I have been trying to figure this out for some time now. I am using auto layout with a scrollview. Inside the scrollview is a UIView, another UIView and then the subview within that. I can't get touch to work with the subview. I have tried touchesbegan along with uitapgesture with no success. Any suggestions? Here is the layout hierarchy.
ScrollView
---- UIView
------- UIView
------ UIView - Need to detect touch here.
EDIT:
Sorry guys, was at work. Here is some code. I have subclassed my scrollview to receive touches as it seems to be working best so far getting down to the subview level of other view subviews.
The following code detects that the view is that class without the pointInside. I am currently having issues receiving the right point for the view.
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
UIView *relatedVidsView = [[[touches allObjects] firstObject] view];
for (int i = 0; i < relatedVidsView.subviews.count; i++) {
UIView *view = [relatedVidsView.subviews objectAtIndex:i];
CGPoint touchPoint = [[[touches allObjects] firstObject] locationInView:self];
if ([view isKindOfClass:[RecipeVideoView class]] && [view pointInside:touchPoint withEvent:nil]) {
NSLog(#"TEST");
}
}
[super touchesBegan:touches withEvent:event]; }
EDIT 2:
So I was able to figure this out. I subclassed the view that was containing the subviews that i needed touch events for. What I did was passed the events from the parent to the subviews using touchesBegan. I will post my code later, thanks for the help anyway.
Related
I have an app in which the user can interact with many objects. These are several UIButtons, a few UILabels and a lot of UIImageViews.
The focus of all interaction centers around touching the UIImageView objects. With a touch I can move the images around, tell them to do this or that. However, my current obstacle is in knowing how to properly have the app distinguish touches that occur when I touch a UIButton.
Why? Well the logic within the Touches Began event is meant to be only for the UIImageViews, however the moment that I touch a button, or any other object, the app is interpreting the touch as if it occurred for a UIImageView object.
So, my approach boils down to: is there a good way of identifying if a touch occurred for a UIButton, UIImageView, UILabel object? That way I can filter out the irrelevant touches in my app from the relevant ones.
EDIT:
The code below outlines how I capture the touch event, however I do not know how to know from the touch event whether it is a button or a view that I touched.
touch = [touches anyObject];
touchLocation = [touch locationInView:[self view]];
To know whether UIButton is pressed follow this:
-(void) touchBegan : (NSSet *) touches withEvent : (UIEvent *) even
{
UITouch *touch = [touched anyObject];
UIView *touchedView = [touch view];
if([touchedView isMemberofClass : [UIButton class])
{
//do something when button is touched
}
}
Call hitTest:withEvent: on the view with the touch event to get the view that is actually being touched. Then you can use isKindOfClass: to check what type of view it is and respond accordingly.
you can use this method :-
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
if ([self pointInside:point withEvent:event]) {
//You clicked inside the object
}
return [super hitTest:point withEvent:event]
}
and wain has already given you the explanation for it..
https://stackoverflow.com/a/18051856/1865424
I have multiple UIViews in a UIViewController and every UIView has UIScrollViews. I have to move UIViews horizontal by touch events. UIScrollViews should scroll only vertical. But UIScrollViews are swallowing touch events and so UIView is not moving. I made a custom UIScrollView class to forward touch events like below, but on that way UIScrollView doesn't scroll.
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event
{
UIView *result = nil;
for (UIView *child in self.subviews)
if ([child pointInside:point withEvent:event])
if ((result = [child hitTest:point withEvent:event]) != nil)
break;
return result;
}
How can I pass touches from UIScrollView to it's parent view by also making UIScrollView work?
Why don't you put your views with scrollviews to big scrollview with only horisontal scrolling enabled? I tried it once, works for me
I have made a UISlider work just like the "slide to unlock" slider.
What I need to do is determine the point at which lifting your finger off is classed as touchUpOUTSIDE and not touchUpINSIDE. This is the point where you slide your finger past the end of the slider too far.
I guess it's the same as with a UIButton, you can press the button then slide your finger off the button and depending how far you go, it can still be classed as touchUpInside.
If possible, i'd like to mark the target area with a circle.
Once i've managed to find where this point is, is it possible to change it? So I could have a bigger target area?
I really don't know where to start with this. Thanks
According to the docs, the UIControlEventTouchUpOutside event is triggered when the finger is outside the bounds of the control. If you're trying to change that area, the slider will scale with it. Why not just tie the action for UIControlEventTouchUpOutside to the same as UIControlEventTouchUpInside?
It's taken me a few hours, but i've managed to sort this.
I've done a lot of testing overriding touchesMoved, touchesEnded and sendAction:action:target:event and it seems that any touch within 70px of the frame classes as a touch INSIDE. So for a UISlider that's 292x52 any touch from x:-70 to x:362 or y:-70 to 122 will count as an inside touch, even though it's outside the frame.
I have come up with this code that will override a custom class to allow a bigger area of 100px around the frame to count as an inside touch:
#import "UICustomSlider.h"
#implementation UICustomSlider {
BOOL callTouchInside;
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
callTouchInside = NO;
[super touchesMoved:touches withEvent:event];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint touchLocation = [[touches anyObject] locationInView:self];
if (touchLocation.x > -100 && touchLocation.x < self.bounds.size.width +100 && touchLocation.y > -100 && touchLocation.y < self.bounds.size.height +100) callTouchInside = YES;
[super touchesEnded:touches withEvent:event];
}
-(void)sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event
{
if (action == #selector(sliderTouchOutside)) { // This is the selector used for UIControlEventTouchUpOutside
if (callTouchInside == YES) {
NSLog(#"Overriding an outside touch to be an inside touch");
[self sendAction:#selector(UnLockIt) to:target forEvent:event]; // This is the selector used for UIControlEventTouchUpInside
} else {
[super sendAction:action to:target forEvent:event];
}
} else {
[super sendAction:action to:target forEvent:event];
}
}
With a little bit more tweaking I should be able to use it for the opposite also. (Using a closer touch as an outside touch).
I am trying to solve a basic problem with drag and drop on iPhone. Here's my setup:
I have a UIScrollView which has one large content subview (I'm able to scroll and zoom it)
Content subview has several small tiles as subviews that should be dragged around inside it.
My UIScrollView subclass has this method:
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
UIView *tile = [contentView pointInsideTiles:[self convertPoint:point toView:contentView] withEvent:event];
if (tile) {
return tile;
} else {
return [super hitTest:point withEvent:event];
}
}
Content subview has this method:
- (UIView *)pointInsideTiles:(CGPoint)point withEvent:(UIEvent *)event {
for (TileView *tile in tiles) {
if ([tile pointInside:[self convertPoint:point toView:tile] withEvent:event])
return tile;
}
return nil;
}
And tile view has this method:
- (void)touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event {
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:self.superview];
self.center = location;
}
This works, but not fully correct: the tile sometimes "falls down" during the drag process. More precisely, it stops receiving touchesMoved: invocations, and scroll view starts scrolling instead. I noticed that this depends on the drag speed: the faster I drag, the quicker the tile "falls".
Any ideas on how to keep the tile glued to the dragging finger?
I was struggling with this same problem - I was trying to do a interface with a lot of "cards" (UIView subclasses) on a cork board, and have the cork board area scrollable, but still able to drag-and-drop the cards. I was doing the hitTest() solution above, but one of the Apple engineers asked me why I was doing it that way. The simpler solution they suggested was as follows:
1) In the UIScrollView class, set the value of canCancelContentTouches to NO - this tells the UIScrollView class to allow touches within subviews (or, in this case, in subviews of subviews).
2) In my "card" class, set exclusiveTouch to YES - this tells the subview it owns the touches inside of it.
After this, I was able to drag around the cards and still scroll the subview. It's a lot simpler and cleaner than the hitTest() solution above.
(BTW, for extra credit, if you are using iOS 3.2 or 4.0 or later, use the UIPanGestureRecognizer class to handle the drag and drop logic - the drag and drop motion is a lot smoother than overriding touchesBegan()/touchesMoved()/touchesEnded().)
Solved: it turned out that there should be also touchesBegan: and touchesEnded: implementations (in my case having empty methods helped) in the tile, otherwise the gesture started propagating to parent views, and they were intercepting the gesture somehow. Dependency on the drag speed was imaginary.
At first, set:
scrollview.canCancelContentTouches = NO;
yourSubView. exclusiveTouch = YES;
Then in your subview gesture handle function,
- (void)handleSubviewMove:(UIPanGestureRecognizer *)gesture {
if(gesture.state == UIGestureRecognizerStateBegan) {
if(_parentScrollView != nil) {
_parentScrollView.scrollEnabled = NO;
}
}
if(gesture.state == UIGestureRecognizerStateEnded) {
if(_parentScrollView != nil) {
_parentScrollView.scrollEnabled = YES;
}
}
CGPoint translation = [gesture translationInView:[self superview]];
/* handle your view's movement here. */
[gesture setTranslation:CGPointZero inView:[self superview]];
}
Based on the code you've shared, it looks like your touchesMoved: method will only be called for gestures within the tile. At each touch, you move the tile to be centered on that touch, so slow movements will each give an update within the tile -- and the tile will "catch up" with the fingertip -- before the gesture exits the tile. When a gesture is faster, however, the (x,y) touchesMoved events will be farther apart, and you'll lose the gesture when one (x,y) point is far enough away from the last one that it is outside of the tile already.
You can work around this by capturing the movements in a superview large enough to cover the whole draggable area, and controlling the movement of the tile from within that superview.
By the way, is there a reason you're overriding the hitTest: method? It might be easier (and possibly more efficient?) to use the built-in implementation.
I have created some buttons and I keep them in NSMutableArray.
In the view where they appear there are a few simple sdk methods to handle touches.
The problem is touching exactly this objects from MutableArray and nothing else.
Here is method touchesBegan:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
if (isEarthquake == NO) {
for (UITouch *touch in touches) {
for (int i = 0; i < 9; i++) {
UIButton *menuButton;
menuButton = [menuButtons objectAtIndex:i];
if (CGRectContainsPoint([menuButton frame], [touch locationInView:self.view])) {
[self startTouchTimer:3.00];
}
}
}
}
isEarthquake is simple bool that checks if action can be performed.
after that I want to check all objects if they are being touched.
What's wrong?
Thanks in advance.
Touches began is a view method, not a view controller method. You are using
locationInView:self.view
this should be
locationInView:self
Check this code is in a view subclass and not a view controller subclass.
Also, you might need to use
[self convertRect:[menuButton bounds] fromView:menuButton];
to convert the CGRect to the proper coordinate space.