So I have a Subclass of UIView that is suppose to detect touches. The view detect touches only if the touches started inside the current view. When the touches start outside of the view and they move inside my custom view touchesMoved doesn't get called. Any solution to detect moving touches that have not started in the current view?
#implementation MycustomView
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
// This only gets called if touches have started in the current View
}
#end
The following solution worked. I have multiple instances of MyCustomView; as the touches move I want to detect the views that are being touched
I ended up moving touch detection from MyCustomView to its superView, so the following code is no longer in MyCustomView class:
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
CGPoint touchLocation = [touch locationInView:self.contentView];
for (UIView *view in self.contentView.subviews)
{
if ([view isKindOfClass:[MyCustomView class]] &&
CGRectContainsPoint(view.frame, touchLocation))
{
}
}
}
this should fix it:
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
for (UIView* subView in self.subviews)
{
if([subView pointInside:[self convertPoint:touch toView:subView] withEvent:event])
{
//do your code here
}
}
}
One way to do it (though there might be others) is to disable user interaction for the subviews and make their parent view track the movement (use the hitTest method to figure out which view the touch is currently over).
Try this....
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
for(UITouch *touch in touches)
{
CGPoint touchPointFirstBtn = [touch locationInView:self.ChordView];
if(CGRectContainsPoint(_btnC.frame, touchPointFirstBtn))
{
if (!_btnC.isHighlighted)
{
if(!Boolean)
{
title = #"C";
[_tlbView reloadData];
NSLog(#"%#",#"touches C");
}
[_btnC setHighlighted:YES];
Boolean = YES;
}
}
else
{
[_btnC setHighlighted:NO];
Boolean = NO;
}
}
Related
I have a 2d-Grid of subviews. As I drag my finger along these subviews I want to call discrete method's per view such that for each view I hover above this method is called once. Logging out the results of the touches parameter it seems that only one view is referenced through the drag, namely the one that touchesbegan was on top of. How do I get the view for where my finger is currently dragging based on coordinates?
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
CGPoint touchLocation = [touch locationInView:self.contentView];
for (UIView *view in self.contentView.subviews)
{
if ([view isKindOfClass:[MyView class]] &&
CGRectContainsPoint(view.frame, touchLocation))
{
}
}
}
Ref: iOS - Detecting touches in a UIView?
In my app I have an UIView on top of UISplitViewController (used "addSubView"). What I wanna do is to let the UIView handle the touch and then redirect it to the parent view so it could also handle it.
I think i have a work around for what you try to do. You'll have to subclass your topView and implement the following two methods:
The first method will handle your touch for the buttomView
- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
CGPoint bottomViewHit = [bottomView convertPoint:point fromView:self];
if ([topView pointInside:topViewHit withEvent:event]) {
//manage your bottomView touch here..
return bottomView;
}
return [super hitTest:point withEvent:event];
}
The second method will handle the topView
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:touch.view];
// manage your touch for topView here...
[view touchesBegan:touches withEvent:event];
}
I would like to be able to retrieve info on a tap, about all the different subviews that are placed in that tap spot. For example, if there was a background, and in front of it was a game character, I would like to be able to tap on that character, and it will retrieve the info saying that both the character and the background are in that tap spot.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//retrieve info about what other subviews lie behind at this point
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch=[touches anyObject];
CGPoint p=[touch locationInView:self.view];
NSLog(#"Coordiantes of Tap Point:(%f,%f)", p.x, p.y);
NSArray *anArrayOfSubviews = [self.view subviews];
NSMutableArray *requiredSubviewArray = [NSMutableArray array];
for (UIView *aSubView in anArrayOfSubviews){
if(CGRectContainsPoint(aSubView.frame, p)) {
//aSubView is there at point 'p'
[requiredSubviewArray addObject:aSubView];
}
}
// requiredSubviewArray contains all the Subviews at the Tap Point.
}
try this.it maybe helpful to you..
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//retrieve info about what other subviews lie behind at this point
NSLog(#"subviews--%#",[self.view subviews]); //it prints all subviews as Array
NSLog(#"superview--%#",[self.view superview]); //it prints superview of your view
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject]; // here you get all subviews on ur touchpoint
if ([touch view] == imageView) {
CGPoint location = [touch locationInView: self.view];
imageView.center = location;
}
}
/// To check both views are in one spot, use this
// CGRectContainsRect() and CGRectIntersectsRect().
You can try this one..
You can get all subviews if you use [self.view subviews]. You can compare those views frames with touch location.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint touchLocation = [touch locationInView:self.view];
startX = touchLocation.x;
startY = touchLocation.y;
for (UIView *view in [self.view subviews]){
//Here you can compare each view frame with touch location
}
}
The code below is based on the idea of how to make a UIImageView be able to be dragged around the ViewController. When I use this code however, I click on a different location instead of pressing on the Image and it teleports to that location instead of requiring me to always drag the image. I want the code below to only work when pressing on that specific image. Please Help-
-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:touch.view];
image.center = location;
[self ifCollided];
}
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
[self touchesBegan:touches withEvent:event];
}
It's teleporting simply because you don't have any check for whether the user has in fact touched the image, so any touch causes the image to jump to that location. What you need to do is check if the user has touched the image, then move it only if they have. Try the following code in the ViewController, assuming 'image' is the draggable view:
You'll need to create a variable/property on your ViewController to track if the view is being dragged. If you need just one image, you can use a BOOL (the code below assumes you've done this, called isDragging).
-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesBegan:touches withEvent:event];
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:image];
if([image pointInside:location withEvent:event]) {
isDragging = YES;
}
}
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesMoved:touches withEvent:event];
if(isDragging)
{
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:self.view];
image.center = location;
[self ifCollided];
}
}
-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesEnded:touches withEvent:event];
isDragging = NO;
}
This code basically does a check in touchesBegan and sets the property to true if you touch inside the image, moves it in touchesMoved if your initial touch was on the image, and finally unsets the check in touchesEnded.
I have two custom uibuttons.
#interface myButton : UIButton
I overwrite several methods like
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
// do something
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesMoved:touches withEvent:event];
[self.nextResponder touchesMoved:touches withEvent:event];
UITouch *touch = [touches anyObject];
CGPoint touchPoint = [touch locationInView:self];
if (!CGRectContainsPoint(self.bounds, touchPoint)) {
[self touchesCancelled:touches withEvent:event];
}
return;
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
// do something
}
-(void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesCancelled:touches withEvent:event];
return;
}
The thing I want is , when I touch a button, I can keep moving my touch to another button. I tired to call touchesCancelled when the touch is out of the bound of the first button I touched. So I "think" then I move to another button it will be a new touch event. But it doesn't work like this.
Did I do something wrong? Or the touchesCancelled method is not used for like this?
Thanks in advance!
Your suspesions are correct, this is not how touchesCancelled:withEvent: was intended to be used. From the documentation:
This method is invoked when the Cocoa Touch framework receives a system interruption requiring cancellation of the touch event; for this, it generates a UITouch object with a phase of UITouchPhaseCancel. The interruption is something that might cause the application to be no longer active or the view to be removed from the window.
Your responder will receive the touches cancelled event if your user receives an incoming phone call, SMS or their alarm goes off etc. It should be used to clean up any state information that was established in the other touch events.
It seems as though you want to change the responder associated with the touch events mid-touch i.e. when you drag the touch from the bounds of the first button and enter that of the second button it should become the responder recieving the touch events. Unfortunately that is not the way responders are designed to work. Once a UIView is identified as being the responder, as returned in hitTest:withEvent:, this will be the UIView to receive touch events.
A possible workout to achieve what you want would be to handle the touch events (touchesBegan:withEvent:, touchesMoved:withEvent: etc.) in a superview that contains both of your buttons. Then your superview will receive the touch events and you can take action depending on which button's frame you are within:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
for (UITouch *touch in touches)
{
CGPoint touchLocation = [touch locationInView:self.view];
UIButton *button;
if (CGRectContainsPoint(self.button1.frame, touchLocation))
{
button = self.button1;
NSLog(#"touchesMoved: First Button");
}
else if (CGRectContainsPoint(self.button2.frame, touchLocation))
{
button = self.button2;
NSLog(#"touchesMoved: Second Button");
}
// Do something with button...
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
for (UITouch *touch in touches)
{
CGPoint touchLocation = [touch locationInView:self.view];
UIButton *button;
if (CGRectContainsPoint(self.button1.frame, touchLocation))
{
button = self.button1;
NSLog(#"touchesMoved: First Button");
}
else if (CGRectContainsPoint(self.button2.frame, touchLocation))
{
button = self.button2;
NSLog(#"touchesMoved: Second Button");
}
// Do something with button...
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
for (UITouch *touch in touches)
{
CGPoint touchLocation = [touch locationInView:self.view];
UIButton *button;
if (CGRectContainsPoint(self.button1.frame, touchLocation))
{
button = self.button1;
NSLog(#"touchesEnded: First Button");
}
else if (CGRectContainsPoint(self.button2.frame, touchLocation))
{
button = self.button2;
NSLog(#"touchesEnded: Second Button");
}
// Do something with button...
}
}