I've run into what I believe is a bug with UICollisionBehavior in UIKit. Adding them to an array of UIViews leads to a memory leak. I put together a simple demo project that creates 10 animations of a group of views falling with gravity applied, and a collision with the enclosing view's bounds. (Code below.) The Leaks template in Instruments reports nine 64-byte leak for each run.
- (void)doAnimation
{
self.animateButton.enabled = NO;
CGFloat left = 12.0f;
NSMutableArray *items = [NSMutableArray new];
// set up an array of views and add them to the superview
while (left < self.view.bounds.size.width - 12.0f) {
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(left, 70, 32, 32)];
left += 34.0f;
[self.view addSubview:view];
view.backgroundColor = [UIColor grayColor];
[items addObject:view];
}
// create a gravityBehavior and initialize with views array
UIGravityBehavior *gravity = [[UIGravityBehavior alloc] initWithItems:items];
[self.animator addBehavior:gravity];
// create a collisionBehavior and initialize with views array
UICollisionBehavior *collision = [[UICollisionBehavior alloc] initWithItems:items];
collision.translatesReferenceBoundsIntoBoundary = YES;
[self.animator addBehavior:collision];
}
// UIDynamicAnimatorDelegate method that's called when collision animation is complete
- (void)dynamicAnimatorDidPause:(UIDynamicAnimator *)animator
{
// get a collision behavior in order to access its items for loop below
UICollisionBehavior *behavior;
for (UIDynamicBehavior *oneBehavior in animator.behaviors) {
if ([oneBehavior isKindOfClass:[UICollisionBehavior class]]) {
behavior = (UICollisionBehavior *)oneBehavior;
break;
}
}
// reset the UIDynamicAnimator property's behaviors for next run
[self.animator removeAllBehaviors];
self.dropCount++;
// remove all subviews
for (UIView *view in behavior.items) {
[view removeFromSuperview];
}
// run the animation again or break
if (self.dropCount < 10) {
[self doAnimation];
} else {
self.animateButton.enabled = YES;
}
}
I'd really like to be able to implement collisions in an app I'm working on, but this leak makes it unusable. I have tried saving the collisionBehavior in property and reusing it. That prevents leaking all but one 64-byte chunk of memory, but the collisions no longer work when that's done. Can anyone suggest a workaround that works?
I ran into the same issue but fixed the memory leak by setting the boundaries using UICollisionBehavior's
addBoundaryWithIdentifier
Unfortunately setting boundaries with translatesReferenceBoundsIntoBoundary and setTranslatesReferenceBoundsIntoBoundaryWithInsets caused leaks for me.
Related
I'm a beginner and still trying to figure out how to read this.
There are 3 custom views and at the start I allocate the first one.
And then the second / deallocate the first and then the third / deallocate the second.
I do empty/nil all arrays right before deallocating each view so from what I see, all memory retained each time I allocated views, should be released whenever I deallocate/nil them but in the graph it keeps increasing, I don't see anything being released at all.
Is that supposed to look like that? I'm nil-ing delegates, arrays, dictionaries etc everything.
-(void)firstTOsecond {
[self.first removeFromSuperview];
self.first.delegate = nil;
self.first = nil;
self.second = [[Second alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
[self.view addSubview:self.second];
self.second.delegate = self;}
-(void)secondTOthird {
[self.second removeFromSuperview];
self.second.delegate = nil;
self.second = nil;
self.third = [[Third alloc]initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)];
[self.view addSubview:self.third];
self.third.delegate = self;}
EDIT
In First.m / Second.m / Third.m
-(instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
self.buttonStartFrame = [[UIImageView alloc]initWithImage:[UIImage imageNamed:#"buttonStartFrame"]];
[self addSubview:self.buttonStartFrame];
self.buttonStartFrame.userInteractionEnabled = YES;
self.buttonStartButton = [[UIImageView alloc]initWithImage:[UIImage imageNamed:#"buttonStartDefault"]];
[self.buttonStartFrame addSubview:self.buttonStartButton];
self.buttonStartButton.userInteractionEnabled = YES;
self.labelStart = [[UILabel alloc]init];
[self.buttonStartButton addSubview:self.labelStart];
self.labelStart.textColor = [UIColor darkGrayColor];
self.labelStart.text = #"Start";
}
return self;}
the memory leak could be that you are continuously creating new view elements when they could be updated instead .. you can create helper methods to avoid allocating new views, and updating the one's on the main thread instead
- (void)limitedUpdateTextColorView:(NSDictionary *)somethingCache {
self.labelStart.textColor = [somethingCache valueForKey:#"bar"];
self.labelStart.text = [somethingCache valueForKey:#"foo"];
}
I'm new to the iOS UI development and I need some help to figure out, what is the best way to implement image belt (sequence of images in horizontal belt). I don't need details (someone to write me the code), just guidance what I should focus on learning as a libraries and most important design patterns (by design patters I mean software design for iOS UI).
The task details:
1. I will have image belt - sequence of few related images. This will be my horizontal transition. The transition animation will be simple push animation (something like push CATransion), initiated by swipe left/right. On top of the images there will be overlay with some text, icon info and etc. The overlay info will be the same for all images in the current belt.
2. I will have multiple image belts - this will be my vertical transition. The transition between belts will be triggered by swipe up/down. The different belts will contain unrelated information, so the information shown in overlays from point 1 must be also changed. The animation will be also simple push animation as in point 1.
I probably should inherit UIView and implement my belt as one object, which will consist of different UIView(overlay) and UIImageViews(for the images). Am I on the right track?
Some helpful brainstorm will be highly appreciated.
Yes - I've done many of these. You add a UIView above the top view. I usually use a full-screen one with some alpha so they can see through the core content a little. Then add stuff on top of that which won't change: things like your text, icons, etc... Then on top of that you put the image you want to swipe and add a swipe gesture recognizer, typically one for left and one for right. When they swipe you init a new UIView off the edge of the device, init it with the image, and animate the frames of both left or right, depending on which way they've swiped. Mine are help tutorials showing how to use my app step-by-step so I also init multi-part animations on some of the frames that fly in; that's a nice looking optional effect. Here's the one I use (with the animation support stripped out or it'd be too much code) and there's lots of variations. Edited to note my app doesn't support rotation but if yours does you have to adjust the frames after a rotation.
- (void)init
{
currentPanelNumber = 10;
self = [super initWithNibName:nil bundle:nil];
if (self)
{
[self.view setBackgroundColor:[UIColor clearColor]];
currentPanelNumber = 10;
overlay = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
overlay.backgroundColor = [UIColor colorWithRed:.9 green:.9 blue:.9 alpha:.9];
[self.view addSubview:overlay];
CGRect currentPanelFrame = CGRectMake(267, 175, 494, 444);
currentPanel =
[[HelpView alloc] initWithFrame:currentPanelFrame withImage:[UIImage imageNamed:#"10"]];
currentPanel.frame = currentPanelFrame;
[overlay addSubview:currentPanel];
// ----------------------------------
// Gesture swipes go here
swipeLeftRecognizer =
[[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipeLeft:)];
[swipeLeftRecognizer setDirection:UISwipeGestureRecognizerDirectionLeft];
[overlay addGestureRecognizer:swipeLeftRecognizer];
swipeRightRecognizer =
[[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipeRight:)];
[swipeRightRecognizer setDirection:UISwipeGestureRecognizerDirectionRight];
[overlay addGestureRecognizer:swipeRightRecognizer];
swipeDownRecognizer =
[[UISwipeGestureRecognizer alloc] initWithTarget:self action:#selector(swipeDown:)];
[swipeDownRecognizer setDirection:UISwipeGestureRecognizerDirectionDown];
[overlay addGestureRecognizer:swipeDownRecognizer];
UITapGestureRecognizer *tapRecognizer =
[[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(handleTap:)];
[overlay addGestureRecognizer:tapRecognizer];
skipIcon = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"SkipAndStartIcon"]];
CGSize size = CGSizeMake(84, 124);
skipIcon.frame = CGRectMake((self.view.frame.size.width/2)-(size.width/2), self.view.frame.size.height-size.height-25, size.width, size.height);
[self.view addSubview:skipIcon];
}
- (void)goNext
{
// Clear out all subviews to remove lingering animations
[[currentPanel subviews] makeObjectsPerformSelector:#selector(removeFromSuperview)];
if(currentPanelNumber>=80)
{
[self closeHelp];
return;
}
NSString *nextImage = [NSString stringWithFormat:#"%i", currentPanelNumber+10];
CGRect nextPanelFrame = CGRectMake(765, 175, 494, 444);
nextPanel = [[HelpView alloc] initWithFrame:nextPanelFrame withImage:[UIImage imageNamed:nextImage]];
nextPanel.frame = nextPanelFrame;
[overlay addSubview:nextPanel];
[UIView animateWithDuration:.2 animations:^
{
nextPanel.frame = currentPanel.frame;
}
completion:^(BOOL finished)
{
currentPanel.image = nextPanel.image;
nextPanel.alpha = 0;
currentPanelNumber += 10;
}
- (void)goPrevious
{
if(currentPanelNumber<=10)
{
return;
}
// Clear out all subviews to remove lingering animations
[[currentPanel subviews] makeObjectsPerformSelector:#selector(removeFromSuperview)];
NSString *nextImage = [NSString stringWithFormat:#"%i", currentPanelNumber-10];
CGRect nextPanelFrame = CGRectMake(-230, 175, 494, 444);
// nextPanel = [[UIImageView alloc] initWithImage:[UIImage imageNamed:nextImage]];
nextPanel = [[HelpView alloc] initWithFrame:nextPanelFrame withImage:[UIImage imageNamed:nextImage]];
nextPanel.frame = nextPanelFrame;
[overlay addSubview:nextPanel];
[UIView animateWithDuration:.2 animations:^
{
nextPanel.frame = currentPanel.frame;
}
completion:^(BOOL finished)
{
currentPanel.image = nextPanel.image;
nextPanel.alpha = 0;
currentPanelNumber -= 10;
}];
}
I am sublassing either an UIImageView or UIView for generating simple color tiles with digits. If I am using UIImageView, I use initWithImage method. If I use UIView, the method initWithFrame is being used.
Either red square image or programmatically generated red view is used for initialization.
The problem can be seen on two screenshots: when initWithImage is being used - everything works fine. If initWithFrame method is being used, I am ending with multiple white views without any information created in even order with normal views. All the screenshots and code attached.
This how it looks when initializing using initWithImage:
- (id)initWithImage:(UIImage *)image {
self = [super initWithImage:image];
if (self) {
//Some non-important, label-related stuff.
[self addSubview:self.numberLabel];
}
return self;
}
And this is how it looks with initWithFrame:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.redView = [self redViewWithFrame:frame];
[self addSubview:self.redView];
//label-related stuff
}
return self;
}
- (UIView *)redViewWithFrame:(CGRect)frame {
UIView *view = [[UIView alloc] initWithFrame:frame];
view.backgroundColor = [UIColor redColor];
view.alpha = 1;
return view;
}
And the for-loop, calling these initializers from another class (UIScrollView subclass). The label value is being set after the view had been initialized.
- (void)setNumberOfBlocks:(NSInteger)numberOfBlocks {
_blocks = [[NSMutableArray alloc] init];
CGSize contentSize;
contentSize.width = BLOCK_WIDTH * (numberOfBlocks);
contentSize.height = BLOCK_HEIGHT;
self.contentSize = contentSize;
for (int i = 0; i < numberOfBlocks; i++) {
CGFloat totalWidth = BLOCK_WIDTH * i;
CGRect frame = CGRectMake(0, 0, BLOCK_WIDTH, BLOCK_HEIGHT);
frame.origin.x = totalWidth;
BlockView *view = [[BlockView alloc] initWithImage:[UIImage imageNamed:#"block.png"]];
OR!!!
BlockView *view = [[BlockView alloc] initWithFrame:frame];
view.frame = frame;
NSString *number = [NSString stringWithFormat:#"%ld", (long)i + 1];
view.numberLabel.text = number;
[self addSubview:view];
[_blocks addObject:view];
}
}
Googling gave me the impression that this is very common problem, but I haven't found any solution how to beat this. Moreover, I still do not understand, why numbers are in totally right order, the only problem is view position.
The problem is that you're setting the frame of the red view to the superview's frame instead of its bounds. Since the red view is a subview of the BlockView, its frame needs to be relative to its superview, which you get with bounds (its not clear why you even need the red view, as opposed to setting the background color of the block view to red).
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
self.redView = [self redViewWithFrame:self.bounds];
[self addSubview:self.redView];
//label-related stuff
}
return self;
}
I think you should set the frame origin to (0,0) in redViewWithFrame in ordre to hâve superposed views
I'm working on an iPad app and at some points, I need to show a popover with options for a user to pick from. For this, I use a UITableView in a UIPopoverController. The problem is that, on an iPad (not on the simulator), when scrolling the tableview, I get a sort of "double vision" effect, where it appears like two sets of of the list exist. One that is stationary, and one that scrolls up and down.
I construct the popover like this:
self.fClassTypeList = [[NSMutableArray alloc] init];
[self.fClassTypeList removeAllObjects];
NSUInteger stringLength = 0;
(populate self.fClassTypeList, and set stringLength to the size of the longest entry)
[self setContentSizeForViewInPopover:CGSizeMake(stringLength * 15.0f, [self.fClassTypeList count] * 30)];
CGFloat tableBorderLeft = 5;
CGFloat tableBorderRight = 5;
CGRect viewFrame = self.view.frame;
viewFrame.size.width -= tableBorderLeft + tableBorderRight; // reduce the width of the table
self.fListOfItems = [[UITableView alloc] initWithFrame:viewFrame style:UITableViewStylePlain];
self.fListOfItems.delegate = self;
self.fListOfItems.dataSource = self;
[self.view addSubview:self.fListOfItems];
I put in the viewDidLayoutSubviews(…) part of the view controller, maybe I should put it somewhere else? I am not sure why this happens on the actual machine, but not the simulator.
-viewDidLayoutSubviews is a weird place to put allocations because that method can be called multiple times. So as far as your main issue goes, I believe you should move your allocations into the -init method, and move your layout code into your -viewWillAppear method.
- (id)init
{
self = [super init];
if (self)
{
self.fClassTypeList = [[NSMutableArray alloc] init];
self.fListOfItems = [[UITableView alloc] initWithFrame:CGRectZero style:UITableViewStylePlain];
self.fListOfItems.delegate = self;
self.fListOfItems.dataSource = self;
[self.view addSubview:self.fListOfItems];
}
return self;
}
- (void )viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
NSUInteger stringLength = 0;
CGFloat tableBorderLeft = 5;
CGFloat tableBorderRight = 5;
CGRect viewFrame = self.view.frame;
viewFrame.size.width -= tableBorderLeft + tableBorderRight; // reduce the width of the table
self.fListOfItems.frame = viewFrame;
[self setContentSizeForViewInPopover:CGSizeMake(stringLength * 15.0f, [self.fClassTypeList count] * 30)];
}
This promotes better memory management.
As an added bonus, I would recommend you refactor the
[self setContentSizeForViewInPopover:CGSizeMake(stringLength * 15.0f, [self.fClassTypeList count] * 30)]; method into a setter method of fClassTypeList. Even better is to simply call -viewWillAppear: in that same setter method instead. This will promote good scalability as you (or someone else) continues to build upon this code later on.
It's a little confusing to see what exactly you're trying to accomplish in this code because it's so hardcoded so let me know if I'm missing the mark you're looking for (w/ an explanation why) and I'll make an edit.
Cheers
I have a weird issue with a UIStepper (and it's accompanying UITextField)
Consider this code snippet:
#interface LTRPageTracker : UIView <UITextFieldDelegate>
{
UIStepper* page_move;
UITextField* page_no_view;
}
-(void) nextOrPrevPage:(id)sender forEvent:(UIControlEvents) event;
#implementation LTRPageTracker
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
CGRect stepperFrame, pageNoframe;
pageNoframe.origin = frame.origin;
pageNoframe.size.height = frame.size.height;
pageNoframe.size.width = frame.size.width/2;
stepperFrame.origin.x = pageNoframe.origin.x + pageNoframe.size.width +1;
stepperFrame.origin.y = frame.origin.y;
stepperFrame.size = pageNoframe.size;
page_move = [[UIStepper alloc] initWithFrame:stepperFrame];
[page_move setMinimumValue:0];
[page_move setValue:7];
page_move.maximumValue =1000;
[page_move addTarget:self action:#selector(nextOrPrevPage:forEvent:) forControlEvents:UIControlEventValueChanged];
page_no_view = [[UITextField alloc] initWithFrame:pageNoframe];
page_no_view.delegate = self;
page_no_view.backgroundColor = [UIColor redColor];
[self addSubview:page_no_view];
[self addSubview:page_move];
[page_move sendActionsForControlEvents:UIControlEventValueChanged];
[page_move setEnabled:YES];
}
return self;
}
-(void) nextOrPrevPage:(id) sender forEvent:(UIControlEvents) event {
//assert(sender == page_move);
NSLog(#"Event is %x", event);
page_no_view.text = [[NSNumber numberWithDouble: page_move.value] stringValue];
}
I have added this View to the navigation bar.
And I can decrement the value of the UIStepper but no increment it (the event will simply not get triggered for increment but will do so decrement).
WHY?
Using iOS 7, running on simulator.
Whenever you have a problem with a UI element not responding, the first thing you should check is whether it (or part of it) is outside the bounds of its superview (the part that's out of the bounds will not respond). An easy way to do this, is to give the superview a background color. In the init method assign a background color to self, and see what that shows you. I'm betting that you'll see that the right side of the stepper is not within its superview, so you'll need to make that view bigger, or change the stepper's position within that view.
If you make the view's frame 150x30, and change these two lines in the view's init method, I think it should work ok for a number as large as 1000:
pageNoframe.size.width = frame.size.width/4; // changed 2 to 4
stepperFrame.origin.x = pageNoframe.origin.x + pageNoframe.size.width+20; // changed 1 to 20