Does anyone else see this issue? I am using a segmented control, and I've overridden it so that when the user hits the same segment(index), it is deselected.
This worked fine in previous versions, but now testing on iOS5. And I am finding that the UIControlEventValueChanged is not sent when you tap on the same segment. So the code works ok when you tap on different segments, but does not for the same segment.
My code.
segmentCtrl = [[MySegmentedControl alloc] initWithItems: segmentCtrlLabels];
segmentCtrl.segmentedControlStyle = UISegmentedControlStyleBar;
// Register for touch events
[segmentCtrl addTarget:self action:#selector(segmentedCtrlTouched:) forControlEvents:UIControlEventValueChanged];
I tried to register for UIControlEventTouchUpInside, and get the same behavior.
Any suggestions for work around?
Regards,
Yenyi
Fixed it by registrering for a touch event. If the touched segment is the same, I manually send the EventChanged event.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSInteger current = self.selectedSegmentIndex;
[super touchesBegan:touches withEvent:event];
if (current == self.selectedSegmentIndex) {
[self setSelectedSegmentIndex:current];
[self sendActionsForControlEvents:UIControlEventValueChanged];
}
}
Yup you need to implement the control events yourself.
- (void) touchesBegan: (NSSet *) touches withEvent: (UIEvent *) event
{
[super touchesBegan: touches withEvent: event];
[self sendActionsForControlEvents: UIControlEventTouchDown];
}
- (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event
{
[super touchesEnded: touches withEvent: event)];
if (CGRectContainsPoint(self.bounds, [touches.anyObject locationInView: self]))
{
[self sendActionsForControlEvents: UIControlEventTouchUpInside];
}
else
{
[self sendActionsForControlEvents: UIControlEventTouchUpOutside];
}
}
- (void) touchesCancelled: (NSSet *) touches withEvent: (UIEvent *) event
{
[super touchesCancelled: touches withEvent: event];
[self sendActionsForControlEvents: UIControlEventTouchCancel];
}
Related
I called the method,
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesBegan:touches withEvent:event];
[self.name resignFirstResponder];
[self.userName resignFirstResponder];
[self.mailId resignFirstResponder];
[self.password resignFirstResponder];
[self.reTypePassword resignFirstResponder];
}
for the purpose of resign first responder.it is working properly without using scrollview.but if i am using scrollview i cant able to use this method.why?
You can add a gesture recognizer if you need to use a scrollview.
Try this:
UITapGestureRecognizer *gestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(resignFirstResponder:)];
gestureRecognizer.delegate = self;
[scrollView addGestureRecognizer:gestureRecognizer];
-(void) resignFirstResponder:(UITapGestureRecognizer *) gesture
{
[self.name resignFirstResponder];
[self.userName resignFirstResponder];
[self.mailId resignFirstResponder];
[self.password resignFirstResponder];
[self.reTypePassword resignFirstResponder];
}
There are many more alternatives: See
UIScrollView prevents touchesBegan, touchesMoved, touchesEnded on view controller ,
UIScrollView touchesBegan
I've setup a tap gesture recognizer and add the recognizer to the uibutton. The button has a background image. When I tap the button it doesn't highlight at all, the only thing I've been able to get it to do is change it's alpha value.
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTapGestureCaptured:)];
singleTap.cancelsTouchesInView = NO;
[btnNext addGestureRecognizer:singleTap];
- (void)singleTapGestureCaptured:(UITapGestureRecognizer *)gesture
{
UIView *tappedView = [gesture.view hitTest:[gesture locationInView:gesture.view] withEvent:nil];
NSLog(#"Touch event view: %#",[tappedView class]);
UIButton *myButton = (UIButton *) tappedView;
[self highlightButton:myButton];
tappedView.alpha = 0.5f;
}
Any would be appreciated. Thanks
You can intercept the touches events with a gesture recognizer, and then programmatically add the recognizer to all your uibuttons. For instance:
//
// HighlighterGestureRecognizer.h
// Copyright 2011 PathwaySP. All rights reserved.
//
#import <Foundation/Foundation.h>
#interface HighlightGestureRecognizer : UIGestureRecognizer {
id *beganButton;
}
#property(nonatomic, assign) id *beganButton;
#end
and the implementation:
//
// HighlightGestureRecognizer.m
// Copyright 2011 PathwaySP. All rights reserved.
//
#import "HighlightGestureRecognizer.h"
#implementation HighlightGestureRecognizer
#synthesize beganButton;
-(id) init{
if (self = [super init])
{
self.cancelsTouchesInView = NO;
}
return self;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
self.beganButton = [[[event allTouches] anyObject] view];
if ([beganButton isKindOfClass: [UIButton class]]) {
[beganButton setBackgroundImage:[UIImage imageNamed:#"grey_screen"] forState:UIControlStateNormal];
[self performSelector:#selector(resetImage) withObject:nil afterDelay:0.2];
}
}
- (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;
}
- (void)resetImage
{
[beganButton setBackgroundImage: nil forState:UIControlStateNormal];
}
#end
The way you'd add the gesture recognizer to your button would be like so:
HighlighterGestureRecognizer * tapHighlighter = [[HighlighterGestureRecognizer alloc] init];
[myButton addGestureRecognizer:tapHighlighter];
[tapHighlighter release];
So basically you're declaring it, initializing it, and then adding it. After that, you'll want to release it, since the addGestureRecognizer retains it.
Also simply try
adjustsImageWhenHighlighted = YES set on your buttons? The default is YES, but maybe you changed it in the xib. It's the "Highlighted Adjusts Image" checkbox in the attributes inspector:
First of all, this problem did not exist in iOS 4.3. I can still run the program in iOS 4.3 and won't see any problem. Secondly, this is an iPad app.
The problem is that when I hold down an image and drag it, it won't be dragged. It worked in iOS 4.3 but not iOS 5.
I created new testing project and cleared everything that's not needed. The project I chose is a Single View Application and did not alter any of the AppDelegate files.
Here is the code.
myUIScrollViewClass.h
#import <UIKit/UIKit.h>
#interface myUIScrollViewClass : UIScrollView
{
}
#end
myUIScrollViewClass.m
#import "myUIScrollViewClass.h"
#implementation myUIScrollViewClass
- (id)init
{
self = [super init];
if (self)
{
}
return self;
}
- (void)didReceiveMemoryWarning
{
[self didReceiveMemoryWarning];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.nextResponder touchesBegan: touches withEvent:event];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.nextResponder touchesMoved: touches withEvent:event];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.nextResponder touchesEnded: touches withEvent:event];
}
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
[self.nextResponder touchesCancelled: touches withEvent:event];
}
#end
ViewController.h
#import <UIKit/UIKit.h>
#import "myUIScrollViewClass.h"
#interface ViewController : UIViewController <UIScrollViewDelegate>
{
myUIScrollViewClass *mainScrollView_;
UIImageView *aTouchedImage_;
}
#property (retain, nonatomic) myUIScrollViewClass *mainScrollView_;
#property (retain, nonatomic) UIImageView *aTouchedImage_;
#end
ViewController.m
#import "ViewController.h"
#implementation ViewController
#synthesize mainScrollView_;
#synthesize aTouchedImage_;
- (void)didReceiveMemoryWarning
{
[super didReceiveMemoryWarning];
// Release any cached data, images, etc that aren't in use.
}
#pragma mark - View lifecycle
- (void)viewDidLoad
{
mainScrollView_ = [[myUIScrollViewClass alloc] initWithFrame:self.view.frame];
[self.view addSubview:mainScrollView_];
mainScrollView_.delegate = self;
mainScrollView_.contentSize = CGSizeMake(1024, 768);
mainScrollView_.clipsToBounds = YES;
mainScrollView_.bounces = NO;
mainScrollView_.bouncesZoom = NO;
mainScrollView_.showsVerticalScrollIndicator = NO;
mainScrollView_.showsHorizontalScrollIndicator = NO;
mainScrollView_.backgroundColor = [UIColor whiteColor];
mainScrollView_.userInteractionEnabled = YES;
aTouchedImage_ = [[UIImageView alloc] initWithImage: [UIImage imageNamed:#"image1.png"]];
[aTouchedImage_ setFrame:CGRectMake(0, 0, 80, 80)];
[mainScrollView_ addSubview:aTouchedImage_];
[aTouchedImage_ setCenter:CGPointMake(512, 334)];
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
}
- (void)viewDidUnload
{
[super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
}
- (void)viewDidDisappear:(BOOL)animated
{
[super viewDidDisappear:animated];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
// Return YES for supported orientations
return YES;
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)anEvent
{
mainScrollView_.scrollEnabled = NO;
for (UITouch *touch in touches)
{
[aTouchedImage_ setCenter:[touch locationInView:self.view]];
}
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)anEvent
{
mainScrollView_.scrollEnabled = NO;
for (UITouch *touch in touches)
{
[aTouchedImage_ setCenter:[touch locationInView:self.view]];
}
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)anEvent
{
mainScrollView_.scrollEnabled = YES;
for (UITouch *touch in touches)
{
}
}
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)anEvent
{
mainScrollView_.scrollEnabled = YES;
for (UITouch *touch in touches)
{
}
}
#end
It seems I will answer my own question.
I have requested a support from Apple Developer Technical Support, and they told me to place my code in the UIScrollView rather than passing the touch events to another view. Apple themselves admitting that there is a problem with passing touch events.
Here is an extract of their reply:
"It looks like not all touch events are getting through to your view controller. Your UIScrollView is blocking touch events from getting through, even though is forwards those events to the next responder. The behaviour is very erratic, some touch events are being forwarded to your view controller, but not all of them."
"Looks like a behaviour change in iOS 5.0.x. My guess it's because of the view controller containment feature that was introduced."
The other way to do it is to use UIGestureRecognizer to implement dragging of views. Something like the code below:
- (void)viewDidLoad
{
// ... other initialization code here
UILongPressGestureRecognizer *longPress = [[[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(dragChild:)] autorelease];
[longPress setMinimumPressDuration:0]; // recognize immediately when a finger comes down
[draggableView addGestureRecognizer:longPress];
}
- (void)dragChild:(UILongPressGestureRecognizer *)longPress
{
[[longPress view] setCenter:[longPress locationInView:[[longPress view] superview]];
}
I am simply trying to get hold of the UIImageView that was tapped on, from the UIScrollView.
I have found 2 ways of achieving the above on the Web.
1st method : create a tap gesture on the uiimageview before adding it to scrollviewer.
This method has not worked for me. the handleSingleTap method never gets called.
I am out of ideas on what I am doing wrong/why this is not working.
UITapGestureRecognizer *singleTap =
[[UITapGestureRecognizer alloc] initWithTarget:self
action:#selector(handleSingleTap:)];
singleTap.numberOfTapsRequired = 1;
[imageView addGestureRecognizer:singleTap];
[singleTap release];
[framesSourceScrollview addSubview:imageView];
[imageView release];
- (void)handleSingleTap:(UIGestureRecognizer *)sender
{
NSLog(#"image tapped!!!");
}
2nd Method : subclass UIScrollView
#interface SingleTapScrollViewer : UIScrollView {
}
#end
#implementation SingleTapScrollViewer
- (id)initWithFrame:(CGRect)frame
{
return [super initWithFrame:frame];
}
- (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event
{
// If not dragging, send event to next responder
if (!self.dragging)
[self.nextResponder touchesEnded: touches withEvent:event];
else
[super touchesEnded: touches withEvent: event];
}
#end
In the ViewController
- (void) touchesEnded: (NSSet *) touches withEvent: (UIEvent *) event
{
// Process the single tap here
NSLog(#"Scroll view single tapped. touches count : %d", touches.count);
UITouch *touch = [touches anyObject];
UIImageView *imgView = (UIImageView*)touch.view;
NSLog(#"tag is %#", imgView.tag);
}
Using this method, the touchesDown responder does get called but the '[touches anyobject]' isn't the UIImageView which was tapped on.
I tried setting the 'tag' on every UIImageView I am adding to the scrollview with an increasing counter but I get back 0 no matter which imageview i tap on.
I am new to cocoa in general and I am not sure how to leverage this responder in any other fashion.
Any suggestions/hints would be great.
thanks in advance.
did you set the userInteractionEnabled=YES on the UIImageView. Its turned off by default.
I am using this method
- (void)tableView:(UITableView *)tableView touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
if ([myPickerView isFirstResponder] && [touch view] != myPickerView) {
[myPickerView resignFirstResponder];
}
[super touchesBegan:touches withEvent:event];
}
but my tableView does not respond to touches (applied to the view works, but this is covered by the tableView!)
If this is not possible - is there any other possibility to capture "out of window" touches?
There is no such delegate method as tableView:touchesBegan:withEvent:. If you want to override -touchesBegan:withEvent: for your UITableView, you will need to subclass UITableView. Most problems like this are often better implemented with a UIGestureRecognizer. In the above, I'd probably use a UITapGestureRecognizer.
I found the simplest way to do this is to add a gesture recognizer to the UITableViewController's view.
I put this code in the UITableViewController's viewDidLoad:
UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
[self.view addGestureRecognizer:tap];
And implemented the event handler:
- (void)handleTap:(UITapGestureRecognizer *)recognizer
{
// your code goes here...
}
EDIT:
You could also add the gesture recognizer to the tableview, just change [self.view addGestureRecognizer:tap]; to [self.tableView addGestureRecognizer:tap];
Here is a UITableView subclass solution that worked for me. Make a subclass of UITableView and override hitTest:withEvent: as below:
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
static UIEvent *e = nil;
if (e != nil && e == event) {
e = nil;
return [super hitTest:point withEvent:event];
}
e = event;
if (event.type == UIEventTypeTouches) {
NSSet *touches = [event touchesForView:self];
UITouch *touch = [touches anyObject];
if (touch.phase == UITouchPhaseBegan) {
NSLog(#"Touches began");
}
}
return [super hitTest:point withEvent:event];
}