Detect diagonal swipe gestures in a UIView - ios

I want to detect a two-finger diagonal swipe that starts from the bottom right of the screen to the middle. I tried adding UISwipeGestureRecognizer with direction set as "UISwipeGestureRecognizerDirectionUp | UISwipeGestureRecognizerDirectionLeft" but to no vail as the handler is getting invoked even if I start the swipe from the middle of the screen to the top left.
Do I need to sub-class UIGestureRecognizer or can I handle this using touchesBegan and touchesMoved ?

You need to subclass it to use touchesBegan and touchesMoved anyway. I'd do UISwipeGestureRecognizerDirectionUp | UISwipeGestureRecognizerDirectionLeft like you said, then set up two CGRects, one for acceptable starting points, one for acceptable end points. Then use the UIGestureRecognizerDelegate method gestureRecognizer:shouldReceiveTouch:, and check if the touch point is in the acceptable start rect by using CGRectContainsPoint(). Then (I think) in your UISwipeGestureRecognizer subclass, override touchesEnded:withEvent:, and check if the end touch is in the acceptable rect. If it's not, set the state to UIGestureRecognizerStateCancelled (or however you're supposed to cancel a gesture). Also make sure the view it's attached to has its multipleTouchEnabled property set. I haven't actually tried this, but something of the sort should do it. Good luck!
EDIT
Actually, if you didn't want to have to worry about specific rect values for the acceptable start/end points, and make it device independent, you could do this:
//swap in whatever percentage of the screen's width/height you want in place of ".75f"
//set the origin for acceptable start points
CGFloat startRect_x = self.view.frame.size.width * .75f;
CGFloat startRect_y = self.view.frame.size.height * .75f;
//set the size
CGFloat rectWidth = self.view.frame.size.width - startRect_x;
CGFloat rectHeight = self.view.frame.size.height - startRect_y;
//make the acceptable start point rect
CGRect startRect = CGRectMake(startRect_x, startRect_y, rectWidth, rectHeight);
//set the origin for the accepable end points
CGFloat endRect_x = self.view.center.x - rectWidth/2;
CGFloat endRect_y = self.view.center.y - rectHeight/2;
//make the acceptable end point rect
CGRect endRect = CGRectMake(endRect_x, endRect_y, rectWidth, rectHeight);

the touches method of cause can do every Gesture, the Gesture is supported since ios3.2.
i can give you a simple code , you maybe modify by yourself.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
isTwoFingersBegin = NO;
isTwoFingersEnd = NO;
UITouch *touch = [touches anyObject];
UIView *touchView = [touch view];
if ([touches count] == 2)
{
isTwoFingersBegin = YES;
}
touchStartPoint = [touch locationInView:self.view];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
isSwip = YES;
}
#define TOUCH_MOVE_EFFECT_DIST 30
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
UIView *touchView = [touch view];
touchEndPoint = [touch locationInView:self.view];
if ([touches count] == 2)
{
isTwoFingersEnd = YES;
}
CGPoint deltaVector = CGPointMake(touchEndPoint.x - touchStartPoint.x, touchEndPoint.y - touchStartPoint.y);
if (fabsf(deltaVector.x) > TOUCH_MOVE_EFFECT_DIST
&&fabsf(deltaVector.y) > TOUCH_MOVE_EFFECT_DIST
&& isSwip &&isTwoFingersBegin&&isTwoFingersEnd) {
theSwipGesture=RightUpGesture;
}
else if (fabsf(deltaVector.x) <- TOUCH_MOVE_EFFECT_DIST
&& fabsf(deltaVector.y) <- TOUCH_MOVE_EFFECT_DIST
&& isSwip&&isTwoFingersBegin&&isTwoFingersEnd) {
theSwipGesture=LeftDownGesture;
}
isSwip = NO;
}

You can use a UIPanGestureRecognizer
- (void)viewPanned:(UIPanGestureRecognizer *)panGR
{
CGPoint translation = [panGR translationInView:self];
CGFloat threshold = self.bounds.size.width/2;
// Detect
Direction direction = DirectionUnknown;
if (translation.x > threshold) {
if (translation.y > threshold) {
direction = DirectionBottomRight;
} else if (translation.y < -threshold) {
direction = DirectionTopRight;
} else {
direction = DirectionRight;
}
} else if (translation.x < -threshold) {
if (translation.y > threshold) {
direction = DirectionBottomLeft;
} else if (translation.y < -threshold) {
direction = DirectionTopLeft;
} else {
direction = DirectionLeft;
}
} else {
if (translation.y > threshold) {
direction = DirectionBottom;
} else if (translation.y < -threshold) {
direction = DirectionTop;
}
}
}

One possible solution would be to map off a group of coordinates on the iPhone's screen where the swipe could potentially start, and another where it could potentially end. Then in the touchesBegan: and touchesMoved: methods, you could compare the starting and ending points of the swipe and determine whether it qualified as diagonal.

Thanks Guys!
I ended up writing custom code in touchesBegan, touchesMoved and touchesEnded and ot works like charm.
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
if ([touches count] == 2) {
CGPoint nowPoint = [[touches anyObject] locationInView:self];
if( nowPoint.x >= ALLOWED_X)
swipeUp = YES;
}
[super touchesBegan:touches withEvent:event];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesMoved:touches withEvent:event];
if ([touches count] == 2 && swipeUp) {
CGPoint nowPoint = [[touches anyObject] locationInView:self];
CGPoint prevPoint = [[touches anyObject] previousLocationInView:self];
if( nowPoint.x <= prevPoint.x && nowPoint.y <= prevPoint.y){
}
else {
swipeUp = NO;
}
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesEnded:touches withEvent:event];
CGPoint nowPoint = [[touches anyObject] locationInView:self];
if ([touches count] == 2 && swipeUp && nowPoint.x <= DELTA_X && nowPoint.y <= DELTA_Y) {
NSLog(#"Invoke Method");
}
swipeUp = NO;
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event {
[super touchesCancelled:touches withEvent:event];
swipeUp = NO;
}

Related

Using collision on bounds of UIView

I have an ImageView that moves around the UIView, is it possible to detect collision of the ImageView and the view its self? For example the ImageView hits the side of the view I want it to run an action. -(void)restart {}
If this is possible can you detect which side it has collided with?
You can create a custom UIImageVIew and implement the methods touchBegan and touchMoved (don't forget to add [self setUserInteractionEnabled:YES] in your init method). Then set the rect you want to interact with :
customImageView.interactRect = myView.frame;
And in your customImageView you can add something like:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [[event allTouches] anyObject];
lastPosition = [touch locationInView: self.superview];
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [[event allTouches] anyObject];
CGPoint position = [touch locationInView:self.superview];
CGRect currentFrame = self.frame;
currentFrame.origin = CGPointMake(currentFrame.origin.x + position.x - lastPosition.x, currentFrame.origin.y + position.y - lastPosition.y);
if (CGRectIntersectsRect(currentFrame, interactRect) && !CGRectIntersectsRect(self.frame, interactRect))
{
NSLog(#"I'm in for the first time");
if(self.frame.origin.x + self.frame.size.width <= interactRect.origin.x && currentFrame.origin.x + currentFrame.size.width > interactRect.origin.x)
{
NSLog(#"Coming from the left");
}
if(self.frame.origin.x >= interactRect.origin.x + interactRect.size.width && currentFrame.origin.x < interactRect.origin.x + interactRect.size.width)
{
NSLog(#"Coming from the right");
}
}
self.frame = currentFrame;
lastPosition = position;
}

Move CCSprite based on users touch - Cocos2d

I have an object that I wish to move 50 pixels in the direction the the touch event occurs. It is a fixed CCSprite called _eyeObject.
I know I need to use
- (void)touchBegan:(UITouch *)touches withEvent:(UIEvent *)event {
CGPoint touchLocation = [touches locationInNode:self];
//Not sure what to do now
}
How would I calculate the CCSprite to move 50 pixels towards the users touch? Then move back to the original position when the touch ends?
A starting point would be great....I don't need to know how to animate or anything, just the calculation.
Whenever a touch happens you want to move 50 pixels in that direction you can do (based on your desire to do it based on a statically positioned eye object sprite):
- (void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
CGPoint touchPos = [touch locationInNode:self];
CGPoint delta = ccpSub(touchPos, self.eyeObject.position);
float moveAmount = 50.0f;
CGPoint moveVec;
if (delta.x > 0.0f)
{
moveVec.x = moveAmount;
}
else
{
moveVec.x = -moveAmount;
}
if (delta.y > 0.0f)
{
moveVec.y = moveAmount;
}
else
{
moveVec.y = -moveAmount;
}
self.spriteStartPosition = self.sprite.position;
self.sprite.position = ccpAdd(self.sprite.position, moveVec);
}
- (void)touchEnded:(UITouch *)touch withEvent:(UIEvent *)event
{
self.sprite.position = self.spriteStartPosition;
}
If the object you are moving IS that eyeObject then it would be:
- (void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
CGPoint touchPos = [touch locationInNode:self];
CGPoint delta = ccpSub(touchPos, self.eyeObject.position);
float moveAmount = 50.0f;
CGPoint moveVec;
if (delta.x > 0.0f)
{
moveVec.x = moveAmount;
}
else
{
moveVec.x = -moveAmount;
}
if (delta.y > 0.0f)
{
moveVec.y = moveAmount;
}
else
{
moveVec.y = -moveAmount;
}
self.eyeObjStartPosition = self.eyeObject.position;
self.eyeObject.position = ccpAdd(self.eyeObject.position, moveVec);
}
- (void)touchEnded:(UITouch *)touch withEvent:(UIEvent *)event
{
self.eyeObject.position = self.eyeObjStartPosition;
}
To move in general if the static object was representing a joystick or gamepad (would do the same in touch began so I'd separate this into its own method):
- (void)touchMoved:(UITouch *)touch withEvent:(UIEvent *)event
{
CGPoint touchPos = [touch locationInNode:self];
CGPoint delta = ccpSub(touchPos, self.dPad.position);
float moveAmount = 50.0f;
if (delta.x > 0.0f)
{
self.sprite.position.x += moveAmount;
}
else
{
self.sprite.position.x -= moveAmount;
}
if (delta.y > 0.0f)
{
self.sprite.position.y += moveAmount;
}
else
{
self.sprite.position.y -= moveAmount;
}
}
Here's a simple solution - get the unit vector between the two points, multiply it by 50, and add it to the current position. AKA this:
- (void)touchBegan:(UITouch *)touches withEvent:(UIEvent *)event {
CGPoint touchLocation = [touches locationInNode:self];
//Not sure what to do now
CGPoint destinationVector = ccpSub(touchPos, self.eyeObject.position);
CGPoint movementVector = ccpNormalize(destinationVector);
movementVector = ccpMult(movementVector, 50);
[_eyeObject runAction:[CCActionMoveTo actionWithDuration:1.0 position:ccpAdd(_eyeObject, movementVector)]];
}
If you want to have it move back on touchEnded, just save the position in a variable before you move it the first time, and send it back to that spot on touchEnded.

Trying to move UIImageView, moving whole Screen View

I want my UIViewImages to be movable with touch. I'm trying to use code implemented in my ViewController:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
if ([touches count]==1) {
UITouch *touch = [touches anyObject];
CGPoint p0 = [touch previousLocationInView:self.view];
CGPoint p1 = [touch locationInView:self.view];
CGPoint center = self.view.center;
center.x += p1.x - p0.x;
center.y += p1.y - p0.y;
self.view.center = center;
}
}
When I try to drag an UIImageView, I'm dragging whole screen, which is incorrect.
Need help!
Karol
You create a gesture recognizer and add it to a view like this:
UIPanGestureRecognizer *panGestureRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(gestureRecognizerMethod:)];
[self.imageView addGestureRecognizer:panGestureRecognizer];
you can adjust the position of the image view
- (void)gestureRecognizerMethod:(UIPanGestureRecognizer *)recogniser
{
if (recognizer.state == UIGestureRecognizerStateBegan || recognizer.state == UIGestureRecognizerStateChanged)
{
CGPoint touchLocation = [recognizer locationInView:self.view];
self.imageView.center = touchLocation;
}
}
read this article.
If I read your code right self.view actually IS the whole screen.
Maybe you mean self.yourImageView instead?

Can't move Xcode UIButtons with touchesbegan

I am trying to move a button, here is my code. I am not even getting the "fires1" output when I try to move my button. It just gets pressed and doesn't move. I've searched around and I always get the same answers, which I have already applied to my code.
Anyone have any idea why my buttons won't move?
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesBegan:touches withEvent:event];
[self.nextResponder touchesBegan:touches withEvent:event];
NSLog(#"%#",#"fires1");
if ([touches count] == 1) {
// one finger
CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
for (UIButton *iView in self.letterButtons) {
// if ([iView isMemberOfClass:[UIButton class]]) {
if (touchPoint.x > iView.frame.origin.x &&
touchPoint.x < iView.frame.origin.x + iView.frame.size.width &&
touchPoint.y > iView.frame.origin.y &&
touchPoint.y < iView.frame.origin.y + iView.frame.size.height)
{
self.dragObject = iView;
self.touchOffset = CGPointMake(touchPoint.x - iView.frame.origin.x,
touchPoint.y - iView.frame.origin.y);
self.homePosition = CGPointMake(iView.frame.origin.x,
iView.frame.origin.y);
[self.view bringSubviewToFront:self.dragObject];
NSLog(#"%#",#"works!");
}
//}
}
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
CGRect newDragObjectFrame = CGRectMake(touchPoint.x - touchOffset.x,
touchPoint.y - touchOffset.y,
self.dragObject.frame.size.width,
self.dragObject.frame.size.height);
self.dragObject.frame = newDragObjectFrame;
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
if (touchPoint.x > self.dropTarget.frame.origin.x &&
touchPoint.x < self.dropTarget.frame.origin.x + self.dropTarget.frame.size.width &&
touchPoint.y > self.dropTarget.frame.origin.y &&
touchPoint.y < self.dropTarget.frame.origin.y + self.dropTarget.frame.size.height )
{
// self.dropTarget.currentTitle = self.dragObject.currentTitle;
}
self.dragObject.frame = CGRectMake(self.homePosition.x, self.homePosition.y,
self.dragObject.frame.size.width,
self.dragObject.frame.size.height);
}
I don't understand why are you implementing touches began if you're using UIButtons?
Remove your touches began method and link all your buttons on TouchDown event to this IBAction
-(IBAction)buttonPressed:(id)sender
{
self.dragObject = (UIButton*)sender;
self.homePosition = CGPointMake(sender.frame.origin.x,
sender.frame.origin.y);
[self.view bringSubviewToFront:self.dragObject];
}
Adjust your touceshMoved method like
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint currentPoint = [touch locationInView:self.view];
self.dragObject.center = currentPoint;
}
Make your touchesEnded method look like this
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
BOOL btnAIntersectsWithBtnB = CGRectIntersectsRect(self.dragTarget.frame,self.dropObject.frame);
if(btnAIntersectsWithBtnB)
{
self.dropTarget.currentTitle = self.dragObject.currentTitle;
}
self.dragObject.frame = CGRectMake(self.homePosition.x, self.homePosition.y,
self.dragObject.frame.size.width,
self.dragObject.frame.size.height);
}

IOS: drag uiimageview only in one direction

I want to drag an uiimageview only in horizontal from a point1 to a point2; how can I do it?
you can use somting like this:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
touchStart = [[touches anyObject] locationInView:/*your main view*/];
point1 = CGPointMake(140, 140);
oldrect = imgview.rect;
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
CGPoint point = [[touches anyObject] locationInView:/*your main view*/];
imgview.center = CGPointMake(imgview.center.x + point.x - touchStart.x, imgview.center.y);
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
CGPoint point = [[touches anyObject] locationInView:/*your main view*/];
[UIView animateWithDuration:0.25
animations:^{
if (((point1.x -15) > point.x) && ((point1.x + 15 ) < point.x) {
Imgview.rect = CGRectMake(point.x, point.x, imgview.frame.size.width,imgview.frame.size.height);
}
else {Imgview.rect = oldrect;}
completion:^(BOOL finished){ }];} }
Simple, check your imageView x position and your touch x position
float lastX = myimageview.center.x;
if the touch point x is bigger than lastX (or smaller, depends on the direction you want)
{
// Do the move
} else {
// Do nothing
}
Your code should look something like that :
- (void) touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event {
// Move relative to the original touch point
CGPoint pt = [[touches anyObject] locationInView:self];
float lastX = myimageview.center.x;
if (pt.x > lastX){
// move myimageview.x to pt.x
}
}

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