UIImageView scale from center using Animation Blocks - ios4

I am using the following to scale image up but it's scaling from it's left top point, how can I make the scale from center
[UIView animateWithDuration:duration delay:delay options:options
animations:^{
myImageView.frame = frame;
myImageView.alpha = alpha;
}
completion:^(BOOL finished) {
}
];

[UIView animateWithDuration:0.5
delay:0
options:UIViewAnimationOptionBeginFromCurrentState
animations:(void (^)(void)) ^{
myImageView.transform=CGAffineTransformMakeScale(1.2, 1.2);
}
completion:^(BOOL finished){
myImageView.transform=CGAffineTransformIdentity;
}];
this will work perfectly
Good Luck

Try this:
[UIView animateWithDuration:2
animations:^{
float zoomScal = 5; //want 5x zoom
CGPoint CenterPoint = CGPointMake(200, 300); // want center point to this
imgArtifactImage.frame = CGRectMake(- CenterPoint.x * (zoomScal-1),- CenterPoint.y * (zoomScal-1),self.view.frame.size.width * zoomScal,self.view.frame.size.height * zoomScal);
} completion:^(BOOL finished){}];
It's working for me.

this can be the block of animation for the scale up the image
here as theView U Can Use the uiimageview
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:GROW_ANIMATION_DURATION_SECONDS];
theView.transform = CGAffineTransformMakeScale(1.2, 1.2);
[UIView commitAnimations];

Related

UIGraphicsBeginImageContext created image stays in memory forever

I'm creating many colour variations of an image using Core Graphics. I need to create about 320 in total but gradually, the memory usage of the app keeps increasing until it crashes. From Instruments, I see that more CGImage objects are being created and stay alive. I want to release them because I store the images to the cache directory in PNG format.
I have searched through all other solutions I could find without success. Any help is appreciated. Thanks.
Here's the main part:
+(UIImage *)tintedImageFromImage:(UIImage *)sourceImage colour:(UIColor *)color intensity:(float)intensity {
if (UIGraphicsBeginImageContextWithOptions != NULL) {
UIGraphicsBeginImageContextWithOptions(sourceImage.size, NO, 0.0);
} else {
UIGraphicsBeginImageContext(sourceImage.size);
}
CGContextRef context = UIGraphicsGetCurrentContext();
CGRect rect = CGRectMake(0, 0, sourceImage.size.width, sourceImage.size.height);
// draw alpha-mask
CGContextSetBlendMode(context, kCGBlendModeNormal);
CGContextDrawImage(context, rect, sourceImage.CGImage);
// draw tint color, preserving alpha values of original image
CGContextSetBlendMode(context, kCGBlendModeSourceIn);
[color setFill];
CGContextFillRect(context, rect);
//Set the original greyscale template as the overlay of the new image
sourceImage = [self verticallyFlipImage:sourceImage];
[sourceImage drawInRect:CGRectMake(0,0, sourceImage.size.width,sourceImage.size.height) blendMode:kCGBlendModeMultiply alpha:intensity];
UIImage *colouredImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
colouredImage = [self verticallyFlipImage:colouredImage];
return colouredImage;
}
this is used to flip the image:
+(UIImage *)verticallyFlipImage:(UIImage *)originalImage {
UIImageView *tempImageView = [[UIImageView alloc] initWithImage:originalImage];
UIGraphicsBeginImageContext(tempImageView.frame.size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGAffineTransform flipVertical = CGAffineTransformMake(1, 0, 0, -1, 0, tempImageView.frame.size.height);
CGContextConcatCTM(context, flipVertical);
[tempImageView.layer renderInContext:context];
UIImage *flippedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return flippedImage;
}
Add to verticallyFlipImage the line tempImageView.image = nil; in order to make the image view release the image. This solves the problem.

NSOperationQueue Calling performSelectorOnMainThread crashes the application

I'm using the following code to download some pic from the server,
-(void)viewDidLoad
{
for (int i = 0 ; i < picsNames.count ; i++) {
UIImageView *imageView = [[UIImageView alloc] initWithFrame: CGRectMake(i * 320.0, 0.0, 320.0, self.view.frame.size.height)];
imageView.backgroundColor = [UIColor blackColor];
imageView.tag = IMAGE_VIEWS_TAG + i;
[scrollView addSubview:imageView];
//getting the image
NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self selector:#selector(getImage:) object:imageView];
[queue addOperation:operation];
}
}
-(void)getImage:(UIImageView *)imageView
{
//getting the "image" from the server .....
[self performSelectorOnMainThread:#selector(loadPic:) withObject:[NSArray arrayWithObjects:imageView, image,nil] waitUntilDone:YES];
}
-(void)loadPic:(NSArray *)imageAndImageViewArray
{
//loading the image to imageview
UIImageView *imageView = (UIImageView *)[imageAndImageViewArray objectAtIndex:0];
imageView.image = (UIImage *)[imageAndImageViewArray objectAtIndex:1];
}
After loading some pictures the following line gives memory warning and crashes the app.
[self performSelectorOnMainThread:#selector(loadPic:) withObject:[NSArray arrayWithObjects:imageView, image,nil] waitUntilDone:YES];
I don't know how to solve this issue.
Thanks everyone :)
So after spending too much time on this I realized that the error is due to having too many UIImage objects alloc at the same time no the NSQueue of main NSTread.
So Just changed to code so I have only 10 UIImage objects at the time.

How to resize MKAnnotationView on iOS6?

Resize MKAnnotationView Image When map zooms in and out? This methord are successful on iOS5, but failed on iOS6.
I change the MKAnnotationView's transform directly, and no luck. The MKAnnotationView only resize in a flash(When touch up inside the MKMapView, after the touch up finish, the MKAnnotationView will restore the original size).
My code are below:
- (void)mapView:(MKMapView *)mapView regionDidChangeAnimated:(BOOL)animated {
for (id <MKAnnotation>annotation in _mapView.annotations) {
// if it's the user location, just return nil.
if ([annotation isKindOfClass:[MKUserLocation class]])
continue;
// handle our custom annotations
//
if ([annotation isKindOfClass:[XPMKAnnotation class]])
{
// try to retrieve an existing pin view first
MKAnnotationView *pinView = [_mapView viewForAnnotation:annotation];
//resize the pin view
double zoomLevel = [_mapView getZoomLevel];
double scale = (1.0 * zoomLevel / 16) + 0.5;
pinView.transform = CGAffineTransformMakeScale(scale, scale);
}
}
}
Can we resize the MKAnnotationView on iOS6? Anybody know any way?
Apple suggests resizing the .image property of an annotation view. In my case shown below, I looked at the UIImage that was set in the viewforAnnotation and re-scaled it to the zoom level in a UIPinchGestureRecognizer
UIImage *orangeImage = [UIImage imageNamed:#"Orange210.PNG"];
CGRect resizeRect;
//rescale image based on zoom level
resizeRect.size.height = orangeImage.size.height * scale;
resizeRect.size.width = orangeImage.size.width * scale ;
NSLog(#"height = %f, width = %f, zoomLevel = %f", resizeRect.size.height, resizeRect.size.width,zoomLevel );
resizeRect.origin = (CGPoint){0,0};
UIGraphicsBeginImageContext(resizeRect.size);
[orangeImage drawInRect:resizeRect];
UIImage *resizedImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
pinView.image = resizedImage;

CALayer as SubLayer Not Visible

I am trying to built an animated circle which would be drawn clockwise until it becomes complete circle as illustrated in iPhone Core Animation - Drawing a Circle
Problem is that CALayer object is not added or build. I tested and saw that it is not accessing my drawInContext:CGContextRef and animatingArc methods.
What so far I have done is:
In AnimateArc.h
#interface AnimateArc : CALayer {
CAShapeLayer *circle;
}
-(void) animatingArc;
#end
In AnimateArc.m
-(void) drawInContext:(CGContextRef)ctx
{
CGFloat radius = 50.0;
circle = [CAShapeLayer layer];
//make a circular shape
circle.path = [UIBezierPath bezierPathWithRoundedRect:CGRectMake(0.0, 0.0, 2 * radius, 2 * radius) cornerRadius:radius].CGPath;
CGPoint centerPoint = CGPointMake(CGRectGetWidth(self.bounds)/2, CGRectGetHeight(self.bounds)/2);
//center the shape in self.view
circle.position = centerPoint;
//configure appearence of circle
circle.fillColor = [UIColor clearColor].CGColor;
circle.strokeColor = [UIColor blackColor].CGColor;
circle.lineWidth = 5;
/*CGPointMake((self.contentsCenter.size.width), (self.contentsCenter.size.height));*/
//path the circle
CGContextAddArc(ctx, centerPoint.x, centerPoint.y, radius, 0.0, 2 * M_PI, 0);
CGContextClosePath(ctx);
//fill it
CGContextSetFillColorWithColor(ctx, [UIColor redColor].CGColor);
CGContextFillPath(ctx); }
///////////////////////////////////////////////////////////////////////
-(void) animatingArc
{
CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:#"arcEnd"];
anim.duration = 20.0; //animate over 20 seconds
anim.repeatCount = 1.0; //animate only once
anim.removedOnCompletion = NO; //Reamin there after completion
//animate from start to end
anim.fromValue = [NSNumber numberWithFloat:50.0f];
anim.toValue = [NSNumber numberWithFloat:150.0f];
//experiment with timing to get appearence to look the way you want
anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
//add animation to circle
[circle addAnimation:anim forKey:#"animatingArc"];
}
/////////////////////
//needed since key not part of animatable properties
+(BOOL) needsDisplayForKey:(NSString *)key
{
if([key isEqualToString:#"arcEnd"])
return YES;
else
return [super needsDisplayForKey:key];
}
//ensure custom properties copied to presentation layer
-(id) initWithLayer:(id)layer
{
if((self = [super initWithLayer:layer]))
{
if ([layer isKindOfClass:[AnimateArc class]])
{
AnimateArc *other = (AnimateArc *) layer;
[other setNeedsDisplay];
}
}
return self; }
And finally in my viewController,
- (void)viewDidLoad
{
[super viewDidLoad];
[self.view.layer addSublayer:AnimateArcObject];
[AnimateArcObject animatingArc];
}
Apology for bad formatting.... Please can someone tell me what am I doing wrong? I have also doubt that my code can crash at any place after accessing those two functions since I am novice about Core Animation and haven't got any idea that I am in right direction or not.
Any help will be appreciated. Thanks.
From my painful experience with CoreAnimation, you must always set the bounds property of any CALayer you instantiate.
So, you're layer is not showing because you are missing something like:
layer.bounds = CGRectMake(0, 0, width, height);
you should place this as soon as you instantiate the layer, and make it a habit to do so, so you don't fall into it again.
As for your code crashing, sorry. It's too distributed and I am not sure how it's linked together, so I can't help you there.
After little searching, I thought that I am going in wrong direction. So I deleted this AnimateArc file and added new one which is inheriting from UIViewController.
Then in viewDidLoad Method, I wrote the code from this link to create circle and animations using path.
In parent view controller, I added AnimatedArc ViewController's subview. Now its working perfectly :)

textFieldShouldReturn is not working in ipad

I am creating an application on IPad. I use a text field with default return key to write message.After writing a message I press return key..Then the keyboard dissappeared, but the method - (BOOL)textFieldShouldReturn:(UITextField *)textField {} does NOT get called. I have some code within the textFieldShouldReturn function...
- (BOOL)textFieldShouldReturn:(UITextField *)textField {
[textField resignFirstResponder];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.3];
if(cPageNavType == CUTSOM_NAV_BAR){
mToolbar.frame = CGRectMake(0, 438, 320, 44);
mTableView.frame = CGRectMake(0, 40, 340, 400);
}else {
mTableView.frame = CGRectMake(0, 0, 340, 480-44-18-28);
mToolbar.frame = CGRectMake(0, 480-44-18-28, 320, 44);
}
[UIView commitAnimations];
//[self postMessage:nil];
return YES;
}
so what can I do? Thanks in advance
Things to check
Add <UITextFieldDelegate> ,make your class receiver of delegate
OfCourse add delegate method(put break points)
Connect the textfield outlets (delegates and referencing outlets if any)

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