Which is the best way to move a UIView.
I have a custom UIView with some custom things in it, like shadows, labels etc.
Today I'm using, for move this UIView.:
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [[event allTouches] anyObject];
if (self.isEditing) {
CGPoint location = [touch locationInView:[rootView view]];
self.center = location;
}
}
Is this the best way to move a UIView? I experience this a bit laggy.
I usually reposition a view using the offset between the touchesBegan location and the touchesMoves location.
Related
I have subclassed UIView and there initially my view will be in a default color and i need to fill some different color on touch (from x axis = 0 to user touched point),here the problem is touchesMoved even if i drag out of my self view bounds it is getting those points,how to restrict it to only for my self view bounds.
I googled & tried below snippets but of no luck
if([self pointInside:point withEvent:nil]){
[self fillColor];
}
My touchesMoved method is as below,
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint point = [touch locationInView:self];
endPoint = point;
NSLog(#"moved x: %f,y: %f",point.x,point.y);
if(CGRectContainsPoint([self frame], endPoint)){ // this also not working
[self fillColor];
}
}
Any help is appreciated in advance.
just set tag in viewDidLoad: method and use bellow logic..
fillColorView.tag = 111;
and use bellow logic in touchesMoved: method like bellow..
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *tap = [touches anyObject];
CGPoint pointToMove = [tap locationInView:fillColorView];
if([tap.view isKindOfClass:[UIView class]])
{
UIView *tempView=(UIView *) tap.view;
if (tempView.tag == 111){
[self fillColor];
}
}
}
hope this help you...
In your touchesMoved method, CGPoint point = [touch locationInView:self]; replcae self by the view in which you wants the touch to be worked.
self will get the complete view, you should pass your drawingView at there, so that it will detetc touch only on that view.
I want to drag image from carousel of image and put it in another imageview.After drag of it should delete from carousel.I have done code for this that will also remove from carousel.
I used touch events.
But problem is that after draging one image when i touch anywhere else in the screen it will select next image automatically.How can i stop it?I want to drag image when i click on it.
My Code.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
CGPoint location = [touch locationInView:touch.view];
btnBackImg.center = location;
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [[event allTouches] anyObject];
CGPoint pointMoved = [touch locationInView:self.view];
btnBackImg.frame = CGRectMake(pointMoved.x, pointMoved.y, btnBackImg.frame.size.width,btnBackImg.frame.size.height);
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
NSLog(#"touch end");
if (btnBackImg != nil)
{
UITouch *touch = [[event allTouches] anyObject];
if (CGRectContainsPoint(basket_image.frame, [touch locationInView:self.view]))
{
basket_image.image=[UIImage imageNamed:[NSString stringWithFormat:#"wit_bas.png"]];
[self.product_categories removeObjectAtIndex:imgIndex+1];
[carousel reloadData];
}
}
}
In this btnCackImg want to move in to basketImg.
If anyone konw then pls help me or if any link then also useful.
Thanks in Advance.
You have used this code in your touches.began CGPoint location = [touch locationInView:touch.view]; where touch.View means touching all the objects in the view namely self.view. What you really need is to add the name of the image to be put instead of touch.View. This will select the image at one time.
CGPoint location = [touch locationInView:imageName];
I want to create a ripple effect on a UIImageView from the point where user touches on the screen. what is the best and simple method for doinf this.
Please look at this question.
Hope it helps
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
NSSet *allTouches = [event allTouches];
UITouch *touch = [[event allTouches] anyObject];
CGPoint lastPoint = [touch locationInView:self.view];
//animation code
}
Using above method you have set UIimageView center on lastPoint and play your animation code.
It will work that u want.
Is it possible to drag UIView around the iOS screen while it has both image and text? e.g. small cards. Could you point me to the similar (solved) topic? I haven't found any.
This is what a neat solution, based on pepouze's answer, would look like (tested, it works!)
- (void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *aTouch = [touches anyObject];
CGPoint location = [aTouch locationInView:self];
CGPoint previousLocation = [aTouch previousLocationInView:self];
self.frame = CGRectOffset(self.frame, (location.x - previousLocation.x), (location.y - previousLocation.y));
}
While UIView does not have a built-in support for moving itself along the user dragging, it should be not so difficult to implement it. It is even easier when you are only dealing with dragging on the view, and not other actions such as tapping, double tapping, multi-touches etc.
First thing to do is to make a custom view, say DraggableView, by subclassing UIView. Then override UIView's touchesMoved:withEvent: method, and you can get a current dragging location there, and move the DraggableView. Look at the following example.
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *aTouch = [touches anyObject];
CGPoint location = [aTouch locationInView:self.superview];
[UIView beginAnimations:#"Dragging A DraggableView" context:nil];
self.frame = CGRectMake(location.x, location.y,
self.frame.size.width, self.frame.size.height);
[UIView commitAnimations];
}
And because all subviews of the DraggableView object will be moved, too. So put all your images and texts as subviews of the DraggableView object.
What I implemented here is very simple. However, if you want more complex behaviors for the dragging, (for example, the user have to tap on the view for a few seconds to move the view), then you will have to override other event handling methods (touchesBegan:withEvent: and touchesEnd:withEvent) as well.
An addition to MHC's answer.
If you don't want the upper left corner of the view
to jump under your finger, you can also override touchesBegan
like this:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *aTouch = [touches anyObject];
offset = [aTouch locationInView: self];
}
and change MHC's touchesMoved to:
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *aTouch = [touches anyObject];
CGPoint location = [aTouch locationInView:self.superview];
[UIView beginAnimations:#"Dragging A DraggableView" context:nil];
self.frame = CGRectMake(location.x-offset.x, location.y-offset.y,
self.frame.size.width, self.frame.size.height);
[UIView commitAnimations];
}
you should also define CGPoint offset in the interface:
#interface DraggableView : UIView
{
CGPoint offset;
}
EDIT:
Arie Litovsky provides more elegant solution that allows you to ditch the ivar: https://stackoverflow.com/a/10378382/653513
Even though rokjarc solution works, using
CGPoint previousLocation = [aTouch previousLocationInView:self.superview];
avoids the CGPoint offset creation and the call to touchesBegan:withEvent:
Here is a solution to drag a custom UIView (it can be scaled or rotated through its transform), which can hold images and/or text (just edit the Tile.xib as required):
- (void) touchesMoved:(NSSet*)touches withEvent:(UIEvent*)event
{
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:self];
CGPoint previous = [touch previousLocationInView:self];
if (!CGAffineTransformIsIdentity(self.transform)) {
location = CGPointApplyAffineTransform(location, self.transform);
previous = CGPointApplyAffineTransform(previous, self.transform);
}
self.frame = CGRectOffset(self.frame,
(location.x - previous.x),
(location.y - previous.y));
}
This work for me. My UIView rotated and scaled
- (void) touchesMoved:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:self];
CGPoint previous = [touch previousLocationInView:self];
if (!CGAffineTransformIsIdentity(self.transform)) {
location = CGPointApplyAffineTransform(location, self.transform);
previous = CGPointApplyAffineTransform(previous, self.transform);
}
CGRect newFrame = CGRectOffset(self.frame,
(location.x - previous.x),
(location.y - previous.y));
float x = CGRectGetMidX(newFrame);
float y = CGRectGetMidY(newFrame);
self.center = CGPointMake(x, y);
}
Basically I'm trying to make UIScrollView only scroll on higher angles. As in right now if you move your finger 10 degrees off horizontal, the scrollview will scroll. I'd like to push that up to, say, 30 degrees.
After doing some reading, I established the best way to do this would be to put a subclassed UIView on top of the scrollview. If the UIView on top's touches are above 30 degrees, pass it down to the scrollview, and otherwise don't.
However, I can't figure out how to pass the touches down. Here's my code right now:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"glass touch began");
UITouch *touch = [touches anyObject];
beginning_touch_point = [touch locationInView:nil];
[scroll_view touchesBegan:touches withEvent:event];
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
NSLog(#"glass touch ended");
UITouch *touch = [touches anyObject];
CGPoint previous_point = beginning_touch_point;
CGPoint current_point = [touch locationInView:nil];
float x_change = fabs(previous_point.x - current_point.x);
float y_change = fabs(previous_point.y - current_point.y);
if(x_change > y_change)
{
if(previous_point.x - current_point.x < 0)
{
[(MyScheduleViewController *)schedule_controller didFlickLeft];
}
else
{
[(MyScheduleViewController *)schedule_controller didFlickRight];
}
[scroll_view touchesCancelled:touches withEvent:event];
}
else
{
[scroll_view touchesEnded:touches withEvent:event];
}
}
I know right now that it's checking for 45 degrees, but that's not the important thing. What is important is that the touches are indeed getting passed down correctly to my scroll_view. I have it doing a NSLog() on touchesbegan and touchesended, and it's doing both correctly. It's just not scrolling. I'm worried touchesBegan and touchesEnded cannot cause a scroll. Does anyone know what can, or what I'm doing wrong?
I also tried to do the same but didn't succeed. It seems scrollView doesn't handle touchesMoved/touchesBegan, but it handles some other events to understand that user wants to scroll the view.
For me the solution was to determine thet shift value and set it explicitly as a scrollView content offset. It looked like this (I don't have the exact source code no, this code may work incorrectly):
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint curr = [touch locationInView: self];
CGPoint offset = [scrollView contentOffset];
[scrollView setContentOffset: CGPointMake(offset.x + (curr.x - prev.x), offset.y) animated:YES];
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
prev = [[touches anyObject] previousLocationInView: self];
}