Adding drag and drop component to iOS app - ios

Question

I apologise if this seems very vague but I'm not sure how else to word it.
I am trying to build an ipad app that will let users populate a workspace with tools they need. I need an example of letting a user drag and drop components into the app interface. So for example if i had an app that the user can make a form and I want the user to be able to drag text boxes, lists, radio buttons etc to make the form, how would i go about doing that? The items that i am using will be in a popup menu so that the user drags up and then will see all the items that i need inside that popup. Im just not sure how to let them drag from the popup to the canvas and also be able to reuse the same item (so have 3 or 4 text boxes in the example). Is this possible? Can anyone direct me to a tutorial on this? I have searched but cant find anything.
If this is laid out wrong or is a stupid quest please let me know how to do it, this is my first time posting on here.
Thank you

Answer 1

There are already many answers explaining this question.
Basically you can make custom UIView, which after touching will be following the touch movement.
Something like this:
-(void) touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
_originalPosition = self.view.center;
_touchOffset = CGPointMake(self.view.center.x-position.x,self.view.center.y-position.y);
}
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint position = [touch locationInView: self.view.superview];
[UIView animateWithDuration:.001
delay:0.0
options:UIViewAnimationOptionCurveEaseInOut
animations:^ {
self.view.center = CGPointMake(position.x+_touchOffset.x, position.y+_touchOffset.y);
}
completion:^(BOOL finished) {}];
}
-(void) touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint positionInView = [touch locationInView:self.view];
CGPoint newPosition;
if (CGRectContainsPoint(_desiredView.frame, positionInView)) {
newPosition = positionInView;
// _desiredView is view where the user can drag the view
} else {
newPosition = _originalPosition;
// its outside the desired view so lets move the view back to start position
}
[UIView animateWithDuration:0.4
delay:0.0
options:UIViewAnimationOptionCurveEaseInOut
animations:^ {
self.view.center = newPosition
// to
}
completion:^(BOOL finished) {}];
}
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Answer 2

From the Question i thing you are going to Build a feature like Add to cart in Most of the Shopping Apps like Amazon, Flip kart and etc..
- (void)viewDidLoad {
[super viewDidLoad];
shoeImageView1 = [[UIImageView alloc]initWithFrame:CGRectMake(46,222, 51 , 51)];
shoeImageView1.image = [UIImage imageNamed:#"shoe.png"];
shoeImageView2 = [[UIImageView alloc]initWithFrame:CGRectMake(150,222, 51 , 51)];
shoeImageView2.image = [UIImage imageNamed:#"shoe1.png"];
shoeImageView3 = [[UIImageView alloc]initWithFrame:CGRectMake(225,222, 51 , 51)];
shoeImageView3.image = [UIImage imageNamed:#"shoe2.png"];
addTOCart = [[UIImageView alloc]initWithFrame:CGRectMake(132,400, 80, 80)];
addTOCart.image = [UIImage imageNamed:#"basket.png"];
[self.view addSubview:addTOCart];
imageViewArray = [[NSMutableArray alloc]initWithObjects: shoeImageView1,shoeImageView2 ,shoeImageView3,nil];
for (int i=0; i<imageViewArray.count; i++) {
[self.view addSubview:[imageViewArray objectAtIndex:i]];
[[imageViewArray objectAtIndex:i]setUserInteractionEnabled:YES];
//[self touchesBegan:imageViewArray[i] withEvent:nil];
}
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
for(int i=0 ; i< imageViewArray.count; i++)
{
CGPoint pt = [[touches anyObject]locationInView:self.view];
startLocation = pt;
newtemp = [imageViewArray objectAtIndex:i];
UITouch* bTouch = [touches anyObject];
if ([bTouch.view isEqual:newtemp])
{
firstTouchPoint = [bTouch locationInView:[self view]];
oldX = firstTouchPoint.x - [[bTouch view]center].x;
oldY = firstTouchPoint.y - [[bTouch view]center].y;
}
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
for(int i=0 ; i< imageViewArray.count; i++)
{
newtemp = [imageViewArray objectAtIndex:i];
//oldLoc = newtemp.frame;
if (CGRectContainsPoint(addTOCart.frame , newtemp.frame.origin))
{
NSLog(#"touched");
dragging = NO;
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:#"Cart" message:#"Added to Cart" delegate:self cancelButtonTitle:#"OK" otherButtonTitles:nil, nil];
[[imageViewArray objectAtIndex:i] setImage:[UIImage imageNamed:#""]];
[imageViewArray removeObjectAtIndex:i];
[alert show];
break;
}
else
{
//[newtemp setCenter:CGPointMake(startLocation.x-oldX, startLocation.y-oldY)];
}
// self.view.userInteractionEnabled= NO;
}
dragging = NO;
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch* mTouch = [touches anyObject];
// if ([mTouch.view isEqual: newtemp]) {
CGPoint cp = [mTouch locationInView:[self view]];
[[mTouch view]setCenter:CGPointMake(cp.x-oldX, cp.y-oldY)];
// }
}
you can use these codes to implement these feauture. Using these code u can drag the object any where in the screen.
for sample project you can use this Link.