How to disable scrolling entirely in a WKWebView? - ios

I know this looks like a simple question one can simply say:
webview.scrollView.scrollEnabled = NO;
webview.scrollView.panGestureRecognizer.enabled = NO;
webview.scrollView.bounces = NO;
or even
for (UIView* subview in webview.subviews) {
if ([subview respondsToSelector:#selector(setScrollEnabled:)]) {
[(id)subview setScrollEnabled:enabled];
}
if ([subview respondsToSelector:#selector(panGestureRecognizer)]) {
[[(id)subview panGestureRecognizer] setEnabled:enabled];
}
}
but while it does prevent scolling (in the contentOffset meaning) inside the WKWebviewit doesn't prevent it from receiving pan gesture events involving scrolling.
So articles like those of the Huffington Post, which have javascript included to automatically change articles when the user scrolls left or right still get that behavior.
How can I prevent this ?

Before Swift 3
You can simply disable scroll on its implicit scrollView
webView.scrollView.scrollEnabled = false
Swift 3
webView.scrollView.isScrollEnabled = false

Took me a while but I figured out a way of doing this.
I had to remove a private gesture recognizer within a private subview of the WKWebView.
I had a category on WKWebView to do so:
#implementation WKWebView (Scrolling)
- (void)setScrollEnabled:(BOOL)enabled {
self.scrollView.scrollEnabled = enabled;
self.scrollView.panGestureRecognizer.enabled = enabled;
self.scrollView.bounces = enabled;
// There is one subview as of iOS 8.1 of class WKScrollView
for (UIView* subview in self.subviews) {
if ([subview respondsToSelector:#selector(setScrollEnabled:)]) {
[(id)subview setScrollEnabled:enabled];
}
if ([subview respondsToSelector:#selector(setBounces:)]) {
[(id)subview setBounces:enabled];
}
if ([subview respondsToSelector:#selector(panGestureRecognizer)]) {
[[(id)subview panGestureRecognizer] setEnabled:enabled];
}
// here comes the tricky part, desabling
for (UIView* subScrollView in subview.subviews) {
if ([subScrollView isKindOfClass:NSClassFromString(#"WKContentView")]) {
for (id gesture in [subScrollView gestureRecognizers]) {
if ([gesture isKindOfClass:NSClassFromString(#"UIWebTouchEventsGestureRecognizer")])
[subScrollView removeGestureRecognizer:gesture];
}
}
}
}
}
#end
Hope this helps anyone some day.

Credit and many thanks to apouche for the Obj-C code. In case anybody else has the same problem, here is the working solution adapted for Swift 2
extension WKWebView {
func setScrollEnabled(enabled: Bool) {
self.scrollView.scrollEnabled = enabled
self.scrollView.panGestureRecognizer.enabled = enabled
self.scrollView.bounces = enabled
for subview in self.subviews {
if let subview = subview as? UIScrollView {
subview.scrollEnabled = enabled
subview.bounces = enabled
subview.panGestureRecognizer.enabled = enabled
}
for subScrollView in subview.subviews {
if subScrollView.dynamicType == NSClassFromString("WKContentView")! {
for gesture in subScrollView.gestureRecognizers! {
subScrollView.removeGestureRecognizer(gesture)
}
}
}
}
}
}

finally
self.webView.scrollView.userInteractionEnabled = NO

Here is a Swift 3 version:
extension WKWebView {
func setScrollEnabled(enabled: Bool) {
self.scrollView.isScrollEnabled = enabled
self.scrollView.panGestureRecognizer.isEnabled = enabled
self.scrollView.bounces = enabled
for subview in self.subviews {
if let subview = subview as? UIScrollView {
subview.isScrollEnabled = enabled
subview.bounces = enabled
subview.panGestureRecognizer.isEnabled = enabled
}
for subScrollView in subview.subviews {
if type(of: subScrollView) == NSClassFromString("WKContentView")! {
for gesture in subScrollView.gestureRecognizers! {
subScrollView.removeGestureRecognizer(gesture)
}
}
}
}
}
}

I found that I had to make my view controller a UIScrollViewDelegate then add this function to prevent scrolling.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
scrollView.setContentOffset(CGPoint(x: 0, y: 0), animated: false)
}

Here is a C# extension for WKWebView based on alain.s's swift solution (based on apouche's solution) for those of us using Xamarin. I am using this in my app.
Notable differences is that I check if subviews exist before looping and instead of dynamically looking for a "WKContentView" (something I'm not sure is even possible in Xamarin) I simply check if each subview has GestureRecognizers and remove them. This will obviously disable all types of gestures so consider this if you expect any user interaction with the web content.
public static class WKWebViewExtension
{
public static void DisableScroll(this WebKit.WKWebView webView)
{
webView.ScrollView.ScrollEnabled = false;
webView.ScrollView.PanGestureRecognizer.Enabled = false;
webView.ScrollView.Bounces = false;
if (webView.Subviews != null)
{
foreach (var subView in webView.Subviews)
{
if (subView is UIScrollView)
{
UIScrollView subScrollView = (UIScrollView)subView;
subScrollView.ScrollEnabled = false;
subScrollView.Bounces = false;
subScrollView.PanGestureRecognizer.Enabled = false;
}
if (subView.Subviews != null)
{
foreach (var subScrollView in subView.Subviews)
{
if (subScrollView.GestureRecognizers != null)
{
foreach (var gesture in subScrollView.GestureRecognizers)
{
subScrollView.RemoveGestureRecognizer(gesture);
}
}
}
}
}
}
}
}

Here's a swift version if anyone's still having trouble with this issue
let subviews = self.theWebView.scrollView.subviews
for subview in subviews{
if(subview.isKindOfClass(NSClassFromString("WKContentView"))){
if let recognizers = subview.gestureRecognizers {
for recognizer in recognizers! {
if recognizer.isKindOfClass(NSClassFromString("UIWebTouchEventsGestureRecognizer")){
subview.removeGestureRecognizer(recognizer as! UIGestureRecognizer)
}
}
}
}
}

Swift 5
disableScrollView(self.webView)
func disableScrollView(_ view: UIView) {
(view as? UIScrollView)?.isScrollEnabled = false
view.subviews.forEach { disableScrollView($0) }
}

Try to disable scrollView zoom in this way:
CGFloat zoomScale = webview.scrollView.zoomScale;
webview.scrollView.maximumZoomScale = zoomScale;
webview.scrollView.minimumZoomScale = zoomScale;

Related

iOS 13 Custom UISearchBar _searchField crash

with the new iOS 13, i got a crash trying to change the UISearchBar textField properties using valueForKey:#"_searchField"
Now seems that Apple has changed something.
I've created a subclass of UIView with the following custom method and now it seems to work!
- (UIView *)findSubview:(NSString *)name resursion:(BOOL)resursion
{
Class class = NSClassFromString(name);
for (UIView *subview in self.subviews) {
if ([subview isKindOfClass:class]) {
return subview;
}
}
if (resursion) {
for (UIView *subview in self.subviews) {
UIView *tempView = [subview findSubview:name resursion:resursion];
if (tempView) {
return tempView;
}
}
}
return nil;
}
You can simply call this method this way to change UITextField properties:
UITextField *textField = (UITextField*)[self findSubview:#"UITextField" resursion:YES];
Obviously this is an Objective-c snippet and if anyone knows how to write the same code in swift can add it to the answers.
Happy coding!
I'm not sure if it would help, but UISearchBar has a new searchTextField property allowing you to access its UISearchTextField and, in turn, its UITextField:
let searchBar = UISearchBar()
var searchField : UITextField
if #available(iOS 13.0, *) {
searchField = searchBar.searchTextField
} else {
searchField = //Your original method
}
You can do it by using below extension
extension UISearchBar {
func getAllSubview<T : UIView>(type : T.Type) -> [T]{
var all = [T]()
func getSubview(view: UIView) {
if let aView = view as? T{
all.append(aView)
}
guard view.subviews.count>0 else { return }
view.subviews.forEach{ getSubview(view: $0) }
}
getSubview(view: self)
return all
}
}
Use like:
self.searchBar.getAllSubview(type: UITextField.self).first
Output:
<UISearchBarTextField: 0x7fc68d850a00; frame = (0 0; 0 0); text = ''; opaque = NO; layer = <CALayer: 0x600000d29aa0>>
My project is in Objective c and i need to support XCode10 as well so, After two days of headache below line saved my day :
txfSearchField = [_searchBar valueForKey:#"searchField"];
Just need to Remove _ from the old code!!!
In Swift also you can use the same.
Hope it will help someone!

UIBarButtonItem: How can I find its frame?

I have a button in a toolbar. How can I grab its frame? Do UIBarButtonItems not have a frame property?
Try this one;
UIBarButtonItem *item = ... ;
UIView *view = [item valueForKey:#"view"];
CGFloat width;
if(view){
width=[view frame].size.width;
}
else{
width=(CGFloat)0.0 ;
}
This way works best for me:
UIView *targetView = (UIView *)[yourBarButton performSelector:#selector(view)];
CGRect rect = targetView.frame;
With Swift, if you needs to often work with bar button items, you should implement an extension like this:
extension UIBarButtonItem {
var frame: CGRect? {
guard let view = self.value(forKey: "view") as? UIView else {
return nil
}
return view.frame
}
}
Then in your code you can access easily:
if let frame = self.navigationItem.rightBarButtonItems?.first?.frame {
// do whatever with frame
}
Oof, lots of rough answers in this thread. Here's the right way to do it:
import UIKit
class ViewController: UIViewController {
let customButton = UIButton(type: .system)
override func viewDidLoad() {
super.viewDidLoad()
customButton.setImage(UIImage(named: "myImage"), for: .normal)
self.navigationItem.rightBarButtonItem = UIBarButtonItem(customView: customButton)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
print(self.customButton.convert(self.customButton.frame, to: nil))
}
}
Thanks to Anoop Vaidya for the suggested answer. An alternative could be (providing you know the position of the button in the toolbar)
UIView *view= (UIView *)[self.toolbar.subviews objectAtIndex:0]; // 0 for the first item
CGRect viewframe = view.frame;
Here's what I'm using in iOS 11 & Swift 4. It could be a little cleaner without the optional but I'm playing it safe:
extension UIBarButtonItem {
var view: UIView? {
return perform(#selector(getter: UIViewController.view)).takeRetainedValue() as? UIView
}
}
And usage:
if let barButtonFrame = myBarButtonItem.view?.frame {
// etc...
}
Edit: I don't recommend using this anymore. I ended up changing my implementation to use UIBarButtonItems with custom views, like Dan's answer
-(CGRect) getBarItemRc :(UIBarButtonItem *)item{
UIView *view = [item valueForKey:#"view"];
return [view frame];
}
You can create a UIBarButtonItem with a custom view, which is a UIButton, then you can do whatever you want. :]
in Swift 4.2 and inspired with luca
extension UIBarButtonItem {
var frame:CGRect?{
return (value(forKey: "view") as? UIView)?.frame
}
}
guard let frame = self.navigationItem.rightBarButtonItems?.first?.frame else{ return }
You can roughly calculate it by using properties like layoutMargins and frame on the navigationBar, combined with icon size guides from Human Interface Guidelines and take into count the current device orientation:
- (CGRect)rightBarButtonFrame {
CGFloat imageWidth = 28.0;
CGFloat imageHeight = UIDevice.currentDevice.orientation == UIDeviceOrientationLandscapeLeft || UIDevice.currentDevice.orientation == UIDeviceOrientationLandscapeRight ? 18.0 : 28.0;
UIEdgeInsets navigationBarLayoutMargins = self.navigationController.navigationBar.layoutMargins;
CGRect navigationBarFrame = self.navigationController.navigationBar.frame;
return CGRectMake(navigationBarFrame.size.width-(navigationBarLayoutMargins.right + imageWidth), navigationBarFrame.origin.y + navigationBarLayoutMargins.top, imageWidth, imageHeight);
}
Try this implementation:
#implementation UIBarButtonItem(Extras)
- (CGRect)frameInView:(UIView *)v {
UIView *theView = self.customView;
if (!theView.superview && [self respondsToSelector:#selector(view)]) {
theView = [self performSelector:#selector(view)];
}
UIView *parentView = theView.superview;
NSArray *subviews = parentView.subviews;
NSUInteger indexOfView = [subviews indexOfObject:theView];
NSUInteger subviewCount = subviews.count;
if (subviewCount > 0 && indexOfView != NSNotFound) {
UIView *button = [parentView.subviews objectAtIndex:indexOfView];
return [button convertRect:button.bounds toView:v];
} else {
return CGRectZero;
}
}
#end
You should do a loop over the subviews and check their type or their contents for identifying.
It is not safe to access view by kvo and you cannot be sure about the index.
Check out this answer: How to apply borders and corner radius to UIBarButtonItem? which explains how to loop over subviews to find the frame of a button.
I used a view on the bar button item with a tag on the view:
for view in bottomToolbar.subviews {
if let stackView = view.subviews.filter({$0 is UIStackView}).first {
//target view has tag = 88
if let targetView = stackView.subviews.filter({$0.viewWithTag(88) != nil}).first {
//do something with target view
}
}
}
Swift 4 up The current best way to do it is to access its frame from :
self.navigationItem.rightBarButtonItems by
let customView = navigationItem.rightBarButtonItems?.first?.customView // access the first added customView
Accessing this way is safer than accessing private api.
check out the answer in this :
After Add a CustomView to navigationItem, CustomView always return nil

How to implement UITableView`s swipe to delete for UICollectionView

I just like to ask how can I implement the same behavior of UITableView`s swipe to delete in UICollectionView. I am trying to find a tutorial but I cannot find any.
Also, I am using PSTCollectionView wrapper to support iOS 5.
Thank you!
Edit:
The swipe recognizer is already good.
What I need now is the same functionality as UITableView's when cancelling the Delete mode, e.g. when user taps on a cell or on a blank space in the table view (that is, when user taps outside of the Delete button).
UITapGestureRecognizer won't work, since it only detects taps on release of a touch.
UITableView detects a touch on begin of the gesture (and not on release), and immediately cancels the Delete mode.
There is a simpler solution to your problem that avoids using gesture recognizers. The solution is based on UIScrollView in combination with UIStackView.
First, you need to create 2 container views - one for the visible part of the cell and one for the hidden part. You’ll add these views to a UIStackView. The stackView will act as a content view. Make sure that the views have equal widths with stackView.distribution = .fillEqually.
You’ll embed the stackView inside a UIScrollView that has paging enabled. The scrollView should be constrained to the edges of the cell. Then you’ll set the stackView’s width to be 2 times the scrollView’s width so each of the container views will have the width of the cell.
With this simple implementation, you have created the base cell with a visible and hidden view. Use the visible view to add content to the cell and in the hidden view you can add a delete button. This way you can achieve this:
I've set up an example project on GitHub. You can also read more about this solution here.
The biggest advantage of this solution is the simplicity and that you don't have to deal with constraints and gesture recognizers.
Its very simple..You need to add a customContentView and customBackgroundView behind the customContentView.
After that and you need to shift the customContentViewto the left as user swipes from right to left. Shifting the view makes visible to the customBackgroundView.
Lets Code:
First of all you need to add panGesture to your UICollectionView as
override func viewDidLoad() {
super.viewDidLoad()
self.panGesture = UIPanGestureRecognizer(target: self, action: #selector(self.panThisCell))
panGesture.delegate = self
self.collectionView.addGestureRecognizer(panGesture)
}
Now implement the selector as
func panThisCell(_ recognizer:UIPanGestureRecognizer){
if recognizer != panGesture{ return }
let point = recognizer.location(in: self.collectionView)
let indexpath = self.collectionView.indexPathForItem(at: point)
if indexpath == nil{ return }
guard let cell = self.collectionView.cellForItem(at: indexpath!) as? CustomCollectionViewCell else{
return
}
switch recognizer.state {
case .began:
cell.startPoint = self.collectionView.convert(point, to: cell)
cell.startingRightLayoutConstraintConstant = cell.contentViewRightConstraint.constant
if swipeActiveCell != cell && swipeActiveCell != nil{
self.resetConstraintToZero(swipeActiveCell!,animate: true, notifyDelegateDidClose: false)
}
swipeActiveCell = cell
case .changed:
let currentPoint = self.collectionView.convert(point, to: cell)
let deltaX = currentPoint.x - cell.startPoint.x
var panningleft = false
if currentPoint.x < cell.startPoint.x{
panningleft = true
}
if cell.startingRightLayoutConstraintConstant == 0{
if !panningleft{
let constant = max(-deltaX,0)
if constant == 0{
self.resetConstraintToZero(cell,animate: true, notifyDelegateDidClose: false)
}else{
cell.contentViewRightConstraint.constant = constant
}
}else{
let constant = min(-deltaX,self.getButtonTotalWidth(cell))
if constant == self.getButtonTotalWidth(cell){
self.setConstraintsToShowAllButtons(cell,animate: true, notifyDelegateDidOpen: false)
}else{
cell.contentViewRightConstraint.constant = constant
cell.contentViewLeftConstraint.constant = -constant
}
}
}else{
let adjustment = cell.startingRightLayoutConstraintConstant - deltaX;
if (!panningleft) {
let constant = max(adjustment, 0);
if (constant == 0) {
self.resetConstraintToZero(cell,animate: true, notifyDelegateDidClose: false)
} else {
cell.contentViewRightConstraint.constant = constant;
}
} else {
let constant = min(adjustment, self.getButtonTotalWidth(cell));
if (constant == self.getButtonTotalWidth(cell)) {
self.setConstraintsToShowAllButtons(cell,animate: true, notifyDelegateDidOpen: false)
} else {
cell.contentViewRightConstraint.constant = constant;
}
}
cell.contentViewLeftConstraint.constant = -cell.contentViewRightConstraint.constant;
}
cell.layoutIfNeeded()
case .cancelled:
if (cell.startingRightLayoutConstraintConstant == 0) {
self.resetConstraintToZero(cell,animate: true, notifyDelegateDidClose: true)
} else {
self.setConstraintsToShowAllButtons(cell,animate: true, notifyDelegateDidOpen: true)
}
case .ended:
if (cell.startingRightLayoutConstraintConstant == 0) {
//Cell was opening
let halfOfButtonOne = (cell.swipeView.frame).width / 2;
if (cell.contentViewRightConstraint.constant >= halfOfButtonOne) {
//Open all the way
self.setConstraintsToShowAllButtons(cell,animate: true, notifyDelegateDidOpen: true)
} else {
//Re-close
self.resetConstraintToZero(cell,animate: true, notifyDelegateDidClose: true)
}
} else {
//Cell was closing
let buttonOnePlusHalfOfButton2 = (cell.swipeView.frame).width
if (cell.contentViewRightConstraint.constant >= buttonOnePlusHalfOfButton2) {
//Re-open all the way
self.setConstraintsToShowAllButtons(cell,animate: true, notifyDelegateDidOpen: true)
} else {
//Close
self.resetConstraintToZero(cell,animate: true, notifyDelegateDidClose: true)
}
}
default:
print("default")
}
}
Helper methods to update constraints
func getButtonTotalWidth(_ cell:CustomCollectionViewCell)->CGFloat{
let width = cell.frame.width - cell.swipeView.frame.minX
return width
}
func resetConstraintToZero(_ cell:CustomCollectionViewCell, animate:Bool,notifyDelegateDidClose:Bool){
if (cell.startingRightLayoutConstraintConstant == 0 &&
cell.contentViewRightConstraint.constant == 0) {
//Already all the way closed, no bounce necessary
return;
}
cell.contentViewRightConstraint.constant = -kBounceValue;
cell.contentViewLeftConstraint.constant = kBounceValue;
self.updateConstraintsIfNeeded(cell,animated: animate) {
cell.contentViewRightConstraint.constant = 0;
cell.contentViewLeftConstraint.constant = 0;
self.updateConstraintsIfNeeded(cell,animated: animate, completionHandler: {
cell.startingRightLayoutConstraintConstant = cell.contentViewRightConstraint.constant;
})
}
cell.startPoint = CGPoint()
swipeActiveCell = nil
}
func setConstraintsToShowAllButtons(_ cell:CustomCollectionViewCell, animate:Bool,notifyDelegateDidOpen:Bool){
if (cell.startingRightLayoutConstraintConstant == self.getButtonTotalWidth(cell) &&
cell.contentViewRightConstraint.constant == self.getButtonTotalWidth(cell)) {
return;
}
cell.contentViewLeftConstraint.constant = -self.getButtonTotalWidth(cell) - kBounceValue;
cell.contentViewRightConstraint.constant = self.getButtonTotalWidth(cell) + kBounceValue;
self.updateConstraintsIfNeeded(cell,animated: animate) {
cell.contentViewLeftConstraint.constant = -(self.getButtonTotalWidth(cell))
cell.contentViewRightConstraint.constant = self.getButtonTotalWidth(cell)
self.updateConstraintsIfNeeded(cell,animated: animate, completionHandler: {(check) in
cell.startingRightLayoutConstraintConstant = cell.contentViewRightConstraint.constant;
})
}
}
func setConstraintsAsSwipe(_ cell:CustomCollectionViewCell, animate:Bool,notifyDelegateDidOpen:Bool){
if (cell.startingRightLayoutConstraintConstant == self.getButtonTotalWidth(cell) &&
cell.contentViewRightConstraint.constant == self.getButtonTotalWidth(cell)) {
return;
}
cell.contentViewLeftConstraint.constant = -self.getButtonTotalWidth(cell) - kBounceValue;
cell.contentViewRightConstraint.constant = self.getButtonTotalWidth(cell) + kBounceValue;
self.updateConstraintsIfNeeded(cell,animated: animate) {
cell.contentViewLeftConstraint.constant = -(self.getButtonTotalWidth(cell))
cell.contentViewRightConstraint.constant = self.getButtonTotalWidth(cell)
self.updateConstraintsIfNeeded(cell,animated: animate, completionHandler: {(check) in
cell.startingRightLayoutConstraintConstant = cell.contentViewRightConstraint.constant;
})
}
}
func updateConstraintsIfNeeded(_ cell:CustomCollectionViewCell, animated:Bool,completionHandler:#escaping ()->()) {
var duration:Double = 0
if animated{
duration = 0.1
}
UIView.animate(withDuration: duration, delay: 0, options: [.curveEaseOut], animations: {
cell.layoutIfNeeded()
}, completion:{ value in
if value{ completionHandler() }
})
}
I have created a sample project here in Swift 3.
It is a modified version of this tutorial.
In the Collection View Programming Guide for iOS, in the section Incorporating Gesture Support, the docs read:
You should always attach your gesture recognizers to the collection view itself and not to a specific cell or view.
So, I think it's not a good practice to add recognizers to UICollectionViewCell.
I followed a similar approach to #JacekLampart, but decided to add the UISwipeGestureRecognizer in the UICollectionViewCell's awakeFromNib function so it is only added once.
UICollectionViewCell.m
- (void)awakeFromNib {
UISwipeGestureRecognizer* swipeGestureRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipeToDeleteGesture:)];
swipeGestureRecognizer.direction = UISwipeGestureRecognizerDirectionLeft;
[self addGestureRecognizer:swipeGestureRecognizer];
}
- (void)swipeToDeleteGesture:(UISwipeGestureRecognizer *)swipeGestureRecognizer {
if (swipeGestureRecognizer.state == UIGestureRecognizerStateEnded) {
// update cell to display delete functionality
}
}
As for exiting delete mode, I created a custom UIGestureRecognizer with an NSArray of UIViews. I borrowed the idea from #iMS from this question: UITapGestureRecognizer - make it work on touch down, not touch up?
On touchesBegan, if the touch point isn't within any of the UIViews, the gesture succeeds and delete mode is exited.
In this way, I am able to pass the delete button within the cell (and any other views) to the UIGestureRecognizer and, if the touch point is within the button's frame, delete mode will not exit.
TouchDownExcludingViewsGestureRecognizer.h
#import <UIKit/UIKit.h>
#interface TouchDownExcludingViewsGestureRecognizer : UIGestureRecognizer
#property (nonatomic) NSArray *excludeViews;
#end
TouchDownExcludingViewsGestureRecognizer.m
#import "TouchDownExcludingViewsGestureRecognizer.h"
#import <UIKit/UIGestureRecognizerSubclass.h>
#implementation TouchDownExcludingViewsGestureRecognizer
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
if (self.state == UIGestureRecognizerStatePossible) {
BOOL touchHandled = NO;
for (UIView *view in self.excludeViews) {
CGPoint touchLocation = [[touches anyObject] locationInView:view];
if (CGRectContainsPoint(view.bounds, touchLocation)) {
touchHandled = YES;
break;
}
}
self.state = (touchHandled ? UIGestureRecognizerStateFailed : UIGestureRecognizerStateRecognized);
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
self.state = UIGestureRecognizerStateFailed;
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
self.state = UIGestureRecognizerStateFailed;
}
#end
Implementation (in the UIViewController containing UICollectionView):
#import "TouchDownExcludingViewsGestureRecognizer.h"
TouchDownExcludingViewsGestureRecognizer *touchDownGestureRecognizer = [[TouchDownExcludingViewsGestureRecognizer alloc] initWithTarget:self action:#selector(exitDeleteMode:)];
touchDownGestureRecognizer.excludeViews = #[self.cellInDeleteMode.deleteButton];
[self.view addGestureRecognizer:touchDownGestureRecognizer];
- (void)exitDeleteMode:(TouchDownExcludingViewsGestureRecognizer *)touchDownGestureRecognizer {
// exit delete mode and disable or remove TouchDownExcludingViewsGestureRecognizer
}
You can try adding a UISwipeGestureRecognizer to each collection cell, like this:
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
CollectionViewCell *cell = ...
UISwipeGestureRecognizer* gestureRecognizer = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(userDidSwipe:)];
[gestureRecognizer setDirection:UISwipeGestureRecognizerDirectionRight];
[cell addGestureRecognizer:gestureRecognizer];
}
followed by:
- (void)userDidSwipe:(UIGestureRecognizer *)gestureRecognizer {
if (gestureRecognizer.state == UIGestureRecognizerStateEnded) {
//handle the gesture appropriately
}
}
With iOS 14, you can use UICollectionViewLayoutListConfiguration in conjunction with UICollectionViewCompositionalLayout to get this functionality natively for free, no custom cells or gesture recognizes needed.
If your minimum deploy target is >= iOS 14.x, this is probably the preferred method from now on, and it will also let you to adopt modern cell configuration with UIContentView and UIContentConfiguration to boot.
There is a more standard solution to implement this feature, having a behavior very similar to the one provided by UITableView.
For this, you will use a UIScrollView as the root view of the cell, and then position the cell content and the delete button inside the scroll view. The code in your cell class should be something like this:
override init(frame: CGRect) {
super.init(frame: frame)
addSubview(scrollView)
scrollView.addSubview(viewWithCellContent)
scrollView.addSubview(deleteButton)
scrollView.isPagingEnabled = true
scrollView.showsHorizontalScrollIndicator = false
}
In this code we set the property isPagingEnabled to true to make the scroll view to stop scrolling only at the boundaries of its content. The layout subviews for this cell should be something like:
override func layoutSubviews() {
super.layoutSubviews()
scrollView.frame = bounds
// make the view with the content to fill the scroll view
viewWithCellContent.frame = scrollView.bounds
// position the delete button just at the right of the view with the content.
deleteButton.frame = CGRect(
x: label.frame.maxX,
y: 0,
width: 100,
height: scrollView.bounds.height
)
// update the size of the scrolleable content of the scroll view
scrollView.contentSize = CGSize(width: button.frame.maxX, height: scrollView.bounds.height)
}
With this code in place, if you run the app you will see that the swipe to delete is working as expected, however, we lost the ability to select the cell. The problem is that since the scroll view is filling the whole cell, all the touch events are processed by it, so the collection view will never have the opportunity to select the cell (this is similar to when we have a button inside a cell, since touches on that button don't trigger the selection process but are handled directly by the button.)
To fix this problem we just have to indicate the scroll view to ignore the touch events that are processed by it and not by one of its subviews. To achieve this just create a subclass of UIScrollView and override the following function:
override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
let result = super.hitTest(point, with: event)
return result != self ? result : nil
}
Now in your cell you should use an instance of this new subclass instead of the standard UIScrollView.
If you run the app now you will see that we have the cell selection back, but this time the swipe isn't working 😳. Since we are ignoring touches that are handled directly by the scroll view, then its pan gesture recognizer won't be able to start recognizing touch events. However, this can be easily fixed by indicating to the scroll view that its pan gesture recognizer will be handled by the cell and not by the scroll. You do this adding the following line at the bottom of your cell's init(frame: CGRect):
addGestureRecognizer(scrollView.panGestureRecognizer)
This may look like a bit hacky, but it isn't. By design, the view that contains a gesture recognizer and the target of that recognizer don't have to be the same object.
After this change all should be working as expected. You can see a full implementation of this idea in this repo

UIPickerView, detect "rolling wheel" start and stop?

I just discovered that if I do the following:
Click the button that animates a UIPickerView into my view
Quickly start the wheel rolling towards, then past, the last item
Dismiss the view with a button
Then it has not yet selected the last item yet.
I tried this by simply outputting to the console whenever the didSelectRow method was fired, and it fires when the wheel stabilizes on the last item.
Can I detect that the wheel is still rolling, so that I can delay checking it for a selected value until it stabilizes?
If it matters, I'm programming in MonoTouch, but I can read Objective-C code well enough to reimplement it, if you have a code example that is.
As animation keys don't work, I wrote this simple function that works for detecting if a UIPickerView is currently moving.
-(bool) anySubViewScrolling:(UIView*)view
{
if( [ view isKindOfClass:[ UIScrollView class ] ] )
{
UIScrollView* scroll_view = (UIScrollView*) view;
if( scroll_view.dragging || scroll_view.decelerating )
{
return true;
}
}
for( UIView *sub_view in [ view subviews ] )
{
if( [ self anySubViewScrolling:sub_view ] )
{
return true;
}
}
return false;
}
It ends up returning true five levels deep.
Swift 4 (updated) version with extension of #DrainBoy answers
extension UIView {
func isScrolling () -> Bool {
if let scrollView = self as? UIScrollView {
if (scrollView.isDragging || scrollView.isDecelerating) {
return true
}
}
for subview in self.subviews {
if ( subview.isScrolling() ) {
return true
}
}
return false
}
}
Since animationKeys seems to not work anymore, I have another solution. If you check the subviews of UIPickerView, you'll see that there is a UIPickerTableView for each component.
This UIPickerTableView is indeed a subclass of UITableView and of course of UIScrollView. Therefore, you can check its contentOffset value to detect a difference.
Besides, its scrollViewDelegate is nil by default, so I assume you can safely set an object of yours to detect scrollViewWillBeginDragging, scrollViewDidEndDecelerating, etc.
By keeping a reference to each UIPickerTableView, you should be able to implement an efficient isWheelRolling method.
Expanded #iluvatar_GR answer
extension UIView {
func isScrolling () -> Bool {
if let scrollView = self as? UIScrollView {
if (scrollView.isDragging || scrollView.isDecelerating) {
return true
}
}
for subview in self.subviews {
if ( subview.isScrolling() ) {
return true
}
}
return false
}
func waitTillDoneScrolling (completion: #escaping () -> Void) {
var isMoving = true
DispatchQueue.global(qos: .background).async {
while isMoving == true {
isMoving = self.isScrolling()
}
DispatchQueue.main.async {
completion()}
}
}
}
Expanded #iluvatar_GR, #Robert_at_Nextgensystems answer
Used Gesture, UIScrollView isDragging or isDecelerating.
// Call it every time when Guesture action.
#objc func respondToSwipeGesture(gesture: UIGestureRecognizer) {
// Changes the button name to scrolling at the start of scrolling.
DispatchQueue.main.async {
self._button.setTitle("Scrolling...", for: .normal)
self._button.isEnabled = false
self._button.backgroundColor = Utils.hexStringToUIColor(hex: "FF8FAE")
}
// Indication according to scrolling status
_datePicker.waitTillDoneScrolling(completion: {
print("completion")
DispatchQueue.main.async {
self._button.setTitle("Completion", for: .normal)
self._button.isEnabled = true
self._button.backgroundColor = Utils.hexStringToUIColor(hex: "7CB0FF")
}
})
}
[SWIFT4] Share Example Source link!
enter Sample Source link
Reference : How to recognize swipe in all 4 directions
I think you can just check if the UIPickerView is in the middle of animating and wait for it to stop. This was answered here link
You can use a SwipeGestureRecognizer on the picker.
I assume this is not a perfect solution at all.
- (void)viewDidLoad
{
[super viewDidLoad];
_pickerSwipeGestureRecognizer.delegate = self;
[_pickerSwipeGestureRecognizer setDirection:(UISwipeGestureRecognizerDirectionDown | UISwipeGestureRecognizerDirectionUp)];
}
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer{
if([gestureRecognizer isEqual:_pickerSwipeGestureRecognizer]){
NSLog(#"start");
}
}
- (void)pickerView:(UIPickerView *)thePickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component {
NSLog(#"end");
}

Change default icon for moving cells in UITableView

I need to change default icon for moving cells in UITableView.
This one:
Is it possible?
This is a really hacky solution, and may not work long term, but may give you a starting point. The re-order control is a UITableViewCellReorderControl, but that's a private class, so you can't access it directly. However, you could just look through the hierarchy of subviews and find its imageView.
You can do this by subclassing UITableViewCell and overriding its setEditing:animated: method as follows:
- (void) setEditing:(BOOL)editing animated:(BOOL)animated
{
[super setEditing: editing animated: YES];
if (editing) {
for (UIView * view in self.subviews) {
if ([NSStringFromClass([view class]) rangeOfString: #"Reorder"].location != NSNotFound) {
for (UIView * subview in view.subviews) {
if ([subview isKindOfClass: [UIImageView class]]) {
((UIImageView *)subview).image = [UIImage imageNamed: #"yourimage.png"];
}
}
}
}
}
}
Or in Swift
override func setEditing(_ editing: Bool, animated: Bool) {
super.setEditing(editing, animated: animated)
if editing {
for view in subviews where view.description.contains("Reorder") {
for case let subview as UIImageView in view.subviews {
subview.image = UIImage(named: "yourimage.png")
}
}
}
}
Be warned though... this may not be a long term solution, as Apple could change the view hierarchy at any time.
Ashley Mills' answer was excellent at the time it was offered, but as others have noted in the comments, the view hierarchy has changed from version to version of iOS. In order to properly find the reorder control, I'm using an approach that traverses the entire view hierarchy; hopefully this will give the approach an opportunity to continue working even if Apple changes the view hierarchy.
Here's the code I'm using to find the reorder control:
-(UIView *) findReorderView:(UIView *) view
{
UIView *reorderView = nil;
for (UIView *subview in view.subviews)
{
if ([[[subview class] description] rangeOfString:#"Reorder"].location != NSNotFound)
{
reorderView = subview;
break;
}
else
{
reorderView = [self findReorderView:subview];
if (reorderView != nil)
{
break;
}
}
}
return reorderView;
}
And here's the code I'm using to override the -(void) setEditing:animated: method in my subclass:
-(void) setEditing:(BOOL)editing animated:(BOOL)animated
{
[super setEditing:editing animated:animated];
if (editing)
{
// I'm assuming the findReorderView method noted above is either
// in the code for your subclassed UITableViewCell, or defined
// in a category for UIView somewhere
UIView *reorderView = [self findReorderView:self];
if (reorderView)
{
// I'm setting the background color of the control
// to match my cell's background color
// you might need to do this if you override the
// default background color for the cell
reorderView.backgroundColor = self.contentView.backgroundColor;
for (UIView *sv in reorderView.subviews)
{
// now we find the UIImageView for the reorder control
if ([sv isKindOfClass:[UIImageView class]])
{
// and replace it with the image we want
((UIImageView *)sv).image = [UIImage imageNamed:#"yourImage.png"];
// note: I have had to manually change the image's frame
// size to get it to display correctly
// also, for me the origin of the frame doesn't seem to
// matter, because the reorder control will center it
sv.frame = CGRectMake(0, 0, 48.0, 48.0);
}
}
}
}
}
Swift 4
// Change default icon (hamburger) for moving cells in UITableView
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
let imageView = cell.subviews.first(where: { $0.description.contains("Reorder") })?.subviews.first(where: { $0 is UIImageView }) as? UIImageView
imageView?.image = #imageLiteral(resourceName: "new_hamburger_icon") // give here your's new image
imageView?.contentMode = .center
imageView?.frame.size.width = cell.bounds.height
imageView?.frame.size.height = cell.bounds.height
}
Swift version of Rick's answer with few improvements:
override func setEditing(editing: Bool, animated: Bool) {
super.setEditing(editing, animated: animated)
if editing {
if let reorderView = findReorderViewInView(self),
imageView = reorderView.subviews.filter({ $0 is UIImageView }).first as? UIImageView {
imageView.image = UIImage(named: "yourImage")
}
}
}
func findReorderViewInView(view: UIView) -> UIView? {
for subview in view.subviews {
if String(subview).rangeOfString("Reorder") != nil {
return subview
}
else {
findReorderViewInView(subview)
}
}
return nil
}
Updated solution of Ashley Mills (for iOS 7.x)
if (editing) {
UIView *scrollView = self.subviews[0];
for (UIView * view in scrollView.subviews) {
NSLog(#"Class: %#", NSStringFromClass([view class]));
if ([NSStringFromClass([view class]) rangeOfString: #"Reorder"].location != NSNotFound) {
for (UIView * subview in view.subviews) {
if ([subview isKindOfClass: [UIImageView class]]) {
((UIImageView *)subview).image = [UIImage imageNamed: #"moveCellIcon"];
}
}
}
}
}
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
for (UIControl *control in cell.subviews)
{
if ([control isMemberOfClass:NSClassFromString(#"UITableViewCellReorderControl")] && [control.subviews count] > 0)
{
for (UIControl *someObj in control.subviews)
{
if ([someObj isMemberOfClass:[UIImageView class]])
{
UIImage *img = [UIImage imageNamed:#"reorder_icon.png"];
((UIImageView*)someObj).frame = CGRectMake(0.0, 0.0, 43.0, 43.0);
((UIImageView*)someObj).image = img;
}
}
}
}
}
I use editingAccessoryView to replace reorder icon.
Make a subclass of UITableViewCell.
Override setEditing. Simply hide reorder control and set editingAccessoryView to an uiimageview with your re-order image.
- (void) setEditing:(BOOL)editing animated:(BOOL)animated
{
[super setEditing: editing animated: YES];
self.showsReorderControl = NO;
self.editingAccessoryView = editing ? [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"yourReorderIcon"]] : nil;
}
If you are not using editing accessory view, this may be a good choice.
I could not get any other answer to work for me, but I found a solution.
Grzegorz R. Kulesza's answer almost worked for me but I had to make a couple changes.
This works with Swift 5 and iOS 13:
// Change default reorder icon in UITableViewCell
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
let imageView = cell.subviews.first(where: { $0.description.contains("Reorder") })?.subviews.first(where: { $0 is UIImageView }) as? UIImageView
imageView?.image = UIImage(named: "your_custom_reorder_icon.png")
let size = cell.bounds.height * 0.6 // scaled for padding between cells
imageView?.frame.size.width = size
imageView?.frame.size.height = size
}
I did this on iOS 12 with swift 4.2
I hope this helps:
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
for view in cell.subviews {
if view.self.description.contains("UITableViewCellReorderControl") {
for sv in view.subviews {
if (sv is UIImageView) {
(sv as? UIImageView)?.image = UIImage(named: "your_image")
(sv as? UIImageView)?.contentMode = .center
sv.frame = CGRect(x: 0, y: 0, width: 25, height: 25)
}
}
}
}
}
After debuging the UITableViewCell, you can use KVC in UITableViewCell subclass to change it.
// key
static NSString * const kReorderControlImageKey = #"reorderControlImage";
// setting when cellForRow calling
UIImage *customImage;
[self setValue:customImage forKeyPath:kReorderControlImageKey];
// to prevent crash
- (void)setValue:(id)value forUndefinedKey:(NSString *)key {
if ([key isEqualToString:kReorderControlImageKey]) return;
else [super setValue:value forUndefinedKey:key];
}
You can also simply add your own custom reorder view above all others inside your cell.
All you have to do is ensure this custom view is always above others, which can be checked in [UITableViewDelegate tableView: willDisplayCell: forRowAtIndexPath: indexPath:].
In order to allow the standard reorder control interaction, your custom view must have its userInteractionEnabled set to NO.
Depending on how your cell looks like, you might need a more or less complex custom reorder view (to mimic the cell background for exemple).
Swift 5 solution:
Subclass UITableViewCell and override didAddSubview method:
override func didAddSubview(_ subview: UIView) {
if !subview.description.contains("Reorder") { return }
(subview.subviews.first as? UIImageView)?.removeFromSuperview()
let imageView = UIImageView()
imageView.image = UIImage()
subview.addSubview(imageView)
imageView.snp.makeConstraints { make in
make.height.width.equalTo(24)
make.centerX.equalTo(subview.snp.centerX)
make.centerY.equalTo(subview.snp.centerY)
}
}
I've used SnapKit to set constraints, you can do it in your way.
Please note, it could be temporary solution in order of Apple updates.
Working with iOS 16 and Swift 5
I tried the above solution, but sometimes my custom image was not displayed in some cells.
This code works fine for me into the UITableViewCell subclass:
private lazy var customReorderImgVw: UIImageView = {
let img = UIImage(named: "imgCustomReorder")!
let imgVw = UIImageView(image: img)
imgVw.contentMode = .center
imgVw.frame = CGRect(origin: .zero, size: img.size)
imgVw.alpha = 0
return imgVw
}()
override func setEditing(_ editing: Bool, animated: Bool) {
super.setEditing(editing, animated: animated)
if editing {
for subVw in subviews {
if "\(subVw.classForCoder)" == "UITableViewCellReorderControl" {
subVw.subviews.forEach { $0.removeFromSuperview() }
customReorderImgVw.center.y = subVw.center.y
subVw.addSubview(customReorderImgVw)
break
}
}
}
showOrHideCustomReorderView(isToShow: editing)
}
private func showOrHideCustomReorderView(isToShow: Bool) {
let newAlpha: CGFloat = (isToShow ? 1 : 0)
UIView.animate(withDuration: 0.25) {
self.customReorderImgVw.alpha = newAlpha
}
}

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