so I have a scroll view and what I would like is that when I end my touch (touchesEnded) in this scroll view : (do something) but it doesn't detect my touchesended I don't know why. How can I solve this please .sorry for my english I'm french :/
Subclass uiScrollview like this and it should work:
In .h file:
#interface MyScrollView : UIScrollView {
}
#end
In .m file:
#implementation MyScrollView
- (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event {
if (!self.dragging) {
[self.nextResponder touchesEnded: touches withEvent:event];
}
[super touchesEnded: touches withEvent: event];
}
#end
Related
touchesBegan: doesn't work in UIScrollView. How do I enable touchesBegan: in UIScrollView?
You have to subclass UIScrollView to allow interception of the touch events.
For example, you could create a "special" UISCrollView like this:
#interface TouchableScrollView : UIScrollView {
}
#end
.m file:
#implementation TouchableScrollView
- (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event {
if (!self.dragging) {
[self.nextResponder touchesEnded: touches withEvent:event];
}
[super touchesEnded: touches withEvent: event];
}
#end
This example only overrides touchesEnded, but you can do the same for touchesBegan
I assume that u are seeking for code to scroll down and hide the scroll down Img. so this is the code.
// scroll down image show and hidder.
- (void)scrollViewDidScroll:(UIScrollView *)myScrollView{
//NSLog(#"%lf",myScrollView.contentOffset.y);
if (myScrollView.contentOffset.y > 220 )
scrollDownImg.hidden = YES ;
else
scrollDownImg.hidden = NO ;
}
U may get the scrolled location by using the myScrollView.contentOffset
How do I capture touch events such as - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event without subclassing a UIView nor using UIViewControllers.
What happens is that I have a simple UIView created programmatically and I need to detect basic tap events.
If you are writing your app for iOS 4, use UIGestureRecognizer. You can then do what you want. Recognize gestures without subclassing.
Otherwise, subclassing is the way to go.
There's just no reason not to. If you subclass and add nothing it's just a UIView called by another name. All you are doing is intercepting those functions that you are interested in. Don't forget you can do [super touchesBegan:touches] inside your subclass' touchesBegan if you don't want to stop responders up the chain from getting those events too.
I don't why you don't want to use the normal method of subclassing a UIView to capture touch events, but if you really need to do something weird or sneaky, you can capture all events (including touch events) before they get sent down the view hierarchy by trapping/handling the sendEvent: method at the UIWindow level.
CustomGestureRecognizer.h
#import <UIKit/UIKit.h>
#interface CustomGestureRecognizer : UIGestureRecognizer
{
}
- (id)initWithTarget:(id)target;
#end
CustomGestureRecognizer.mm
#import "CustomGestureRecognizer.h"
#import <UIKit/UIGestureRecognizerSubclass.h>
#interface CustomGestureRecognizer()
{
}
#property (nonatomic, assign) id target;
#end
#implementation CustomGestureRecognizer
- (id)initWithTarget:(id)target
{
if (self = [super initWithTarget:target action:Nil]) {
self.target = target;
}
return self;
}
- (void)reset
{
[super reset];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesBegan:touches withEvent:event];
[self.target touchesBegan:touches withEvent:event];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesMoved:touches withEvent:event];
[self.target touchesMoved:touches withEvent:event];
}
- (void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesEnded:touches withEvent: event];
[self.target touchesEnded:touches withEvent:event];
}
#end
Usage:
CustomGestureRecognizer *customGestureRecognizer = [[CustomGestureRecognizer alloc] initWithTarget:self];
[glView addGestureRecognizer:customGestureRecognizer];
I want to preface this question with the fact I am new to the iphone application development and many times believe I may be over my head. I am trying to find an action that will allow me to double tap anywhere within my full screen UIScrollView to return to my main menu (MainMenuViewController).
I currently have the following code running for my ScrollViewController...
ScrollViewController.h
#import <UIKit/UIKit.h>
#interface ScrollViewController : UIViewController <UIScrollViewDelegate>
{
}
#end
ScrollViewController.m
#import "ScrollViewController.h"
UIScrollView *myScrollView;
UIPageControl *myPageControl;
#implementation ScrollViewController
- (void)loadScrollViewWithPage:(UIView *)page
{
int pageCount = [[myScrollView subviews] count];
CGRect bounds = myScrollView.bounds;
bounds.origin.x = bounds.size.width * pageCount;
bounds.origin.y = 0;
page.frame = bounds;
[myScrollView addSubview:page];
}
...etc
Any advice or sample code to implement a double tap within the ScrollView Controller to allow me to return to my MainMenuViewController would be greatly appreciated. Also please include any Interface Builder changes to the view (if necessary). I have been pouring over the forums for days and have not been able to successfully implement this action. Thanks...R.J.
First of all, create a subclass of a UIScrollView:
#import <UIKit/UIKit.h>
#interface MyScrollView : UIScrollView {
}
#end
Implement it:
#import "MyScrollView.h"
#implementation MyScrollView
- (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event {
if (!self.dragging) {
[self.nextResponder touchesEnded: touches withEvent:event];
}
[super touchesEnded: touches withEvent: event];
}
- (void)dealloc {
[super dealloc];
}
#end
Then, use this subclass instead of a normal UIScrollView in your main View Controller. This will call the touchesEnded:withEvent: method (alternatively, you can call any method you want). Then, track for double taps (if you need info on how to do that, let me know).
this is my program .
//Interface file.
#import <Foundation/Foundation.h>
#interface reportView : UIView {
}
- (void)touchesBegan: (NSSet *)touches withEvent: (UIEvent *)event;
- (void)touchesEnded: (NSSet *)touches withEvent: (UIEvent *)event;
- (void)touchesMoved: (NSSet *)touches withEvent: (UIEvent *)event;
#end
//ImplementationFile.
#import "reportView.h"
#implementation reportView
- (void) touchesBegan: (NSSet *)touches withEvent: (UIEvent *)event{
[self.nextResponder manageTouches:touches];
}
- (void) touchesEnded: (NSSet *)touches withEvent: (UIEvent *) event{
[self.nextResponder manageTouches:touches];
}
- (void) touchesMoved: (NSSet *)touches withEvent: (UIEvent *)event{
[self.nextResponder manageTouches:touches];
}
#end
I am getting the warning.
warning:'UIResponder' may not respond to '-manageTouches:'
I got 3 warnings as above.
I am getting the needed output correctly but how to resolve the warnings.
First, since your code looks exactly like listing 14.2 from iPhone in Action, did you remember to copy the code for -manageTouches: from listing 14.3 into your class?
Assuming that you did, the issue is that the nextResponder property points to an instance of UIResponder, which could be just about anything (your class, a window, some other OS-managed thing....), and the compiler doesn't know for sure that this particular responder implements a method -manageTouches:. Your options are basically to either live with the warning, or cast the value of nextResponder to your class. (FWIW, the bottom of page 247 mentions this.)
For that matter, you don't really know, at runtime, that the next responder will respond to that message. To be on the safe side, you might want to use -respondsToSelector: or -isKindOfClass: to validate that assumption.
Is there a bug in the 3.0 SDK that disables real-time zooming and intercepting the zoom-in gesture for the MKMapView? I have some real simple code so I can detect tap events, but there are two problems:
zoom-in gesture is always interpreted as a zoom-out
none of the zoom gestures update the Map's view in realtime.
In hitTest, if I return the "map" view, the MKMapView functionality works great, but I don't get the opportunity to intercept the events.
Any ideas?
MyMapView.h:
#interface MyMapView : MKMapView
{
UIView *map;
}
MyMapView.m:
- (id)initWithFrame:(CGRect)frame
{
if (![super initWithFrame:frame])
return nil;
self.multipleTouchEnabled = true;
return self;
}
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
NSLog(#"Hit Test");
map = [super hitTest:point withEvent:event];
return self;
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(#"%s", __FUNCTION__);
[map touchesCancelled:touches withEvent:event];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent*)event
{
NSLog(#"%s", __FUNCTION__);
[map touchesBegan:touches withEvent:event];
}
- (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event
{
NSLog(#"%s, %x", __FUNCTION__, mViewTouched);
[map touchesMoved:touches withEvent:event];
}
- (void)touchesEnded:(NSSet*)touches withEvent:(UIEvent*)event
{
NSLog(#"%s, %x", __FUNCTION__, mViewTouched);
[map touchesEnded:touches withEvent:event];
}
The best way I have found to achieve this is with a Gesture Recognizer. It's unclear if you want to recognize zoom events yourself or just detect when the user is zooming/panning.
I don't need to detect a map pan or zoom--i just care if the user has put a finger down anywhere in the MKMapView. If you need to detect zooming or panning with 100% recall and precision, it might be more complicated than this. What we really need is an open source implementation of MKMapView so we can add this to the delegate, among many other features.
Here's what I do: Implement a gesture recognizer that cannot be prevented and that cannot prevent other gesture recognizers. Add it to the map view and deal with the relevant touch events as you desire.
How to detect any tap inside an MKMapView (sans tricks)
WildcardGestureRecognizer * tapInterceptor = [[WildcardGestureRecognizer alloc] init];
tapInterceptor.touchesBeganCallback = ^(NSSet * touches, UIEvent * event) {
self.lockedOnUserLocation = NO;
};
[mapView addGestureRecognizer:tapInterceptor];
WildcardGestureRecognizer.h
//
// WildcardGestureRecognizer.h
// Copyright 2010 Floatopian LLC. All rights reserved.
//
#import <Foundation/Foundation.h>
typedef void (^TouchesEventBlock)(NSSet * touches, UIEvent * event);
#interface WildcardGestureRecognizer : UIGestureRecognizer {
TouchesEventBlock touchesBeganCallback;
}
#property(copy) TouchesEventBlock touchesBeganCallback;
#end
WildcardGestureRecognizer.m
//
// WildcardGestureRecognizer.m
// Created by Raymond Daly on 10/31/10.
// Copyright 2010 Floatopian LLC. All rights reserved.
//
#import "WildcardGestureRecognizer.h"
#implementation WildcardGestureRecognizer
#synthesize touchesBeganCallback;
-(id) init{
if (self = [super init])
{
self.cancelsTouchesInView = NO;
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
if (touchesBeganCallback)
touchesBeganCallback(touches, event);
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
}
- (void)reset
{
}
- (void)ignoreTouch:(UITouch *)touch forEvent:(UIEvent *)event
{
}
- (BOOL)canBePreventedByGestureRecognizer:(UIGestureRecognizer *)preventingGestureRecognizer
{
return NO;
}
- (BOOL)canPreventGestureRecognizer:(UIGestureRecognizer *)preventedGestureRecognizer
{
return NO;
}
#end
I had the same problem - I wanted to draw map scales on top of Map View. In order to do it I had to intercept the touch events, and then send them back to the Map View. Unfortunately, when the MKMapView isn't the original receiver of the events, some smooth panning and zooming animations are not working any more.
However I have found a solution to this problem - a bit hacky but works:
1. I have put my MapScales UIView on top of MKMapView, and turned off receiving events in it, so that underlying MKMapView received the events by default.
2. I have subclassed UIWindow with MyMainWindow class and in it I have overriden the method:
- (void) sendEvent:(UIEvent*)event {
[super sendEvent:event];
[self send_the_event_also_to_my_MapScales_component_with_use_of_listener_design_pattern];
}
I have made the main window of my application an instasnce of MyMainWindow.
In this way my MapScales component receives and can react to all the touch events, and at the same time it is not spoiling the underlying MKMapView :)
#import <UIKit/UIKit.h>
#import "UIViewTouch.h"
#import <MapKit/MapKit.h>
#interface MapTouchAppDelegate : NSObject <UIApplicationDelegate>
{
UIViewTouch *viewTouch;
MKMapView *mapView;
UIWindow *window;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) UIViewTouch *viewTouch;
#property (nonatomic, retain) MKMapView *mapView;
#end
#import "MapTouchAppDelegate.h"
#implementation MapTouchAppDelegate
#synthesize window;
#synthesize viewTouch;
#synthesize mapView;
- (void)applicationDidFinishLaunching:(UIApplication *)application
{
//We create a view wich will catch Events as they occured and Log them in the Console
viewTouch = [[UIViewTouch alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
//Next we create the MKMapView object, which will be added as a subview of viewTouch
mapView = [[MKMapView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
[viewTouch addSubview:mapView];
//And we display everything!
[window addSubview:viewTouch];
// Override point for customization after application launch
[window makeKeyAndVisible];
}
- (void)dealloc {
[window release];
[super dealloc];
}
#import <UIKit/UIKit.h>
#interface UIViewTouch : UIView
{
UIView *viewTouched;
}
#property (nonatomic, retain) UIView * viewTouched;
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;
#end
#import "UIViewTouch.h"
#implementation UIViewTouch
#synthesize viewTouched;
//The basic idea here is to intercept the view which is sent back as the firstresponder in hitTest.
//We keep it preciously in the property viewTouched and we return our view as the firstresponder.
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
NSLog(#"Hit Test");
self.multipleTouchEnabled = true;
viewTouched = [super hitTest:point withEvent:event];
return self;
}
//Then, when an event is fired, we log this one and then send it back to the viewTouched we kept, and voilà!!! :)
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(#"Touch Began");
[viewTouched touchesBegan:touches withEvent:event];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(#"Touch Moved");
[viewTouched touchesMoved:touches withEvent:event];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(#"Touch Ended");
[viewTouched touchesEnded:touches withEvent:event];
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(#"Touch Cancelled");
}
#end
This code will detect touches as well as zooming.
Try
[super touchesEnded:touches withEvent:event];
instead of
[map touchesEnded:touches withEvent:event];
And apply this idea to all of the touch event methods. That way, the touches should travel down the responder chain, and peace will be restored.
To extend up on #chomasek's answer, in order to only process those touches for the map view, I do the following:
Give the map view a tag, like 99
When I get touch, traverse up the view hierarchy of the receiving view, looking for a view with the above tag.
Here is the code:
// this is in the view controller containing the map view
// kICTagForMapView is just a constant
_mapView.tag = kICTagForMapView;
Then in sendEvent:
// this does into the UIWindow subclass
BOOL isMapView = NO;
UIView* superView = touch.view.superview;
while(superView)
{
//Debug(#"superView = %#", superView);
if (superView.tag == kICTagForMapView)
{
isMapView = YES;
break;
}
superView = superView.superview;
}
if (isMapView == NO) return;
// do stuff here
MKMapView does not respond to the touch methods listed above...