Getting the lowest view on UIView using hitTest:? - iphone

So my view look like this from lowest view
[L] UIView -> [K] view -> [M] view
Since [K] is under [M] in some cases, when I do UIView hitTest: check on [L], it always returns [M] view.
Is there any way to get the lowest subview from hitTest: ?
Thanks.

I hope I understood your question:
You have the following view hierarchy and View 1 is covered by View 2
+ Root View
| - View 1
| - View 2
Then you perform -[UIView hitTest:withEvent:] on the Root View, knowing the point lies inside View 1 as well as inside View 2. But this method returns View 2 because it is on the top.
If you want to get View 1 instead you can use the following:
#implementation UIView (ExtendedHitTest)
- (UIView *)extendedHitTest:(CGPoint)point withEvent:(UIEvent *)event
{
__block UIView *result;
NSArray *hitTestSiblings = [self hitTest:point withEvent:event].superview.subviews;
[hitTestSiblings enumerateObjectsUsingBlock:^(UIView *view, NSUInteger idx, BOOL *stop) {
if ([view pointInside:[self convertPoint:point toView:view] withEvent:event]) {
result = view;
*stop = YES;
}
}];
return result;
}
#end
With anUIView.superview.subviews you get all the siblings of anUIView with the topmost view as the last object—this means you'd first encounter View 1 and then View 2

You can traverse the superviews to find out the top one.
// Assume self is a UIView. If it's a UIViewController, replace self with self.view
UIView* v = [self hitTest:p withEvent:e];
if (v == self) {
// The current view has been hit ...
}
while (v.superview != self) {
v = v.superview;
}
// Now v is the view that you wanted

Related

Make scrollbar always visible on UIScrollView?

I need to make a scrollbar always visible on viewDidLoad so that the user can understand that there is content to scroll. I did the following:
[myscrollView flashScrollIndicators];
But then the scrollbars only appear for some time after viewDidLoad and disappear again only to reappear when the user touches the screen..
I need to make scrollbars always visible. How can I do it?
Apple indirectly discourage constantly displaying scroll indicators in their iOS Human Interface Guidelines but guidelines are just guidelines for a reason, they don't account for every scenario and sometimes you may need to politely ignore them.
The scroll indicators of any content views are UIImageView subviews of those content views. This means you can access the scroll indicators of a UIScrollView as you would any of its other subviews (i.e. myScrollView.subviews) and modify the scroll indicators as you would any UIImageView (e.g. scrollIndicatorImageView.backgroundColor = [UIColor redColor];).
The most popular solution appears to be the following code:
#define noDisableVerticalScrollTag 836913
#define noDisableHorizontalScrollTag 836914
#implementation UIImageView (ForScrollView)
- (void) setAlpha:(float)alpha {
if (self.superview.tag == noDisableVerticalScrollTag) {
if (alpha == 0 && self.autoresizingMask == UIViewAutoresizingFlexibleLeftMargin) {
if (self.frame.size.width < 10 && self.frame.size.height > self.frame.size.width) {
UIScrollView *sc = (UIScrollView*)self.superview;
if (sc.frame.size.height < sc.contentSize.height) {
return;
}
}
}
}
if (self.superview.tag == noDisableHorizontalScrollTag) {
if (alpha == 0 && self.autoresizingMask == UIViewAutoresizingFlexibleTopMargin) {
if (self.frame.size.height < 10 && self.frame.size.height < self.frame.size.width) {
UIScrollView *sc = (UIScrollView*)self.superview;
if (sc.frame.size.width < sc.contentSize.width) {
return;
}
}
}
}
[super setAlpha:alpha];
}
#end
Which is originally credited to this source.
This defines a category for UIImageView that defines a custom setter for the alpha property. This works because at some point in the underlying code for the UIScrollView, it will set its scroll indicator's alpha property to 0 in order to hide it. At this point it will run through our category and, if the hosting UIScrollView has the right tag, it will ignore the value being set, leaving it displayed.
In order to use this solution ensure your UIScrollView has the appropriate tag e.g.
If you want to display the scroll indicator from the moment its UIScrollView is visible simply flash the scroll indicators when the view appears .e.g
- (void)viewDidAppear:(BOOL)animate
{
[super viewDidAppear:animate];
[self.scrollView flashScrollIndicators];
}
Additional SO references:
UIScrollView - showing the scroll bar
UIScrollView indicator always show?
Scroll Indicators Visibility
Make scrollbars always visible in uiscrollview
I want to offer my solution. I don't like the most popular variant with category (overriding methods in category can be the reason of some indetermination what method should be called in runtime, since there is two methods with the same selector).
I use swizzling instead. And also I don't need to use tags.
Add this method to your view controller, where you have scroll view (self.categoriesTableView in my case)
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
// Do swizzling to turn scroll indicator always on
// Search correct subview with scroll indicator image across tableView subviews
for (UIView * view in self.categoriesTableView.subviews) {
if ([view isKindOfClass:[UIImageView class]]) {
if (view.alpha == 0 && view.autoresizingMask == UIViewAutoresizingFlexibleLeftMargin) {
if (view.frame.size.width < 10 && view.frame.size.height > view.frame.size.width) {
if (self.categoriesTableView.frame.size.height < self.categoriesTableView.contentSize.height) {
// Swizzle class for found imageView, that should be scroll indicator
object_setClass(view, [AlwaysOpaqueImageView class]);
break;
}
}
}
}
}
// Ask to flash indicator to turn it on
[self.categoriesTableView flashScrollIndicators];
}
Add new class
#interface AlwaysOpaqueImageView : UIImageView
#end
#implementation AlwaysOpaqueImageView
- (void)setAlpha:(CGFloat)alpha {
[super setAlpha:1.0];
}
#end
The scroll indicator (vertical scroll indicator in this case) will be always at the screen.
Update November, 2019
Starting from iOS 13 UIScrollView subclasses are changed. Now scroll indicators are inherited from UIView and has their own private class called _UIScrollViewScrollIndicator. This means, that they are not subclasses of UIImageView now, so old method won't work anymore.
Also we are not able to implement subclass of _UIScrollViewScrollIndicator because it is private class and we don't have access to it. So the only solution is to use runtime. Now to have support for iOS 13 and earlier implement the next steps:
Add this method to your view controller, where you have scroll view (self.categoriesTableView in my case)
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
// Do swizzling to turn scroll indicator always on
// Search correct subview with scroll indicator image across tableView subviews
for (UIView * view in self.categoriesTableView.subviews) {
if ([view isKindOfClass:[UIImageView class]]) {
if (view.alpha == 0 && view.autoresizingMask == UIViewAutoresizingFlexibleLeftMargin) {
if (view.frame.size.width < 10 && view.frame.size.height > view.frame.size.width) {
if (self.categoriesTableView.frame.size.height < self.categoriesTableView.contentSize.height) {
// Swizzle class for found imageView, that should be scroll indicator
object_setClass(view, [AlwaysOpaqueImageView class]);
break;
}
}
}
} else if ([NSStringFromClass(view.class) isEqualToString:#"_UIScrollViewScrollIndicator"]) {
if (view.frame.size.width < 10 && view.frame.size.height > view.frame.size.width) {
if (self.categoriesTableView.frame.size.height < self.categoriesTableView.contentSize.height) {
// Swizzle class for found scroll indicator, (be sure to create AlwaysOpaqueScrollIndicator in runtime earlier!)
// Current implementation is in AlwaysOpaqueScrollTableView class
object_setClass(view, NSClassFromString(#"AlwaysOpaqueScrollIndicator"));
break;
}
}
}
}
// Ask to flash indicator to turn it on
[self.categoriesTableView flashScrollIndicators];
}
Add new class (this is for iOS earlier than 13)
#interface AlwaysOpaqueImageView : UIImageView
#end
#implementation AlwaysOpaqueImageView
- (void)setAlpha:(CGFloat)alpha {
[super setAlpha:1.0];
}
#end
Add these methods somewhere in you code (either the same view controller as in step 1, or to the desired UIScrollView subclass).
+ (void)load {
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
// Create child class from _UIScrollViewScrollIndicator since it is private
Class alwaysOpaqueScrollIndicatorClass = objc_allocateClassPair(NSClassFromString(#"_UIScrollViewScrollIndicator"), "AlwaysOpaqueScrollIndicator", 0);
objc_registerClassPair(alwaysOpaqueScrollIndicatorClass);
// Swizzle setAlpha: method of this class to custom
Class replacementMethodClass = [self class];
SEL originalSelector = #selector(setAlpha:);
SEL swizzledSelector = #selector(alwaysOpaque_setAlpha:);
Method originalMethod = class_getInstanceMethod(alwaysOpaqueScrollIndicatorClass, originalSelector);
Method swizzledMethod = class_getInstanceMethod(replacementMethodClass, swizzledSelector);
BOOL didAddMethod =
class_addMethod(alwaysOpaqueScrollIndicatorClass,
originalSelector,
method_getImplementation(swizzledMethod),
method_getTypeEncoding(swizzledMethod));
if (didAddMethod) {
class_replaceMethod(alwaysOpaqueScrollIndicatorClass,
swizzledSelector,
method_getImplementation(originalMethod),
method_getTypeEncoding(originalMethod));
} else {
method_exchangeImplementations(originalMethod, swizzledMethod);
}
});
}
#pragma mark - Method Swizzling
- (void)alwaysOpaque_setAlpha:(CGFloat)alpha {
[self alwaysOpaque_setAlpha:1.0];
}
This step creates the subclass of _UIScrollViewScrollIndicator called AlwaysOpaqueScrollIndicator in runtime and swizzle setAlpha: method implementation to alwaysOpaque_setAlpha:.
Do not forget to add
#import <objc/runtime.h>
to the files you've inserted this code. Thanks to #Smartcat for reminder about this
I dont know whether this will work or not. But just a hint for you.
Scrollbar inside the Scrollview is a Imageview. Which is a subview of UIScrollview
So get the Scrollbar Imageview of the UIscrollview. Then try to set that image property hidden to NO or Change Alpha value
static const int UIScrollViewHorizontalBarIndexOffset = 0;
static const int UIScrollViewVerticalBarIndexOffset = 1;
-(UIImageView *)scrollbarImageViewWithIndex:(int)indexOffset
{
int viewsCount = [[yourScrollview subviews] count];
UIImageView *scrollBar = [[yourScrollview subviews] objectAtIndex:viewsCount - indexOffset - 1];
return scrollBar;
}
-(void) viewDidLoad
{
//Some Code
//Get Scrollbar
UIImageView *scrollBar = [self scrollbarImageViewWithIndex: UIScrollViewVerticalBarIndexOffset];
//The try setting hidden property/ alpha value
scrollBar.hidden=NO;
}
Got reference from here
This is Swift version of #Accid Bright's answer:
class AlwaysOpaqueImageView: UIImageView {
override var alpha: CGFloat {
didSet {
alpha = 1
}
}
static func setScrollbarToAlwaysVisible(from scrollView: UIScrollView) {
// Do swizzling to turn scroll indicator always on
// Search correct subview with scroll indicator image across tableView subviews
for view in scrollView.subviews {
if view.isKind(of: UIImageView.self),
view.alpha == 0 && view.autoresizingMask == UIView.AutoresizingMask.flexibleLeftMargin,
view.frame.size.width < 10 && view.frame.size.height > view.frame.size.width,
scrollView.frame.size.height < scrollView.contentSize.height {
// Swizzle class for found imageView, that should be scroll indicator
object_setClass(view, AlwaysOpaqueImageView.self)
break
}
}
// Ask to flash indicator to turn it on
scrollView.flashScrollIndicators()
}
}
One difference is that setting scrollbar is extracted out as a static method.

-[CustomWindow hitTest:withEvent:] implementation to forward events

I have a custom window (that should be on top of everything, including the keyboard) to show an overlay thing, something like the overlay you see when pressing the volume up/down buttons in the device.
So I made a custom window OverlayWindow so far everything works fine and windows in the back are receiving their events normally. However hitTest:withEvent: is called several times and sometimes it even returns nil. I wonder if that is normal/correct? If not how can I fix that?
// A small (WIDTH_MAX:100) window in the center of the screen. If it matters
const CGSize screenSize = [[UIScreen mainScreen] bounds].size;
const CGRect rect = CGRectMake(((int)(screenSize.width - WIDTH_MAX)*0.5),
       ((int)(screenSize.height - WIDTH_MAX)*0.5), WIDTH_MAX, WIDTH_MAX);
overlayWindow = [[CustomWindow alloc] initWithFrame:rect];
overlayWindow.windowLevel = UIWindowLevelStatusBar; //1000.0
overlayWindow.hidden = NO; // I don't need it to be the key (no makeKeyAndVisible)
 
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
// Find the front most window (with the highest window level) and
// call this method on that window. It should will make the event be
// forwarded to it
// Situation1: This method is called twice (or even more, it depend
// on the number of windows the app has) per event: Why? Is this the
// *normal* behaviour?
NSLog(#" ");
NSLog(#"Point: %# Event: %p\n", NSStringFromCGPoint(point), event);
UIView *view = nil;
if (CGRectContainsPoint(self.bounds, point)) {
NSLog(#"inside window\n");
NSArray *wins = [[UIApplication sharedApplication] windows];
__block UIWindow *frontMostWin = nil;
[wins enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
NSLog(#"win: %#\n", obj);
if ([obj windowLevel] >= [frontMostWin windowLevel] && obj != self) {
frontMostWin = obj;
}
}];
NSLog(#"frontMostWindow:%#\n finding a new view ...\n", frontMostWin);
CGPoint p = [frontMostWindow convertPoint:point fromWindow:self];
view = [frontMostWindow hitTest:p withEvent:event];
// Situation2: sometimes view is nil here, Is that correct?
}
NSLog(#"resultView: %#\n", view);
return view;
}
EDIT:
Also I've noticed that
if hitTest:withEvent: always returns nil it works too. This is only when I call overlayWindow.hidden = NO;
if I call [overlayWindow makeKeyAndVisible] returning nil in hitTest:withEvent: does not always work. It looks like a key window requires a proper implementation of the hit testing method?
Am I missing something about event forwarding here?
Do frontMostWindow means frontMostWin?
It looks like even if we use only one UIWindow, hitTest:withEvent: will be executed on it at least 2 times. So, I guess it is normal.
You can receive null at
view = [frontMostWindow hitTest:p withEvent:event];
due to following reasons:
frontMostWindow is null itself (as example, if you have only one window)
p is ouside frontMostWindow bounds (as example, when frontMostWindow is keyboard and your touch is somewhere else)
frontMostWindow have property userInteractionEnabled set to NO;
hitTest:withEvent: being call several times is normal. This is probably because you only display a UILabel or UIImageView on the overlayed window and thus touches are automatically forwareded.
However I think you don't really need another OverlayWindow, instead you might consider a UIView on the top of the keyWindow. This should make your application cleaner...
I did face the same problem.
I tried to solve it based your post and another solution was found.
This code implemented in uiwindow overlaying on the top.
This code will pass events through the under window when area has no view.
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
NSLog(#" ");
NSLog(#"Point: %# Event: %p\n", NSStringFromCGPoint(point), event);
UIView *view = nil;
UIView *resultView = [super hitTest:point withEvent:event];
if (resultView == self) {
NSLog(#"touched in transparent window !!");
return nil;
}
NSLog(#"touched in view!!");
return resultView;
}
After all, Thanks. Your post is very helpful.

Why does UINavigationBar steal touch events?

I have a custom UIButton with UILabel added as subview. Button perform given selector only when I touch it about 15points lower of top bound. And when I tap above that area nothing happens.
I found out that it hasn't caused by wrong creation of button and label, because after I shift the button lower at about 15 px it works correctly.
UPDATE I forgot to say that button located under the UINavigationBar and 1/3 of upper part of the button don't get touch events.
Image was here
View with 4 buttons is located under the NavigationBar. And when touch the "Basketball" in top, BackButton get touch event, and when touch "Piano" in top, then rightBarButton (if exists) get touch. If not exists, nothing happened.
I didn't find this documented feature in App docs.
Also I found this topic related to my problem, but there is no answer too.
I noticed that if you set userInteractionEnabled to OFF, the NavigationBar doesn't "steal" the touches anymore.
So you have to subclass your UINavigationBar and in your CustomNavigationBar do this:
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
if ([self pointInside:point withEvent:event]) {
self.userInteractionEnabled = YES;
} else {
self.userInteractionEnabled = NO;
}
return [super hitTest:point withEvent:event];
}
Info about how to subclass UINavigationBar you can find here.
I found out the answer here(Apple Developer Forum).
Keith at Apple Developer Technical Support, on 18th May 2010 (iPhone OS 3):
I recommend that you avoid having touch-sensitive UI in such close proximity to the nav bar or toolbar. These areas are typically known as "slop factors" making it easier for users to perform touch events on buttons without the difficulty of performing precision touches. This is also the case for UIButtons for example.
But if you want to capture the touch event before the navigation bar or toolbar receives it, you can subclass UIWindow and override:
-(void)sendEvent:(UIEvent *)event;
Also I found out,that when I touch the area under the UINavigationBar, the location.y defined as 64,though it was not.
So I made this:
CustomWindow.h
#interface CustomWindow: UIWindow
#end
CustomWindow.m
#implementation CustomWindow
- (void) sendEvent:(UIEvent *)event
{
BOOL flag = YES;
switch ([event type])
{
case UIEventTypeTouches:
//[self catchUIEventTypeTouches: event]; perform if you need to do something with event
for (UITouch *touch in [event allTouches]) {
if ([touch phase] == UITouchPhaseBegan) {
for (int i=0; i<[self.subviews count]; i++) {
//GET THE FINGER LOCATION ON THE SCREEN
CGPoint location = [touch locationInView:[self.subviews objectAtIndex:i]];
//REPORT THE TOUCH
NSLog(#"[%#] touchesBegan (%i,%i)", [[self.subviews objectAtIndex:i] class],(NSInteger) location.x, (NSInteger) location.y);
if (((NSInteger)location.y) == 64) {
flag = NO;
}
}
}
}
break;
default:
break;
}
if(!flag) return; //to do nothing
/*IMPORTANT*/[super sendEvent:(UIEvent *)event];/*IMPORTANT*/
}
#end
In AppDelegate class I use CustomWindow instead of UIWindow.
Now when I touch area under navigation bar, nothing happens.
My buttons still don't get touch events,because I don't know how to send this event (and change coordinates) to my view with buttons.
Subclass UINavigationBar and add this method. It will cause taps to be passed through unless they are tapping a subview (such as a button).
-(UIView*) hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView *v = [super hitTest:point withEvent:event];
return v == self? nil: v;
}
The solution for me was the following one:
First:
Add in your application (It doesn't matter where you enter this code) an extension for UINavigationBar like so:
The following code just dispatch a notification with the point and event when the navigationBar is being tapped.
extension UINavigationBar {
open override func hitTest(_ point: CGPoint, with event: UIEvent?) -> UIView? {
NotificationCenter.default.post(name: NSNotification.Name(rawValue: "tapNavigationBar"), object: nil, userInfo: ["point": point, "event": event as Any])
return super.hitTest(point, with: event)
}
}
Then in your specific view controller you must listen to this notification by adding this line in your viewDidLoad:
NotificationCenter.default.addObserver(self, selector: #selector(tapNavigationBar), name: NSNotification.Name(rawValue: "tapNavigationBar"), object: nil)
Then you need to create the method tapNavigationBar in your view controller as so:
func tapNavigationBar(notification: Notification) {
let pointOpt = notification.userInfo?["point"] as? CGPoint
let eventOpt = notification.userInfo?["event"] as? UIEvent?
guard let point = pointOpt, let event = eventOpt else { return }
let convertedPoint = YOUR_VIEW_BEHIND_THE_NAVBAR.convert(point, from: self.navigationController?.navigationBar)
if YOUR_VIEW_BEHIND_THE_NAVBAR.point(inside: convertedPoint, with: event) {
//Dispatch whatever you wanted at the first place.
}
}
PD: Don't forget to remove the observation in the deinit like so:
deinit {
NotificationCenter.default.removeObserver(self)
}
That's it... That's a little bit 'tricky', but it's a good workaround for not subclassing and getting a notification anytime the navigationBar is being tapped.
I just wanted to share another prospective to solving this problem. This is not a problem by design, but it was meant to help user get back or navigate. But we need to put things tightly in or below nav bar and things look sad.
First lets look at the code.
class MyNavigationBar: UINavigationBar {
private var secondTap = false
private var firstTapPoint = CGPointZero
override func pointInside(point: CGPoint, withEvent event: UIEvent?) -> Bool {
if !self.secondTap{
self.firstTapPoint = point
}
defer{
self.secondTap = !self.secondTap
}
return super.pointInside(firstTapPoint, withEvent: event)
}
}
You might be see why am i doing second touch handling. There is the recipe to the solution.
Hit test is called twice for a call. The first time the actual point on the window is reported. Everything goes well. On the second pass, this happens.
If system sees a nav bar and the hit point is around 9 pixels more on Y side, it tries to decrease that gradually to below 44 points which is where the nav bar is.
Take a look at the screen to be clear.
So theres a mechanism that will use nearby logic to the second pass of hittest. If we can know its second pass and then call the super with first hit test point. Job done.
The above code does that exactly.
There are 2 things that might be causing problems.
Did you try setUserInteractionEnabled:NO for the label.
Second thing i think might work is apart from that after adding label on top of button you can send the label to back (it might work, not sure although)
[button sendSubviewToBack:label];
Please let me know if the code works :)
Your labels are huge. They start at {0,0} (the left top corner of the button), extend over the entire width of the button and have a height of the entire view. Check your frame data and try again.
Also, you have the option of using the UIButton property titleLabel. Maybe you are setting the title later and it goes into this label rather than your own UILabel. That would explain why the text (belonging to the button) would work, while the label would be covering the rest of the button (not letting the taps go through).
titleLabel is a read-only property, but you can customize it just as your own label (except perhaps the frame) including text color, font, shadow, etc.
This solved my problem..
I added hitTest:withEvent: code to my navbar subclass..
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
int errorMargin = 5;// space left to decrease the click event area
CGRect smallerFrame = CGRectMake(0 , 0 - errorMargin, self.frame.size.width, self.frame.size.height);
BOOL isTouchAllowed = (CGRectContainsPoint(smallerFrame, point) == 1);
if (isTouchAllowed) {
self.userInteractionEnabled = YES;
} else {
self.userInteractionEnabled = NO;
}
return [super hitTest:point withEvent:event];
}
Extending Alexander's solution:
Step 1. Subclass UIWindow
#interface ChunyuWindow : UIWindow {
NSMutableArray * _views;
#private
UIView *_touchView;
}
- (void)addViewForTouchPriority:(UIView*)view;
- (void)removeViewForTouchPriority:(UIView*)view;
#end
// .m File
// #import "ChunyuWindow.h"
#implementation ChunyuWindow
- (void) dealloc {
TT_RELEASE_SAFELY(_views);
[super dealloc];
}
- (void)motionBegan:(UIEventSubtype)motion withEvent:(UIEvent *)event {
if (UIEventSubtypeMotionShake == motion
&& [TTNavigator navigator].supportsShakeToReload) {
// If you're going to use a custom navigator implementation, you need to ensure that you
// implement the reload method. If you're inheriting from TTNavigator, then you're fine.
TTDASSERT([[TTNavigator navigator] respondsToSelector:#selector(reload)]);
[(TTNavigator*)[TTNavigator navigator] reload];
}
}
- (void)addViewForTouchPriority:(UIView*)view {
if ( !_views ) {
_views = [[NSMutableArray alloc] init];
}
if (![_views containsObject: view]) {
[_views addObject:view];
}
}
- (void)removeViewForTouchPriority:(UIView*)view {
if ( !_views ) {
return;
}
if ([_views containsObject: view]) {
[_views removeObject:view];
}
}
- (void)sendEvent:(UIEvent *)event {
if ( !_views || _views.count == 0 ) {
[super sendEvent:event];
return;
}
UITouch *touch = [[event allTouches] anyObject];
switch (touch.phase) {
case UITouchPhaseBegan: {
for ( UIView *view in _views ) {
if ( CGRectContainsPoint(view.frame, [touch locationInView:[view superview]]) ) {
_touchView = view;
[_touchView touchesBegan:[event allTouches] withEvent:event];
return;
}
}
break;
}
case UITouchPhaseMoved: {
if ( _touchView ) {
[_touchView touchesMoved:[event allTouches] withEvent:event];
return;
}
break;
}
case UITouchPhaseCancelled: {
if ( _touchView ) {
[_touchView touchesCancelled:[event allTouches] withEvent:event];
_touchView = nil;
return;
}
break;
}
case UITouchPhaseEnded: {
if ( _touchView ) {
[_touchView touchesEnded:[event allTouches] withEvent:event];
_touchView = nil;
return;
}
break;
}
default: {
break;
}
}
[super sendEvent:event];
}
#end
Step 2: Assign ChunyuWindow instance to AppDelegate Instance
Step 3: Implement touchesEnded:widthEvent: for view with buttons, for example:
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesEnded: touches withEvent: event];
UITouch *touch = [touches anyObject];
CGPoint point = [touch locationInView: _buttonsView]; // a subview contains buttons
for (UIButton* button in _buttons) {
if (CGRectContainsPoint(button.frame, point)) {
[self onTabButtonClicked: button];
break;
}
}
}
Step 4: call ChunyuWindow's addViewForTouchPriority when the view we care about appears, and call removeViewForTouchPriority when the view disappears or dealloc, in viewDidAppear/viewDidDisappear/dealloc of ViewControllers, so _touchView in ChunyuWindow is NULL, and it is the same as UIWindow, having no side effects.
An alternative solution that worked for me, based on the answer provided by Alexandar:
self.navigationController?.barHideOnTapGestureRecognizer.enabled = false
Instead of overriding the UIWindow, you can just disable the gesture recogniser responsible for the "slop area" on the UINavigationBar.
Give a extension version according to Bart Whiteley. No need to subclass.
#implementation UINavigationBar(Xxxxxx)
- (UIView*)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView *v = [super hitTest:point withEvent:event];
return v == self ? nil: v;
}
#end
The following worked for me:
self.navigationController?.isNavigationBarHidden = true

(UIView *)hitTest problem?

I have one Masterview.it has lot of childviews.I am using the following code to detect the touched view and to bring front the corresponding view.the code works fine.But When I add subview to childview,it did not work , any help please?
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event;
{
self.hitView = nil;
self.hitView = [super hitTest:point withEvent:event];
int x = self.hitView.frame.origin.x;
int y = self.hitView.frame.origin.y;
NSLog(#"x = %d",x);
NSLog(#"y = %d",y);
if ([self.viewDelegate respondsToSelector:
#selector(view:hitTest:withEvent:hitView:)])
{
return [self.viewDelegate view:self hitTest:point
withEvent:event hitView:hitView];
}
else
{
[self bringSubviewToFront:self.hitView];
return hitView;
}
}
If I get it right, it's pretty easy: hitTest always returns the farthest descendant subview in the view. If there is no subview this is always the same view. If there is one, that subview might be returned instead. Here's how you could fix it:
self.hitView = [super hitTest:point withEvent:event];
if ([self.hitView isDescendantOfView: self])
self.hitView = self;
EDIT Now that I understand the problem better, you should maybe do the following. This code returns the superview that's a direct descendant of the outer view:
UIView *hitView = [super hitTest:point withEvent:event];
while (hitView && hitView.superview != self)
hitView = hitView.superview;
(Please also note that you should use a local variable and change your property later than).
As you said you're moving UIViews around. You should check out the video from WWDC 2010 where they achieve this effect with the new GestureRecognizer Class.
The video you should look for is named somthing with "Gesture Recognition". If you don't find it I can link it when I'm home from work.
I wish you the best of luck!

Customizing UIPickerView

I have a requirement where UIPickerView should be customized. The picker view should look something like this:
The application which has customized the pickerView similarly is:
http://itunes.apple.com/us/app/convert-the-unit-calculator/id325758140?mt=8
I have tried removing the default pickerView selection bar by resetting the property showsSelectionIndicator of UIImagePicker and adding a overlay view. But the problem is, the overlay view should be transparent so that the wheel behind it is visible. But the other application somehow does it even though the selection bar is not transparent.
Any ideas on how to achieve this feat?
Thanks and Regards,
Raj
You're going to have to write your own from scratch on this one. UIPickerview isn't customizable. At. All. Sucks, but that's how it is. I'd start out creating a uitableview and layering a frame around it, and trying to mimic uipickerview.
I think you can print the subviews under the picker and modify them.
The UIPickerView create subviews after the data is first loaded.
With performSelecter:WithObject:afterDelay:, you can remove them or insert whatever you need.
- (void)viewDidLoad
{
[super viewDidLoad];
[self refreshClock];
[timePicker_ performSelector:#selector(leakSelf) withObject:nil afterDelay:0];
[self performSelector:#selector(setupTimePicker) withObject:nil afterDelay:0];
}
- (void)setupTimePicker {
[[timePicker_ subviewOfClass:NSClassFromString(#"_UIPickerViewTopFrame")] removeFromSuperview];
CGRect frame = timePicker_.frame;
frame.size.width += 20;
frame.origin.x -= 10;
timePicker_.frame = frame;
}
#implementation UIView(UIViewDebugTool)
- (void)leakSubview:(UIView*)subroot atDepth:(NSUInteger)dep {
DLog( #"trace sub view[%u] %#", dep, [subroot description] );
CALayer* layer = subroot.layer;
for( CALayer* l in layer.sublayers ) {
DLog( #"layer[%u] %#", dep, l );
}
for( UIView* v in subroot.subviews ) {
[self leakSubview:v atDepth:dep+1];
}
}
- (void)leakSelf {
NSUInteger dep = 0;
[self leakSubview: self atDepth:dep];
}
#end