making drop shadows on UIViews - ios

I use this code in my customized UIView initialization:
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
// Initialization code
...
UIBezierPath *shadowPath = [UIBezierPath bezierPathWithRect:CGRectMake(frame.origin.x, frame.size.height, frame.size.width, 15)];
self.layer.masksToBounds = NO;
self.layer.shadowColor = [UIColor blackColor].CGColor;
self.layer.shadowOffset = CGSizeMake(0.0f, 4.0f);
self.layer.shadowOpacity = 0.5f;
self.layer.shadowPath = shadowPath.CGPath;
}
return self;
}
trying to make a drop shadow like this:
1)
But I got this effect:
2)
You can see this is an upside down version of what I want to achieve. How to make the shadow effect of the first image?

The issue is just with your shadowPath.
Using CGRectMake(frame.origin.x, frame.size.height, frame.size.width, 15) to create your UIBezierPath will set an incorrect origin.
First, origin.x should be 0.0f or the shadow will shift far away if your UIView's origin.x != 0.0f. Second, you need to line up the bottom of the shadowPath with the bottom of your UIView.
This is a screenshot of UIViews using your shadow code illustrating these issues. (In the lower UIView you cannot see the shadow because it is far off the right of the screen).
You will see what you intended if you change the rect to:
const CGFloat shadowRectHeight = 15.0f;
CGRect shadowRect = CGRectMake(0.0f, self.bounds.size.height - shadowRectHeight, self.bounds.size.width, shadowRectHeight)];

Do like this and set the UIView alpha
CAGradientLayer *gradient = [CAGradientLayer layer];
gradient.frame = rect;
gradient.colors = [NSArray arrayWithObjects:(id)[UIColor blackColor].CGColor,
(id)[UIColor grayColor].CGColor,
(id)[UIColor blackColor].CGColor,nil];
[self.layer insertSublayer:gradient atIndex:0];
you can add or remove UIColor you want to display.

Related

How to add one border line for UIView

I am trying to add border line between 2 UIView, as i researched, the following code can add 4 borders.
CGFloat borderWidth = 5.0f;
self.imgview.frame = CGRectInset(self.imgview. frame, -borderWidth, -borderWidth);
self.imgview. layer.borderColor = [UIColor blueColor].CGColor;
self.imgview. layer.borderWidth = borderWidth;
However, i just need to add one border, any advice? Thanks in advance.
You can add one One more UIView (BorderView) between two UIView (View1 and View2). Give the border view appropriate width and background color.
If you want to set these borders programmatically, you can use the following snippet of code
+(void)SetImageViewBottomBorder :(UIImageView *)imageView{
CALayer *border = [CALayer layer];
CGFloat borderWidth = 1;
border.borderColor = [[self colorWithHexString:#"9B9B9B"] CGColor];
border.frame = CGRectMake(0, imageView.frame.size.height - borderWidth, imageView.frame.size.width, imageView.frame.size.height);
border.borderWidth = borderWidth;
[imageView.layer addSublayer:border];
imageView.userInteractionEnabled = YES;
imageView.layer.masksToBounds = YES;
}
you can replace the UIImageView with UIView and it will be working like a charm.

How to create a gradient perimeter using CALayer

I've been trying for some time now, using CAGradientLayer to produce this .
Initially I tried having a gradient background using the .colors property, however this is only a background fill. Trying this approach, I tried to add another CALayer inside that had a black background, however i could never get the radius correct, and it would create a line of various thickness at the rounded corners.
Is there a better way to create this rounded rect border with a gradient to it? Will CALayer not achieve this and should I move over to UIBezierPath or CGContextRef?
Code for failed attempt:
UIView *view = [[UIView alloc]initWithFrame:CGRectMake(12*twelthWidth - squareCentre.x - squareSize.width, squareCentre.y, squareSize.width, squareSize.height)];
// Create the rounded layer, and mask it using the rounded mask layer
CAGradientLayer *roundedLayer = [CAGradientLayer layer];
[roundedLayer setFrame:view.bounds];
roundedLayer.cornerRadius = view.bounds.size.width/5;
roundedLayer.masksToBounds = YES;
roundedLayer.colors = [NSArray arrayWithObjects:(id)[[UIColor redColor] CGColor], (id)[[UIColor blueColor] CGColor], nil];
roundedLayer.borderWidth = 4;
roundedLayer.borderColor = [UIColor clearColor].CGColor;
// Add these two layers as sublayers to the view
int BorderWidth = 5;
CALayer *solidColour = [CALayer layer];
solidColour.cornerRadius = view.bounds.size.width/5;
solidColour.masksToBounds = YES;
solidColour.backgroundColor = [UIColor blackColor].CGColor;
[solidColour setFrame:CGRectMake(BorderWidth, BorderWidth, roundedLayer.bounds.size.width - 2*BorderWidth, roundedLayer.bounds.size.height - 2*BorderWidth)];
[view.layer insertSublayer:roundedLayer atIndex:0];
[view.layer insertSublayer:solidColour above:roundedLayer];
[self.view addSubview:view];
Which produces:
Whereby the corners aren't right. Could it be that I need to calculate a different radius for the second layer?
Edit
After setting the radius of the solid colour to solidColour.bounds.size.width/5, it still isn't right - It goes too thin at the corners.
The problem you are seeing is because the inner and outer corner radius are the same. That is what causes the line thickness to vary. This illustration from CSS-Tricks highlights the issue (even thought you aren't using CSS, the problem is still the same):
The solution is to calculate the inner radius as:
innerRadis = outerRadius - lineThickness
As shown in this illustration by Joshua Hibbert:
Instead of using the view bounds to set the cornerRadius of the solid layer, use the layer's frame value after you've set it to the correct inset value:
solidColour.masksToBounds = YES;
solidColour.backgroundColor = [UIColor blackColor].CGColor;
[solidColour setFrame:CGRectMake(BorderWidth, BorderWidth, roundedLayer.bounds.size.width - 2*BorderWidth, roundedLayer.bounds.size.height - 2*BorderWidth)];
solidColour.cornerRadius = solidColour.frame.size.width/5;
[view.layer insertSublayer:roundedLayer atIndex:0];
[view.layer insertSublayer:solidColour above:roundedLayer];
With this I get the following image
Just for your convenience if you use swift
let v = yourUIVIEW
let outerRadius:CGFloat = 60
let borderWidth:CGFloat = 8;
let roundedLayer = CAGradientLayer()
roundedLayer.frame = v.bounds
roundedLayer.cornerRadius = outerRadius
roundedLayer.masksToBounds = true
roundedLayer.endPoint = CGPoint(x: 1 , y: 0.5)
roundedLayer.colors = [ UIColor.redColor().CGColor, UIColor.blueColor()!.CGColor]
let innerRadius = outerRadius - borderWidth
//Solid layer
let solidLayer = CALayer()
solidLayer.masksToBounds = true
solidLayer.backgroundColor = UIColor.whiteColor().CGColor
solidLayer.cornerRadius = innerRadius
solidLayer.frame = CGRect(x: borderWidth, y: borderWidth, width: roundedLayer.bounds.width - 2*borderWidth, height:roundedLayer.bounds.height - 2*borderWidth )
v.layer.insertSublayer(roundedLayer, atIndex: 0)
v.layer.insertSublayer(solidLayer, above: roundedLayer)

text with sharp shadow around

I want to achieve the text appearance like in the pictures below:
Now I'm working on shadow around the letters and I can't figure out how to do that.
What I've tried so far:
- The solution with:
label.shadowColor = [UIColor blackColor];
label.shadowOffset = CGSizeMake(1, 2);
gives a nice sharp shadow, but it doesn't fit my needs by two reasons:
It gives a shadow only from one side, set up by shadowOffset, whereas I need a "wrapping" shadow;
This solution doesn't give the soft part of the shadow (gradient) as there is in the pictures;
-The solution with:
label.layer.shadowOffset = CGSizeMake(0, 0);
label.layer.shadowRadius = 5.0;
label.layer.shouldRasterize = YES;
label.layer.shadowOpacity = 1;
label.layer.shadowColor = [UIColor blackColor].CGColor;
label.layer.masksToBounds = NO;
Works great, but it gives too soft shadow even though the shadowOpacity is set to 1 and the shadowColor is set to black:
Obviously it's not enough and I already think about drawing in labels' context. But it is not clear to me how would I achieve the goal even through context drawing.
Any idea would be much appreciated.
Try this
Create a Custom UILabel SubClass and Override the following method
- (void)drawTextInRect:(CGRect)rect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextSaveGState(context);
CGContextSetShadow(context, CGSizeMake(0.0, 0.0), 10);
CGContextSetShadowWithColor(context, CGSizeMake(0.0, 0.0), 10, [UIColor blackColor].CGColor);
[super drawTextInRect:rect];
CGContextRestoreGState(context);
}
and this bottomColorLayer to the Label
CALayer *bottomColorLayer = [CALayer layer];
bottomColorLayer.frame = CGRectMake(0, labelRect.size.height/2, labelRect.size.width, labelRect.size.height/2);
bottomColorLayer.backgroundColor = [[UIColor colorWithWhite:0 alpha:.5] CGColor];
[label.layer insertSublayer:bottomColorLayer above:(CALayer *)label.layer];
or If you want Gradient
CAGradientLayer *bottomGradient = [CAGradientLayer layer];
bottomGradient.frame = CGRectMake(0, labelRect.size.height/2, labelRect.size.width, labelRect.size.height/2);
bottomGradient.cornerRadius = 0.0f;
bottomGradient.colors = #[(id)[[UIColor colorWithWhite:1 alpha:.5] CGColor], (id)[[UIColor colorWithWhite:0 alpha:.5] CGColor]];
[label.layer insertSublayer:bottomGradient above:(CALayer *)label.layer];
Use an explicit shadow path that's the shape you want. It sounds like you want a shadow the same shape as your text, but larger, with each shadow-letter centered on its corresponding letter. Once you have that, use the shadow radius to soften the edges of the shadow to whatever degree you want.
The code you have relies on the shadow radius alone to make the shadow larger than the text, which removes your ability to control the softness.
Try with the code below :-
[_testLable setText:#"TION ERRO"];
[_testLable setTextColor:[UIColor whiteColor]];
[_testLable setFont:[UIFont boldSystemFontOfSize:22] ];
_testLable.layer.shadowOffset = CGSizeMake(0, 0);
_testLable.layer.shadowRadius = 10.0;
_testLable.layer.shouldRasterize = YES;
_testLable.layer.shadowOpacity = 1;
_testLable.layer.shadowColor = [UIColor blackColor].CGColor;
_testLable.layer.masksToBounds = NO;
CGPathRef shadowPath = CGPathCreateWithRect(_testLable.bounds, NULL);
_testLable.layer.shadowPath = shadowPath;
CGPathRelease(shadowPath);
Its output is like this:-

Why does a CAShapeLayer's stroke extend out of the frame?

Here's sample code:
//Called by VC:
HICircleView *circleView = [[HICircleView alloc] initWithFrame:CGRectMake(0, 0, 100, 100)];
// init of circle view
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
CAShapeLayer *borderLayer = [CAShapeLayer layer];
borderLayer.fillColor = [UIColor whiteColor].CGColor;
borderLayer.path = [UIBezierPath bezierPathWithOvalInRect:self.frame].CGPath;
borderLayer.strokeColor = [[UIColor redColor] CGColor];
borderLayer.lineWidth = 5;
[self.layer addSublayer:borderLayer];
}
return self;
}
OK, thanks for the answer. to shift i:
CGRect rect = CGRectMake(3, 3, self.frame.size.width, self.frame.size.height);
borderLayer.path = [UIBezierPath bezierPathWithOvalInRect:rect].CGPath;
And made 6 the line width.
Setting the lineWidth draws a line, where the actual path is exactly in the middle of the drawn line.
If you want the drawn line to line up with something, you will have to shift the path by half the lineWidth.
You can shift the path by using - (void)applyTransform:(CGAffineTransform)transform on UIBezierPath and apply a translate transform.
If you want a drawn path to be contained in a certain area, shifting the path doesn't help. In that case just create a smaller path. If you want to draw a 100ptx100pt rect with a line width of 5, you have to draw a path in a 95pt*95pt rect (2.5pt space on either side).
You'd rather choose your view's bounds property for calculation. Frame property won't work properly if it's origin is greater than (0,0). You can use CGRectInsets to adjust your circle's rectangle instead of performing transform calculations. This will automatically position the rectangle centered within the original rectangle.
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self) {
CAShapeLayer *borderLayer = [CAShapeLayer layer];
borderLayer.fillColor = [UIColor whiteColor].CGColor;
CGFloat lineWidth = 5;
CGRect rect = CGRectInset(self.bounds, lineWidth / 2, lineWidth / 2);
borderLayer.path = [UIBezierPath bezierPathWithOvalInRect:rect].CGPath;
borderLayer.strokeColor = [[UIColor redColor] CGColor];
borderLayer.lineWidth = lineWidth;
[self.layer addSublayer:borderLayer];
}
return self;
}

Add just a top border to an UIView with Quartzcore/layer?

Is it possible to add a border just on top of a UIView, if so, how please?
I just Testing Bellow few line of Code and it works very nice, just test it in to your Project. hope you'll get your solution easily.
Why to create new View and adding it into your existing view..? For this task simply create one CALayer and add it into your existing UIView's Layer do as following:-
#import <QuartzCore/QuartzCore.h>
- (void)viewDidLoad
{
CALayer *TopBorder = [CALayer layer];
TopBorder.frame = CGRectMake(0.0f, 0.0f, myview.frame.size.width, 3.0f);
TopBorder.backgroundColor = [UIColor redColor].CGColor;
[myview.layer addSublayer:TopBorder];
[super viewDidLoad];
}
and It's Output is:-
i've find solution for me, here's the tricks :
CGSize mainViewSize = self.view.bounds.size;
CGFloat borderWidth = 1;
UIColor *borderColor = [UIColor colorWithRed:37.0/255 green:38.0/255 blue:39.0/255 alpha:1.0];
UIView *topView = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, mainViewSize.width, borderWidth)];
topView.opaque = YES;
topView.backgroundColor = borderColor;
topView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin;
[self.view addSubview:topView];
GilbertOOI's answer in Swift 2:
let topBorder: CALayer = CALayer()
topBorder.frame = CGRectMake(0.0, 0.0, myView.frame.size.width, 3.0)
topBorder.backgroundColor = UIColor.redColor().CGColor
myView.layer.addSublayer(topBorder)
Here's a UIView category that lets you add a layer-back or view-backed border on any side of the UIView: UIView+Borders
GilbertOOI's answer in Swift 4:
let topBorder: CALayer = CALayer()
topBorder.frame = CGRect(x: 0, y: 0, width: myView.frame.size.width, height: 1)
topBorder.backgroundColor = UIColor.purple.cgColor
myView.layer.addSublayer(topBorder)
I created this simple UIView subclass so that it works in Interface Builder and works with constraints:
https://github.com/natrosoft/NAUIViewWithBorders
Here's my blog post about it:
http://natrosoft.com/?p=55
-- Basically just drop in a UIView in Interface Builder and change its class type to NAUIViewWithBorders.
-- Then in your VC's viewDidLoad do something like:
/* For a top border only ———————————————- */
self.myBorderView.borderColorTop = [UIColor redColor];
self.myBorderView..borderWidthsAll = 1.0f;
/* For borders with different colors and widths ————————— */
self.myBorderView.borderWidths = UIEdgeInsetsMake(2.0, 4.0, 6.0, 8.0);
self.myBorderView.borderColorTop = [UIColor blueColor];
self.myBorderView.borderColorRight = [UIColor redColor];
self.myBorderView.borderColorBottom = [UIColor greenColor];
self.myBorderView.borderColorLeft = [UIColor darkGrayColor];
Here's a direct link to the .m file so you can see the implementation: NAUIViewWithBorders.m
There is a demo project as well.
remus' answer in Obj-C:
CALayer *topBorder = [CALayer new];
topBorder.frame = CGRectMake(0.0, 0.0, self.frame.size.width, 3.0);
topBorder.backgroundColor = [UIColor redColor].CGColor;
[myView.layer addSublayer:topBorder];
Swift5:
We will write a separate method to add borders to this view. To add borders to this view we will create two layers with the desired thickness. We will set the frame of these two layers to the top and bottom of the view. We will set the desired background color of the borders on these layers and add these layers as subLayers to the view.
func addTopBorders() {
let thickness: CGFloat = 1.0
let topBorder = CALayer()
topBorder.frame = CGRect(x: 0.0, y: 0.0, width:
self.down_view_outlet.frame.size.width, height: thickness)
topBorder.backgroundColor = UIColor.white.cgColor
down_view_outlet.layer.addSublayer(topBorder)
}

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