Simple problem, I have a webview that is supposed to hold just an image for the user to be able to zoom in and out. To keep my look clean, I want to completely disable bouncing on this view, but still allow scrolling. This solution does work for the vertical bounce, but as soon as I zoom the image to a size larger than the screen, horizontal bounce is still possible:
for (id subview in webView.subviews
{
if ( [[subview class] isSubclassOfClass:[UIScrollView class]] )
{
((UIScrollView*) subview).bounces = NO;
((UIScrollView*) subview).alwaysBounceVertical = NO;
((UIScrollView*) subview).alwaysBounceHorizontal = NO;
((UIScrollView*) subview).bouncesZoom = NO;
}
}
The following code did the trick for us to stop bouncing:
NSString* scriptToPreventBouncing = #"<script type=\"text/javascript\"> document.ontouchmove = function(e){ e.preventDefault(); } </script>";
NSString* footerHTML = #"<div>All rights reserved</div>";
[footer loadHTMLString: [scriptToPreventBouncing stringByAppendingString:footerHTML] baseURL:[NSURL URLWithString:#"http://somewebsite.com"]];
I am not sure if this will disable the zooming of image. But it should stop the bouncing.
On iOS 5 you can solve your problem this way:
UIWebView *webView = [[UIWebView alloc] ....];
webView.scrollView.scrollEnabled = NO;
webView.scrollView.bounces = NO;
NOTE: this will work only on iOS5 and higher
Related
Unable to click the dots in Page Control. Also, need to change the UICollectionView while clicking the dots. Anyone help me regarding this?
-(void)changepage:(UIPageControl *)sender {
// UIPageControl *pager=sender;
page = sender.currentPage;
CGRect frame = self.AchievementCollection.frame;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0;
[self.AchievementCollection scrollRectToVisible:frame animated:YES];
NSLog(#"page control value %li",(long)sender.currentPage);
}
in Cell For Item at Index Path
AchievementCollectionCell* cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"AchievementCollection" forIndexPath:indexPath];
[pageControls addTarget:self action:#selector(changepage:) forControlEvents:UIControlEventValueChanged];
cell.MiddleLabel.text = [[items objectAtIndex: indexPath.row]valueForKey:#"userCertificateName"];
cell.BottomLabel.text = [[items objectAtIndex: indexPath.row]valueForKey:#"userCertificateDesc"];
return cell;
}
I don't think you're supposed to let the dot clickable, since it's too small for a finger gesture. If you would like something like next / back, then you better have other 2 buttons to handle that.
But, IMHO, the best UX is still let user scroll the scrollview manually.
I have a fixed portrait app using objective-c, and i have a button click for open MWPhotoBrowser for browsing images. Now It works well in portrait mode but I want to make the MWPhotoBrowser for both portrait and landscape mode for rotate the phone. How can I do that, here is my code:
- (void) prepareForPhotoAlbum:(NSArray*)photoObjs {
self.photoURLArrays = [[NSMutableArray alloc]init];
for(int i=0 ; i<photoObjs.count ; i++){
NSDictionary* dictOfImageObj = photoObjs[i];
[self.photoURLArrays addObject:[MWPhoto photoWithURL: [NSURL URLWithString:[NSString stringWithFormat:#"%#/%#",ServerTopicImageURL,dictOfImageObj[#"filename"]]]]];
}
MWPhotoBrowser *browser = [[MWPhotoBrowser alloc] initWithDelegate:self];
// Set options
browser.displayActionButton = YES;
browser.displayNavArrows = NO;
browser.zoomPhotosToFill = YES;
[browser setCurrentPhotoIndex:0];
browser.wantsFullScreenLayout = YES;
[self.navigationController pushViewController:browser animated:YES];
[browser showPreviousPhotoAnimated:YES];
[browser showNextPhotoAnimated:YES];
}
You have 2 options, you can enable the app to be portrait + landscape and go through your VCs and add the 3 rotation methods, shouldAutorotate, preferredOrientation and presentationOrientation, OR, you on this specific VC you can register for NotificationCenter notifications for device orientation, and even though the phone orientation may be locked and / or the apps orientation locked you should get a notification of the rotation happening and apply your own animation transformation to make it appear landscape, this is how most camera apps seem to do it as far as I am aware, becuase you dont want a view port of the camera rotating.
NotificationCenter.default.addObserver(self, selector: Selector, name: NSNotification.Name.UIDeviceOrientationDidChange, object: nil)
In my navigation bar, I have a magnifying glass icon that brings up a search bar. I'm not using a UISearchDisplayController, so I opted to build my own UINavigationItem and then push it over the standard UINavigationItem using pushNavigationItem.
The problem is that the UINavigationItem seems to be pushed around 8 pixels to the right. This causes the cancel button (with localized text 'Annuleren') to be really close to the edge of the screen.
I tried inspecting the self.mySearchBar.bounds at runtime, but the origin is 0,0. I've played around a bit with AutoLayout and programmatically added constraints, but I haven't been successful. I hope it's possible without AutoLayout.
This is my code:
- (IBAction)displaySearchBar:(id)sender {
if (!self.mySearchNavigationItem)
{
self.mySearchNavigationItem = [[UINavigationItem alloc] initWithTitle:#""];
self.mySearchNavigationItem.hidesBackButton = YES;
self.mySearchBar = [[UISearchBar alloc] initWithFrame:CGRectZero];
self.mySearchBar.showsCancelButton = YES;
self.mySearchBar.delegate = self;
[self.mySearchBar sizeToFit];
[self.mySearchBar setPlaceholder:#"Zoeken..."];
UIView *barWrapper = [[UIView alloc]initWithFrame:self.mySearchBar.bounds];
[barWrapper addSubview:self.mySearchBar];
self.mySearchNavigationItem.leftBarButtonItem = nil;
self.mySearchNavigationItem.backBarButtonItem = nil;
self.mySearchNavigationItem.titleView = barWrapper;
UIButton *cancelButton;
UIView *topView = self.mySearchBar.subviews[0];
for (UIView *subView in topView.subviews) {
if ([subView isKindOfClass:NSClassFromString(#"UINavigationButton")]) {
cancelButton = (UIButton*)subView;
}
}
if (cancelButton) {
[cancelButton setTitle:#"Annuleren" forState:UIControlStateNormal];
}
}
[self.navigationController.navigationBar pushNavigationItem:self.mySearchNavigationItem animated:YES];
NSTimeInterval delay;
if (self.tableView.contentOffset.y >1000) delay = 0.4;
else delay = 0.1;
[self performSelector:#selector(activateSearch) withObject:nil afterDelay:delay];
}
try:
self.navigationController.navigationBar.barTintColor = self.mySearchBar.barTintColor;
if that doesn't work, you can add an underlay view to the navigation controller that is the color you would like. this may be useful: Get the right color in iOS7 translucent navigation bar
After searching for many hours, I gave up and went for a dirty fix. I'll leave it open for a while, in case someone knows why my searchbar is moved 8 pixels to the right.
Right before showing the UINavigationItem, I move the whole UINavigationBar to x-coordinate -8.
self.navigationController.navigationBar.frame = CGRectMake(-8.0, self.navigationController.navigationBar.frame.origin.y, self.navigationController.navigationBar.frame.size.width, self.navigationController.navigationBar.frame.size.height);
[self.navigationController.navigationBar pushNavigationItem:self.mySearchNavigationItem animated:YES];
And then on the cancel button click, I move it back to x-coordinate 0.
- (IBAction)cancelSearchBar:(id)sender {
[self.navigationController.navigationBar popNavigationItemAnimated:YES];
self.navigationController.navigationBar.frame = CGRectMake(0.0, self.navigationController.navigationBar.frame.origin.y, self.navigationController.navigationBar.frame.size.width, self.navigationController.navigationBar.frame.size.height);
}
I'm creating an app that can slide between pages of a book, left and right (covering or revealing like a card deck), and sliding up and down will either slide down (and cover) a settings page, or slide up (and reveal) to detailed info on the book.
Essentially, its a "card deck" Sliding functionality, similar to this project https://github.com/sweetmandm/CardSliderView-for-iOS which I'm considering using, however I require BOTH vertical AND horizontal "card deck" sliding capability.
To give you another example of the slide/left cover/reveal effect I'm looking, take a look at the new CNN app, where you can slide between articles.
I've also considered using UIPageViewController, however this does not support the "Slide and Reveal / Slide and Cover" transition I'm looking for, rather only a "Slide Over Left or Right" transition, so I would have to hack it somehow and use multiple UIPageViewControllers, one on top of the over, to allow the "reveal and cover" effect to work, using just the gestures from the UIPageViewController to allow the user to swipe.
I'm familiar with the directionalLockEnabled property on UIScrollview, however I'm wondering still what is the overall best approach to get the effect I'm looking for, one that will support both vertical and horizontal, UIScrollView? UIPageViewController? Nested UIScrollviews? Instead of playing around with the directionalLockEnabled property? Something Else?
What would be the best way to achieve the exact user experience I'm looking to provide?
Ok, I found a solution to my own question, using nested UIScrollViews. I also added a very rough solution as project to github: https://github.com/cohen72/InfiniteDeckScroller.
For the horizontal scrolling, I have three horizontal scroll views, one nested into the other. UIScrollview is automatically handling the proper scrolling of each. Depending on the content offset and which scrollview is being scrolled, I know how to "re-arrange/re-order" the nested scrollviews.
Here is a snippet of the solution I came up.
This particular solution allows sliding up to reveal, however I did not yet implement the sliding down to cover, however doing so would use the same approach as the horizontal solution.
#define BOTTOM 1
#define MIDDLE 2
#define TOP 3
#define VERTICAL_SUB 4
- (void)viewDidLoad{
[super viewDidLoad];
UIScrollView *scroll1 = [[UIScrollView alloc] initWithFrame:self.view.bounds];
UIScrollView *scroll2 = [[UIScrollView alloc] initWithFrame:self.view.bounds];
UIScrollView *scroll3 = [[UIScrollView alloc] initWithFrame:self.view.bounds];
UIScrollView *scroll4 = [[UIScrollView alloc] initWithFrame:self.view.bounds];
scroll1.contentSize = CGSizeMake(self.view.frame.size.width * 2, self.view.frame.size.height * 1);
scroll1.tag = BOTTOM;
scroll1.pagingEnabled = YES;
scroll1.bounces = NO;
scroll1.delegate = self;
[scroll1 addSubview:[self labelForScrollView:scroll1 withBgColor:[UIColor redColor]]];
[scroll1 setContentOffset:CGPointMake(0, 0)];
scroll2.contentSize = CGSizeMake(self.view.frame.size.width * 2, self.view.frame.size.height * 1);
scroll2.tag = MIDDLE;
scroll2.pagingEnabled = YES;
scroll2.bounces = NO;
scroll2.delegate = self;
[scroll2 addSubview:[self labelForScrollView:scroll2 withBgColor:[UIColor orangeColor]]];
[scroll2 setContentOffset:CGPointMake(0, 0)];
scroll3.contentSize = CGSizeMake(self.view.frame.size.width * 2, self.view.frame.size.height * 1);
scroll3.tag = TOP;
scroll3.pagingEnabled = YES;
scroll3.bounces = NO;
scroll3.delegate = self;
[scroll3 addSubview:[self labelForScrollView:scroll3 withBgColor:[UIColor yellowColor]]];
[scroll3 setContentOffset:CGPointMake(320, 0)];
scroll4.contentSize = CGSizeMake(self.view.frame.size.width * 1, self.view.frame.size.height * 2);
scroll4.delegate = self;
scroll4.bounces = NO;
scroll4.pagingEnabled = YES;
scroll4.alwaysBounceVertical = NO;
scroll4.tag = VERTICAL_SUB;
[scroll4 addSubview:scroll1];
[scroll1 addSubview:scroll2];
[scroll2 addSubview:scroll3];
[self.view addSubview:scroll4];
}
- (UILabel*)labelForScrollView:(UIScrollView*)scrollView withBgColor:(UIColor*)color{
UILabel *lbl = [[UILabel alloc] initWithFrame:scrollView.bounds];
lbl.textAlignment = NSTextAlignmentCenter;
lbl.backgroundColor = color;
lbl.text = [NSString stringWithFormat:#"ScrollView: %d", scrollView.tag];
return lbl;
}
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView{
NSLog(#"content offset: %f, tag: %d ", scrollView.contentOffset.x, scrollView.tag);
UIScrollView *newMiddleScrollView, *newBottomScrollView, *newTopScrollView;
// swipe left
if (scrollView.contentOffset.x == 0 && scrollView.tag == TOP) {
newMiddleScrollView = (UIScrollView*)[self.view viewWithTag:TOP];
newTopScrollView = (UIScrollView*)[self.view viewWithTag:BOTTOM];
newBottomScrollView = (UIScrollView*)[self.view viewWithTag:MIDDLE];
}
// swipe right
else if (scrollView.contentOffset.x == 320 && scrollView.tag == MIDDLE) {
newMiddleScrollView = (UIScrollView*)[self.view viewWithTag:BOTTOM];
newTopScrollView = (UIScrollView*)[self.view viewWithTag:MIDDLE];
newBottomScrollView = (UIScrollView*)[self.view viewWithTag:TOP];
}
else {
return;
}
newMiddleScrollView.tag = MIDDLE;
newBottomScrollView.tag = BOTTOM;
newTopScrollView.tag = TOP;
newBottomScrollView.contentOffset = CGPointMake(0, 0);
newMiddleScrollView.contentOffset = CGPointMake(0, 0);
newTopScrollView.contentOffset = CGPointMake(320, 0);
UIScrollView *verticalScrollView_sub = (UIScrollView*)[self.view viewWithTag:VERTICAL_SUB];
[verticalScrollView_sub addSubview:newBottomScrollView];
[newBottomScrollView addSubview:newMiddleScrollView];
[newMiddleScrollView addSubview:newTopScrollView];
}
That's a good question - correct me if I'm wrong here, but it sounds that from left to right there's an arbitrary number of pages/cards, but only a few standard cards to come in from the top or bottom (your settings and details panels).
If that's the case, then you may well want to stick with something along the lines of a UIPageController alongside some gesture recognisers. You set up your page controller (or whatever controller you end up using to achieve your desired cards animation), and then add two gesture recognizers for swipe up and swipe down.
You can then animate your details/settings views in when you receive those gestures, giving you the card like interface without needing to bother with multiple UIPageViewControllers or a scroll view.
This approach isn't so great if you want an arbitrary number of cards in both the horizontal and vertical, but it sounds as if that's not the case.
There would be a lot of different ways to accomplish this, depending on how you want your different controllers to relate to each other. The slide transition itself is pretty simple. I've implemented it this way in a controller that's the superclass of the controller that calls the method:
-(void)SlideInController:(RDSlideController *) next {
next.presentingVC = self;
next.view.frame = CGRectMake(self.view.frame.origin.x + 320, self.view.frame.origin.y, self.view.frame.size.width, self.view.frame.size.height);
[self.view.window addSubview:next.view];
[UIView animateWithDuration:1 animations:^{
next.view.frame = self.view.frame;
} completion:^(BOOL finished) {
self.view.window.rootViewController = next;
}];
}
Then from the newly presented controller, you can call this method to go back:
-(void)SlideOut {
UIViewController *prev = self.presentingVC;
prev.view.frame = self.view.frame;
[self.view.window insertSubview:prev.view belowSubview:self.view];
[UIView animateWithDuration:1 animations:^{
self.view.frame = CGRectMake(self.view.frame.origin.x + 320, self.view.frame.origin.y, self.view.frame.size.width, self.view.frame.size.height);
} completion:^(BOOL finished) {
self.view.window.rootViewController = prev;
}];
}
I am relatively new to programming on the iPad and I was trying to put together a simple program. Basically, it's a children's book and I need the functionality of a comic book style (or photo) viewer, where people swipe to change "pages" (or images).
Each image is 1024x768. Currently, they are stored as JPGs because of the very large file sizes PNGs seem to produce. For this story, there are 28 pages.
I took a look at the PageControl example, implementing a UIScrollView. On initialization, I create a big enough scrollview area. Then as the user scrolls, I load in the previous and next images. Again, just like the example only without implementing the page control at the bottom.
The problem I am running into is a very slight pause in the animation when I am flipping. Once the images are loaded or cached, this doesn't happen. Now, I know the photo application doesn't do this and I'm not sure what is causing it.
Here is my code for the scrollViewDidScroll method. I keep up with the page number and it will only call the loadPageIntoScrollView when a page has changed - I was thinking that the insane number of calls it was making was causing the slight pause in animation, but it turned out not to be the case.
- (void) scrollViewDidScroll: (UIScrollView *) sender
{
CGFloat pageWidth = scrollView.frame.size.width;
int localPage = floor( (scrollView.contentOffset.x - pageWidth / 2 ) / pageWidth ) + 1;
if( localPage != currentPage )
{
currentPage = localPage;
[self loadPageIntoScrollView:localPage - 1];
[self loadPageIntoScrollView:localPage];
[self loadPageIntoScrollView:localPage + 1];
}
} // scrollViewDidScroll
And here is my loadPageIntoScrollView method. I'm only creating a UIImageView and loading an image into that - I don't see how that could be much "leaner". But somehow it's causing the pause. Again, it's not a HUGE pause, just one of those things you notice and is enough to make the scrolling look like it has a very. very slight hiccup.
Thank you in advance for any help you could provide.
- (void) loadPageIntoScrollView: (int)page
{
if( page < 0 || page >= kNumberOfPages )
return;
UIImageView *controller = [pages objectAtIndex:page];
NSLog( #"checking pages" );
if( (NSNull *)controller == [NSNull null] )
{
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleSingleTap:)];
NSString *pageName = [[NSString alloc] initWithFormat:#"%d.jpg", page];
controller = [[UIImageView alloc]initWithImage:[UIImage imageNamed:pageName]];
[controller setUserInteractionEnabled:YES];
[controller addGestureRecognizer:singleTap];
[pages replaceObjectAtIndex:page withObject:controller];
[controller release];
} // if controller == null
// add the page to the scrollview
if( controller.superview == nil )
{
NSLog(#"superview was nil, adding page %d", page );
CGRect frame = scrollView.frame;
frame.origin.x = frame.size.width * page;
frame.origin.y = 0;
controller.frame = frame;
[scrollView addSubview:controller];
} // if
} // loadPageIntoScrollView
Since you say after an image is loaded in it no longer lags, I'd suspect that it is disk access that is causing your lag, but you should run your app through instruments to try to rule out cpu-spikes as well as evaluate file system usage. You may try to pre-load images to the left and right of whatever image you are on so that the user doesn't perceive as much lag.
First off, you should be able to use PNG's just fine. I have build several apps that do exactly what you are doing here, you can fit 3 1024 x 768 PNGs in memory without running out (but you can't do much more). You should also use PNG's as they are the preferred format for iOS as they are optimized when the app is bundled together during build.
The slight lag is caused by loading the image, in this line:
controller = [[UIImageView alloc]initWithImage:[UIImage imageNamed:pageName]];
What I usually do is load the images in a separate thread, using something like this:
[self performSelectorInBackground:#selector(loadPageIntoScrollView:) withObject:[NSNumber numberWithInt:localPage]];
Note that you need to put your localPage integer into a NSNumber object to pass it along, so don't forget to change your loadPageIntoScrollView: method:
- (void) loadPageIntoScrollView: (NSNumber *)pageNumber
{
int page = [pageNumber intValue];
....