Support of hidden Brightness slider.

Colorful/Classes/ColorPicker.swift

@@ -17,6 +17,28 @@ public final class ColorPicker: UIControl {
             return hsvColor.uiColor
         }
     }
+
+    public var isBrightnessSliderHidden: Bool {
+        set(hidden) {
+            setBrightness(hidden ? brightnessLevel : brightnessSlider.brightness)
+            brightnessSlider.isHidden = hidden
+            brightnessCursor.isHidden = hidden
+            layoutSubviews(withBrightnessSlider: !hidden)
+            layoutIfNeeded()
+        }
+        get {
+            return brightnessSlider.isHidden
+        }
+    }
+
+    public var brightnessLevel: CGFloat {
+        set(level) {
+            setBrightness(level)
+        }
+        get {
+            return hsvColor.brightness
+        }
+    }
 
     private let brightnessCursor = BrightnessCursor()
     private let brightnessSlider = BrightnessSlider()
@@ -27,6 +49,9 @@ public final class ColorPicker: UIControl {
 
     private let feedbackGenerator = UISelectionFeedbackGenerator()
 
+    private var layoutWithBrightness: [NSLayoutConstraint] = []
+    private var layoutWithoutBrightness: [NSLayoutConstraint] = []
+
     public override init(frame: CGRect) {
         super.init(frame: frame)
         setup()
@@ -42,6 +67,8 @@ public final class ColorPicker: UIControl {
         addSubview(brightnessSlider)
         addSubview(brightnessCursor)
         addSubview(colorMapCursor)
+
+        setupConstraints()
 
         let colorMapPan = UIPanGestureRecognizer(target: self, action: #selector(self.handleColorMapPan(pan:)))
         colorMapPan.delegate = self
@@ -55,6 +82,40 @@ public final class ColorPicker: UIControl {
 
         feedbackGenerator.prepare()
     }
+
+    private func setupConstraints() {
+        colorMap.translatesAutoresizingMaskIntoConstraints = false
+        brightnessCursor.translatesAutoresizingMaskIntoConstraints = false
+        brightnessSlider.translatesAutoresizingMaskIntoConstraints = false
+
+        let margin: CGFloat = 12
+        let brightnessWidth: CGFloat = 72
+        let cursorHeight:CGFloat = 28
+
+        layoutWithBrightness = [
+            colorMap.topAnchor.constraint(equalTo: topAnchor, constant: margin),
+            colorMap.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -margin),
+            colorMap.leftAnchor.constraint(equalTo: leftAnchor, constant: margin),
+            colorMap.rightAnchor.constraint(equalTo: brightnessSlider.leftAnchor, constant: -margin),
+
+            brightnessSlider.widthAnchor.constraint(equalToConstant: brightnessWidth),
+            brightnessSlider.topAnchor.constraint(equalTo: topAnchor),
+            brightnessSlider.bottomAnchor.constraint(equalTo: bottomAnchor),
+            brightnessSlider.rightAnchor.constraint(equalTo: rightAnchor, constant: -margin),
+
+            brightnessCursor.centerYAnchor.constraint(equalTo: brightnessSlider.centerYAnchor),
+            brightnessCursor.centerXAnchor.constraint(equalTo: brightnessSlider.centerXAnchor),
+            brightnessCursor.heightAnchor.constraint(equalToConstant: cursorHeight),
+            brightnessCursor.widthAnchor.constraint(equalToConstant: brightnessWidth),
+        ]
+
+        layoutWithoutBrightness = [
+            colorMap.topAnchor.constraint(equalTo: topAnchor, constant: margin),
+            colorMap.bottomAnchor.constraint(equalTo: bottomAnchor, constant: -margin),
+            colorMap.leftAnchor.constraint(equalTo: leftAnchor, constant: margin),
+            colorMap.rightAnchor.constraint(equalTo: rightAnchor, constant: -margin),
+        ]
+    }
 
     public func set(color: UIColor, colorSpace: HRColorSpace) {
         self.colorSpace = colorSpace
@@ -66,25 +127,21 @@ public final class ColorPicker: UIControl {
     }
 
     public override func layoutSubviews() {
+        self.layoutSubviews(withBrightnessSlider: !self.brightnessSlider.isHidden)
         super.layoutSubviews()
-
-        let margin: CGFloat = 12
-        let brightnessSliderWidth: CGFloat = 72
-        let colorMapSize = min(bounds.width - brightnessSliderWidth - margin * 3, bounds.height - 2 * margin)
-
-        let colorMapX = (bounds.width - (colorMapSize + margin * 2 + brightnessSliderWidth)) / 2
-
-        colorMap.frame = CGRect(x: colorMapX, y: (bounds.height - colorMapSize)/2, width: colorMapSize + margin * 2, height: colorMapSize)
-        brightnessSlider.frame = CGRect(x: colorMap.frame.maxX, y: (bounds.height - colorMapSize)/2,
-                                        width: brightnessSliderWidth, height: colorMapSize)
-
-        let brightnessCursorSize = CGSize(width: brightnessSliderWidth, height: 28)
-        brightnessCursor.frame = CGRect(x: colorMap.frame.maxX,
-                                        y: (bounds.height - brightnessCursorSize.height)/2,
-                                        width: brightnessCursorSize.width, height: brightnessCursorSize.height)
         mapColorToView(initialize: true)
     }
 
+    private func layoutSubviews(withBrightnessSlider: Bool) {
+        if withBrightnessSlider {
+            NSLayoutConstraint.deactivate(layoutWithoutBrightness)
+            NSLayoutConstraint.activate(layoutWithBrightness)
+        } else {
+            NSLayoutConstraint.deactivate(layoutWithBrightness)
+            NSLayoutConstraint.activate(layoutWithoutBrightness)
+        }
+    }
+
     private func mapColorToView(initialize: Bool = false) {
         brightnessCursor.set(hsv: hsvColor)
         colorMap.set(brightness: hsvColor.brightness)
@@ -96,6 +153,13 @@ public final class ColorPicker: UIControl {
         }
     }
 
+    private func setBrightness(_ brightness: CGFloat) {
+        hsvColor = hsvColor.hueAndSaturation.with(brightness: brightness)
+        mapColorToView()
+        feedbackIfNeeds()
+        sendActionIfNeeds()
+    }
+
     @objc
     private func handleColorMapPan(pan: UIPanGestureRecognizer) {
         switch pan.state {
@@ -151,9 +215,6 @@ extension ColorPicker: UIGestureRecognizerDelegate {
 
 extension ColorPicker: BrightnessSliderDelegate {
     func handleBrightnessChanged(slider: BrightnessSlider) {
-        hsvColor = hsvColor.hueAndSaturation.with(brightness: slider.brightness)
-        mapColorToView()
-        feedbackIfNeeds()
-        sendActionIfNeeds()
+        setBrightness(slider.brightness)
     }
 }