Related
- (void) drawTextLink:(NSString *) text inFrame:(CGRect) frameRect {
CGContextRef context = UIGraphicsGetCurrentContext();
CGAffineTransform ctm = CGContextGetCTM(context);
// Translate the origin to the bottom left.
// Notice that 842 is the size of the PDF page.
CGAffineTransformTranslate(ctm, 0.0, 842);
// Flip the handedness of the coordinate system back to right handed.
CGAffineTransformScale(ctm, 1.0, -1.0);
// Convert the update rectangle to the new coordiante system.
CGRect xformRect = CGRectApplyAffineTransform(frameRect, ctm);
NSURL *url = [NSURL URLWithString:text];
UIGraphicsSetPDFContextURLForRect( url, xformRect );
CGContextSaveGState(context);
NSDictionary *attributesDict;
NSMutableAttributedString *attString;
NSNumber *underline = [NSNumber numberWithInt:NSUnderlineStyleSingle];
attributesDict = #{NSUnderlineStyleAttributeName : underline,
NSForegroundColorAttributeName : [UIColor blueColor]};
attString = [[NSMutableAttributedString alloc] initWithString:url.absoluteString attributes:attributesDict];
[attString drawInRect:frameRect];
CGContextRestoreGState(context);
}
It's code I found to make url's in a pdf clickable.
I'm still getting the hang of objective-c so your help is greatly apprecaited. Thank you very much in advance!
Right now here is what I have translated, and I'm pretty sure there are a couple mistakes:
func drawTextLink(text: NSString, frameRect: CGRect) {
let context: CGContext = UIGraphicsGetCurrentContext()!
var c = context.ctm
let cc = CGAffineTransform.translatedBy(c)
cc.(0.0, 842)
}
Above method in Swift 4.0 should be like this.
func drawTextLink(text: String, frame: CGRect) {
guard let context = UIGraphicsGetCurrentContext() else {return}
let ctm = context.ctm
ctm.translatedBy(x: 0.0, y: 842)
ctm.scaledBy(x: 1.0, y: -1.0)
let newFrame = frame.applying(ctm)
guard let url = URL(string: text) else {return}
UIGraphicsSetPDFContextURLForRect(url, newFrame)
context.saveGState()
let dict = [NSAttributedStringKey.underlineStyle: 1, .foregroundColor: UIColor.red] as [NSAttributedStringKey : Any]
let attrString = NSAttributedString(string: text, attributes: dict)
attrString.draw(in: frame)
context.restoreGState()
}
In my custom view, i have code as below:
- (void)drawRect:(NSRect)dirtyRect {
[super drawRect:dirtyRect];
//Drawing code here.
[self setWantsLayer: YES];
[self.layer setBorderWidth: 1];
[self.layer setBorderColor:[NSColor colorWithRed:205/255.0 green:211/255.0 blue:232/255.0 alpha:1.0].CGColor];
[self.layer setCornerRadius: 10];
}
This is OK to set border line and color for my NSView, but i want to set a dash line, anyone know how to do this?
And i tried some codes from the web search, but it doens't draw a border at all.
- (void)drawRect:(NSRect)dirtyRect {
[super drawRect:dirtyRect];
// Drawing code here.
CGFloat dashPattern[] = {10,4}; //make your pattern here
NSBezierPath *textViewSurround = [NSBezierPath bezierPathWithRoundedRect:self.frame xRadius:10 yRadius:10];
[textViewSurround setLineWidth:2.0f];
[textViewSurround setLineDash:dashPattern count:2 phase:0];
[[NSColor colorWithRed:205/255.0 green:211/255.0 blue:232/255.0 alpha:1.0] set];
[textViewSurround stroke];
}
here is a complete example using a subclass of NSView in Swift 3:
class BorderedView: NSView {
override func draw(_ dirtyRect: NSRect) {
super.draw(dirtyRect)
// dash customization parameters
let dashHeight: CGFloat = 3
let dashLength: CGFloat = 10
let dashColor: NSColor = .red
// setup the context
let currentContext = NSGraphicsContext.current()!.cgContext
currentContext.setLineWidth(dashHeight)
currentContext.setLineDash(phase: 0, lengths: [dashLength])
currentContext.setStrokeColor(dashColor.cgColor)
// draw the dashed path
currentContext.addRect(bounds.insetBy(dx: dashHeight, dy: dashHeight))
currentContext.strokePath()
}
}
In case you want to setup line border with CAShapeLayer (Swift 4.2):
class StrokeWithDashedLineView: NSView {
private let shapeLayer = CAShapeLayer()
private let fillLayer = CALayer()
private let textLabel = NSTextField().autolayoutView()
override init(frame frameRect: NSRect) {
super.init(frame: frameRect)
setupUI()
setupLayout()
}
required init?(coder decoder: NSCoder) {
fatalError()
}
override var intrinsicContentSize: NSSize {
return CGSize(intrinsicHeight: 76)
}
override func layout() {
super.layout()
updateLayers()
}
private func updateLayers() {
layer?.cornerRadius = 0.5 * bounds.height // Making ourselves rounded.
// Stroke Layer
let shapeBounds = CGRect(width: bounds.width - shapeLayer.lineWidth, height: bounds.height - shapeLayer.lineWidth)
let shapeRadius = 0.5 * shapeBounds.height
let path = CGMutablePath()
path.addRoundedRect(in: shapeBounds, cornerWidth: shapeRadius, cornerHeight: shapeRadius)
shapeLayer.path = path
shapeLayer.bounds = shapeBounds
shapeLayer.position = CGPoint(x: 0.5 * shapeLayer.lineWidth, y: 0.5 * shapeLayer.lineWidth)
// Fill Layer
let fillBounds = CGRect(width: bounds.width - 2 * shapeLayer.lineWidth, height: bounds.height - 2 * shapeLayer.lineWidth)
fillLayer.cornerRadius = 0.5 * fillBounds.height
fillLayer.bounds = fillBounds
fillLayer.position = CGPoint(x: shapeLayer.lineWidth, y: shapeLayer.lineWidth)
}
private func setupUI() {
wantsLayer = true
layer?.masksToBounds = true
shapeLayer.lineWidth = 3
shapeLayer.strokeColor = NSColor.red.cgColor
shapeLayer.fillColor = nil
shapeLayer.lineDashPattern = [11.2, 11.2]
shapeLayer.lineCap = .round
shapeLayer.anchorPoint = .zero
fillLayer.backgroundColor = NSColor.yellow.cgColor
fillLayer.anchorPoint = .zero
layer?.addSublayer(shapeLayer)
layer?.addSublayer(fillLayer)
addSubview(textLabel)
textLabel.text = "Drag Xib or Storyboard files onto\nthis window to open them"
textLabel.alignment = .center
textLabel.textColor = .black
textLabel.font = NSFont.semibold(size: 13)
textLabel.isEditable = false
textLabel.drawsBackground = false
textLabel.isBezeled = false
}
private func setupLayout() {
textLabel.centerXAnchor.constraint(equalTo: centerXAnchor).activate()
textLabel.centerYAnchor.constraint(equalTo: centerYAnchor).activate()
}
}
Result:
You can do this through CGContext Here is an answer that worked for me:
how to make dashed line moveable
And my result:
You can do this like,
[yourView.layer setBorderWidth:5.0];
[yourView.layer setBorderColor:[[UIColor colorWithPatternImage:[UIImage imageNamed:#"DotedImage.png"]] CGColor]];
Add dashed image in project and import QuartzCore/QuartzCore.hin project,
#import <QuartzCore/QuartzCore.h>
Update :
Image size and View size should be same.
On UIView you can change the backgroundColour animated. And on a UISlideView you can change the value animated.
Can you add a custom property to your own UIView subclass so that it can be animated?
If I have a CGPath within my UIView then I can animate the drawing of it by changing the percentage drawn of the path.
Can I encapsulate that animation into the subclass.
i.e. I have a UIView with a CGPath that creates a circle.
If the circle is not there it represents 0%. If the circle is full it represents 100%. I can draw any value by changing the percentage drawn of the path. I can also animate the change (within the UIView subclass) by animating the percentage of the CGPath and redrawing the path.
Can I set some property (i.e. percentage) on the UIView so that I can stick the change into a UIView animateWithDuration block and it animate the change of the percentage of the path?
I hope I have explained what I would like to do well.
Essentially, all I want to do is something like...
[UIView animateWithDuration:1.0
animations:^{
myCircleView.percentage = 0.7;
}
completion:nil];
and the circle path animate to the given percentage.
If you extend CALayer and implement your custom
- (void) drawInContext:(CGContextRef) context
You can make an animatable property by overriding needsDisplayForKey (in your custom CALayer class) like this:
+ (BOOL) needsDisplayForKey:(NSString *) key {
if ([key isEqualToString:#"percentage"]) {
return YES;
}
return [super needsDisplayForKey:key];
}
Of course, you also need to have a #property called percentage. From now on you can animate the percentage property using core animation. I did not check whether it works using the [UIView animateWithDuration...] call as well. It might work. But this worked for me:
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:#"percentage"];
animation.duration = 1.0;
animation.fromValue = [NSNumber numberWithDouble:0];
animation.toValue = [NSNumber numberWithDouble:100];
[myCustomLayer addAnimation:animation forKey:#"animatePercentage"];
Oh and to use yourCustomLayer with myCircleView, do this:
[myCircleView.layer addSublayer:myCustomLayer];
Complete Swift 3 example:
public class CircularProgressView: UIView {
public dynamic var progress: CGFloat = 0 {
didSet {
progressLayer.progress = progress
}
}
fileprivate var progressLayer: CircularProgressLayer {
return layer as! CircularProgressLayer
}
override public class var layerClass: AnyClass {
return CircularProgressLayer.self
}
override public func action(for layer: CALayer, forKey event: String) -> CAAction? {
if event == #keyPath(CircularProgressLayer.progress),
let action = action(for: layer, forKey: #keyPath(backgroundColor)) as? CAAnimation,
let animation: CABasicAnimation = (action.copy() as? CABasicAnimation) {
animation.keyPath = #keyPath(CircularProgressLayer.progress)
animation.fromValue = progressLayer.progress
animation.toValue = progress
self.layer.add(animation, forKey: #keyPath(CircularProgressLayer.progress))
return animation
}
return super.action(for: layer, forKey: event)
}
}
/*
* Concepts taken from:
* https://stackoverflow.com/a/37470079
*/
fileprivate class CircularProgressLayer: CALayer {
#NSManaged var progress: CGFloat
let startAngle: CGFloat = 1.5 * .pi
let twoPi: CGFloat = 2 * .pi
let halfPi: CGFloat = .pi / 2
override class func needsDisplay(forKey key: String) -> Bool {
if key == #keyPath(progress) {
return true
}
return super.needsDisplay(forKey: key)
}
override func draw(in ctx: CGContext) {
super.draw(in: ctx)
UIGraphicsPushContext(ctx)
//Light Grey
UIColor.lightGray.setStroke()
let center = CGPoint(x: bounds.midX, y: bounds.midY)
let strokeWidth: CGFloat = 4
let radius = (bounds.size.width / 2) - strokeWidth
let path = UIBezierPath(arcCenter: center, radius: radius, startAngle: 0, endAngle: twoPi, clockwise: true)
path.lineWidth = strokeWidth
path.stroke()
//Red
UIColor.red.setStroke()
let endAngle = (twoPi * progress) - halfPi
let pathProgress = UIBezierPath(arcCenter: center, radius: radius, startAngle: startAngle, endAngle: endAngle , clockwise: true)
pathProgress.lineWidth = strokeWidth
pathProgress.lineCapStyle = .round
pathProgress.stroke()
UIGraphicsPopContext()
}
}
let circularProgress = CircularProgressView(frame: CGRect(x: 0, y: 0, width: 80, height: 80))
UIView.animate(withDuration: 2, delay: 0, options: .curveEaseInOut, animations: {
circularProgress.progress = 0.76
}, completion: nil)
There is a great objc article here, which goes into details about how this works
As well as a objc project that uses the same concepts here:
Essentially action(for layer:) will be called when an object is being animated from an animation block, we can start our own animations with the same properties (stolen from the backgroundColor property) and animate the changes.
For the ones who needs more details on that like I did:
there is a cool example from Apple covering this question.
E.g. thanks to it I found that you don't actually need to add your custom layer as sublayer (as #Tom van Zummeren suggests). Instead it's enough to add a class method to your View class:
+ (Class)layerClass
{
return [CustomLayer class];
}
Hope it helps somebody.
you will have to implement the percentage part yourself. you can override layer drawing code to draw your cgpath accroding to the set percentage value. checkout the core animation programming guide and animation types and timing guide
#David Rees answer get me on the right track, but there is one issue. In my case
completion of animation always returns false, right after animation has began.
UIView.animate(withDuration: 2, delay: 0, options: .curveEaseInOut, animations: {
circularProgress.progress = 0.76
}, completion: { finished in
// finished - always false
})
This is the way it've worked for me - action of animation is handled inside of CALayer.
I have also included small example how to make layer with additional properties like "color".
In this case, without initializer that copies the values, changing the color would take affect only on non-animating view. During animation it would be visble with "default setting".
public class CircularProgressView: UIView {
#objc public dynamic var progress: CGFloat {
get {
return progressLayer.progress
}
set {
progressLayer.progress = newValue
}
}
fileprivate var progressLayer: CircularProgressLayer {
return layer as! CircularProgressLayer
}
override public class var layerClass: AnyClass {
return CircularProgressLayer.self
}
}
/*
* Concepts taken from:
* https://stackoverflow.com/a/37470079
*/
fileprivate class CircularProgressLayer: CALayer {
#NSManaged var progress: CGFloat
let startAngle: CGFloat = 1.5 * .pi
let twoPi: CGFloat = 2 * .pi
let halfPi: CGFloat = .pi / 2
var color: UIColor = .red
// preserve layer properties
// without this specyfic init, if color was changed to sth else
// animation would still use .red
override init(layer: Any) {
super.init(layer: layer)
if let layer = layer as? CircularProgressLayer {
self.color = layer.color
self.progress = layer.progress
}
}
override init() {
super.init()
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override class func needsDisplay(forKey key: String) -> Bool {
if key == #keyPath(progress) {
return true
}
return super.needsDisplay(forKey: key)
}
override func action(forKey event: String) -> CAAction? {
if event == #keyPath(CircularProgressLayer.progress) {
guard let animation = action(forKey: #keyPath(backgroundColor)) as? CABasicAnimation else {
setNeedsDisplay()
return nil
}
if let presentation = presentation() {
animation.keyPath = event
animation.fromValue = presentation.value(forKeyPath: event)
animation.toValue = nil
} else {
return nil
}
return animation
}
return super.action(forKey: event)
}
override func draw(in ctx: CGContext) {
super.draw(in: ctx)
UIGraphicsPushContext(ctx)
//Light Gray
UIColor.lightGray.setStroke()
let center = CGPoint(x: bounds.midX, y: bounds.midY)
let strokeWidth: CGFloat = 4
let radius = (bounds.size.width / 2) - strokeWidth
let path = UIBezierPath(arcCenter: center, radius: radius, startAngle: 0, endAngle: twoPi, clockwise: true)
path.lineWidth = strokeWidth
path.stroke()
// Red - default
self.color.setStroke()
let endAngle = (twoPi * progress) - halfPi
let pathProgress = UIBezierPath(arcCenter: center, radius: radius, startAngle: startAngle, endAngle: endAngle , clockwise: true)
pathProgress.lineWidth = strokeWidth
pathProgress.lineCapStyle = .round
pathProgress.stroke()
UIGraphicsPopContext()
}
}
The way to handle animations differently and copy layer properties I have found in this article:
https://medium.com/better-programming/make-apis-like-apple-animatable-view-properties-in-swift-4349b2244cea
I'm working on a design application that has a section for selecting colors by three sliders for RGB.
As we can see in xcode, where we want to select a color by RGB values, the slider tint color is a gradient color that changes when we change the sliders. I want to use this in my application. but I have no idea about how to do this?
I've found this code in a blog. but didn't work for me.
- (void)setGradientToSlider:(UISlider *)Slider WithColors:(NSArray *)Colors{
UIView * view = (UIView *)[[Slider subviews]objectAtIndex:0];
UIImageView * maxTrackImageView = (UIImageView *)[[view subviews]objectAtIndex:0];
CAGradientLayer * maxTrackGradient = [CAGradientLayer layer];
CGRect rect = maxTrackImageView.frame;
rect.origin.x = view.frame.origin.x;
maxTrackGradient.frame = rect;
maxTrackGradient.colors = Colors;
[maxTrackGradient setStartPoint:CGPointMake(0.0, 0.5)];
[maxTrackGradient setEndPoint:CGPointMake(1.0, 0.5)];
[[maxTrackImageView layer] insertSublayer:maxTrackGradient atIndex:0];
/////////////////////////////////////////////////////
UIImageView * minTrackImageView = (UIImageView *)[[view subviews]objectAtIndex:1];
CAGradientLayer * minTrackGradient = [CAGradientLayer layer];
rect = minTrackImageView.frame;
rect.size.width = maxTrackImageView.frame.size.width;
rect.origin.x = 0;
rect.origin.y = 0;
minTrackGradient.frame = rect;
minTrackGradient.colors = Colors;
[minTrackGradient setStartPoint:CGPointMake(0.0, 0.5)];
[minTrackGradient setEndPoint:CGPointMake(1.0, 0.5)];
[minTrackImageView.layer insertSublayer:minTrackGradient atIndex:0];
}
I would appreciate any helps. Thanks.
While it didnt give me the desired results here is a down and dirty Swift version of the answer above for those that want to try it.
func setSlider(slider:UISlider) {
let tgl = CAGradientLayer()
let frame = CGRectMake(0, 0, slider.frame.size.width, 5)
tgl.frame = frame
tgl.colors = [UIColor.blueColor().CGColor, UIColor.greenColor().CGColor, UIColor.yellowColor().CGColor, UIColor.orangeColor().CGColor, UIColor.redColor().CGColor]
tgl.startPoint = CGPointMake(0.0, 0.5)
tgl.endPoint = CGPointMake(1.0, 0.5)
UIGraphicsBeginImageContextWithOptions(tgl.frame.size, tgl.opaque, 0.0);
tgl.renderInContext(UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
image.resizableImageWithCapInsets(UIEdgeInsetsZero)
slider.setMinimumTrackImage(image, forState: .Normal)
//slider.setMaximumTrackImage(image, forState: .Normal)
}
UPDATE for Swift 4.0
func setSlider(slider:UISlider) {
let tgl = CAGradientLayer()
let frame = CGRect.init(x:0, y:0, width:slider.frame.size.width, height:5)
tgl.frame = frame
tgl.colors = [UIColor.blue.cgColor, UIColor.green.cgColor, UIColor.yellow.cgColor, UIColor.orange.cgColor, UIColor.red.cgColor]
tgl.startPoint = CGPoint.init(x:0.0, y:0.5)
tgl.endPoint = CGPoint.init(x:1.0, y:0.5)
UIGraphicsBeginImageContextWithOptions(tgl.frame.size, tgl.isOpaque, 0.0);
tgl.render(in: UIGraphicsGetCurrentContext()!)
if let image = UIGraphicsGetImageFromCurrentImageContext() {
UIGraphicsEndImageContext()
image.resizableImage(withCapInsets: UIEdgeInsets.zero)
slider.setMinimumTrackImage(image, for: .normal)
}
}
Here is possible solution:
Usage:
//array of CGColor objects, color1 and color2 are UIColor objects
NSArray *colors = [NSArray arrayWithObjects:(id)color1.CGColor, (id)color2.CGColor, nil];
//your UISlider
[slider setGradientBackgroundWithColors:colors];
Implementation:
Create category on UISlider:
- (void)setGradientBackgroundWithColors:(NSArray *)colors
{
CAGradientLayer *trackGradientLayer = [CAGradientLayer layer];
CGRect frame = self.frame;
frame.size.height = 5.0; //set the height of slider
trackGradientLayer.frame = frame;
trackGradientLayer.colors = colors;
//setting gradient as horizontal
trackGradientLayer.startPoint = CGPointMake(0.0, 0.5);
trackGradientLayer.endPoint = CGPointMake(1.0, 0.5);
UIImage *trackImage = [[UIImage imageFromLayer:trackGradientLayer] resizableImageWithCapInsets:UIEdgeInsetsZero];
[self setMinimumTrackImage:trackImage forState:UIControlStateNormal];
[self setMaximumTrackImage:trackImage forState:UIControlStateNormal];
}
Where colors is array of CGColor.
I have also created a category on UIImage which creates image from layer as you need an UIImage for setting gradient on slider.
+ (UIImage *)imageFromLayer:(CALayer *)layer
{
UIGraphicsBeginImageContextWithOptions(layer.frame.size, layer.opaque, 0.0);
[layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *outputImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return outputImage;
}
For Swift 3 and to prevent the slider from scaling the Min image, apply this when setting the its image. Recalculating the slider's left side is not necessary. Only recalc if you can changing the color of the gradient. The Max image does not seem to scale, but you should probably apply the same setting for consistency. There is a slight difference on the Max image when not applying its insets.
slider.setMinimumTrackImage(image?.resizableImage(withCapInsets:.zero), for: .normal)
For some reason it only works properly when resizableImage(withCapInsets:.zero) is all done at the same time. Running that part separate does not allow the image to work and gets scaled.
Here is the entire routine in Swift 3:
func setSlider(slider:UISlider) {
let tgl = CAGradientLayer()
let frame = CGRect(x: 0.0, y: 0.0, width: slider.bounds.width, height: 5.0 )
tgl.frame = frame
tgl.colors = [ UIColor.yellow.cgColor,UIColor.black.cgColor]
tgl.endPoint = CGPoint(x: 1.0, y: 1.0)
tgl.startPoint = CGPoint(x: 0.0, y: 1.0)
UIGraphicsBeginImageContextWithOptions(tgl.frame.size, false, 0.0)
tgl.render(in: UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
slider.setMaximumTrackImage(image?.resizableImage(withCapInsets:.zero), for: .normal)
slider.setMinimumTrackImage(image?.resizableImage(withCapInsets:.zero), for: .normal)
}
This is a really effective approach that I've found after a lot of web search. So it's better to share it here as a complete answer. The following code is a Swift Class That you can use to create and use gradients as UIView or UIImage.
import Foundation
import UIKit
class Gradient: UIView{
// Gradient Color Array
private var Colors: [UIColor] = []
// Start And End Points Of Linear Gradient
private var SP: CGPoint = CGPoint.zeroPoint
private var EP: CGPoint = CGPoint.zeroPoint
// Start And End Center Of Radial Gradient
private var SC: CGPoint = CGPoint.zeroPoint
private var EC: CGPoint = CGPoint.zeroPoint
// Start And End Radius Of Radial Gradient
private var SR: CGFloat = 0.0
private var ER: CGFloat = 0.0
// Flag To Specify If The Gradient Is Radial Or Linear
private var flag: Bool = false
// Some Overrided Init Methods
required init(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
}
override init(frame: CGRect) {
super.init(frame: frame)
}
// Draw Rect Method To Draw The Graphics On The Context
override func drawRect(rect: CGRect) {
// Get Context
let context = UIGraphicsGetCurrentContext()
// Get Color Space
let colorSpace = CGColorSpaceCreateDeviceRGB()
// Create Arrays To Convert The UIColor to CG Color
var colorComponent: [CGColor] = []
var colorLocations: [CGFloat] = []
var i: CGFloat = 0.0
// Add Colors Into The Color Components And Use An Index Variable For Their Location In The Array [The Location Is From 0.0 To 1.0]
for color in Colors {
colorComponent.append(color.CGColor)
colorLocations.append(i)
i += CGFloat(1.0) / CGFloat(self.Colors.count - 1)
}
// Create The Gradient With The Colors And Locations
let gradient: CGGradientRef = CGGradientCreateWithColors(colorSpace, colorComponent, colorLocations)
// Create The Suitable Gradient Based On Desired Type
if flag {
CGContextDrawRadialGradient(context, gradient, SC, SR, EC, ER, 0)
} else {
CGContextDrawLinearGradient(context, gradient, SP, EP, 0)
}
}
// Get The Input Data For Linear Gradient
func CreateLinearGradient(startPoint: CGPoint, endPoint: CGPoint, colors: UIColor...) {
self.Colors = colors
self.SP = startPoint
self.EP = endPoint
self.flag = false
}
// Get The Input Data For Radial Gradient
func CreateRadialGradient(startCenter: CGPoint, startRadius: CGFloat, endCenter: CGPoint, endRadius: CGFloat, colors: UIColor...) {
self.Colors = colors
self.SC = startCenter
self.EC = endCenter
self.SR = startRadius
self.ER = endRadius
self.flag = true
}
// Function To Convert Gradient To UIImage And Return It
func getImage() -> UIImage {
// Begin Image Context
UIGraphicsBeginImageContext(self.bounds.size)
// Draw The Gradient
self.drawRect(self.frame)
// Get Image From The Current Context
let image = UIGraphicsGetImageFromCurrentImageContext()
// End Image Context
UIGraphicsEndImageContext()
// Return The Result Gradient As UIImage
return image
}
}
SOLUTION: Here is the GitHub link for the class I eventually created / will expand on https://github.com/ckalas/SimpleSwiftBarGraph
I'm trying to (in playground) draw a bar graph using Core Graphics. I'm basing it off this code in Obj-C:
- (void)drawRect:(CGRect)rect {
CGFloat height = self.bounds.size.height;
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextClearRect(context, rect);
CGContextSetFillColorWithColor(context, [UIColor grayColor].CGColor);
CGFloat barWidth = 30;
int count = 0;
for (NSNumber *num in values) {
CGFloat x = count * (barWidth + 10);
CGRect barRect = CGRectMake(x, height - ([num floatValue] * height), barWidth, [num floatValue] * height);
CGContextAddRect(context, barRect);
count++;
}
CGContextFillPath(context);
}
I'm trying to convert this, but at the second line, Xcode doesn't know about UIGraphicsGetCurrentContext(). Can anyone offer help?
EDIT: Here is my current code...issues now are in the for loop where I commented, no matter what combination of stuff I try I cannot get that line to work. Just errors can't convert type to type, I've tried declaring the array as an [NSNumber], no luck.
class CustomView: UIView {
init(frame: CGRect) {
super.init(frame: frame)
}
override func drawRect(rect: GCRect) {
let values: [UInt8] = [1,2,3]
let height = self.bounds.size.height
let context = UIGraphicsGetCurrentContext()
CGContextClearRect(context, self.frame)
CGContextSetFillColorWithColor(context, UIColor.grayColor().CGColor!);
let barWidth = 30.0 as CGFloat
var count = 0 as CGFloat
for number in values {
let x = count * (barWidth + 10) as CGFloat
let barRect = CGRectMake(x, (height - number*height), barWidth, number*height) // issues here can't convert one type to another
CGContextAddRect(context, barRect)
count++
}
CGContextFillPath(context)
}
Declare your values array to be of type [CGFloat]. I made a few other stylistic changes (removed semicolons, CGColor is already implicitly unwrapped so ! is not needed, and prefer type declaration to cast).
class CustomView: UIView {
init(frame: CGRect) {
super.init(frame: frame)
}
override func drawRect(rect: CGRect) {
let values: [CGFloat] = [0.3, 0.6, 0.9]
let height = self.bounds.size.height
let context = UIGraphicsGetCurrentContext()
CGContextClearRect(context, self.frame)
CGContextSetFillColorWithColor(context, UIColor.grayColor().CGColor)
let barWidth:CGFloat = 30.0
var count:CGFloat = 0
for number in values {
let x = count * (barWidth + 10)
let barRect = CGRectMake(x, (height - number*height), barWidth, number*height)
CGContextAddRect(context, barRect)
count++
}
CGContextFillPath(context)
}
}
The values in the values array should range from 0.0 for no bar height to 1.0 for full bar height.