iOS: understanding frame and views - ios

I am working programmatically an application for iOS based on a ViewController. I am trying to do so programmatically as I want to understand the underlying concepts.
I have created a subclass of UIImageView and initialized this using an image. In the initialization method I added also a second UIImageView as I would like to handle the two differently but be part of the same object. Ultimately I would like to be able to scale the object (and hence the 2 UIImages) according to the device screen resolution (e.g. if resolution is low then I will scale the two images by 50%). I want to do this because I would like to be able to implement a zoom in and zoom out feature as well as supporting multiple resolutions and screen layouts.
Additional information:
The two images have different size (500x500 pixels) and (350x350
pixels).
My questions are:
how do I position the second image exactly in the center of the first? (I used the center property of the main UIImage but I think I got it wrong.. I thought that the center was the exact center of the square but either I am using it incorrectly or there is something I am missing)
are there any negative side effects for using this approach (UIView subclass class containing an additional UIView?) (E.g. Is it going to create confusion when applying transformation algorithms? Does it reduce the randering speed? Or more simply is it a bad design pattern?)
I find it difficult to understand the positioning of the second image. See code snipped below, this is what I use:
CGRect innerButtonFrame = CGRectMake(self.center.x/2, self.center.y/2,innerButtonSelectedImage.size.width,innerButtonSelectedImage.size.height);
Taken from:
-(id) initWithImage:(UIImage *)image
{
if(self = [super initWithImage:image]){
//
self.userInteractionEnabled = true;
// Initialize gesture recognizers
UITapGestureRecognizer *tapInView = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(tapInImageView:)];
[self addGestureRecognizer:tapInView];
UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc] initWithTarget:self action:#selector(longPressInView:)];
[self addGestureRecognizer:longPress];
// Initialize labels
..
// Inner circle image
innerButtonView = [[UIImageView alloc] init];
innerButtonSelectedImage = [UIImage imageNamed:#"inner circle.png"];
CGRect innerButtonFrame = CGRectMake(self.center.x/2, self.center.y/2,innerButtonSelectedImage.size.width,innerButtonSelectedImage.size.height);
innerButtonView.frame = innerButtonFrame;
[innerButtonView setImage:innerButtonSelectedImage];
// Add additional ui components to view
[self addSubview:innerButtonView];
..
[self addSubview:descriptionLabel];
}
return self;
}
EDIT: This is how it looks like if I change the positioning code to the following:
CGRect innerButtonFrame = CGRectMake(0, 0,innerButtonSelectedImage.size.width,innerButtonSelectedImage.size.height);
innerButtonView.frame = innerButtonFrame;
I also don't understand why the image is bigger than the screen.. as the blue one should be 500x500 pixel wide and the screen of the iPhone 6 should be 1334 x 750.

How about:
CGRect innerButtonFrame = CGRectMake(0, 0, innerButtonSelectedImage.size.width,innerButtonSelectedImage.size.height);
innerButtonFrame.center = self.center;

If you need 500*500 circle then add the circle half means Replace 500*500 with 250*250 . And small circle replace 350*350 with 175*175 And solve your problem.
I hope your problem will solve..Enjoy
Thanks..

Related

Zoom and Pan on a UIPageViewController

I have a simple application which consists of a UITableViewController with cells of Languages. When the user clicks a specific language, it brings up a UIPageViewController to show horizontally, 6 images in a pageView. That part is working really well and the images are loading.
I have implemented this, using this tutorial: http://code.tutsplus.com/tutorials/using-scrollstyle-with-uipageviewcontroller--mobile-13551.
I would like to achieve a zoom and pan functionality within this as well now.
I have zoom working with the following code.
CGFloat scale = pinchRecognizer.scale;
self.pageViewController.view.transform = CGAffineTransformScale(self.pageViewController.view.transform, scale, scale);
pinchRecognizer.scale = 1.0;
The problem is that the zoom is always in the centre of the image with no way to pan around the image like you can in a normal Photo on an iOS device.
I have found lots of good tutorials on how to achieve this, like http://iosdeveloperzone.com/2012/07/07/tutorial-all-about-images-part-2-panning-zooming-with-uiscrollview/ as an example. However, my confusion stems from the very first part.
I am loading my UIPageViewController using a NSArray:
self.modelArray = [NSMutableArray arrayWithObjects:[[ImageModel alloc] initWithImageName:#"3facts-english-page1.jpg"], [[ImageModel alloc] initWithImageName:#"3facts-english-page2.jpg"], [[ImageModel alloc] initWithImageName:#"3facts-english-page3.jpg"], nil];
How to I extract each image into a UIImageView?
I can see that fundamentally, I need to have most of this code to enable the Pan:
UIImage* image = [UIImage imageNamed:#"KinkakuJi"];
self.imageView.image = image;
[self.imageView sizeToFit];
self.scrollView.contentSize = image.size;
In my case however, I'm not loading a single UIImage but rather a NSArray. How do I extract the UIImage from the NSArray to make this pan happen?
Any thoughts on this would really be appreciated.

Making transparent Circles in iOs

I want to create a black UIView with transparent circles.
I think about create one view (with black color and transparence 50%), and add multiple circles inside of it, but I don't know how to set the transparence for each. I know how to create a circle View (an example: how to draw a custom uiview that is just a circle iphone-app).
I want to do is something like iShowcase library but with multiple dots:
Any clue? thanks.
SOLVED
I took a look to the code of iShowcase library and I solved my probblem. now, I am working in a library based in iShowcase library.
I will post here when I finish it.
Please have a look of below link hope this will helpful for you.
Link : Here is Answer to set shadow in your view.
Use alpha for your circleView. As in your link example,then add as subviews in yourmainview:
UIView *circleView = [[UIView alloc] initWithFrame:CGRectMake(10,20,100,100)];
circleView.alpha = 0.5;
circleView.layer.cornerRadius = 50;
circleView.backgroundColor = [UIColor whiteColor];
[yourmainview addSubview: circleView];
Btw in your picture I think white circles have 100% alpha. You can use individual alpha for each circleView, or use a randomizer :)
As for updated example why don't you add more buttons and showcase in your h file, synthesize them and use multiple instances .... showcase setupShowcaseForTarget:btn_custom_1 title:#"title" details:#"other"]; ? I think you should modify main classes, becouse what you want are different containerView for multiple views [circles].
Using modifyed iShowcase.m [- (void) calculateRegion], and different views as containers, I was able to make something like: http://tinypic.com/view.php?pic=2iwao6&s=8#.VLPTRqYsRE8 So the answer is: use custom views for multiple showcase [ex [showcase2 setContainerView:self.view2];], then custom frame for each showcase [ showcase2.frame = CGRectMake(0,0,100,100);] I don;t habe time to fine tuning the example, but yes, you can achieve desired result...
I finally solved my question inspired by iShowCase library I did this simple class and Upload to github.
https://github.com/tato469/FVEasyShowCase
Simplest what you can do is to have your main view (black 50% transparant) and add shapes to the mask layer of that.
So basically:
//Set up your main view.
UIView* mainView = [UIView new];
mainView.backgroundColor = [UIColor blackColor];
mainView.alpha = 0.5;
UIView* circle1 = [YourCircleClassHere new];
UIView* circle2 = [YourCircleClassHere new];
UIView* circle3 = [YourCircleClassHere new];
UIView* container = [UIView new];
[UIView addSubview:circle1];
[UIView addSubview:circle2];
[UIView addSubview:circle3];
//Make a new layer to put images in to mask out
CALayer* maskLayer = [CALAyer layer];
//Assign the mask view to the contents layer.
maskLayer.contents = (id)container;
//This will set the mask layer to the top left corner.
maskLayer.frame = CGRectMake(0,0,container.frame.size.width,container.frame.size.height);
//Lastly you assign the layer to the mask layer of the main view.
mainView.layer.mask = maskLayer;
//Applies basically the same as clipToBounds, but a bit reversed..
mainView.layer.mask = true/false;
On a sidenote:
I achieved this with images "contents = (id) [UIImage CGImage]", but I'm sure it should work with UIViews as well.
Also mind some mistakes, since I just wrote this from my mind, also I didn't test this out.. So keep me updated if it works/!works ^_^

How to Clone A UIImageView

I have a UIImageView and I want to make a copy of it and place it somewhere on the screen. How do I do this?
I currently only know how to copy and paste the image manually and make a separate IBOutlet for each one, but this is very inefficient because I want to make a game that generates obstacles (UIImageViews) forever so I can't do it the manual way.
You want to make sure you match all of the properties up as well, like size, clipping, image aspect, opacity, etc.
CGPoint locationOfCloneImageView = CGPointMake(0, 0);//x and y coordinates of where you want your image. (More specifically, the x and y coordinated of where you want the CENTER of your image to be)
UIImageView *cloneImageView = [[UIImageView alloc] initWithImage:originalImageView.image];
cloneImageView.frame = CGRectMake(0, 0, originalImageView.frame.size.width, originalImageView.frame.size.height);//same size as old image view
cloneImageView.alpha = originalImageView.alpha;//same view opacity
cloneImageView.layer.opacity = originalImageView.layer.opacity;//same layer opacity
cloneImageView.clipsToBounds = originalImageView.clipsToBounds;//same clipping settings
cloneImageView.backgroundColor = originalImageView.backgroundColor;//same BG color
cloneImageView.tintColor = originalImageView.tintColor;//matches tint color.
cloneImageView.contentMode = originalImageView.contentMode;//matches up things like aspectFill and stuff.
cloneImageView.highlighted = originalImageView.highlighted;//matches whether it's highlighted or not
cloneImageView.opaque = originalImageView.opaque;//matches can-be-opaque BOOL
cloneImageView.userInteractionEnabled = originalImageView.userInteractionEnabled;//touches are detected or not
cloneImageView.multipleTouchEnabled = originalImageView.multipleTouchEnabled;//multi-touches are detected or not
cloneImageView.autoresizesSubviews = originalImageView.autoresizesSubviews;//matches whether or not subviews resize upon bounds change of image view.
//cloneImageView.hidden = originalImageView.hidden;//commented out because you probably never need this one haha... But if the first one is hidden, so is this clone (if uncommented)
cloneImageView.layer.zPosition = originalImageView.layer.zPosition+1;//places it above other views in the parent view and above the original image. You can also just use `insertSubview: aboveSubview:` in code below to achieve this.
[originalImageView.superview addSubview:cloneImageView];//adds this image view to the same parent view that the other image view is in.
cloneImageView.center = locationOfCloneImageView;//set at start of code.
You will need to create one new UIImageView with its new frame where you want to place it. set its image property of your existing imageView's image, and after that add it to your view.
UIImageView *newImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0,0,50,50)];
newImageView.image = oldImageView.image;
[self.view addSubView:newImageView]

iOS Sprite Kit - SKSpriteNode's .centerRect property not working

I was going through the SpriteKit documentation by Apple and came across a really useful feature that I could use when programming my UI. The problem is I can't get it to work.
Please see this page and scroll down to "Resizing a Sprite" - Apple Docs
I have literally copied the image dimensions and used the same code incase I was doing something wrong. But I always end up with a stretched looking image rather than the correct "end caps" staying the same scale.
I am referring to this code:
SKSpriteNode *button = [SKSpriteNode spriteWithImageNamed:#"stretchable_button.png"];
button.centerRect = CGRectMake(12.0/28.0,12.0/28.0,4.0/28.0,4.0/28.0);
What am I doing wrong? Is there a step I have missed?
EDIT:
Here is the code I have been using. I stripped it of my button class and tried to use it with an SKSPriteNode but still the problem persists. I also changed the image just to make sure it wasnt that. The image im using is a 32x32 at normal size.
SKSpriteNode *button = [SKSpriteNode spriteNodeWithImageNamed:#"Button.png"];
[self addChild:button];
button.position = ccp(200, 200);
button.size = CGSizeMake(128, 64);
button.centerRect = CGRectMake(9/32, 9/32, 14/32, 14/32);
The .centerRect property works as documented if you adjust the sprites .scale property.
Try:
SKTexture *texture = [SKTexture textureWithImageNamed:#"Button.png"];
SKSpriteNode *button = [[SKSpriteNode alloc] initWithTexture:texture];
button.centerRect = CGRectMake(9/32, 9/32, 14/32, 14/32);
[self addChild:button];
button.xScale = 128.0/texture.size.width;
button.yScale = 64.0/texture.size.height;
9/32 is integer division, so the result passed to CGRectMake is zero. Ditto the other three parameters. If you use floating point literals like the example you cite, you might get better results.
Here's a refresh of how exactly this works. By the way, my image size width is 48 pixels and height is 52 pixels, but this doesn't matter at all. Any image can be used:
SKSpriteNode *button = [SKSpriteNode spriteNodeWithImageNamed:#"Button.png"];
//(x, y, width, height). First two values are the four corners of the image that you DON'T want touched/resized (They will just be moved).
//The second two values represent how much of images width & height you want cut out & used as stretching material. Cut out happens from the center of the image.
button.centerRect = CGRectMake(20/button1.frame.size.width, 20/button1.frame.size.height, 5/button1.frame.size.width, 15/button1.frame.size.height);
button.position = CGPointMake(self.frame.size.width/2, self.frame.size.height/2); //Positions sprite in the middle of the screen.
button.xScale = 4; //Resizes width (This is all I needed).
//button.yScale = 2; //Resizes height (Commented out because I didn't need this. You can uncomment if the button needs to be higher).
[self addChild:button];
Read the section called "Resizing a Sprite" in this document: https://developer.apple.com/library/ios/documentation/GraphicsAnimation/Conceptual/SpriteKit_PG/Sprites/Sprites.html#//apple_ref/doc/uid/TP40013043-CH9-SW10
'Figure 2-4 A stretchable button texture' demonstrates how the (x, y, width, height) works.
Based on rwr's answer here is a working init method for a SKSpriteNode. I use this in my own game. Basically you make insets of 10px all around the the output image. And then call it like this:
[[HudBoxScalable alloc] initWithTexture:[atlas textureNamed:#"hud_box_9grid.png"] inset:10 size:CGSizeMake(300, 100) delegate:(id<HudBoxDelegate>)clickedObject];
-(id) initWithTexture:(SKTexture *)texture inset:(float)inset size:(CGSize)size {
if (self=[super initWithTexture:texture]) {
self.centerRect = CGRectMake(inset/texture.size.width,inset/texture.size.height,(texture.size.width-inset*2)/texture.size.width,(texture.size.height-inset*2)/texture.size.height);
self.xScale = size.width/texture.size.width;
self.yScale = size.height/texture.size.height;
}
return self;
}

Shadow in separate view from UIImage for dynamic adjustments

I would like to obtain this effect (http://stackoverflow.com/questions/7023271/how-to-adjust-drop-shadow-dynamically-during-an-uiimageview-rotation) but from a more complex image than just a red square ! If the link ever gets broken, it's a about how to adjust drop shadow dynamically during an UIImageView rotation.
So I tried implementing something but I just can't get the shadow in a separate layer... Here is my code, very simple, but doesn't work:
// here is my code
- (void)viewDidLoad {
[super viewDidLoad];
testView = [[UIImageView alloc] initWithImage: [UIImage imageNamed:#"handNoShadow.png"]];
testViewShadow = [[UIView alloc] initWithFrame:testView.frame];
testViewShadow.layer.shadowPath = [[testView layer] shadowPath];
testViewShadow.layer.shadowOpacity = 1.0;
testViewShadow.layer.shadowOffset = CGSizeMake(10, 10);
testViewShadow.layer.shadowRadius = 5.0;
[self.view addSubview:testViewShadow];
[self.view addSubview:testView];
}
PS: i did #import
I do get an image but no shadow... =(
Any lead, help, code, link... is welcome !
Thanks
possible cause:
your testViewShadow.clipToBounds property is set to YES (should be NO)
your testViewShadow do the drawing of the shadow correctly but another UIView is on top and mask it. Check your Z order. Either the order in Storyboard/Nib file (or the order you added the subviews programmatically). Last in the list (or last one added) is on top. For my app I had to put the UIView that need a shadow last so that no other view mask it.

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