Drag image from one view to another view In iphone/ipad - iphone

I am facing below problem:-
Please have a look in the below image the thing what i want is:-
I want to drag default images from view 1 to view 2 and images have to be always thr in view1 so its not like touch moved to draging images .
i tried a lot things in that but i succeed in draging image from one view to another but in view2 i am not able to get touch points so its just adding thr as frame
But i cnt able to touch tht image across view2 and even in view2
i want to do other functionality like zooming and others but first want to get touch points in view2.
I am giving description image about this problem.
The edited question is:-
i have done this simple demo in this i am transferring one view to another view and after getting view2 points its been in its limit boundaries.
but how can i get the default things remain in their.
i will modify this code i will add images in this view. but its just shows my thinking here so guide me here.
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
if ([touch view] == view3) {
CGPoint location = [touch locationInView:self.view];
view3.center = location;
return;
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
int tmpValue = 0;
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
{
onceDone = TRUE;
if(onceDone == TRUE)
{
UITouch *touch = [touches anyObject];
CGPoint pt = [touch locationInView:self.view];
NSLog(#"X = %f y=%f",pt.x,pt.y);
view3.center = pt;
if(view3.frame.origin.x < view2.frame.origin.x )
//view3.frame.origin.x < view2.frame.origin.x)
[view3 setFrame:CGRectMake(159,view3.frame.origin.y, view3.frame.size.width, view3.frame.size.height)];
}
}
[UIView commitAnimations];
}
Please help me.
it is urgent.
Thanks in advance

If you are using pan gestures are touchesMoved method to drag and drop the images.Make super view of view1 and view2 to same UIView and calculate your gesture location or touched point with respect to that common super view.That means your view1 and view2 will be on the same view and each subView(image)is also added to main view only.So you can move images on main view where ever you want and can perform any operation on them.

We have been working in a similar issue, and we have made up with this solution:
We have an UIPanGestureRecognizer added to each button.
When we detect the pan gesture begin, we create the object we want to drag (in this case, it could be a copy of your image). You should have to set a rect equals to the button, or if you create the object in a different view, you should have to convert the object coordinates so the object seems in the same position as the button, but inside his view.
After that we move the last created object, instead of move the button.
And that is, the trick here is the UIPanGestureRecognizer works until you untouch the screen, but it is triggered while you move your finger for all the screen, not only inside the button!
I hope this works for you.

Related

Bring UIImageView on top of the other UIImageViews in my main view

I have a lot of UIImageViews in my main view, some of these have images, others are blank. I have setup code that will check which UIImageView currently contains an image. At the same time, this code will take care of allowing a UIImageView with an image to be moved around.
Now what happens is this: when moving a selected UIImageView around (for some reason and quite randomly), the image will not stay on top of the other UImageViews in the screen. The reason why I say that this is random is because it will stay on top of some of the other views, but not on top of others.
The behavior is unexpected, several problems arise:
Visually it looks bad; there is no reason why a touched UIImageView should slip under another.
The way I have the code going is to allow UIImageViews to be moved only if they contain an image. So if the UIImageView goes under another who does not contain an image, I cannot touch and move it again. It looks like it is stuck in place.
Please note that I have not been setting subviews at all for this code, thus why this behavior occurs is beyond me.
So what my question boils down to, is there any way that I can tell the code to:
Get the object that was touched.
If it is a UIImageView with an image, then allow me to move the UIImageView.
allow this UIImageView to supersede (be on top of) all other UIImageViews.
Code reference:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{UITouch *touch;
UITouch *touch;
CGPoint touchLocation;
for (UIImageView *fruit in fruitArray)
{
// Check that the UIImageView contains an image
if([fruit image] != nil)
{
// Get the touch event.
touch = [touches anyObject];
// Get the location for the touched object within the view.
touchLocation = [touch locationInView:[self view]];
// Bring the UIImageView touch location to the image's center.
if([touch view] == fruit)
{
fruit.center = touchLocation;
}
}
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
//allow the selected event (in our case a UIImageView) to be dragged
[self touchesBegan:touches withEvent:event];
}
Thank you for your help! Let me know if you need a better explanation
[self.view bringSubviewToFront:imageView];
This was what you were looking for...

How to detect touch end of image view when touches moving

I have an image view. i detected touch in image view like this
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
int viewTag=[touch view].tag;
if ([[touch view] isKindOfClass:[UIImageView class]])
{
//My code
}
}
and touches moved on image view. whenever my touch moved out off the image view in that particular time i need one alert view. how to detect that touch over from the image view in touches moving?...
I recommend using a UIPanGestureRecognizer and adding it to a larger super-view of the image-view you want to detect on. That way even if the touch starts outside and moves into and out of your image-view you can follow the movement of the touch in your gesture handler.
It's pretty easy, make a method called handlePan: for example, create the gesture recognizer using your handler method, add it to the appropriate super-view. Now whenever the gesture is active and the touch moves your handler method will get called and you can check to see if it is inside your image view.
You should use this method...
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
int viewTag=[touch view].tag;
if ([[touch view] isKindOfClass:[UIImageView class]])
{
//My code
}
else
{
//show the alertView here
}
}
and to check that the initial click was on the imageView you have to set a flag in the touchesBegan method... and check it accordingly in the touchesMoved method
You may add a transparent UIButton of the same size on top of the UIImageViewand track UIControlEventTouchDragOutside
[button addTarget:self action:#selector(draggedOutside:) forControlEvents:UIControlEventTouchDragExit];

touchesEnded:withEvent: not called when a drag event moved out of the screen top/bottom

My problem is quite strange but simple.
I subclassed a my customer UIScrollView: MyScrollView, where i disabled the scroll:
self.scrollEnabled = NO;
that means apart from
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
all other UIScrollViewDelegate method won't be called
and in MyScrollView i do the content scroll by detecting the user touch movement on screen, that is to say no flipping, no bounces, my implementation is in the touchesMoved:withEvent: method
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
// NSLog(#"touch.phase:%d",touch.phase);
CGPoint currentPosition = [touch locationInView:self];
CGPoint lastTouchPosition = [touch previousLocationInView:self];
CGFloat deltaY = lastTouchPosition.y - currentPosition.y;
CGFloat contentYOffset = self.contentOffset.y + deltaY;
[self setContentOffset:CGPointMake(0,contentYOffset) animated:NO];
}
after the user drag movement have been finished, i do my own method according to the content offset of MyScrollView in touchesEnded:withEvent:
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
//some implementation according to current content offset
}
user moves finger on screen, whenever the finger left the screen surface, the touchesEnded:withEvent: get called and i can implement my own method correctly.
BUT, when user move finger on screen surface from inside the screen to outside either on top or bottom, then lift the finger up, the touchesEnded:withEvent: method never got called, it seems like the ios doesn't treat the move out bounds(top or bottom) event as a touches end event, also ios wouldn't know the what is going on when touch is outside it screen bounds
someone may suggest me to detect the current position in touchesMoved:withEvent: to check out whether it is inbounds or not. this MAY WORK WHEN THE MOVEMENT IS VERY SLOW, but when you move very fast, the system can not detect every point position, it seems like the movement is detected in a certain time interval.
can any one help me out how could i detect if the user finger has moved out of bounds or not
I think the touchesCancelled:withEvent: method will be called !
I have resolved this problem
bcs UIScrollView does too much work that we can not handle some event ourselves, fortunately the UIView can detect the touche move out of bounds and will invoke the touchesEnd:withEvent: method.
considering that replacing MyScrollView's superclass with UIView has too much work to do, so i figured out a simple way to resolve:
i added an TouchActionDetectView subclassed from UIView, whose work is to detect all user touches event and deliver those event to MyScrollView. of course i have to clear the background color of TouchActionDetectView to avoid blocking other view content.

ios is it possible for a uiscrollview to detect a single tap by a user while still providing its dragging, scrolling capabilities?

I currently am using a UIScrollView to work as a way of scrolling/ dragging the cursor/ marker of a graph that I am displaying on my app. I use scrollViewDidScroll, etc. to detect the contentoffset's position and manipulate what I display on the screen based on this position.
My question is if it is possible to also detect a user's single tap on the screen and get this tap's position (to then set the contentoffset to this position)?
I have read some tutorials that describe creating a subclass of a uiscrollview, but it seems like these subclasses will ONLY account for a single tap and not drags/scrolls also.
Does anyone have any insight on how I might be able to detect a user's single tap on my UIScrollView while still having its scrolling/ dragging capabilities?
Thank you in advance!
Use the following code for your scrollView object :
UITapGestureRecognizer *singleTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(singleTap:)];
singleTapGestureRecognizer.numberOfTapsRequired = 1;
singleTapGestureRecognizer.enabled = YES;
singleTapGestureRecognizer.cancelsTouchesInView = NO;
[scrollView addGestureRecognizer:singleTapGestureRecognizer];
//[singleTapGestureRecognizer release]; Not needed in ARC-enabled Project
}
- (void)singleTap:(UITapGestureRecognizer *)gesture {
//handle taps
}
Swift 5
let scrollViewTapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(scrollViewTapped(_:)))
scrollViewTapGestureRecognizer.numberOfTapsRequired = 1
scrollViewTapGestureRecognizer.isEnabled = true
scrollViewTapGestureRecognizer.cancelsTouchesInView = false
scrollView.addGestureRecognizer(scrollViewTapGestureRecognizer)
#objc func scrollViewTapped(_ sender: UITapGestureRecognizer) {
print("UIScrollView was tapped.")
}
The first part of the question is pretty simple to get going. If you have a UIScrollView subclass, you can just add a touchesEnded override that looks like this:
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
if ([touch tapCount] == 1) {
CGPoint location = [touch locationInView:self];
[self setContentOffset:location animated:YES];
}
}
In the case of the scroll view, the -locationInView for the touch will actually already have the ContentOffset added into it. What this code will do is scroll the scroll view so that the point the user touched is at the top-left of the view. This probably isn't what you want exactly, so you'll have to do things like add in an offset if you want the scroll to end up 10 pixels in, or you'd make another CGPoint with only the x value out of the location if your scroller isn't left-to-right.
This won't interfere with being able to actually do the scroll.
Have you looked into attaching UITapGestureRecognizer to the scrollView? I've attached a UITapGestureRecognizer to a UIScrollView and used –gestureRecognizerShouldBegin: and/or –gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer: to cancel the built in panning when a touch is desired.

Why doesn't the touch event arrive at my UIImageView?

I have some nested views like this:
First, there is an big UIView. Inside this, there is another UIView. And inside this, there is an MyNiceButtons class that inherits from UIView. So I have:
UIView > UIView > MyNiceButtons (= an UIView).
In detail, the UIView creates an UIImageView and adds it as a child view to itself, which represents an graphical button. So inside the MyNiceButtons class implementation, I have this code to handle a touch event on the fake button image:
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject]; // i just need single touches
// just to see which view is affected
UIView *tview = [touch view];
CGRect rect = tview.frame;
rect.origin.x = rect.origin.x + 20.0f;
tview.frame = rect;
[tview setBackgroundColor:[UIColor yellowColor]];
if ([touch view] == self.fakeButtonImageView) {
NSLog(#"touch on fake button detected");
}
}
All views in the hierarchy have userInteractionEnabled=YES. The touch arrives at the first view in the hierarchy (the parent of the parent).
UIView *tview = [touch view];
This returns just the parent of the parent, but not the UIImageView where the user actually tapped on.
What's the trick to recognize if the touch was on the button UIImageView?
I would first suggest that you take a good look at what you can do with a Custom-type UIButton (can set images for various states). 95% of the time, this should address your needs.
If you have some other need, I can help you debug w/ hitTest, etc.