I have a situation in which I would like to place a UIView (that is not my code) on top of another UIView and have events propagated to the bottom most view. To be more concrete I would like to place a UIView on top of a MKMapView.
I have a UIView that contains both the views (as subviews). I would like my uiview to forward on the events from its view to both its subviews.
.h:
#interface MyUIView : UIView
#end
.m:
#import "MyMapView.h"
#import <MapKit/MapKit.h>
#import "MapGestureRecognizer.h"
#implementation MyMapView
MKMapView *mkMapView;
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
mkMapView = [[MKMapView alloc] initWithFrame:frame];
[self addSubview:mkMapView];
// Create another view to place on top of the mkMapView
// This is not my view I do not control is codebase. I would like to put it on top of the mkMapView
// and still have the mkMapView receive touch events
UIView * otherView = [[UIView alloc] initWithFrame:frame];
otherView.backgroundColor = [UIColor clearColor];
[self addSubview:otherView];
MapGestureRecognizer *mgr = [[MapGestureRecognizer alloc] init];
mgr.touchesBeganCallback = ^(NSSet * touches, UIEvent * event) {
UITouch *touch = [[event allTouches] anyObject];
NSLog(#"touches began=%#", [NSString stringWithFormat:#"%i", touch.view.tag]);
[mkMapView touchesBegan:touches withEvent:event];
};
mgr.touchesCancelledCallback = ^(NSSet * touches, UIEvent * event) {
UITouch *touch = [[event allTouches] anyObject];
NSLog(#"touches cancelled=%#", [NSString stringWithFormat:#"%i", touch.view.tag]);
[mkMapView touchesCancelled:touches withEvent:event];
};
mgr.touchesEndedCallback = ^(NSSet * touches, UIEvent * event) {
UITouch *touch = [[event allTouches] anyObject];
NSLog(#"touches ended=%#", [NSString stringWithFormat:#"%i", touch.view.tag]);
[mkMapView touchesEnded:touches withEvent:event];
};
mgr.touchesMovedCallback = ^(NSSet * touches, UIEvent * event) {
UITouch *touch = [[event allTouches] anyObject];
NSLog(#"touches moved=%#", [NSString stringWithFormat:#"%i", touch.view.tag]);
[mkMapView touchesMoved:touches withEvent:event];
};
[self addGestureRecognizer:mgr];
return self;
}
#end
I implemented my own gesture recognizer to intercept these events and I am trying to pass to intercepted events through to the mkMapView. I see the log messages however it does not seem to pass the events through as I can make the mkmapview scroll/pan.
The gesture recogniser works with the topmost view if another view is on top of the view with the attached gesture recogniser, the recogniser does not fire off. A quick and dirty way would be to assign the same set of recognisers to otherView and drop them appropriately when not needed. The action need not be performed on the same view that receives the gestures so receiving the pan gestures in Otherviews and then panning the map in the background should work.
change your code to below one->
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
mkMapView = [[MKMapView alloc] initWithFrame:frame];
[self addSubview:mkMapView];
UIView * otherView = [[UIView alloc] initWithFrame:frame];
otherView.backgroundColor = [UIColor clearColor];
[self addSubview:otherView];
return self;
}
-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{
return mkMapView;
}
I want to call a method whenever a specific UIViewController is touched.
-touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event is a method that does what I'm looking for, exept it doesn't detect a touch on neither the statur bar, navigation bar or toolbar. How can I make a method that runs everytime the UIViewController is touched? Or in other words, the whole screen?
try adding a gesture recognition. to your window object, since it's a subclass of a uiview.
or like #Bamsworld said. "For full screen detection (including status bar) I think you'll need to sub class UIWindow and make it becomeFirstResponder: Override touches and handle from window sub class."
Subclass UIApplication say MyApplication and implement the method
- (void)sendEvent:(UIEvent *)event {
[super sendEvent:event];
// Do whatever you want
}
Then in main.m change the default implementation to
int main(int argc, char *argv[])
{
#autoreleasepool {
return UIApplicationMain(argc, argv, NSStringFromClass([MyApplication class]), NSStringFromClass([YourAppdelegate class]));
}
}
You will get each and every action in method
- (void)sendEvent:(UIEvent *)event
#import <QuartzCore/QuartzCore.h>
- (void)viewDidLoad
{
[super viewDidLoad];
[self.view setMultipleTouchEnabled:YES];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
// Remove old red circles on screen
NSArray *subviews = [self.view subviews];
for (UIView *view in subviews) {
[view removeFromSuperview];
}
// Enumerate over all the touches and draw a red dot on the screen where the touches were
[touches enumerateObjectsUsingBlock:^(id obj, BOOL *stop) {
// Get a single touch and it's location
UITouch *touch = obj;
CGPoint touchPoint = [touch locationInView:self.view];
// Draw a red circle where the touch occurred
UIView *touchView = [[UIView alloc] init];
[touchView setBackgroundColor:[UIColor redColor]];
touchView.frame = CGRectMake(touchPoint.x, touchPoint.y, 30, 30);
touchView.layer.cornerRadius = 15;
[self.view addSubview:touchView];
[touchView release];
}];
}
I have a very complex app with lots of stacked views which contain lots of buttons ,drawing areas and other custom touch handling . I am displaying a draggable helper view which can be on top of all the other views . I need to dismiss this view if the user taps anywhere outside the helper view . I have tried using multiple UIWindows and adding Gesture recognizers to the UIWindow .
A easy is to add a transparent button which bounds is equal the superview's bounds. And the superview insert the transparent button below your helper view.
The transparent button add a click event which can dismiss the helper view and the transparent button it self.
For example :
UIButton *transparencyButton = [[UIButton alloc] initWithFrame:superview.bounds];
transparencyButton.backgroundColor = [UIColor clearColor];
[superview insertSubview:transparencyButton belowSubview:helperView];
[transparencyButton addTarget:self action:#selector(dismissHelper:) forControlEvents:UIControlEventTouchUpInside];
and the dismissHelper: method can do this :
- (void)dismissHelper:(UIButton *)sender
{
[helperView dismiss];
sender.hidden = YES;
// or [sender removeFromSuperview]
}
You can check the view being touched by going through the touches and looking at the .view property of the touch. It reflects the view from where the view actually originates.
Assuming that you keep a reference to your view (either via an IBOutlet or otherwise) to your view called "myView" the below works.
In your .m file. The touchesBegan: function is triggered every time the user touches a finger down. We loop through the touches to see if the originating view of the touch is NOT equal to "myView". This comparison could also be done via checking the class, tag or any other property you use to identify your view. Examples given below.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"touches began");
UITouch *touch = [touches anyObject];
if(touch.view!=myView){
myView.hidden = YES;
}
}
Or in case of using a tag:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"touches began");
UITouch *touch = [touches anyObject];
if(touch.view.tag!=23){
myView.hidden = YES;
}
}
create an hittestintercept view. this can make the view below handle events like before.
#protocol HitTestInterceptViewDelegate <NSObject>
- (BOOL)interceptHitTest:(CGPoint)point withEvent:(UIEvent *)event;
#end
#interface HitTestInterceptView : UIView
#property(nonatomic, weak) id<HitTestInterceptViewDelegate> hitTestInterceptDelegate;
#end
HtiTestInterceptView.m
#import "HitTestInterceptView.h"
#implementation HitTestInterceptView
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
if ([_hitTestInterceptDelegate interceptHitTest:point withEvent:event] == NO) {
return [super hitTest:point withEvent:event];
}
return nil;
}
#end
then use it in the toast view
- (void)dismissIfTouchOutsideInView:(UIView *)view {
if (_interceptView != nil) return;
_interceptView = [[HitTestInterceptView alloc] initWithFrame:view.bounds];
_interceptView.backgroundColor = [UIColor clearColor];
_interceptView.hitTestInterceptDelegate = self;
[view insertSubview:_interceptView belowSubview:self];
}
- (BOOL)interceptHitTest:(CGPoint)point withEvent:(UIEvent *)event {
dispatch_async(dispatch_get_main_queue(), ^{
// [self dismiss];
});
return YES;
}
I put UIButton inside UITableViewCell in UITableView that is behind UIScrollView. I subclassed UIScrollView to forward touches to UITableView.
So method from UITableViewDelegate didSelectRow is calling properly. The problem is that UIButton inside table cell is not receiving TouchUpInside actions.
How can I solve this problem without deleting ScrollView over TableView?
EDIT:
I resolved this issue by detecting which view will receive touch. Here's the code:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UIView *hitView = [self hitTest:[(UITouch*)[[touches allObjects] objectAtIndex:0] locationInView:self] withEvent:event];
if ([hitView isKindOfClass:[UIButton class]]) {
[(UIButton*)hitView sendActionsForControlEvents:UIControlEventTouchUpInside];
}
[super touchesBegan:touches withEvent:event];
}
If you want to enable actions for bouth objects - UIScrollView and UIButton you should to implement custom hit test mechanism for ScrollView.
In your UIScrollView subclass override - (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event method to make views behind ScrollView available for getting events.
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
return __touchesEnabled;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
_touchesEnabled = NO;
UIWindow *window = [UIApplication sharedApplication].delegate.window;
for(UITouch *touch in touches) {
CGPoint point = [touch locationInView:self];
point = [window convertPoint:point fromView:self];
UIView *view = [window hitTest:point withEvent:event];
[view touchesBegan:touches withEvent:event];
}
_touchesEnabled = YES;
}
It works for me
Since you have added your scroll view over the UIButton, all the touch actions will not be passed to the button.
[yourScrollView setUserInteractionEnabled:NO];
This may solve your problem.
I'm not sure what I am doing wrong but I try to catch touches on a MKMapView object. I subclassed it by creating the following class :
#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>
#interface MapViewWithTouches : MKMapView {
}
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *) event;
#end
And the implementation :
#import "MapViewWithTouches.h"
#implementation MapViewWithTouches
- (void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *) event {
NSLog(#"hello");
//[super touchesBegan:touches withEvent:event];
}
#end
But it looks like when I use this class, I see nothing on the Console :
MapViewWithTouches *mapView = [[MapViewWithTouches alloc] initWithFrame:self.view.frame];
[self.view insertSubview:mapView atIndex:0];
Any idea what I'm doing wrong?
The best way I have found to achieve this is with a Gesture Recognizer. Other ways turn out to involve a lot of hackish programming that imperfectly duplicates Apple's code, especially in the case of multitouch.
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 then use the gestureRecognizer's touchesBegan, touchesMoved, etc. to your fancy.
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
SWIFT 3
let tapInterceptor = WildCardGestureRecognizer(target: nil, action: nil)
tapInterceptor.touchesBeganCallback = {
_, _ in
self.lockedOnUserLocation = false
}
mapView.addGestureRecognizer(tapInterceptor)
WildCardGestureRecognizer.swift
import UIKit.UIGestureRecognizerSubclass
class WildCardGestureRecognizer: UIGestureRecognizer {
var touchesBeganCallback: ((Set<UITouch>, UIEvent) -> Void)?
override init(target: Any?, action: Selector?) {
super.init(target: target, action: action)
self.cancelsTouchesInView = false
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent) {
super.touchesBegan(touches, with: event)
touchesBeganCallback?(touches, event)
}
override func canPrevent(_ preventedGestureRecognizer: UIGestureRecognizer) -> Bool {
return false
}
override func canBePrevented(by preventingGestureRecognizer: UIGestureRecognizer) -> Bool {
return false
}
}
After a day of pizzas, screamings, I finally found the solution! Very neat!
Peter, I used your trick above and tweaked it a little bit to finally have a solution which work perfectly with MKMapView and should work also with UIWebView
MKTouchAppDelegate.h
#import <UIKit/UIKit.h>
#class UIViewTouch;
#class MKMapView;
#interface MKTouchAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
UIViewTouch *viewTouch;
MKMapView *mapView;
}
#property (nonatomic, retain) UIViewTouch *viewTouch;
#property (nonatomic, retain) MKMapView *mapView;
#property (nonatomic, retain) IBOutlet UIWindow *window;
#end
MKTouchAppDelegate.m
#import "MKTouchAppDelegate.h"
#import "UIViewTouch.h"
#import <MapKit/MapKit.h>
#implementation MKTouchAppDelegate
#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];
[window makeKeyAndVisible];
}
- (void)dealloc {
[window release];
[super dealloc];
}
#end
UIViewTouch.h
#import <UIKit/UIKit.h>
#class UIView;
#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
UIViewTouch.m
#import "UIViewTouch.h"
#import <MapKit/MapKit.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");
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
I hope that will help some of you!
Cheers
UITapGestureRecognizer *tgr = [[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(handleGesture:)];
tgr.numberOfTapsRequired = 2;
tgr.numberOfTouchesRequired = 1;
[mapView addGestureRecognizer:tgr];
[tgr release];
- (void)handleGesture:(UIGestureRecognizer *)gestureRecognizer
{
if (gestureRecognizer.state != UIGestureRecognizerStateEnded)
return;
CGPoint touchPoint = [gestureRecognizer locationInView:mapView];
CLLocationCoordinate2D touchMapCoordinate = [mapView convertPoint:touchPoint toCoordinateFromView:mapView];
//.............
}
For a MKMapView the real working solution is with gesture recognization !
Me I wanted to stop updating the center of the map on my location when I drag the map or pinch to zoom.
So, create and add your gesture recognizer to the mapView :
- (void)viewDidLoad {
...
// Add gesture recognizer for map hoding
UILongPressGestureRecognizer *longPressGesture = [[[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(handleLongPressAndPinchGesture:)] autorelease];
longPressGesture.delegate = self;
longPressGesture.minimumPressDuration = 0; // In order to detect the map touching directly (Default was 0.5)
[self.mapView addGestureRecognizer:longPressGesture];
// Add gesture recognizer for map pinching
UIPinchGestureRecognizer *pinchGesture = [[[UIPinchGestureRecognizer alloc] initWithTarget:self action:#selector(handleLongPressAndPinchGesture:)] autorelease];
pinchGesture.delegate = self;
[self.mapView addGestureRecognizer:pinchGesture];
// Add gesture recognizer for map dragging
UIPanGestureRecognizer *panGesture = [[[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePanGesture:)] autorelease];
panGesture.delegate = self;
panGesture.maximumNumberOfTouches = 1; // In order to discard dragging when pinching
[self.mapView addGestureRecognizer:panGesture];
}
Look the UIGestureRecognizer Class Reference to see all available gesture recognizer.
Because we've defined the delegate to self, we have to implement the protocole UIGestureRecognizerDelegate :
typedef enum {
MapModeStateFree, // Map is free
MapModeStateGeolocalised, // Map centred on our location
MapModeStateGeolocalisedWithHeading // Map centred on our location and oriented with the compass
} MapModeState;
#interface MapViewController : UIViewController <CLLocationManagerDelegate, UIGestureRecognizerDelegate> {
MapModeState mapMode;
}
#property (nonatomic, retain) IBOutlet MKMapView *mapView;
...
And override the methode gestureRecognizer:gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer: in order to allow recognize multiple gestures simultaneously, if I understood right :
// Allow to recognize multiple gestures simultaneously (Implementation of the protocole UIGestureRecognizerDelegate)
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
return YES;
}
Now write the methodes which will be called by our gesture recognizers :
// On map holding or pinching pause localise and heading
- (void)handleLongPressAndPinchGesture:(UIGestureRecognizer *)sender {
// Stop to localise and/or heading
if (sender.state == UIGestureRecognizerStateBegan && mapMode != MapModeStateFree) {
[locationManager stopUpdatingLocation];
if (mapMode == MapModeStateGeolocalisedWithHeading) [locationManager stopUpdatingHeading];
}
// Restart to localise and/or heading
if (sender.state == UIGestureRecognizerStateEnded && mapMode != MapModeStateFree) {
[locationManager startUpdatingLocation];
if (mapMode == MapModeStateGeolocalisedWithHeading) [locationManager startUpdatingHeading];
}
}
// On dragging gesture put map in free mode
- (void)handlePanGesture:(UIGestureRecognizer *)sender {
if (sender.state == UIGestureRecognizerStateBegan && mapMode != MapModeStateFree) [self setMapInFreeModePushedBy:sender];
}
Just in case somebody is trying to do the same like me: I wanted to create an annotation at the point where the user taps. For that I used the UITapGestureRecognizer solution:
UITapGestureRecognizer *tapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(didTapOnMap:)];
[self.mapView addGestureRecognizer:tapGestureRecognizer];
[tapGestureRecognizer setDelegate:self];
- (void)didTapOnMap:(UITapGestureRecognizer *)gestureRecognizer
{
CGPoint point = [gestureRecognizer locationInView:self.mapView];
CLLocationCoordinate2D coordinate = [self.mapView convertPoint:point toCoordinateFromView:self.mapView];
.......
}
However, didTapOnMap: was also called when I tapped on the annotation and a new one would be created. The solution is to implement the UIGestureRecognizerDelegate:
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldReceiveTouch:(UITouch *)touch
{
if ([touch.view isKindOfClass:[MKAnnotationView class]])
{
return NO;
}
return YES;
}
You probably will need to overlay a transparent view to catch the touches just like is done so often with UIWebView-based controls. The Map View already does a bunch of special things with a touch in order to allow the map to be moved, centered, zoomed, etc... that the messages are not getting bubbled up to your app.
Two other (UNTESTED) options I can think of:
1) Resign the first responder via IB and set it to "File's Owner" to allow file's Owner to respond to the touches. I an dubious that this will work because MKMapView extends NSObject, not UIView ans a result the touch events still may not get propagated up to you.
2) If you want to trap when the Map state changes (such as on a zoom) just implement the MKMapViewDelegate protocol to listen for particular events. My hunch is this is your best shot at trapping some interaction easily (short of implementing the transparent View over the Map). Do not forget to set the View Controller housing the MKMapView as the map's delegate (map.delegate = self).
Good Luck.
I haven't experimented, but there's a good chance MapKit is based around a class cluster, and therefore subclassing it is difficult and ineffective.
I'd suggest making the MapKit view a subview of a custom view, which should allow you to intercept touch events before they reach it.
So after half a day of messing around with this I found the following:
As everyone else found, pinching doesn't work. I tried both subclassing MKMapView and the method described above (intercepting it). And the result is the same.
In the Stanford iPhone videos, a guy from Apple says that many of the UIKit things will
cause alot of errors if you "transfer" the touch requests (aka the two methods described above), and you probably won't get it to work.
THE SOLUTION: is described here: Intercepting/Hijacking iPhone Touch Events for MKMapView. Basically you "catch" the event before any responder gets it, and interpret it there.
In Swift 3.0
import UIKit
import MapKit
class CoordinatesPickerViewController: UIViewController {
#IBOutlet var mapView: MKMapView!
override func viewDidLoad() {
super.viewDidLoad()
let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(clickOnMap))
mapView.addGestureRecognizer(tapGestureRecognizer)
}
#objc func clickOnMap(_ sender: UITapGestureRecognizer) {
if sender.state != UIGestureRecognizerState.ended { return }
let touchLocation = sender.location(in: mapView)
let locationCoordinate = mapView.convert(touchLocation, toCoordinateFrom: mapView)
print("Tapped at lat: \(locationCoordinate.latitude) long: \(locationCoordinate.longitude)")
}
}
Make the MKMapView a subview of a custom view and implement
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
in the custom view to return self instead of the subview.
Thanks for the pizza and screamings - you saved me lots of time.
multipletouchenabled will work sporadically.
viewTouch.multipleTouchEnabled = TRUE;
In the end, I switched out the views when I needed to capture the touch (different point in time than needing pinchzooms):
[mapView removeFromSuperview];
[viewTouch addSubview:mapView];
[self.view insertSubview:viewTouch atIndex:0];
I notice that you can track the number and location of touches, and get the location of each in a view:
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"Touch Moved %d", [[event allTouches] count]);
NSEnumerator *enumerator = [touches objectEnumerator];
id value;
while ((value = [enumerator nextObject])) {
NSLog(#"touch description %f", [value locationInView:mapView].x);
}
[viewTouched touchesMoved:touches withEvent:event];
}
Has anyone else tried using these values to update the map's zoom level? It would be a matter of recording the start positions, and then the finish locations, calculating the relative difference and updating the map.
I'm playing with the basic code provided by Martin, and this looks like it will work...
Here's what I put together, that does allow pinch zooms in the simulator (haven't tried on a real iPhone), but I think would be fine:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"Touch Began %d", [touches count]);
reportTrackingPoints = NO;
startTrackingPoints = YES;
[viewTouched touchesBegan:touches withEvent:event];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
if ([[event allTouches] count] == 2) {
reportTrackingPoints = YES;
if (startTrackingPoints == YES) {
BOOL setA = NO;
NSEnumerator *enumerator = [[event allTouches] objectEnumerator];
id value;
while ((value = [enumerator nextObject])) {
if (! setA) {
startPointA = [value locationInView:mapView];
setA = YES;
} else {
startPointB = [value locationInView:mapView];
}
}
startTrackingPoints = NO;
} else {
BOOL setA = NO;
NSEnumerator *enumerator = [[event allTouches] objectEnumerator];
id value;
while ((value = [enumerator nextObject])) {
if (! setA) {
endPointA = [value locationInView:mapView];
setA = YES;
} else {
endPointB = [value locationInView:mapView];
}
}
}
}
//NSLog(#"Touch Moved %d", [[event allTouches] count]);
[viewTouched touchesMoved:touches withEvent:event];
}
- (void) updateMapFromTrackingPoints {
float startLenA = (startPointA.x - startPointB.x);
float startLenB = (startPointA.y - startPointB.y);
float len1 = sqrt((startLenA * startLenA) + (startLenB * startLenB));
float endLenA = (endPointA.x - endPointB.x);
float endLenB = (endPointA.y - endPointB.y);
float len2 = sqrt((endLenA * endLenA) + (endLenB * endLenB));
MKCoordinateRegion region = mapView.region;
region.span.latitudeDelta = region.span.latitudeDelta * len1/len2;
region.span.longitudeDelta = region.span.longitudeDelta * len1/len2;
[mapView setRegion:region animated:YES];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
if (reportTrackingPoints) {
[self updateMapFromTrackingPoints];
reportTrackingPoints = NO;
}
[viewTouched touchesEnded:touches withEvent:event];
}
The main idea is that if the user is using two fingers, you track the values. I record the starting and ending points in startPoints A and B. Then I record the current tracking points, and when I'm done, on touchesEnded, I can call a routine to calculate the relative lengths of the line between the points I start with, and the line between the point I end with using simple hypotenuse calc. The ratio between them is the zoom amount: I multiply the region span by that amount.
Hope it's useful to someone.
I took the idea of an "overlay" transparent view, from MystikSpiral's answer, and it worked perfectly for what I was trying to achieve; quick, and clean solution.
In short, I had a custom UITableViewCell (designed in IB) with a MKMapView on the left-hand-side and some UILabels on the right. I wanted to make the custom cell so you could touch it anywhere and this would push a new view controller. However touching the map didn't pass touches 'up' to the UITableViewCell until I simply added a UIView of the same size as the map view right on top of it (in IB) and made it's background the 'clear color' in code (don't think you can set clearColor in IB??):
dummyView.backgroundColor = [UIColor clearColor];
Thought it might help someone else; certainly if you want to achieve the same behaviour for a table view cell.
I don't understand why other answers are so complicated. The solution is really just one line:
mapView.addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(mapTapped)))
#objc func mapTapped() {}