when I select a image, I want an animation from the picker to the mainView(which is the blur area), anybody have a good idea?
Basic Idea:
Create a new temp-ImageView with the selected Image.
add this to the window at the exact position of the original-ImageView.
remove original-ImageView (if you want so)
Move/scale the temp-ImageView over the desired position on the screen.
Add the final-ImageView to the desired position in the blue area.
Remove temp-ImageView.
You will have to do some calculations with - (CGRect)convertRect:(CGRect)rect fromView:(UIView *)view
Not sure, but the Picker may lay in a different window than your blue area.
CGRect destRect; // position in window, height/width need to be flipped, so the size is correct after rotation
// add a ContainerView so rotation-handling is easier, esp. durring moving/scaling
UIView *containerView = [[UIView alloc] initWithFrame:destRect];
// set the frame of the imageView, origin 0/0 so rotation is easy to handle, height/width flipp back
UIImageView *tempImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, destRect.size.height, destRect.size.width)];
// flip layer center as well
[tempImageView setCenter:CGPointMake(camView.center.y, camView.center.x)];
// add the rotation
[tempImageView setTransform:CGAffineTransformMakeRotation(M_PI_2)];
[tempImageView setAutoresizingMask:UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight];
Related
I have a circle image with radius 50, and now I want to put the circyle's center the same as my View's center like this:
- (void)drawRect:(CGRect)rect {
UIImage *arrow = [UIImage imageWithPDFNamed:#"circle" atSize:CGSizeMake(50, 50)];
[arrow drawAtPoint:self.center];
}
But drawAtPoint is not drawing at the center.
I want to know how to locate the center of the image? so I can draw it?
From Apple's documentation for UIImage
This method draws the entire image in the current graphics context,
respecting the image’s orientation setting. In the default coordinate
system, images are situated down and to the right of the specified
point. This method respects any transforms applied to the current
graphics context, however.
So offset the center with half the image width and height to draw the center of the image on the center of your view.
- (void)drawRect:(CGRect)rect {
CGSize imageSize = CGSizeMake(50,50);
UIImage *arrow = [UIImage imageWithPDFNamed:#"circle" atSize:imageSize];
[arrow drawAtPoint:CGPointMake(self.center.x-imageSize.width/2., self.center.y-imageSize.height/2.)];
}
You don't need to draw it, just assign it's center to your view's center
arrowsuperview.center = self.center
Try this. This is how you find the center of a subview inside a view
childView.center = CGPointMake(parentView.bounds.size.width / 2, parentView.bounds.size.height / 2);
try this..
UIImageView *circleImageView = [[UIImageView alloc] initWithFrame:CGRectMake(10, 10, 50, 50)];
circleImageView.image = yourCircleImage;
circleImageView.center = self.view.center;
[circleImageView setContentMode:UIViewContentModeCenter];
[self.view addSubview:circleImageView];
Calculate the center of the UIView using following code and draw the image using the drawAtPoint function.
- (void)drawRect:(CGRect)rect
{
CGPoint ptCenter = {rect.size.width / 2.0f, rect.size.height / 2.0f};
[arrow drawAtPoint:ptCenter];
}
Another simple approach:
You can also achieve the result using storyboard/xib and Auto Layout. Instead of drawing the image in drawRect use an UIImageView to hold your image and position the imageview using Autolayout constraints.
I am trying to implement iOS7 parallax effect. For this purpose I am using standard UIInterpolatingMotionEffect class.
Here is what I am trying to achieve:
Place photo inside UIView. Photo is larger than View's frame (on each side)
Set View's size, and CornerRadius (with masksToBounds = YES)
Move phone and watch parallax effect. Something similar as you are peaking inside hole :)
Almost every tutorial on web is simply moving whole view (by setting center.x) , but I don't know how to move content only (and clip it in same time). I have tried something, but obviously is not working:
Inside viewDidLoad I am doing next:
- (void)viewDidLoad
{
[super viewDidLoad];
_myView.layer.contents = (id) [UIImage imageNamed:#"dog"].CGImage;
_myView.layer.contentsGravity = kCAGravityCenter;
_myView.layer.masksToBounds = YES;
UIInterpolatingMotionEffect *horizontalMotionEffect = [[UIInterpolatingMotionEffect alloc] initWithKeyPath:#"layer.position.x" type:UIInterpolatingMotionEffectTypeTiltAlongHorizontalAxis];
horizontalMotionEffect.minimumRelativeValue = #(-80);
horizontalMotionEffect.maximumRelativeValue = #(80);
[_myView addMotionEffect:horizontalMotionEffect];
}
CALayer don't have addMotionEffect so I am accessing view.
Maybe my approach is not good from start, so if you have some other solution - it will help.
Thank you for any help.
I think a better approach here might just be to use 2 separate views.
The wrapping UIView you have now, sized to what you want with a corner radius and clipsToBounds set to YES.
a UIImageView with the image you want, added as a subview of the UIView.
Then, just apply the motion effect to the image view. This will keep the containing view static and achieve the keyhole effect you are looking for.
So normally when you have a view and you want to add a drop shadow I do something like this:
UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRect:diptic.bounds];
diptic.layer.masksToBounds = NO;
diptic.layer.shadowColor = [UIColor blackColor].CGColor;
diptic.layer.shadowOffset = CGSizeMake(0.0f, 0.0f);
diptic.layer.shadowRadius = 10;
diptic.layer.shadowOpacity = .5f;
diptic.layer.shadowPath = shadowPath.CGPath;
Where diptic is my UIScrollView.
The problem is that because diptic is a scroll view, that I have content in the scroll view that I don't want to be on the screen until they scroll to it, so I want to have masksToBounds set to YES but if I do that then I can't see my shadow..
you can see the description of the dartboard ("A basically new dartboard...") I want to be hidden until the user scrolls to it. Also, the rounded corners of the diptic isn't clipping the square corners on the top of the image.
Is there any way to be selective of what is masked and what isn't?
Put diptic into another view with the same bounds, that way you can mask diptic to bounds but apply the shadow to the containing view that wouldn't have its content masked to its bounds.
I have created mainView objcet of UIView and added one subview on it. I applied transform on mainView for reducing frame size. But frame of subview of mainView was not reduced. How to reduce the size of this subview.
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
CGFloat widthM=1200.0;
CGFloat heightM=1800.0;
UIView *mainView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, widthM, heightM)];
mainView.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:#"te.png"]];
[self.view addSubview:mainView];
CGFloat yourDesiredWidth = 250.0;
CGFloat yourDesiredHeight = yourDesiredWidth *heightM/widthM;
CGAffineTransform scalingTransform;
scalingTransform = CGAffineTransformMakeScale(yourDesiredWidth/mainView.frame.size.width, yourDesiredHeight/mainView.frame.size.height);
mainView.transform = scalingTransform;
mainView.center = self.view.center;
NSLog(#"mainView:%#",mainView);
UIView *subMainView= [[UIView alloc] initWithFrame:CGRectMake(100, 100, 1000, 1200)];
subMainView.backgroundColor = [UIColor redColor];
[mainView addSubview:subMainView];
NSLog(#"subMainView:%#",subMainView);
}
NSlog of these views:
mainView:<UIView: 0x8878490; frame = (35 62.5; 250 375); transform = [0.208333, 0, 0, 0.208333, 0, 0]; layer = <CALayer: 0x8879140>>
subMainView:<UIView: 0x887b8c0; frame = (100 100; 1000 1200); layer = <CALayer: 0x887c160>>
Here the width of mainView is 250, the width of subview is 1000. but when i get the output in simulator, subview is occupied correctly, but it's not cross the mainView. How it is possible? How to get frame of subview with respect mainView frame after transformation?
What you're seeing is expected behavior. The frame of an UIView is relative to its parent, so it doesn't change when you apply a transformation to its superview. While the view will appear 'distorted' too, the frame won't reflect the changes since it's still at exact the same position relative to its parent.
However, I assume you would like to get the frame of the view relative to the topmost UIView. In that case UIKit offers these functions:
– [UIView convertPoint:toView:]
– [UIView convertPoint:fromView:]
– [UIView convertRect:toView:]
– [UIView convertRect:fromView:]
I applied these to your example:
CGRect frame = [[self view] convertRect:[subMainView frame] fromView:mainView];
NSLog(#"subMainView:%#", NSStringFromCGRect(frame));
And this is the output:
subMainView:{{55.8333, 83.3333}, {208.333, 250}}
In addition to s1m0n answer, the beautiful thing about applying a transform matrix to your view, is that you can keep reasoning in terms of its original coordinate system (in your case, you can handle subMainView using the non-transformed coordinate system, which is why, even though subMainView's frame is bigger than mainView's transformed frame, it still doesn't cross the parent view, as it gets automatically transformed). This means that when you have a transformed parent view (for example rotated and scaled) and you want to add a subview in a particular point relative to this parent view, you don't have to first keep track of the previous transformations in order to do so.
If you really are interested in knowing the subview's frame in terms of the transformed coordinate system, it will be enough to apply the same transformation to the subview's rectangle with:
CGRect transformedFrame = CGRectApplyAffineTransform(subMainView.frame, mainView.transform);
If you then NSLog this CGRect, you will obtain:
Transformed frame: {{20.8333, 20.8333}, {208.333, 250}}
Which, I believe, are the values that you were looking for. I hope this answers your question!
What is the best way to go about making an app that does the following: the user taps at locations, and on the locations, a square is drawn. There is no way to erase the squares. You simply tap wherever you want and squares of a predefined size are drawn.
I was thinking to make a custom UIView and override the drawRect method by keeping a list of all the (x,y) locations of the squares and then calling [customView setNeedsDisplay] and drawing all the squares everytime a new square is drawn.
Is there a better way?
In Java, I would use an offscreen image, draw the square onto the offscreen image, and then draw the image onto the screen on every repaint() call. But, is this good to do for iPad? If so, what is code that will let me initialize a UIImage and draw a square onto it?
You could just add an empty UIView, which you only set the background color on, and then add it to the view you are tapping.
Example of adding a yellow square in the viewcontroller's viewDidLoad
- (void)viewDidLoad
{
[super viewDidLoad];
UIView *square = [[UIView alloc] initWithFrame:CGRectMake(30, 30, 30, 30)];
square.backgroundColor = [UIColor yellowColor];
[self.view addSubview:square];
[square release];
}
Note: You can also give each square an id in its tag and later retrieve them with viewWithTag: from their superview (i.e. self.view from the controller)