UIView bottom border?

Question

To a UIScrollView *toScrollView (which is the width of the screen), I want to add a gray bottom border (exactly like that of the to-field of the compose view of the iPhone's native Messages app).

To achieve this, I followed Cocoa Touch: How To Change UIView's Border Color And Thickness? and just covered the top border with the custom UINavigationBar and made the toScrollView's x-coordinate -1 & width 322 so that the left & right borders are just off screen.

This looks fine, but it's sort of a hack, and I was wondering if there's a better way to do this.

- (void)viewDidLoad {
    [super viewDidLoad];

    // Add UINavigationBar *navigationBar at top.
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]
                                             initWithBarButtonSystemItem:UIBarButtonSystemItemCancel
                                             target:self action:@selector(cancelAction)];
    UINavigationBar *navigationBar = [[UINavigationBar alloc]
                                      initWithFrame:CGRectMake(0.0f, 0.0f, 320.0f, 44.0f)];
    navigationBar.items = [NSArray arrayWithObject:self.navigationItem];

    // Add UIScrollView *toScrollView below navigationBar.
    UIScrollView *toScrollView = [[UIScrollView alloc]
                                  initWithFrame:CGRectMake(-1.0f, 43.0f, 322.0f, 45.0f)];
    toScrollView.backgroundColor = [UIColor whiteColor];
    toScrollView.layer.borderColor = [UIColor colorWithWhite:0.8f alpha:1.0f].CGColor;
    toScrollView.layer.borderWidth = 1.0f;
    [self.view addSubview:toScrollView];
    [self.view addSubview:navigationBar]; // covers top of toScrollView
}

Answer 1

Swift 4 extension with border width and color. Works great!

@IBDesignable
final class SideBorders: UIView {
@IBInspectable var topColor: UIColor = UIColor.clear
@IBInspectable var topWidth: CGFloat = 0

@IBInspectable var rightColor: UIColor = UIColor.clear
@IBInspectable var rightWidth: CGFloat = 0

@IBInspectable var bottomColor: UIColor = UIColor.clear
@IBInspectable var bottomWidth: CGFloat = 0

@IBInspectable var leftColor: UIColor = UIColor.clear
@IBInspectable var leftWidth: CGFloat = 0

override func draw(_ rect: CGRect) {
    let topBorder = CALayer()
    topBorder.backgroundColor = topColor.cgColor
    topBorder.frame = CGRect(x: 0, y: 0, width: self.frame.size.width, height: topWidth)
    self.layer.addSublayer(topBorder)

    let rightBorder = CALayer()
    rightBorder.backgroundColor = rightColor.cgColor
    rightBorder.frame = CGRect(x: self.frame.size.width - rightWidth, y: 0, width: rightWidth, height: self.frame.size.height)
    self.layer.addSublayer(rightBorder)

    let bottomBorder = CALayer()
    bottomBorder.backgroundColor = bottomColor.cgColor
    bottomBorder.frame = CGRect(x: 0, y: self.frame.size.height - bottomWidth, width: self.frame.size.width, height: bottomWidth)
    self.layer.addSublayer(bottomBorder)

    let leftBorder = CALayer()
    leftBorder.backgroundColor = leftColor.cgColor
    leftBorder.frame = CGRect(x: 0, y: self.frame.size.height - leftWidth, width: self.frame.size.width, height: leftWidth)
    self.layer.addSublayer(leftBorder)
}

}

Answer 2

Implemented in a category as below:

UIButton+Border.h:

@interface UIButton (Border)

- (void)addBottomBorderWithColor: (UIColor *) color andWidth:(CGFloat) borderWidth;

- (void)addLeftBorderWithColor: (UIColor *) color andWidth:(CGFloat) borderWidth;

- (void)addRightBorderWithColor: (UIColor *) color andWidth:(CGFloat) borderWidth;

- (void)addTopBorderWithColor: (UIColor *) color andWidth:(CGFloat) borderWidth;

@end

UIButton+Border.m:

@implementation UIButton (Border)

- (void)addTopBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;

    border.frame = CGRectMake(0, 0, self.frame.size.width, borderWidth);
    [self.layer addSublayer:border];
}

- (void)addBottomBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;

    border.frame = CGRectMake(0, self.frame.size.height - borderWidth, self.frame.size.width, borderWidth);
    [self.layer addSublayer:border];
}

- (void)addLeftBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;

    border.frame = CGRectMake(0, 0, borderWidth, self.frame.size.height);
    [self.layer addSublayer:border];
}

- (void)addRightBorderWithColor:(UIColor *)color andWidth:(CGFloat) borderWidth {
    CALayer *border = [CALayer layer];
    border.backgroundColor = color.CGColor;

    border.frame = CGRectMake(self.frame.size.width - borderWidth, 0, borderWidth, self.frame.size.height);
    [self.layer addSublayer:border];
}

@end

Answer 3

I wrote a general method that will add a border on whichever sides you wish in any UIView. You can define thickness, color, margins and zOrder for each side.

/*
 view: the view to draw border around
 thickness: thickness of the border on the given side
 color: color of the border on the given side
 margin: space between the border's outer edge and the view's frame edge on the given side.
 zOrder: defines the order to add the borders to the view.  The borders will be added by zOrder from lowest to highest, thus making the highest priority border visible when two borders overlap at the corners.
*/

    +(void) drawBorderAroundUIView:(UIView *) view thicknessLeft:(CGFloat) thicknessLeft colorLeft:(UIColor *)colorLeft marginLeft:(CGFloat) marginLeft zOrderLeft:(int) zOrderLeft thicknessRight:(CGFloat) thicknessRight colorRight:(UIColor *)colorRight marginRight:(CGFloat) marginRight zOrderRight:(int) zOrderRight thicknessTop:(CGFloat) thicknessTop colorTop:(UIColor *)colorTop marginTop:(CGFloat) marginTop zOrderTop:(int) zOrderTop thicknessBottom:(CGFloat) thicknessBottom colorBottom:(UIColor *)colorBottom marginBottom:(CGFloat) marginBottom zOrderBottom:(int) zOrderBottom{
    //make margins be the outside edge and make positive margin represent a smaller rectangle
    marginBottom = -1 * marginBottom - thicknessBottom;
    marginTop = -1 * marginTop - thicknessTop;
    marginLeft = -1 * marginLeft - thicknessLeft;
    marginRight = -1 * marginRight - thicknessRight;

    //get reference points for corners
    CGPoint upperLeftCorner = CGPointZero;
    CGPoint lowerLeftCorner = CGPointMake(upperLeftCorner.x, upperLeftCorner.y + view.frame.size.height);
    CGPoint upperRightCorner = CGPointMake(upperLeftCorner.x + view.frame.size.width, upperLeftCorner.y);

    //left
    CALayer *leftBorder = [CALayer layer];
    leftBorder.frame = CGRectMake(upperLeftCorner.x - thicknessLeft - marginLeft, upperLeftCorner.y - thicknessTop - marginTop, thicknessLeft, view.frame.size.height + marginTop + marginBottom + thicknessBottom + thicknessTop);
    leftBorder.backgroundColor = colorLeft.CGColor;

    //right
    CALayer *rightBorder = [CALayer layer];
    rightBorder.frame = CGRectMake(upperRightCorner.x + marginRight, upperRightCorner.y - thicknessTop - marginTop, thicknessRight, view.frame.size.height + marginTop + marginBottom + thicknessBottom + thicknessTop);
    rightBorder.backgroundColor = colorRight.CGColor;

    //top
    CALayer *topBorder = [CALayer layer];
    topBorder.frame = CGRectMake(upperLeftCorner.x - thicknessLeft - marginLeft, upperLeftCorner.y - thicknessTop - marginTop, view.frame.size.width + marginLeft + marginRight + thicknessLeft + thicknessRight, thicknessTop);
    topBorder.backgroundColor = colorTop.CGColor;

    //bottom
    CALayer *bottomBorder = [CALayer layer];
    bottomBorder.frame = CGRectMake(upperLeftCorner.x - thicknessLeft - marginLeft, lowerLeftCorner.y + marginBottom, view.frame.size.width + marginLeft + marginRight + thicknessLeft + thicknessRight, thicknessBottom);
    bottomBorder.backgroundColor = colorBottom.CGColor;

    //define dictionary keys to be used for adding borders in order of zOrder
    NSString *borderDK = @"border";
    NSString *zOrderDK = @"zOrder";

    //storing borders in dictionaries in preparation to add them in order of zOrder
    NSDictionary *leftBorderDictionary = [NSDictionary dictionaryWithObjectsAndKeys:leftBorder, borderDK, [NSNumber numberWithInt:zOrderLeft], zOrderDK, nil];
    NSDictionary *rightBorderDictionary = [NSDictionary dictionaryWithObjectsAndKeys:rightBorder, borderDK, [NSNumber numberWithInt:zOrderRight], zOrderDK, nil];
    NSDictionary *topBorderDictionary = [NSDictionary dictionaryWithObjectsAndKeys:topBorder, borderDK, [NSNumber numberWithInt:zOrderTop], zOrderDK, nil];
    NSDictionary *bottomBorderDictionary = [NSDictionary dictionaryWithObjectsAndKeys:bottomBorder, borderDK, [NSNumber numberWithInt:zOrderBottom], zOrderDK, nil];

    NSMutableArray *borders = [NSMutableArray arrayWithObjects:leftBorderDictionary, rightBorderDictionary, topBorderDictionary, bottomBorderDictionary, nil];

    //add borders in order of zOrder (lowest -> highest).  Thus the highest zOrder will be added last so it will be on top.
    while (borders.count)
    {
        //look for the next lowest zOrder border to add
        NSDictionary *nextBorderToLayDown = [borders objectAtIndex:0];
        for (int indexOfBorder = 0; indexOfBorder < borders.count; indexOfBorder++)
        {
            NSDictionary *borderAtIndex = [borders objectAtIndex:indexOfBorder];
            if ([[borderAtIndex objectForKey:zOrderDK] intValue] < [[nextBorderToLayDown objectForKey:zOrderDK] intValue])
            {
                nextBorderToLayDown = borderAtIndex;
            }
        }
        //add the border to the view
        [view.layer addSublayer:[nextBorderToLayDown objectForKey:borderDK]];
        [borders removeObject:nextBorderToLayDown];
    }
}

Answer 4

You can add a separate UIView with 1 point height and gray background color to self.view and position it right below toScrollView.

EDIT: Unless you have a good reason (want to use some services of UIView which are not offered by CALayer), you should use CALayer as @MattDiPasquale suggests. UIView has a greater overhead, which might not be a problem in most cases, but still, the other solution is more elegant.

Answer 5

There is also improved code with remove border functionality. Based on confile answer.

import UIKit

enum viewBorder: String {
    case Left = "borderLeft"
    case Right = "borderRight"
    case Top = "borderTop"
    case Bottom = "borderBottom"
}

extension UIView {

    func addBorder(vBorder: viewBorder, color: UIColor, width: CGFloat) {
        let border = CALayer()
        border.backgroundColor = color.CGColor
        border.name = vBorder.rawValue
        switch vBorder {
            case .Left:
                border.frame = CGRectMake(0, 0, width, self.frame.size.height)
            case .Right:
                border.frame = CGRectMake(self.frame.size.width - width, 0, width, self.frame.size.height)
            case .Top:
                border.frame = CGRectMake(0, 0, self.frame.size.width, width)
            case .Bottom:
                border.frame = CGRectMake(0, self.frame.size.height - width, self.frame.size.width, width)
        }
        self.layer.addSublayer(border)
    }

    func removeBorder(border: viewBorder) {
        var layerForRemove: CALayer?
        for layer in self.layer.sublayers! {
            if layer.name == border.rawValue {
                layerForRemove = layer
            }
        }
        if let layer = layerForRemove {
            layer.removeFromSuperlayer()
        }
    }

}

Update: Swift 3

import UIKit

enum ViewBorder: String {
    case left, right, top, bottom
}

extension UIView {

    func add(border: ViewBorder, color: UIColor, width: CGFloat) {
        let borderLayer = CALayer()
        borderLayer.backgroundColor = color.cgColor
        borderLayer.name = border.rawValue
        switch border {
        case .left:
            borderLayer.frame = CGRect(x: 0, y: 0, width: width, height: self.frame.size.height)
        case .right:
            borderLayer.frame = CGRect(x: self.frame.size.width - width, y: 0, width: width, height: self.frame.size.height)
        case .top:
            borderLayer.frame = CGRect(x: 0, y: 0, width: self.frame.size.width, height: width)
        case .bottom:
            borderLayer.frame = CGRect(x: 0, y: self.frame.size.height - width, width: self.frame.size.width, height: width)
        }
        self.layer.addSublayer(borderLayer)
    }

    func remove(border: ViewBorder) {
        guard let sublayers = self.layer.sublayers else { return }
        var layerForRemove: CALayer?
        for layer in sublayers {
            if layer.name == border.rawValue {
                layerForRemove = layer
            }
        }
        if let layer = layerForRemove {
            layer.removeFromSuperlayer()
        }
    }

}

Answer 6

Swift 4/3

You can use this solution beneath. It works on UIBezierPaths which are lighter than layers, causing quick startup times. It is easy to use, see instructions beneath.

class ResizeBorderView: UIView {
    var color = UIColor.white
    var lineWidth: CGFloat = 1
    var edges = [UIRectEdge](){
        didSet {
            setNeedsDisplay()
        }
    }
    override func draw(_ rect: CGRect) {
        if edges.contains(.top) || edges.contains(.all){
            let path = UIBezierPath()
            path.lineWidth = lineWidth
            color.setStroke()
            UIColor.blue.setFill()
            path.move(to: CGPoint(x: 0, y: 0 + lineWidth / 2))
            path.addLine(to: CGPoint(x: self.bounds.width, y: 0 + lineWidth / 2))
            path.stroke()
        }
        if edges.contains(.bottom) || edges.contains(.all){
            let path = UIBezierPath()
            path.lineWidth = lineWidth
            color.setStroke()
            UIColor.blue.setFill()
            path.move(to: CGPoint(x: 0, y: self.bounds.height - lineWidth / 2))
            path.addLine(to: CGPoint(x: self.bounds.width, y: self.bounds.height - lineWidth / 2))
            path.stroke()
        }
        if edges.contains(.left) || edges.contains(.all){
            let path = UIBezierPath()
            path.lineWidth = lineWidth
            color.setStroke()
            UIColor.blue.setFill()
            path.move(to: CGPoint(x: 0 + lineWidth / 2, y: 0))
            path.addLine(to: CGPoint(x: 0 + lineWidth / 2, y: self.bounds.height))
            path.stroke()
        }
        if edges.contains(.right) || edges.contains(.all){
            let path = UIBezierPath()
            path.lineWidth = lineWidth
            color.setStroke()
            UIColor.blue.setFill()
            path.move(to: CGPoint(x: self.bounds.width - lineWidth / 2, y: 0))
            path.addLine(to: CGPoint(x: self.bounds.width - lineWidth / 2, y: self.bounds.height))
            path.stroke()
        }
    }
}

1. Set your UIView's class to ResizeBorderView
2. Set the color and line width by using yourview.color and yourview.lineWidth in your viewDidAppear method
3. Set the edges, example: yourview.edges = [.right, .left] ([.all]) for all
4. Enjoy quick start and resizing borders