrameAnimation = [IFTTTFrameAnimation new];
screenshotViewFrameAnimation.view = self.screenshotView;
[self.animator screenshotViewFrameAnimation];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(1) andFrame:self.screenshotView.frame]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(2) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width, 0.0)]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(3) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width, 0.0)]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(4) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width * 2, 0.0)]];

Can't update a UIImageView properly

I call this method in my ViewController, which contains a UIScrollView, when the user taps a button.
-(void) updateView:(NSURL *) urlPicture{
UIImageView *imageNews = [[UIImageView alloc]initWithFrame:CGRectMake(0,0,300,200)];
imageNews.contentMode = UIViewContentModeScaleAspectFit;
[imageNews setImageWithURL:urlPicture];
[self.scrollView addSubview:imageNews];
}
It seems to work fine, but when I got a strange behavior.
It doesn't clear the previous image to put the new one.
E.g: if the first image is 300x200 and the second one is 200x200 I still can see the sides of the first one when the app download the second.
I would like to know how to clear the previous image before download the second.
I already try imageNews.image = nil; but it didn't work
First you need to remove old view from scrollView. You can edit your code as mentioned below
#define IMAGE_VIEW_TAG 1001
-(void) updateView:(NSURL *) urlPicture{
UIView *oldView = [self.scrollView viewWithTag:IMAGE_VIEW_TAG];
if(oldView)
[oldView removeFromSuperView]
UIImageView *imageNews = [[UIImageView alloc]initWithFrame:CGRectMake(0,0,300,200)];
imageNews.tag = IMAGE_VIEW_TAG;
imageNews.contentMode = UIViewContentModeScaleAspectFit;
[imageNews setImageWithURL:urlPicture];
[self.scrollView addSubview:imageNews];
}
Well I am not really sure what your application does ,
but seems like you need to have only 1 image
so I would suggest you to remove the previous image.
There are 2 ways to do so:
1) you could use your image as property and simply call [_imageNews removeFromSuperView];
2) you can iterate through your self.scrollView's sub views and remove it from there.

Shadow in separate view from UIImage for dynamic adjustments

I would like to obtain this effect (http://stackoverflow.com/questions/7023271/how-to-adjust-drop-shadow-dynamically-during-an-uiimageview-rotation) but from a more complex image than just a red square ! If the link ever gets broken, it's a about how to adjust drop shadow dynamically during an UIImageView rotation.
So I tried implementing something but I just can't get the shadow in a separate layer... Here is my code, very simple, but doesn't work:
// here is my code
- (void)viewDidLoad {
[super viewDidLoad];
testView = [[UIImageView alloc] initWithImage: [UIImage imageNamed:#"handNoShadow.png"]];
testViewShadow = [[UIView alloc] initWithFrame:testView.frame];
testViewShadow.layer.shadowPath = [[testView layer] shadowPath];
testViewShadow.layer.shadowOpacity = 1.0;
testViewShadow.layer.shadowOffset = CGSizeMake(10, 10);
testViewShadow.layer.shadowRadius = 5.0;
[self.view addSubview:testViewShadow];
[self.view addSubview:testView];
}
PS: i did #import
I do get an image but no shadow... =(
Any lead, help, code, link... is welcome !
Thanks
possible cause:
your testViewShadow.clipToBounds property is set to YES (should be NO)
your testViewShadow do the drawing of the shadow correctly but another UIView is on top and mask it. Check your Z order. Either the order in Storyboard/Nib file (or the order you added the subviews programmatically). Last in the list (or last one added) is on top. For my app I had to put the UIView that need a shadow last so that no other view mask it.

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