i have a details view controller with a scrollview on it. And i have load UILabel, UIImageView on top of UIScrollView. The scrollview is set to scroll vertically only. and the view need to be able to recognize swipe left and right to navigate to next/previous page by adding
self.leftGestureRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipeRecognizer:)];
[self.leftGestureRecognizer setDirection:UISwipeGestureRecognizerDirectionLeft];
[self.view addGestureRecognizer:self.leftGestureRecognizer];
So when i swipe within UILabel, it is working. If i swipe start from UIScrollView, it is not working. I guess it is the UIScrollView conflict the swipe gesture.
In short, swipe gesture is only working on the subview but not UIScrollView .Does anyone have any idea on this?
UPDATE:
If i swipe start from scrollview first then end at UILabel, it won't recognize the swipe gesture. If i swipe within UILabel(start and end in the UILAbel) it is able to recognize.
Make sure that if the UIImage allows zooming, the swipe recognizer won't work, since it is trying to zoom. If this is the case, you will need to enable the zoom only in certain case. hope it helps.
Initialize the scroll view with scrolling disabled. Then you need to disable scrolling in the scroll view when the image is not zoomed in, and renabled it when it is zoomed in. This provides the expected behavior.
- (void)scrollViewDidZoom:(UIScrollView *)scrollView {
if (scrollView.zoomScale != 1.0) {
scrollView.scrollEnabled = YES;
} else {
scrollView.scrollEnabled = NO;
}
}
To enable zoom provide an image on a delegate.
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView {
return myImage;
}
Also add the gesture to instance of scrollview like this -
leftGestureRecognizer.delaysTouchesBegan = YES;
[myScrollView addGestureRecognizer:leftGestureRecognizer];
OR You can try the following -
[scrollView.panGestureRecognizer requireGestureRecognizerToFail: leftGestureRecognizer]
Related
I have NSScrollView with drawable content.
It works fine with scrolling until I press Cmd+Tab or hide window in any other way.
When I open window with scrollView second time it doesn't redraw content on scrolling.
so drawRect function for documentView doesn't work anymore.
setting content view (I need to redraw it on scrolling because self.documentView is much wider than window's width)
[self.documentScroll setDocumentView:self.documentView];
in NSClipView
-(void) drawRect:(NSRect)dirtyRect {
[self setCopiesOnScroll: NO];
[super drawRect:dirtyRect];
NSArray* ar = self.subviews;
NSView* docView = ar.firstObject;
BOOL b = docView.needsDisplay;
}
docView.needsDisplay is always NO after window was hidden and shown second time. On application's launch it's always YES and drawRect method calls for documentView on every scrolling event
I am using a UIPanGestureRecognizer on a UIView that is in a UICollectionViewCell. I am using the translationInView method to get the translation along the X axis and slide the UIView left and right. It works fine, but now I cannot scroll up and down in the CollectionView if my finger is on a cell. Is there a way to make the PanGestureRecognizer pass the vertical scrolling to the UICollectionView?
I am trying to replicate the sliding seen in Reeder.app for iOS.
Once the UIPanGestureRecognizer activates in your UIView touches are no longer forwarded through the responder chain, because of that your UICollectionView is not receiving the touches anymore.
You can try setting your UIView as the delegate of your UIPanGestureRecognizer and place the logic of whether the UIPanGestureRecognizer should activate. You have to implement the delegate's method in your UIView:
-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer;
For example with the code below you would tell it not to activate if the velocity on the y axis of the view is greater than the velocity of the x axis (therefore sending the touches to the UICollectionView under it)
-(BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
UIPanGestureRecognizer *recognizer = (UIPanGestureRecognizer *)gestureRecognizer;
CGPoint velocity =[recognizer velocityInView:self];
if(abs(velocity.y)>=(abs(velocity.x))){
return NO;
}else return YES;
}
Hope this is helpful.
Hopefully someone can help with this issue. I have a class derived from UIScrollView and I'd like to prevent the user from being able to zoom or scroll via manual pinch and swipe gestures. All view navigation will instead be controlled by programmatic means in response to where a user taps (think of an ebook reader where tapping on the left or right sides of the display causes the view to scroll by exactly one page width). Any suggestions on how to implement this?
On your - (void)viewDidLoad; you should be able to just disable whatever gesture recognizer you want. In this case:
UIPinchGestureRecognizer *pinchRecognizer = self.pinchGestureRecognizer;
pinchRecognizer.enabled = NO;
or
UIPanGestureRecognizer *panRecognizer = self.scrollView.panGestureRecognizer;
panRecognizer.enabled = NO;
I sometimes do this from view controllers that contain UIScrollViews. I just target the scroll view (self.scrollView.pinchGestureRecognizer) and temporarily disable gestures when the app. is in a certain state.
To prevent user-controller zooming and panning but still allow programmatic zooming and panning of a scrollview, the best approach is to override the UIScrollView's -addGestureRecognizer: method in a subclass.
In my use I wanted to block all the recognizers and control the viewable area completely from my view controller, I did so like this:
-(void)addGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer {
//Prevent any of the default panning and zooming controls from working
gestureRecognizer.enabled = NO;
[super addGestureRecognizer:gestureRecognizer];
}
Each gesture recognizer is simply disabled, for finer control (allowing the pan control but only allow zooming via a double tap for instance) you'd simply check the incoming gesture recognizer via -isKindOfClass: and disabling as appropriate.
-(void)addGestureRecognizer:(UIGestureRecognizer *)gestureRecognizer {
//Prevent zooming but not panning
if ([gestureRecognizer isKindOfClass:[UIPinchGestureRecognizer class]]) {
gestureRecognizer.enabled = NO;
}
[super addGestureRecognizer:gestureRecognizer];
}
I used this method in a comic reading app that uses guided navigation to animate between cropped panels on a page with the full page being contained in a UIScrollView.I can smoothly zoom in and out on a selected area by simply setting the view bounds to the region I want to display.
A quick note here. It seems UIScrollView's panGestureRecognizer and pinchGestureRecognizer are both enabled the first time a view controller is added to a window.
Basically what that means is setting them to enabled = NO in viewDidLoad won't work in some cases. I moved my enabled = NO to viewWillAppear: and it stuck. :)
I don't have too much experience with UIScrollViews, but looking at the docs, it looks like you can set maximumZoomScale, minimumZoomScale, and scrollEnabled to disable everything you want to disable.
Here are the docs: http://developer.apple.com/library/ios/#documentation/uikit/reference/UIScrollView_Class/Reference/UIScrollView.html
From the docs:
scrollEnabled:
If the value of this property is YES ,
scrolling is enabled, and if it is NO
, scrolling is disabled. The default
is YES.
When scrolling is disabled, the scroll
view does not accept touch events; it
forwards them up the responder chain.
maximumZoomScale:
This value determines how large the
content can be scaled. It must be
greater than the minimum zoom scale
for zooming to be enabled. The default
value is 1.0.
In your UIScrollView subclass overwrite also the setZoomScale: method which automatically re-disables the gesture
- (void)setZoomScale:(CGFloat)zoomScale {
[super setZoomScale:zoomScale];
self.pinchGestureRecognizer.enabled = NO;
}
I am using uiwebview in my code and implemented swipe function on uiwebview. For swipe function i have set YES for scaleToFir property for webview, when we give, scaleToFit=YES, content get shrinked. But for my case both needed. swipe aswell as content should not shrink. But disable horizontal bar is fine. can you please help me out?
Srini
for (UIScrollView *scroll in [webview subviews]) {
// Make sure it really is a scroll view and reset the zoom scale.
if ([scroll respondsToSelector:#selector(setZoomScale:)]){
scroll.bounces=FALSE;
}
}
Try This:
- (void)webViewDidFinishLoad:(UIWebView *)webView {
NSLog(#"loaded");
[webView.scrollView setContentSize: CGSizeMake(webView.frame.size.width, webView.scrollView.contentSize.height)];
}
I am busy with an application and I want to implement a scrollview like the tweetdeck application.
You can zoom in en out UITableviews within an UIScrollview.
I was wondering how they did that. What I can imagine is that there are two UIScrollviews.
This because of the zoom in and out of one item in the UIScrollview.
What I don't understand is how the animation precise work and how they zoom out the UITableView.
I was wondering if someone can help me to get in the right direction
Actually a UITableView is a UIScrollView, so if you add some code like following, you will be able to zoom your table view.
self.tableView.maximumZoomScale = 2.0;
self.tableView.minimumZoomScale = 1.0;
And a UIScrollView delegate method
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.tableView;
}