I'm making an iphone app and I made a method that creates a new UIImageView programmatically and it's working great (well.. somewhat great) BUT obviously theres an issue.
Whenever the method gets called, every other UIImageView that I created in the storyboard gets refreshed, meaning, they all get placed back to where I placed them originally on the storyboard (they're supposed to be moving randomly)
heres the method
- (UIImageView *)shootNewBullet {
UIImageView *newBullet = [[UIImageView alloc] initWithFrame:CGRectMake(80, playerShip.center.y,15,3)];
newBullet.Image=[UIImage imageNamed: #"bullet2.png"];
newBullet.hidden = NO;
[bulletArray addObject:newBullet];
[self.view addSubview:newBullet];
return newBullet;
}
heres where the method gets called
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint point = [touch locationInView:self.view];
if (point.x > 101) {
bullets = [self shootNewBullet];
}
}
if more code is necessary to give good answers please let me know
This is probably a consequence of using auto layout (you can turn that off in IB to see if this is the problem). When using auto layout, you shouldn't set any frames. If you do, as soon as the view needs to be redrawn, all frames will be reset to the frames defined by the constraints. If you want to leave auto layout turned on, then you should do any changing of size or position by modifying the constraints rather than directly setting frames.
Related
I am trying to figure out how I can determine if my touchpoint is where I have a UIView as subview or not. The background is UIView itself that I am adding multiple other UIViews to ... So as I long press and am changing the position while holding the touch, I'd like to know if there's a UIView at that point or not.
I have been thinking, still not clear how to go about it but came across this which makes me think of getting the indexes of hierarchy and check of it is larger than 1. But how could I do that for where I'm touching?
Any hint or clue would be appreciated.
You have to store both reference in two objects myParentView and mySubView now just use this method..
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
CGPoint locationPoint = [[touches anyObject] locationInView: myParentView];
UIView* viewYouWishToObtain = [self hitTest:locationPoint withEvent:event];
if(mySubView == viewYouWishToObtain){
//That view is touched
}else{
//That view is not touched
}
}
I'm trying to make an image go full screen on tap, which doesn't sound so complicated.
This it currently doing the work after the tap is detected:
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint touchLocation = [touch locationInView:self.view];
if (self.contentView.frame.origin.y >= 0 && CGRectContainsPoint(self.bottleImageView.frame, touchLocation)) {
[UIView animateWithDuration:0.5 delay:0 options:0 animations:^{
[bottleImageView setFrame:[[UIScreen mainScreen] bounds]];
bottleImageView.backgroundColor = [UIColor blackColor];
}completion:^(BOOL finished){}];
...
}
There's a problem though. I need to bring the UIImageView to the front, so that it draws the image in front of the other views. When I add in [self.view bringSubviewToFront:bottleImageView]; to the mix (either before the animation block, in the completion block, or after this code), things change. On the first tap, the UIImageView background changes to black, and on the second tap the view expands to full screen.
I'm sure it's just something small and dumb that I've overlooked.
EDIT: I've added the touch code
EDIT (2): I may have missed some vital information. I thought I'd try auto layout for this project. I'm guessing there's something there that's not letting everything work as intended?
You can use MHFacebookImageViewer
for this purpose. It is very simple to use.
Perhaps you have the wrong view content mode, add this line to where after the image is being set:
bottleImageView.contentMode = UIViewContentModeScaleAspectFit;
OK. The code above is fine for expanding a view.
I found there was a problem with the Autolayout restraints. I couldn't tell you exactly what I changed that fixed the problem - but a few hours debugging restraints solved the issue.
I found a much better solution however - Facebook POP works much better, and looks a lot slicker.
Add
[self.view bringSubviewToFront:bottleImageView]
immediately after you add
[self.view addSubview:bottleImageView]
How would I create a program so a dot starts in the center, and when I click the screen the dot follows where I clicked? Not as in teleports to it, I mean like changes it's coordinates towards it slightly every click. I get how I could do it in theory, as in like
if (mouseIsClicked) {
[mouseX moveX];
[mouseY moveY];
}
And make the class that mouseX and mouseY are have some methods to move closer to where the mouse is, but I just don't know any specifics to actually make it happen. Heck, I don't even know how to generate a dot in the first place! None of those guides are helping at all. I really want to learn this language though. I've been sitting at my mac messing around trying to get anything to work, but nothing's working anywhere near how I want it to.
Thanks for helping a total newbie like me.
If you are going to subclass UIView, you can use the touchesBegan/touchesMoved/touchesEnded methods to accomplish this. Something like:
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint p = [touch locationInView:self];
//slightly update location of your object with p.x and p.y cgpoints
[self setNeedsDisplay];
}
-(void)drawRect{
//draw your object with updated coordinates
}
You can create a dot and move it around based on taps all within your UIViewController subclass.
Make your dot by creating a UIView configured to draw the way you want - look into CALayer and setting dotview.layer.cornerRadius to make it be round (alternately you can make a UIView subclass that overrides drawRect: to make the right CoreGraphics calls to draw what you want). Set dotview.center to position it.
Create a UITapGestureRecognizer with an action method in your view controller that updates dotview.center as desired. If you want it animated, simply set the property within a view animation call & animation block like this:
[UIView animateWithDuration:0.3 animations:^{
dotview.center = newposition;
}];
You can download the sample code here that will show you general iOS gestures. In particular it has a sample that shows how to drag and drop UIViews or how to swipe them around. The sample code includes both driven and fire-n-forget animations. Check it out, its commented and I'd be happy to answer any specific questions you have after reviewing the code.
Generating a simple circle
// Above Implementation
#import <QuartzCore/QuartzCore.h>
// In viewDidLoad or somewhere
UIView *circleView = [[UIView alloc] initWithFrame:CGRectMake(32.0, 32.0, 64.0, 64.0)];
[circleView setBackgroundColor:[UIColor redColor]];
[circleView.layer setCornerRadius:32.0];
self.view addSubview:circleView];
I am creating a UIButton that follows the UITouch point, I want that when I Keep pressing the touch and the animation boundaries reach my touch point I perform some activity there.
Following is the code.
I am always getting x,y 0 for the UIButton.
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[UIView beginAnimations:#"MoveAndStrech" context:nil];
[UIView setAnimationDuration:1];
[UIView setAnimationBeginsFromCurrentState:YES];
if([touches count] == 1) {
UITouch *touch = [touches anyObject];
self.uiButton.center = [touch locationInView:self.view];
}
[UIView commitAnimations];
UITouch *touchTemp = [touches anyObject];
CGPoint pCurrent = [touchTemp locationInView:self.view];
CGRect currentRect = self.uiButton.layer.bounds;
NSLog(#"Current Rect x:%f,Current y:%f",
currentRect.origin.x,
currentRect.origin.y);
NSLog(#"TouchPoint x:%f,TouchPoint y:%f",
pCurrent.x,
pCurrent.y);
if(CGRectContainsPoint(currentRect, pCurrent)) {
NSLog(#"Touched....in rect");
}
}
Regards
Sara
Replace
CGRect currentRect = self.uiButton.layer.bounds;
with
CGRect currentRect = self.uiButton.frame;
If that doesn't work, then
CGRect currentRect = self.uiButton.presentationLayer.frame;
Also, why aren't you using UIView animation blocks? It'd make your life much easier and your code much cleaner.
Several things. At first I thought you were missing the call to commitAnimations.
DO NOT PUT MULTIPLE STATEMENTS ON THE SAME LINE!!!! That is a very nasty coding habit that makes your code all but impossible to read.
Next, the old style beginAnimations/commitAnimations calls are outdated, and should not be used in iOS 4 or later. To quote the docs of beginAnimations:context:
Use of this method is discouraged in iOS 4.0 and later. You should use
the block-based animation methods to specify your animations instead.
You should be using the new block-based animation calls (of the form (animateWithDuration:animations:)
Next, UIView animations cause the object being animated to move to it's final location instantly. They only LOOK LIKE they are moving to their final location over time. They also disable user interaction during animations by default.
If you want to figure out where the view appears on the screen at any given moment then you need to check the view's layer's animationLayer. I have a sample project on Github (link) that includes a UIView animation of an image where you can tap on the image and the animation stops. This sample project shows how to use the view's layer's animation layer to figure out where the animation is located at the instant the user taps the screen.
If you want code that does something when the animated view gets to a certain point it would be more tricky. You might need to attach a CADisplayLink to your view (which will be called on each screen refresh) and use that to check the position of your animation and compare it to the current touch location.
In my application I have many UIButtons dynamically added to the View and I use below method
to Drag them around the View.
//forDragAction
[btnTarget addTarget:self action:#selector(wasDragged:withEvent:)
forControlEvents:UIControlEventTouchDragInside];
- (void)wasDragged:(UIButton *)button withEvent:(UIEvent *)event
{
// get the touch
UITouch *touch = [[event touchesForView:button] anyObject];
// get delta
CGPoint previousLocation = [touch previousLocationInView:button];
// frameof buttonChanged here
}
I want to stop dragging action if the dragged one intersect with anyother, I know that I can use for loop like below to check if any UIButton is Interacting
for(UIButton *btn in [[button superview] subViews])
{
//check if the btn frame interact with any others if so comeout of loop
}
I want to know if there is someother way, As mentioned way will get slower if the subViews count increse to such great amount
Edit:- the UIButtons are dynamically added to the UIView (But total amount of subViews won't exceed 120)
Try brute force first. You might be surprised at how well it does. (But remember that a loop through [[button superview] subviews] will contain the button itself, so it will always stop because the button intersects itself. Be sure to exclude the button).
Optimize after you have something working that is demonstrably slow with real data.
If that's really the case, there's a whole lot of algorithmic work done on this problem, which can be summarized as preprocessing the data into structures that allow cheaper initial tests to reject distant objects. This is a good SO answer on the topic, referring to this article.
I don't think that count of subviews, that may fill the screen (without intersections), is too large. So use function:
bool CGRectIntersectsRect (
CGRect rect1,
CGRect rect2
);
for detect whether frame of dragged button intersects with another subview.