UIImageView's shadow gets bigger than intended when shadowPath is set - iphone

CGRect rect = biggerImageView.bounds;
if([biggerImageView.layer respondsToSelector:#selector(setShadowColor:)])
{
float shadowOffset = rect.size.width * 0.02;
biggerImageView.layer.shadowColor = [UIColor colorWithWhite: 0.25 alpha: 0.55].CGColor;
biggerImageView.layer.shadowOffset = CGSizeMake(shadowOffset, shadowOffset);
biggerImageView.layer.shadowOpacity = 0.8;
// biggerImageView.layer.shadowPath = [UIBezierPath bezierPathWithRect: rect].CGPath;
}
The commented out line causes the shadow becomes bigger than intended.
(vertically longer shadows on top and bottom)
I looked up CALayer reference but got no clue there.

That is probably because the UIView bounds is not the real one yet. (Like in awakeFromNib or viewDidLoad)
Wait for the view layoutSubviews or viewController viewWillLayoutSubviews to be called, and update the path of your shadow there.
I created this swift extension to add the same shadow (with cornerRadius support) everywhere I need to :
import UIKit
extension UIView {
/// Call this from `layoutSubviews` or `viewWillLayoutSubviews`.
/// The shadow will be the same color as this view background.
func layoutShadow() {
// Update frame
if let shadowView = superview?.viewWithTag(978654123) {
shadowView.frame = frame
shadowView.layer.shadowPath = UIBezierPath(roundedRect: bounds, cornerRadius: layer.cornerRadius).cgPath
return
}
// Create the shadow the first time
let shadowView = UIView(frame: frame)
shadowView.tag = 978654123
shadowView.translatesAutoresizingMaskIntoConstraints = false
superview?.insertSubview(shadowView, belowSubview: self)
shadowView.layer.shadowColor = (backgroundColor ?? UIColor.black).cgColor
shadowView.layer.shadowOpacity = 0.8
shadowView.layer.shadowOffset = CGSize(width: -2.0, height: 4.0)
shadowView.layer.shadowRadius = 4.0
shadowView.layer.shadowPath = UIBezierPath(roundedRect: bounds, cornerRadius: layer.cornerRadius).cgPath
}
}

Related

CAGradientLayer not fit perfectly on UITableViewCell bounds

i am developing simple UITableView with custom UITableViewCell with Xib file
i have added MainView and pin it to ContentView in order to add all my views inside MainView
as shown below
UITableViewCell layout
when i try to add CAGradientLayer to MainView it doesnt fit perfectly on mainView bounds as i show below
whats happening on simulator
i use this piece of code to add CAGradientLayer
override func awakeFromNib() {
super.awakeFromNib()
let gradient = CAGradientLayer()
mainView.layer.cornerRadius = 10
gradient.frame = mainView.frame
gradient.colors = [ColorCompatibility.gradEnd.cgColor, ColorCompatibility.gradStart.cgColor]
gradient.endPoint = CGPoint(x: 0.5, y: 1)
gradient.startPoint = CGPoint(x: 0.5, y: 0)
// gradient.cornerRadius = 20
gradient.shadowColor = ColorCompatibility.systemBackground.cgColor
gradient.shadowOpacity = 0.8
gradient.shadowOffset = .zero
gradient.shadowRadius = 5
gradient.shadowPath = UIBezierPath(roundedRect: mainView.layer.bounds, cornerRadius: 20).cgPath
gradient.shouldRasterize = true
gradient.rasterizationScale = UIScreen.main.scale
contentView.layer.insertSublayer(gradient, at: 0)
}
how can i fix this?
Two issues here. The first is that in awakeFromNib the cell (and its content view) most likely doesn't have the correct frame so you could use another life cycle hook where the frame is correct but then you would run into problems when the device is rotated so the cell frame changes at runtime.
I would suggest to update the gradient layers frame in layoutSublayers(of:). Let's assume you created a property for the layer called gradient:
override func layoutSublayers(of layer: CALayer) {
super.layoutSublayers(of: layer)
gradient.frame = mainView.bounds
}

How can i achieve this kind of corner redius with shadow view iOS swift?

I am trying to make a design which have top left corner radius and bottom right corner radius with shadow. I am able to make shadow also corner radius around the view.But when i am trying to give corner radius only to side shadow or radius is not showing. Hare what i have done
extension UIview {
//corner radius function
func roundCornersForView(corners:UIRectCorner, radius: CGFloat) {
DispatchQueue.main.async {
let path = UIBezierPath(roundedRect: self.bounds,
byRoundingCorners: corners,
cornerRadii: CGSize(width: radius, height: radius))
let maskLayer = CAShapeLayer()
maskLayer.frame = self.bounds
maskLayer.path = path.cgPath
self.layer.mask = maskLayer
}
}
func setShadow(){
self.layer.masksToBounds = false
// set the shadow properties
self.layer.shadowColor = UIColor.black.cgColor
self.layer.shadowOffset = CGSize(width: 0, height: 1.0)
self.layer.shadowOpacity = 0.2
self.layer.shadowRadius = 4.0
self.roundCornersForView(corners: [.topLeft, .bottomRight], radius: 20)
}
}
/// finally call it table cell
cell?.BackView.setShadow()
here is the design what i want to do
1) Why write a separate function to draw rect and then apply cornerRadius mask to your view? Replace the function's contents with:
yourView.layer.masksToBounds = true
yourView.layer.cornerRadius = 20
yourView.layer.maskedCorners = [.layerMinXMinYCorner, .layerMaxXMaxYCorner]
2) Once you mask your view's corners and set its masksToBounds property to true, you can set shadow to the view's layer and it will automatically wrap around the rounded corners as you desire:-
yourView.layer.shadowOffset = CGSize(width: 0, height: -0.5)
yourView.layer.shadowRadius = 1
yourView.layer.shadowColor = UIColor(red:0.01, green:0.05, blue:0.09, alpha:0.18).cgColor
yourView.layer.shadowOpacity = 0.8
3) It's advised to play with your cell's UI attributes(a subview's cornerRadius and shadow in your case) in the cell class's awakeFromNib() or an init() method rather than in your delegate methods as they get called a lot of times and hence break the whole point of reusability
Have tested the code to apply shadow and it works fine for me. Hope this helps!

UIBezierPath: How to add a border around a view with rounded corners?

I am using UIBezierPath to have my imageview have round corners but I also want to add a border to the imageview. Keep in mind the top is a uiimage and the bottom is a label.
Currently using this code produces:
let rectShape = CAShapeLayer()
rectShape.bounds = myCell2.NewFeedImageView.frame
rectShape.position = myCell2.NewFeedImageView.center
rectShape.path = UIBezierPath(roundedRect: myCell2.NewFeedImageView.bounds,
byRoundingCorners: .TopRight | .TopLeft,
cornerRadii: CGSize(width: 25, height: 25)).CGPath
myCell2.NewFeedImageView.layer.mask = rectShape
I want to add a green border to that but I cant use
myCell2.NewFeedImageView.layer.borderWidth = 8
myCell2.NewFeedImageView.layer.borderColor = UIColor.greenColor().CGColor
because it cuts off the top left and top right corner of the border as seen in this image:
Is there a way too add in a border with UIBezierPath along with my current code?
You can reuse the UIBezierPath path and add a shape layer to the view. Here is an example inside a view controller.
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Create a view with red background for demonstration
let v = UIView(frame: CGRectMake(0, 0, 100, 100))
v.center = view.center
v.backgroundColor = UIColor.redColor()
view.addSubview(v)
// Add rounded corners
let maskLayer = CAShapeLayer()
maskLayer.frame = v.bounds
maskLayer.path = UIBezierPath(roundedRect: v.bounds, byRoundingCorners: .TopRight | .TopLeft, cornerRadii: CGSize(width: 25, height: 25)).CGPath
v.layer.mask = maskLayer
// Add border
let borderLayer = CAShapeLayer()
borderLayer.path = maskLayer.path // Reuse the Bezier path
borderLayer.fillColor = UIColor.clearColor().CGColor
borderLayer.strokeColor = UIColor.greenColor().CGColor
borderLayer.lineWidth = 5
borderLayer.frame = v.bounds
v.layer.addSublayer(borderLayer)
}
}
The end result looks like this.
Note that this only works as expected when the view's size is fixed. When the view can resize, you will need to create a custom view class and resize the layers in layoutSubviews.
As it says above:
It is not easy to do this perfectly.
Here's a drop-in solution.
This
correctly addresses the issue that you are drawing HALF OF THE BORDER LINE
is totally usable in autolayout
completely re-works itself when the size of the view changes or animates
is totally IBDesignable - you can see it in realtime in your storyboard
for 2019 ...
#IBDesignable
class RoundedCornersAndTrueBorder: UIView {
#IBInspectable var cornerRadius: CGFloat = 10 {
didSet { setup() }
}
#IBInspectable var borderColor: UIColor = UIColor.black {
didSet { setup() }
}
#IBInspectable var trueBorderWidth: CGFloat = 2.0 {
didSet { setup() }
}
override func layoutSubviews() {
setup()
}
var border:CAShapeLayer? = nil
func setup() {
// make a path with round corners
let path = UIBezierPath(
roundedRect: self.bounds, cornerRadius:cornerRadius)
// note that it is >exactly< the size of the whole view
// mask the whole view to that shape
// note that you will ALSO be masking the border we'll draw below
let mask = CAShapeLayer()
mask.path = path.cgPath
self.layer.mask = mask
// add another layer, which will be the border as such
if (border == nil) {
border = CAShapeLayer()
self.layer.addSublayer(border!)
}
// IN SOME APPROACHES YOU would INSET THE FRAME
// of the border-drawing layer by the width of the border
// border.frame = bounds.insetBy(dx: borderWidth, dy: borderWidth)
// so that when you draw the line, ALL of the WIDTH of the line
// DOES fall within the actual mask.
// here, we will draw the border-line LITERALLY ON THE EDGE
// of the path. that means >HALF< THE LINE will be INSIDE
// the path and HALF THE LINE WILL BE OUTSIDE the path
border!.frame = bounds
let pathUsingCorrectInsetIfAny =
UIBezierPath(roundedRect: border!.bounds, cornerRadius:cornerRadius)
border!.path = pathUsingCorrectInsetIfAny.cgPath
border!.fillColor = UIColor.clear.cgColor
// the following is not what you want:
// it results in "half-missing corners"
// (note however, sometimes you do use this approach):
//border.borderColor = borderColor.cgColor
//border.borderWidth = borderWidth
// this approach will indeed be "inside" the path:
border!.strokeColor = borderColor.cgColor
border!.lineWidth = trueBorderWidth * 2.0
// HALF THE LINE will be INSIDE the path and HALF THE LINE
// WILL BE OUTSIDE the path. so MAKE IT >>TWICE AS THICK<<
// as requested by the consumer class.
}
}
So that's it.
Beginner help for the question in the comments ...
Make a "new Swift file" called "Fattie.swift". (Note, funnily enough it actually makes no difference what you call it. If you are at the stage of "don't know how to make a new file" seek basic Xcode tutorials.)
Put all of the above code in the file
You've just added a class "RoundedCornersAndTrueBorder" to your project.
On your story board. Add an ordinary UIView to your scene. In fact, make it actually any size/shape whatsoever, anything you prefer.
Look at the Identity Inspector. (If you do not know what that is, seek basic tutorials.) Simply change the class to "RoundedCornersAndTrueBorder". (Once you start typing "Roun...", it will guess which class you mean.
You're done - run the project.
Note that you have to, of course, add complete and correct constraints to the UIView, just as with absolutely anything you do in Xcode. Enjoy!
Similar solutions:
https://stackoverflow.com/a/57465440/294884 - image + rounded + shadows
https://stackoverflow.com/a/41553784/294884 - two-corner problem
https://stackoverflow.com/a/59092828/294884 - "shadows + hole" or "glowbox" problem
https://stackoverflow.com/a/57400842/294884 - the "border AND gap" problem
https://stackoverflow.com/a/57514286/294884 - basic "adding" beziers
And please also see the alternate answer below! :)
Absolutely perfect 2019 solution
Without further ado, here's exactly how you do this.
Don't actually use the "basic" layer that comes with the view
Make a new layer only for the image. You can now mask this (circularly) without affecting the next layer
Make a new layer for the border as such. It will safely not be masked by the picture layer.
The key facts are
With a CALayer, you can indeed apply a .mask and it only affects that layer
When drawing a circle (or indeed any border), have to attend very carefully to the fact that you only get "half the width" - in short never crop using the same path you draw with.
Notice the original cat image is exactly as wide as the horizontal yellow arrow. You have to be careful to paint the image so that the whole image appears in the roundel, which is smaller than the overall custom control.
So, setup in the usual way
import UIKit
#IBDesignable class GreenCirclePerson: UIView {
#IBInspectable var borderColor: UIColor = UIColor.black { didSet { setup() } }
#IBInspectable var trueBorderThickness: CGFloat = 2.0 { didSet { setup() } }
#IBInspectable var trueGapThickness: CGFloat = 2.0 { didSet { setup() } }
#IBInspectable var picture: UIImage? = nil { didSet { setup() } }
override func layoutSubviews() { setup() }
var imageLayer: CALayer? = nil
var border: CAShapeLayer? = nil
func setup() {
if (imageLayer == nil) {
imageLayer = CALayer()
self.layer.addSublayer(imageLayer!)
}
if (border == nil) {
border = CAShapeLayer()
self.layer.addSublayer(border!)
}
Now carefully make the layer for the circularly-cropped image:
// the ultimate size of our custom control:
let box = self.bounds.aspectFit()
let totalInsetOnAnyOneSide = trueBorderThickness + trueGapThickness
let boxInWhichImageSits = box.inset(by:
UIEdgeInsets(top: totalInsetOnAnyOneSide, left: totalInsetOnAnyOneSide,
bottom: totalInsetOnAnyOneSide, right: totalInsetOnAnyOneSide))
// just a note. that version of inset#by is much clearer than the
// confusing dx/dy variant, so best to use that one
imageLayer!.frame = boxInWhichImageSits
imageLayer!.contents = picture?.cgImage
imageLayer?.contentsGravity = .resizeAspectFill
let halfImageSize = boxInWhichImageSits.width / 2.0
let maskPath = UIBezierPath(roundedRect: imageLayer!.bounds,
cornerRadius:halfImageSize)
let maskLayer = CAShapeLayer()
maskLayer.path = maskPath.cgPath
imageLayer!.mask = maskLayer
Next as a completely separate layer, draw the border as you wish:
// now create the border
border!.frame = bounds
// To draw the border, you must inset it by half the width of the border,
// otherwise you'll be drawing only half the border. (Indeed, as an additional
// subtle problem you are clipping rather than rendering the outside edge.)
let halfWidth = trueBorderThickness / 2.0
let borderCenterlineBox = box.inset(by:
UIEdgeInsets(top: halfWidth, left: halfWidth,
bottom: halfWidth, right: halfWidth))
let halfBorderBoxSize = borderCenterlineBox.width / 2.0
let borderPath = UIBezierPath(roundedRect: borderCenterlineBox,
cornerRadius:halfBorderBoxSize)
border!.path = borderPath.cgPath
border!.fillColor = UIColor.clear.cgColor
border!.strokeColor = borderColor.cgColor
border!.lineWidth = trueBorderThickness
}
}
Everything works perfectly as in iOS standard controls:
Everything which is invisible is invisible; you can see-through the overall custom control to any material behind, there are no "half thickness" problems or missing image material, you can set the custom control background color in the usual way, etc etc. The inspector controls all work properly. (Phew!)
Similar solutions:
https://stackoverflow.com/a/57465440/294884 - image + rounded + shadows
https://stackoverflow.com/a/41553784/294884 - two-corner problem
https://stackoverflow.com/a/59092828/294884 - "shadows + hole" or "glowbox" problem
https://stackoverflow.com/a/57400842/294884 - the "border AND gap" problem
https://stackoverflow.com/a/57514286/294884 - basic "adding" beziers
**use this extension for round borders and corner**
extension UIView {
func roundCorners(corners: UIRectCorner, radius: CGFloat) {
let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
let mask = CAShapeLayer()
mask.path = path.cgPath
layer.mask = mask
}
func roundCornersWithBorder(corners: UIRectCorner, radius: CGFloat) {
let maskLayer = CAShapeLayer()
maskLayer.frame = bounds
maskLayer.path = UIBezierPath(roundedRect: bounds, byRoundingCorners: [.topLeft, .topRight], cornerRadii: CGSize(width: radius, height: radius)).cgPath
layer.mask = maskLayer
// Add border
let borderLayer = CAShapeLayer()
borderLayer.path = maskLayer.path // Reuse the Bezier path
borderLayer.fillColor = UIColor.clear.cgColor
borderLayer.strokeColor = UIColor(red:3/255, green:33/255, blue:70/255, alpha: 0.15).cgColor
borderLayer.lineWidth = 2
borderLayer.frame = bounds
layer.addSublayer(borderLayer)
}
}
Use like this
myView.roundCornersWithBorder(corners: [.topLeft, .topRight], radius: 8.0)
myView.roundCorners(corners: [.topLeft, .topRight], radius: 8.0)
There sure is! Every view has a layer property (which you know from giving your layer rounded corners). Another two properties on layer are borderColor and borderWidth. Just by setting those you can add a border to your view! (The border will follow the rounded corners.) Be sure to use UIColor.CGColor for borderColor as a plain UIColor won't match the type.

How do you create a DropShadow on a UIView [duplicate]

I'm trying to draw a shadow under the bottom edge of a UIView in Cocoa Touch. I understand that I should use CGContextSetShadow() to draw the shadow, but the Quartz 2D programming guide is a little vague:
Save the graphics state.
Call the function CGContextSetShadow, passing the appropriate values.
Perform all the drawing to which you want to apply shadows.
Restore the graphics state
I've tried the following in a UIView subclass:
- (void)drawRect:(CGRect)rect {
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGContextSaveGState(currentContext);
CGContextSetShadow(currentContext, CGSizeMake(-15, 20), 5);
CGContextRestoreGState(currentContext);
[super drawRect: rect];
}
..but this doesn't work for me and I'm a bit stuck about (a) where to go next and (b) if there's anything I need to do to my UIView to make this work?
A by far easier approach is to set some layer attributes of the view on initialization:
self.layer.masksToBounds = NO;
self.layer.shadowOffset = CGSizeMake(-15, 20);
self.layer.shadowRadius = 5;
self.layer.shadowOpacity = 0.5;
You need to import QuartzCore.
#import <QuartzCore/QuartzCore.h>
self.layer.masksToBounds = NO;
self.layer.cornerRadius = 8; // if you like rounded corners
self.layer.shadowOffset = CGSizeMake(-15, 20);
self.layer.shadowRadius = 5;
self.layer.shadowOpacity = 0.5;
This will slow down the application.
Adding the following line can improve performance as long as your view is visibly rectangular:
self.layer.shadowPath = [UIBezierPath bezierPathWithRect:self.bounds].CGPath;
Same solution, but just to remind you: You can define the shadow directly in the storyboard.
Ex:
In your current code, you save the GState of the current context, configure it to draw a shadow .. and the restore it to what it was before you configured it to draw a shadow. Then, finally, you invoke the superclass's implementation of drawRect: .
Any drawing that should be affected by the shadow setting needs to happen after
CGContextSetShadow(currentContext, CGSizeMake(-15, 20), 5);
but before
CGContextRestoreGState(currentContext);
So if you want the superclass's drawRect: to be 'wrapped' in a shadow, then how about if you rearrange your code like this?
- (void)drawRect:(CGRect)rect {
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGContextSaveGState(currentContext);
CGContextSetShadow(currentContext, CGSizeMake(-15, 20), 5);
[super drawRect: rect];
CGContextRestoreGState(currentContext);
}
You can try this .... you can play with the values.
The shadowRadius dictates the amount of blur. shadowOffset dictates where the shadow goes.
Swift 2.0
let radius: CGFloat = demoView.frame.width / 2.0 //change it to .height if you need spread for height
let shadowPath = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 2.1 * radius, height: demoView.frame.height))
//Change 2.1 to amount of spread you need and for height replace the code for height
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.blackColor().CGColor
demoView.layer.shadowOffset = CGSize(width: 0.5, height: 0.4) //Here you control x and y
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
demoView.layer.masksToBounds = false
demoView.layer.shadowPath = shadowPath.CGPath
Swift 3.0
let radius: CGFloat = demoView.frame.width / 2.0 //change it to .height if you need spread for height
let shadowPath = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 2.1 * radius, height: demoView.frame.height))
//Change 2.1 to amount of spread you need and for height replace the code for height
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.black.cgColor
demoView.layer.shadowOffset = CGSize(width: 0.5, height: 0.4) //Here you control x and y
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
demoView.layer.masksToBounds = false
demoView.layer.shadowPath = shadowPath.cgPath
Example with spread
To create a basic shadow
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.blackColor().CGColor
demoView.layer.shadowOffset = CGSizeMake(0.5, 4.0); //Here your control your spread
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
Basic Shadow example in Swift 2.0
Simple and clean solution using Interface Builder
Add a file named UIView.swift in your project (or just paste this in any file) :
import UIKit
#IBDesignable extension UIView {
/* The color of the shadow. Defaults to opaque black. Colors created
* from patterns are currently NOT supported. Animatable. */
#IBInspectable var shadowColor: UIColor? {
set {
layer.shadowColor = newValue!.CGColor
}
get {
if let color = layer.shadowColor {
return UIColor(CGColor:color)
}
else {
return nil
}
}
}
/* The opacity of the shadow. Defaults to 0. Specifying a value outside the
* [0,1] range will give undefined results. Animatable. */
#IBInspectable var shadowOpacity: Float {
set {
layer.shadowOpacity = newValue
}
get {
return layer.shadowOpacity
}
}
/* The shadow offset. Defaults to (0, -3). Animatable. */
#IBInspectable var shadowOffset: CGPoint {
set {
layer.shadowOffset = CGSize(width: newValue.x, height: newValue.y)
}
get {
return CGPoint(x: layer.shadowOffset.width, y:layer.shadowOffset.height)
}
}
/* The blur radius used to create the shadow. Defaults to 3. Animatable. */
#IBInspectable var shadowRadius: CGFloat {
set {
layer.shadowRadius = newValue
}
get {
return layer.shadowRadius
}
}
}
Then this will be available in Interface Builder for every view in the Utilities Panel > Attributes Inspector :
You can easily set the shadow now.
Notes:
- The shadow won't appear in IB, only at runtime.
- As Mazen Kasser said
To those who failed in getting this to work [...] make sure Clip Subviews (clipsToBounds) is not enabled
I use this as part of my utils. With this we can not only set shadow but also can get a rounded corner for any UIView. Also you could set what color shadow you prefer. Normally black is preferred but sometimes, when the background is non-white you might want something else. Here's what I use -
in utils.m
+ (void)roundedLayer:(CALayer *)viewLayer
radius:(float)r
shadow:(BOOL)s
{
[viewLayer setMasksToBounds:YES];
[viewLayer setCornerRadius:r];
[viewLayer setBorderColor:[RGB(180, 180, 180) CGColor]];
[viewLayer setBorderWidth:1.0f];
if(s)
{
[viewLayer setShadowColor:[RGB(0, 0, 0) CGColor]];
[viewLayer setShadowOffset:CGSizeMake(0, 0)];
[viewLayer setShadowOpacity:1];
[viewLayer setShadowRadius:2.0];
}
return;
}
To use this we need to call this - [utils roundedLayer:yourview.layer radius:5.0f shadow:YES];
Swift 3
extension UIView {
func installShadow() {
layer.cornerRadius = 2
layer.masksToBounds = false
layer.shadowColor = UIColor.black.cgColor
layer.shadowOffset = CGSize(width: 0, height: 1)
layer.shadowOpacity = 0.45
layer.shadowPath = UIBezierPath(rect: bounds).cgPath
layer.shadowRadius = 1.0
}
}
If you would like to use StoryBoard and wouldnt like to keep typing in runtime attributes, you can easily create an extension to views and make them usable in storyboard.
Step 1. create extension
extension UIView {
#IBInspectable var shadowRadius: CGFloat {
get {
return layer.shadowRadius
}
set {
layer.shadowRadius = newValue
}
}
#IBInspectable var shadowOpacity: Float {
get {
return layer.shadowOpacity
}
set {
layer.shadowOpacity = newValue
}
}
#IBInspectable var shadowOffset: CGSize {
get {
return layer.shadowOffset
}
set {
layer.shadowOffset = newValue
}
}
#IBInspectable var maskToBound: Bool {
get {
return layer.masksToBounds
}
set {
layer.masksToBounds = newValue
}
}
}
step 2. you can now use these attributes in storyboard
To those who failed in getting this to work (As myself!) after trying all the answers here, just make sure Clip Subviews is not enabled at the Attributes inspector...
Sketch Shadow Using IBDesignable and IBInspectable in Swift 4
HOW TO USE IT
SKETCH AND XCODE SIDE BY SIDE
CODE
#IBDesignable class ShadowView: UIView {
#IBInspectable var shadowColor: UIColor? {
get {
if let color = layer.shadowColor {
return UIColor(cgColor: color)
}
return nil
}
set {
if let color = newValue {
layer.shadowColor = color.cgColor
} else {
layer.shadowColor = nil
}
}
}
#IBInspectable var shadowOpacity: Float {
get {
return layer.shadowOpacity
}
set {
layer.shadowOpacity = newValue
}
}
#IBInspectable var shadowOffset: CGPoint {
get {
return CGPoint(x: layer.shadowOffset.width, y:layer.shadowOffset.height)
}
set {
layer.shadowOffset = CGSize(width: newValue.x, height: newValue.y)
}
}
#IBInspectable var shadowBlur: CGFloat {
get {
return layer.shadowRadius
}
set {
layer.shadowRadius = newValue / 2.0
}
}
#IBInspectable var shadowSpread: CGFloat = 0 {
didSet {
if shadowSpread == 0 {
layer.shadowPath = nil
} else {
let dx = -shadowSpread
let rect = bounds.insetBy(dx: dx, dy: dx)
layer.shadowPath = UIBezierPath(rect: rect).cgPath
}
}
}
}
OUTPUT
You can use my utility function created for shadow and corner radius as below:
- (void)addShadowWithRadius:(CGFloat)shadowRadius withShadowOpacity:(CGFloat)shadowOpacity withShadowOffset:(CGSize)shadowOffset withShadowColor:(UIColor *)shadowColor withCornerRadius:(CGFloat)cornerRadius withBorderColor:(UIColor *)borderColor withBorderWidth:(CGFloat)borderWidth forView:(UIView *)view{
// drop shadow
[view.layer setShadowRadius:shadowRadius];
[view.layer setShadowOpacity:shadowOpacity];
[view.layer setShadowOffset:shadowOffset];
[view.layer setShadowColor:shadowColor.CGColor];
// border radius
[view.layer setCornerRadius:cornerRadius];
// border
[view.layer setBorderColor:borderColor.CGColor];
[view.layer setBorderWidth:borderWidth];
}
Hope it will help you!!!
Swift 3
self.paddingView.layer.masksToBounds = false
self.paddingView.layer.shadowOffset = CGSize(width: -15, height: 10)
self.paddingView.layer.shadowRadius = 5
self.paddingView.layer.shadowOpacity = 0.5
All Answer all well but I want to add one more point
If you encounter a problem when you have table cells, Deque a new cell there is a mismatch in shadow so in this case, you need to place your shadow code in a layoutSubviews method so that it will behave nicely in all conditions.
-(void)layoutSubviews{
[super layoutSubviews];
[self.contentView setNeedsLayout];
[self.contentView layoutIfNeeded];
[VPShadow applyShadowView:self];
}
or in ViewControllers for specific view place shadow code inside the following method so that it's work well
-(void)viewDidLayoutSubviews{
[super viewDidLayoutSubviews];
[self.viewShadow layoutIfNeeded];
[VPShadow applyShadowView:self.viewShadow];
}
I have modified my shadow implementation for new devs for more generalized form ex:
/*!
#brief Add shadow to a view.
#param layer CALayer of the view.
*/
+(void)applyShadowOnView:(CALayer *)layer OffsetX:(CGFloat)x OffsetY:(CGFloat)y blur:(CGFloat)radius opacity:(CGFloat)alpha RoundingCorners:(CGFloat)cornerRadius{
UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRoundedRect:layer.bounds cornerRadius:cornerRadius];
layer.masksToBounds = NO;
layer.shadowColor = [UIColor blackColor].CGColor;
layer.shadowOffset = CGSizeMake(x,y);// shadow x and y
layer.shadowOpacity = alpha;
layer.shadowRadius = radius;// blur effect
layer.shadowPath = shadowPath.CGPath;
}
For fellow Xamarians, the Xamarin.iOS/C# version of the answer would look like the following:
public override void DrawRect(CGRect area, UIViewPrintFormatter formatter)
{
CGContext currentContext = UIGraphics.GetCurrentContext();
currentContext.SaveState();
currentContext.SetShadow(new CGSize(-15, 20), 5);
base.DrawRect(area, formatter);
currentContext.RestoreState();
}
The main difference is that you acquire an instance of CGContext on which you directly call the appropriate methods.
You can use this Extension to add shadow
extension UIView {
func addShadow(offset: CGSize, color: UIColor, radius: CGFloat, opacity: Float)
{
layer.masksToBounds = false
layer.shadowOffset = offset
layer.shadowColor = color.cgColor
layer.shadowRadius = radius
layer.shadowOpacity = opacity
let backgroundCGColor = backgroundColor?.cgColor
backgroundColor = nil
layer.backgroundColor = backgroundCGColor
}
}
you can call it like
your_Custom_View.addShadow(offset: CGSize(width: 0, height: 1), color: UIColor.black, radius: 2.0, opacity: 1.0)

How do I draw a shadow under a UIView?

I'm trying to draw a shadow under the bottom edge of a UIView in Cocoa Touch. I understand that I should use CGContextSetShadow() to draw the shadow, but the Quartz 2D programming guide is a little vague:
Save the graphics state.
Call the function CGContextSetShadow, passing the appropriate values.
Perform all the drawing to which you want to apply shadows.
Restore the graphics state
I've tried the following in a UIView subclass:
- (void)drawRect:(CGRect)rect {
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGContextSaveGState(currentContext);
CGContextSetShadow(currentContext, CGSizeMake(-15, 20), 5);
CGContextRestoreGState(currentContext);
[super drawRect: rect];
}
..but this doesn't work for me and I'm a bit stuck about (a) where to go next and (b) if there's anything I need to do to my UIView to make this work?
A by far easier approach is to set some layer attributes of the view on initialization:
self.layer.masksToBounds = NO;
self.layer.shadowOffset = CGSizeMake(-15, 20);
self.layer.shadowRadius = 5;
self.layer.shadowOpacity = 0.5;
You need to import QuartzCore.
#import <QuartzCore/QuartzCore.h>
self.layer.masksToBounds = NO;
self.layer.cornerRadius = 8; // if you like rounded corners
self.layer.shadowOffset = CGSizeMake(-15, 20);
self.layer.shadowRadius = 5;
self.layer.shadowOpacity = 0.5;
This will slow down the application.
Adding the following line can improve performance as long as your view is visibly rectangular:
self.layer.shadowPath = [UIBezierPath bezierPathWithRect:self.bounds].CGPath;
Same solution, but just to remind you: You can define the shadow directly in the storyboard.
Ex:
In your current code, you save the GState of the current context, configure it to draw a shadow .. and the restore it to what it was before you configured it to draw a shadow. Then, finally, you invoke the superclass's implementation of drawRect: .
Any drawing that should be affected by the shadow setting needs to happen after
CGContextSetShadow(currentContext, CGSizeMake(-15, 20), 5);
but before
CGContextRestoreGState(currentContext);
So if you want the superclass's drawRect: to be 'wrapped' in a shadow, then how about if you rearrange your code like this?
- (void)drawRect:(CGRect)rect {
CGContextRef currentContext = UIGraphicsGetCurrentContext();
CGContextSaveGState(currentContext);
CGContextSetShadow(currentContext, CGSizeMake(-15, 20), 5);
[super drawRect: rect];
CGContextRestoreGState(currentContext);
}
You can try this .... you can play with the values.
The shadowRadius dictates the amount of blur. shadowOffset dictates where the shadow goes.
Swift 2.0
let radius: CGFloat = demoView.frame.width / 2.0 //change it to .height if you need spread for height
let shadowPath = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 2.1 * radius, height: demoView.frame.height))
//Change 2.1 to amount of spread you need and for height replace the code for height
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.blackColor().CGColor
demoView.layer.shadowOffset = CGSize(width: 0.5, height: 0.4) //Here you control x and y
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
demoView.layer.masksToBounds = false
demoView.layer.shadowPath = shadowPath.CGPath
Swift 3.0
let radius: CGFloat = demoView.frame.width / 2.0 //change it to .height if you need spread for height
let shadowPath = UIBezierPath(rect: CGRect(x: 0, y: 0, width: 2.1 * radius, height: demoView.frame.height))
//Change 2.1 to amount of spread you need and for height replace the code for height
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.black.cgColor
demoView.layer.shadowOffset = CGSize(width: 0.5, height: 0.4) //Here you control x and y
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
demoView.layer.masksToBounds = false
demoView.layer.shadowPath = shadowPath.cgPath
Example with spread
To create a basic shadow
demoView.layer.cornerRadius = 2
demoView.layer.shadowColor = UIColor.blackColor().CGColor
demoView.layer.shadowOffset = CGSizeMake(0.5, 4.0); //Here your control your spread
demoView.layer.shadowOpacity = 0.5
demoView.layer.shadowRadius = 5.0 //Here your control your blur
Basic Shadow example in Swift 2.0
Simple and clean solution using Interface Builder
Add a file named UIView.swift in your project (or just paste this in any file) :
import UIKit
#IBDesignable extension UIView {
/* The color of the shadow. Defaults to opaque black. Colors created
* from patterns are currently NOT supported. Animatable. */
#IBInspectable var shadowColor: UIColor? {
set {
layer.shadowColor = newValue!.CGColor
}
get {
if let color = layer.shadowColor {
return UIColor(CGColor:color)
}
else {
return nil
}
}
}
/* The opacity of the shadow. Defaults to 0. Specifying a value outside the
* [0,1] range will give undefined results. Animatable. */
#IBInspectable var shadowOpacity: Float {
set {
layer.shadowOpacity = newValue
}
get {
return layer.shadowOpacity
}
}
/* The shadow offset. Defaults to (0, -3). Animatable. */
#IBInspectable var shadowOffset: CGPoint {
set {
layer.shadowOffset = CGSize(width: newValue.x, height: newValue.y)
}
get {
return CGPoint(x: layer.shadowOffset.width, y:layer.shadowOffset.height)
}
}
/* The blur radius used to create the shadow. Defaults to 3. Animatable. */
#IBInspectable var shadowRadius: CGFloat {
set {
layer.shadowRadius = newValue
}
get {
return layer.shadowRadius
}
}
}
Then this will be available in Interface Builder for every view in the Utilities Panel > Attributes Inspector :
You can easily set the shadow now.
Notes:
- The shadow won't appear in IB, only at runtime.
- As Mazen Kasser said
To those who failed in getting this to work [...] make sure Clip Subviews (clipsToBounds) is not enabled
I use this as part of my utils. With this we can not only set shadow but also can get a rounded corner for any UIView. Also you could set what color shadow you prefer. Normally black is preferred but sometimes, when the background is non-white you might want something else. Here's what I use -
in utils.m
+ (void)roundedLayer:(CALayer *)viewLayer
radius:(float)r
shadow:(BOOL)s
{
[viewLayer setMasksToBounds:YES];
[viewLayer setCornerRadius:r];
[viewLayer setBorderColor:[RGB(180, 180, 180) CGColor]];
[viewLayer setBorderWidth:1.0f];
if(s)
{
[viewLayer setShadowColor:[RGB(0, 0, 0) CGColor]];
[viewLayer setShadowOffset:CGSizeMake(0, 0)];
[viewLayer setShadowOpacity:1];
[viewLayer setShadowRadius:2.0];
}
return;
}
To use this we need to call this - [utils roundedLayer:yourview.layer radius:5.0f shadow:YES];
Swift 3
extension UIView {
func installShadow() {
layer.cornerRadius = 2
layer.masksToBounds = false
layer.shadowColor = UIColor.black.cgColor
layer.shadowOffset = CGSize(width: 0, height: 1)
layer.shadowOpacity = 0.45
layer.shadowPath = UIBezierPath(rect: bounds).cgPath
layer.shadowRadius = 1.0
}
}
If you would like to use StoryBoard and wouldnt like to keep typing in runtime attributes, you can easily create an extension to views and make them usable in storyboard.
Step 1. create extension
extension UIView {
#IBInspectable var shadowRadius: CGFloat {
get {
return layer.shadowRadius
}
set {
layer.shadowRadius = newValue
}
}
#IBInspectable var shadowOpacity: Float {
get {
return layer.shadowOpacity
}
set {
layer.shadowOpacity = newValue
}
}
#IBInspectable var shadowOffset: CGSize {
get {
return layer.shadowOffset
}
set {
layer.shadowOffset = newValue
}
}
#IBInspectable var maskToBound: Bool {
get {
return layer.masksToBounds
}
set {
layer.masksToBounds = newValue
}
}
}
step 2. you can now use these attributes in storyboard
To those who failed in getting this to work (As myself!) after trying all the answers here, just make sure Clip Subviews is not enabled at the Attributes inspector...
Sketch Shadow Using IBDesignable and IBInspectable in Swift 4
HOW TO USE IT
SKETCH AND XCODE SIDE BY SIDE
CODE
#IBDesignable class ShadowView: UIView {
#IBInspectable var shadowColor: UIColor? {
get {
if let color = layer.shadowColor {
return UIColor(cgColor: color)
}
return nil
}
set {
if let color = newValue {
layer.shadowColor = color.cgColor
} else {
layer.shadowColor = nil
}
}
}
#IBInspectable var shadowOpacity: Float {
get {
return layer.shadowOpacity
}
set {
layer.shadowOpacity = newValue
}
}
#IBInspectable var shadowOffset: CGPoint {
get {
return CGPoint(x: layer.shadowOffset.width, y:layer.shadowOffset.height)
}
set {
layer.shadowOffset = CGSize(width: newValue.x, height: newValue.y)
}
}
#IBInspectable var shadowBlur: CGFloat {
get {
return layer.shadowRadius
}
set {
layer.shadowRadius = newValue / 2.0
}
}
#IBInspectable var shadowSpread: CGFloat = 0 {
didSet {
if shadowSpread == 0 {
layer.shadowPath = nil
} else {
let dx = -shadowSpread
let rect = bounds.insetBy(dx: dx, dy: dx)
layer.shadowPath = UIBezierPath(rect: rect).cgPath
}
}
}
}
OUTPUT
You can use my utility function created for shadow and corner radius as below:
- (void)addShadowWithRadius:(CGFloat)shadowRadius withShadowOpacity:(CGFloat)shadowOpacity withShadowOffset:(CGSize)shadowOffset withShadowColor:(UIColor *)shadowColor withCornerRadius:(CGFloat)cornerRadius withBorderColor:(UIColor *)borderColor withBorderWidth:(CGFloat)borderWidth forView:(UIView *)view{
// drop shadow
[view.layer setShadowRadius:shadowRadius];
[view.layer setShadowOpacity:shadowOpacity];
[view.layer setShadowOffset:shadowOffset];
[view.layer setShadowColor:shadowColor.CGColor];
// border radius
[view.layer setCornerRadius:cornerRadius];
// border
[view.layer setBorderColor:borderColor.CGColor];
[view.layer setBorderWidth:borderWidth];
}
Hope it will help you!!!
Swift 3
self.paddingView.layer.masksToBounds = false
self.paddingView.layer.shadowOffset = CGSize(width: -15, height: 10)
self.paddingView.layer.shadowRadius = 5
self.paddingView.layer.shadowOpacity = 0.5
All Answer all well but I want to add one more point
If you encounter a problem when you have table cells, Deque a new cell there is a mismatch in shadow so in this case, you need to place your shadow code in a layoutSubviews method so that it will behave nicely in all conditions.
-(void)layoutSubviews{
[super layoutSubviews];
[self.contentView setNeedsLayout];
[self.contentView layoutIfNeeded];
[VPShadow applyShadowView:self];
}
or in ViewControllers for specific view place shadow code inside the following method so that it's work well
-(void)viewDidLayoutSubviews{
[super viewDidLayoutSubviews];
[self.viewShadow layoutIfNeeded];
[VPShadow applyShadowView:self.viewShadow];
}
I have modified my shadow implementation for new devs for more generalized form ex:
/*!
#brief Add shadow to a view.
#param layer CALayer of the view.
*/
+(void)applyShadowOnView:(CALayer *)layer OffsetX:(CGFloat)x OffsetY:(CGFloat)y blur:(CGFloat)radius opacity:(CGFloat)alpha RoundingCorners:(CGFloat)cornerRadius{
UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRoundedRect:layer.bounds cornerRadius:cornerRadius];
layer.masksToBounds = NO;
layer.shadowColor = [UIColor blackColor].CGColor;
layer.shadowOffset = CGSizeMake(x,y);// shadow x and y
layer.shadowOpacity = alpha;
layer.shadowRadius = radius;// blur effect
layer.shadowPath = shadowPath.CGPath;
}
For fellow Xamarians, the Xamarin.iOS/C# version of the answer would look like the following:
public override void DrawRect(CGRect area, UIViewPrintFormatter formatter)
{
CGContext currentContext = UIGraphics.GetCurrentContext();
currentContext.SaveState();
currentContext.SetShadow(new CGSize(-15, 20), 5);
base.DrawRect(area, formatter);
currentContext.RestoreState();
}
The main difference is that you acquire an instance of CGContext on which you directly call the appropriate methods.
You can use this Extension to add shadow
extension UIView {
func addShadow(offset: CGSize, color: UIColor, radius: CGFloat, opacity: Float)
{
layer.masksToBounds = false
layer.shadowOffset = offset
layer.shadowColor = color.cgColor
layer.shadowRadius = radius
layer.shadowOpacity = opacity
let backgroundCGColor = backgroundColor?.cgColor
backgroundColor = nil
layer.backgroundColor = backgroundCGColor
}
}
you can call it like
your_Custom_View.addShadow(offset: CGSize(width: 0, height: 1), color: UIColor.black, radius: 2.0, opacity: 1.0)