Hi I have a UIScrollView inside of a UIView. I have tried to use code snippets that I found online but they simply don't change anything. Also they are mostly for an image or custom view done within UIView, whereas in my case I have an array of programatically created UILabels. I have tried to change boundary values as well, it simply does not do anything. This is basically how I establish the size of it within viewDidAppear:
[scrollView setContentSize:CGSizeMake([screenView getWidth], [screenView getHeight])];
scrollView.showsHorizontalScrollIndicator = true;
scrollView.showsVerticalScrollIndicator = true;
screenView is a UIView variable.
This is the settings that I use(also in viewDidAppear):
doubleTapRecogniser = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(doubleTapResponse:)];
[doubleTapRecogniser addTarget:self action:#selector(doubleTapResponse:)];
doubleTapRecogniser.delegate = self;
doubleTapRecogniser.numberOfTapsRequired = 2;
[self.scrollView addGestureRecognizer:doubleTapRecogniser];
This is how I implemented my double tap method:
- (void) doubleTapResponse:(UITapGestureRecognizer *)recogniser
{
CGFloat newZoomScale = self.scrollView.zoomScale / 1.5f;
newZoomScale = MAX(newZoomScale, self.scrollView.minimumZoomScale);
[self.scrollView setZoomScale:newZoomScale animated:YES];
}
When I use NSLog messages within my doubleTapResponse, I can get responses from my console. However it does not do anything. What could be the problem?I am using iOS6.1
The error clearly says that the run time searched for a method named doubleTapResponse in the scrollview class you are using. Even if changing the target to self doesn't work, its the method definition place you have to change either the scrollview or the viewcontroller.
[doubleTapRecogniser addTarget:scrollView action:#selector(doubleTapResponse:)];
should be
[doubleTapRecogniser addTarget:self action:#selector(doubleTapResponse:)];
because the scrollview does not know what that method doubleTapResponse is.
Currently it is throwing an exception because it is trying to call the target of the UISCrollView with your doubleTapResponse method, you must add the target of self, and implement this method yourself. In here goes the logic for zooming I presume.
You must also define: doubleTapResponse in your viewcontroller (or class that you are using)
see this for more info:
Ray Wenderlich guide
In order to zoom please look at the following article: QUESTION
Related
I use JazzHands to create a key frame based animation in a UIScrollView.
Here is an example. Look at the view at the top. When you move from page to page. While the animation is running the view at the top is slightly moving from left to right. The animation appears a bit fuzzy.
Here is the code taken from the example here:
IFTTTFrameAnimation *titleView1FrameAnimation = [IFTTTFrameAnimation new];
titleView1FrameAnimation.view = self.titleView1;
[self.animator addAnimation:titleView1FrameAnimation];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(1)
andFrame:self.titleView1.frame]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(2)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(2), 0)]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(3)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(3), 0)]];
[titleView1FrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(4)
andFrame:CGRectOffset(self.titleView1.frame, timeForPage(4), 0)]];
When running the demo take a look at the part marked with red in the following screenshot:
Edit: Here is the code containing this problem: https://github.com/steffimueller/Intro-Guide-View-for-Talk.ai
How can I make the animation running smooth and less fuzzy?
This is due to the frame rate in the JazzHands IFTTTAnimatedScrollViewController being set for non-retina displays. You need to double the number in timeForPage, and also use double the number of the contentOffset in animate, but use the original non-doubled values of timeForPage in places where you were using that for laying out the positions of views instead of using it for the animation time.
Here's a Gist of the changes you'd have to make to your example to get it working. Fixed Demo Gist
You need this method for setting the animation times:
#define timeForPage(page) (NSInteger)(self.view.frame.size.width * (page - 1) * 2.0)
And this one for setting the centers of your views based on the page dimensions:
#define centerForPage(page) (NSInteger)(self.view.frame.size.width * (page - 1))
Then you need to override the scrollViewDidScroll: method in IFTTTAnimatedScrollViewController to use double the numbers it's currently using.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
[self.animator animate:(NSInteger)(scrollView.contentOffset.x * 2)];
}
We'll work on getting the JazzHands demo updated!
Before you start your animation call:
view.layer.shouldRasterize = YES; (seems that you are using objective-c so I put YES here, for swift should be true)
As soon as the animation is finished call
view.layer.shouldRasterize = NO; (seems that you are using objective-c so I put NO here, for swift should be false)
You should always use it when you animating a view
You can see more details about it in the WWDC 2012 Polishing Your Interface Rotations video (paid developer subscription needed)
I hope that helps you!
[EDIT]
Every Time you call the method animate set shouldRasterize to YES before it, like in the example bellow:
titleView1FrameAnimation.view.layer.shouldRasterize = YES;
[self. titleView1FrameAnimation animate:scrollView.contentOffset.x];
I've messed around a bit with the code and it seems that keeping those top views in place while the scrollview is scrolling made it jiggle left and right.
What I did is take out the title view from the scroll view and add it to the view controller view.
You can see it in action here
Later edit:
To actually see what I've changed you can check the file differences in Git. Basically I moved your titleViews (titleView1, titleView2, etc) from the scrollView to the view controller's view (so basically I've replaced all the lines that were like this:
[self.scrollView addSubView:self.titleView1]
to something like this:
[self.view addSubView:self.titleView1]
After that I've also took out the keyframe animations that were keeping your title views in place since they were not moving with the scrollview anymore. Practically I've deleted all the lines that were adding a frame animation to your titleviews from each configurePageXAnimation.
2nd question answer:
Say your screenshot view is called screenshotView. You can go ahead and create it like this:
UIImageView *screenshotView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"ScreenshotImage"]];
[self.view addSubview:screenshotView];
self.screenshotView = screenshotView;
[self.screenshotView setCenter:CGPointMake(self.view.center.x + self.view.bounds.size.width, <#yourDesiredY#>)];
And animate it like this:
//screenshotView frame animation
IFTTTFrameAnimation *screenshotViewFrameAnimation = [IFTTTFrameAnimation new];
screenshotViewFrameAnimation.view = self.screenshotView;
[self.animator screenshotViewFrameAnimation];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(1) andFrame:self.screenshotView.frame]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(2) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width, 0.0)]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(3) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width, 0.0)]];
[screenshotViewFrameAnimation addKeyFrame:[[IFTTTAnimationKeyFrame alloc] initWithTime:timeForPage(4) andFrame:CGRectOffset(self.screenshotView.frame, -self.scrollView.bounds.size.width * 2, 0.0)]];
I have an project using autolayout,
And I notice that after viewWillAppear, viewWillLayoutSubViews and viewDidLayoutSubViews pair will be called several times on iOS 8, for my case, it is 2-3 times usually.
The fist viewDidLayoutSubViews will get incorrect frame size, so I have to avoid for first viewDidLayoutSubViews, and init my views afterwards.
However, when I tested it on iOS 7, I found that only ONE viewWillLayoutSubViews and viewDidLayoutSubViews pair got called, so my code broke again.
My question is, what is changed on iOS 8 for this behaviour?
EDIT:
I have pasted my demo code here:
In the code, _pieChart will be added to self.ChartViewCanvas, and self.ChartViewCanvas is using autolayout. _pieChart is from old project code, which is drawn without auto layout.
I was required to draw the pie chart before viewDidAppear, because drawing in viewDidAppear will have a 1 sec delay compare to other views in storyboard. This is not allowed for me.
Is there any way to know when is the final viewDidLayoutSubViews? Calling [self.ChartViewCanvas addSubview:_pieChart]; multiple times will lead to lower performance, and sometimes _pieChart's drawInRect will not be called every time, so the chart is not update.
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
_pieChart.delegate = self;
if (!_pieChart) {
_pieChart = [[PieChartView alloc] initWithFrame:CGRectMake(0, 0, pieRadius * 2, pieRadius * 2)];
}else {
[_pieChart setFrame:CGRectMake(0, 0, pieRadius * 2, pieRadius * 2)];
}
//_pieChart.translatesAutoresizingMaskIntoConstraints = NO;
if ([_pieChart superview]) {
[_pieChart removeFromSuperview];
}
[self.ChartViewCanvas addSubview:_pieChart];
}
Probably only Apple knows, but I won't deal with that too much if everything is working fine. In iOS8 Apple changed a lot view controllers (again) in they way they are presented from containers VC as for rotation and UITraitCollections.
For instance UIAlertView is now a view controller, when you show one you trigger all the mechanism related to present a VC.
If this fact is creating an issue it must be said that you should not rely on how many times those methods are called because they were always be unpredictable there are too many variables to be taken into account.
A quick and dirty solution could be wrap your code in a dispatch_once if you want that it will be called only one time.
If you add your view using auto layout correctly you won't see any sort of bug.
[EDIT]
Here is a little snippet about how it might look your viewDidLoad:
- (void)viewDidLoad
{
[super viewDidLoad];
//.. your stuff
//We don't need any frame autolayout wil take care of calculating it on its pass
_pieChart = [[PieChartView alloc]initWithFrame:CGRectZero];
_pieChart.delegate = self;
_pieChart.translatesAutoresizingMaskIntoConstraints = NO;
[self.ChartViewCanvas addSubview:_pieChart];
NSDictionary *bindings = NSDictionaryOfVariableBindings(_pieChart);
// We create constraints to tell the view that it needs to sctretch its bounds to the superview
NSString *formatTemplate = #"%#:|[_pieChart]|";
for (NSString * axis in #[#"H",#"V"]) {
NSString * format = [NSString stringWithFormat:formatTemplate,axis];
NSArray * constraints = [NSLayoutConstraint constraintsWithVisualFormat:format options:0 metrics:nil views:bindings];
[_pieChart.superview addConstraints:constraints];
}
// Do any additional setup after loading the view.
}
Of course that is going to call drawRect:, draw rect is called when a view is marked as dirty in the display pass, but before display is usually called the autolayout engine to calculate frames of views in needs for layout.
I tried this out on my application and found the same as you: 1 call on iOS7 and 3 on iOS8. From the stack traces this seems to be down to doing double layout after viewWillAppear and an extra layout following viewDidAppear not seen on iOS7.
My suggestion would be that you add any views in viewDidLoad (or viewWillAppear), then only do layout adjustments in the layout subview runs. Based on your updated post something like:
- (void)viewDidLoad{
[super viewDidLoad];
_pieChart = [[PieChartView alloc] initWithFrame:CGRectMake(0, 0, pieRadius * 2, pieRadius * 2)];
[self.ChartViewCanvas addSubview:_pieChart];
_pieChart.delegate = self;
}
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
[_pieChart setFrame:CGRectMake(0, 0, pieRadius * 2, pieRadius * 2)];
}
For interest the difference between iOS7 and 8 calling sequence was:
iOS7
i) viewWillAppear is called.
ii) layout of subviews is called. From the stack this seems to relate to the navigation bar and animation.
ii) viewDidAppear is called.
iOS8
i) viewWillAppear is called.
ii) layout of subviews is called. From the stack this seems to relate to the navigation bar and animation.
iii) exact same layout with exact same stack is called again. So something in the stack must request a rerun from some point.
iv) viewDidAppear is called.
v) An extra layout of subviews is called. This seems driven from a transaction pushed onto the run loop.
I am adding the following UITapGestureRecognizer to my view.
- (void)viewDidLoad {
_focusView = [[PBJFocusView alloc] initWithFrame:CGRectZero];
_focusTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(_handleFocusTapGesterRecognizer:)];
_focusTapGestureRecognizer.delegate = self;
_focusTapGestureRecognizer.numberOfTapsRequired = 1;
_focusTapGestureRecognizer.enabled = NO;
[_previewView addGestureRecognizer:_focusTapGestureRecognizer];
}
- (void)_handleFocusTapGesterRecognizer:(UIGestureRecognizer *)gestureRecognizer {
NSLog(#"Focus");
}
_focusTapGestureRecognizer should be enable. Try this
_focusTapGestureRecognizer.enabled = YES;
OR
Remove this line
_focusTapGestureRecognizer.enabled = NO;
Try this inside your code
_focusView.userInteractionEnabled = YES;
May be helpfull...
_focusTapGestureRecognizer.enabled = NO;
Remove this line
To make this work check these three things as it is suggested by other guys i only writing them step by step
Check did you set the delegate of TapGesture in .h file.
Check on the UIView you are adding gesture its userInteractionEnabled is True.
Make that enable of UITapGesture Yes .//Why it is no ?
Fourth is , did you gave any size to the UIView , for checking that add some background color to it,see is it visible or not .
if these 4 doesnot help you out type your code what you used it .
You might also want to check that you're not trying to reuse the UITapGestureRecognizer object for different views.
It seems like you can because you add the gesture to the view, but in ultimately the view needs to be assigned to the view property on the gesture object so adding the gesture object to a second view will just overwrite the first.
Here's my code:
if([pantallas objectForKey:par]){
UIView *vista= [[UIView alloc] initWithFrame:self.Botones.frame];
vista.backgroundColor= [UIColor brownColor];
CGSize la= CGSizeMake(50,60);
int cuantos= [part2 count];
NSArray *arr= [COLGenerales tileN:cuantos RectsOfSize:la intoSpaceOf:vista.frame withMaxPerRow:5 spaceVertical:10 spaceHorizontal:10];
for(int j=0; j<cuantos; j++){
UIButton *bot= [[UIButton alloc] initWithFrame:[[arr objectAtIndex:j] CGRectValue]];
bot.tag=j;
bot.titleLabel.text=par;
bot.titleLabel.hidden=true;
bot.imageView.image = [UIImage imageNamed:[[part2 allKeys] objectAtIndex:j]];
[bot addTarget:self action:#selector(registrar:) forControlEvents:UIControlEventTouchDown];
[vista addSubview:bot];
}
[pantallas setObject:vista forKey:par];
self.Botones= vista;
}else{
self.Botones= [pantallas objectForKey:par];
}
Botones is a simple view embedded into the view this class controls (first initiated by the Nib file), the class method of COLGenerales returns an array of CGRects coded as NSValues, and registrar: is a local method.
Everything gets properly set (I've thoroughly checked this with the debugger). The view gets successfully created, set, and added to the dictionary.
However, I absolutely never get the actual screen to change. I even included the background color change just to check if it isn't some kind of problem with the buttons. Nothing. Any suggested solution to this?
A property that is an IBOutlet does not have an intrinsic connection to the view hierarchy—it only makes it possible to populate that property from a xib. When you set self.Botones, you'll need to do something like the following:
[self.Botones removeFromSuperview];
self.Botones = newValue;
[self.BotonesSuperview addSubview:self.Botones];
If you update self.Botones in many places, and you always want the change reflected on-screen, you could add this into a setter implementation:
-(void)setBotones:(UIView*)newValue {
if (newValue != _Botones) {
[_Botones removeFromSuperview];
_Botones = newValue;
[self.BotonesSuperview addSubview:_Botones];
}
}
I recommend using a UINavigation controller that houses these two views.
You can reference this link Swapping between UIViews in one UIViewController
Basically, you create one view, removeSubview for the first and then add the second one with addSubview!
[view1 removeFromSuperview];
[self.view addSubview: view2];
Other reference sources:
An easy, clean way to switch/swap views?
How to animate View swap on simple View iPhone App?
Hopefully this helps!
When subclassing UIView, I usually place all my initialisation and layout code in its init method. But I'm told that the layout code should be done by overriding layoutSuviews. There's a post on SO that explains when each method gets called, but I'd like to know how to use them in practice.
I currently put all my code in the init method, like this:
MyLongView.m
- (id)initWithHorizontalPlates:(int)theNumberOfPlates
{
self = [super initWithFrame:CGRectMake(0, 0, 768, 1024)];
if (self) {
// Initialization code
_numberOfPlates = theNumberOfPlates;
UIScrollView *scrollView = [[UIScrollView alloc] initWithFrame:self.frame];
[scrollView setContentSize:CGSizeMake(self.bounds.size.width* _numberOfPlates, self.bounds.size.height)];
[self addSubview:scrollView];
for(int i = 0; i < _numberOfPlates; i++){
UIImage *img = [UIImage imageNamed:[NSString stringWithFormat:#"a1greatnorth_normal_%d.jpg", i+1]];
UIImageView *plateImage = [[UIImageView alloc] initWithImage:img];
[scrollView addSubview:plateImage];
plateImage.center = CGPointMake((plateImage.bounds.size.width/2) + plateImage.bounds.size.width*i, plateImage.bounds.size.height/2);
}
}
return self;
}
It's the usual tasks: setting up the view's frame, initialising an ivar, setting up a scrollview, initialising UIImages, placing them in UIImageViews, laying them out.
My question is: which of these should be done in init, and which of these should be done in layoutSubviews?
Your init should create all the objects, with the required data. Any frame you pass to them in init should ideally be their starting positions.
Then, within layoutSubviews:, you change the frames of all your elements to place them where they should go. No alloc'ing or init'ing should take place in layoutSubviews:, only the changing of their positions, sizes etc...
In case you're autoresizing works perfectly with just autoresizingFlags, or autolayout, you may just use init to setup the whole view.
But in general your should do layouting in layoutSubviews, since this will be called on every change of the views frame and in other situation, where layout is needed again. Sometimes you just don't know the final frame of a view within init, so you need to be flexible as mentioned, or use layoutSubviews, since you do the layout there after the final size has been set.
As mentioned by WDUK, all initialization code / object creation should be in your init method or anywhere, but not in layoutSubviews.