From 65c3972b73777348d0b393f98fad45b437e794c0 Mon Sep 17 00:00:00 2001
From: BlackyHawky <blackyhawky@protonmail.com>
Date: Thu, 10 Aug 2023 20:50:49 +0200
Subject: [PATCH] Added HSL properties to lighten or darken colors (#57)

* Added HSL properties to lighten or darken colors

* Adjusted lightening and darkening value
---
 .../inputmethod/latin/common/Colors.java      | 38 +++++++++----------
 1 file changed, 18 insertions(+), 20 deletions(-)

diff --git a/app/src/main/java/org/dslul/openboard/inputmethod/latin/common/Colors.java b/app/src/main/java/org/dslul/openboard/inputmethod/latin/common/Colors.java
index 731aae362..ec3d60ba0 100644
--- a/app/src/main/java/org/dslul/openboard/inputmethod/latin/common/Colors.java
+++ b/app/src/main/java/org/dslul/openboard/inputmethod/latin/common/Colors.java
@@ -7,6 +7,8 @@ import android.graphics.ColorFilter;
 
 import androidx.core.graphics.BlendModeColorFilterCompat;
 import androidx.core.graphics.BlendModeCompat;
+import androidx.annotation.ColorInt;
+import androidx.core.graphics.ColorUtils;
 
 import org.dslul.openboard.inputmethod.keyboard.KeyboardTheme;
 
@@ -142,16 +144,6 @@ public class Colors {
         return getBrightnessSquared(color) < 50*50;
     }
 
-    private static int brighten(final int color) {
-        // brighten is stronger, because often the drawables get darker when pressed
-        // todo (maybe): remove the darker pressed colors to have more consistent behavior?
-        return blendARGB(color, Color.WHITE, 0.14f);
-    }
-
-    private static int darken(final int color) {
-        return blendARGB(color, Color.BLACK, 0.11f);
-    }
-
     public static int brightenOrDarken(final int color, final boolean preferDarken) {
         if (preferDarken) {
             if (isDarkColor(color)) return brighten(color);
@@ -160,16 +152,6 @@ public class Colors {
         else return brighten(color);
     }
 
-    // taken from androidx ColorUtils, modified to keep alpha of color1
-    private static int blendARGB(int color1, int color2, float ratio) {
-        final float inverseRatio = 1 - ratio;
-        float a = Color.alpha(color1);
-        float r = Color.red(color1) * inverseRatio + Color.red(color2) * ratio;
-        float g = Color.green(color1) * inverseRatio + Color.green(color2) * ratio;
-        float b = Color.blue(color1) * inverseRatio + Color.blue(color2) * ratio;
-        return Color.argb((int) a, (int) r, (int) g, (int) b);
-    }
-
     private static int getBrightnessSquared(final int color) {
         // See http://www.nbdtech.com/Blog/archive/2008/04/27/Calculating-the-Perceived-Brightness-of-a-Color.aspx
         int[] rgb = {Color.red(color), Color.green(color), Color.blue(color)};
@@ -177,4 +159,20 @@ public class Colors {
         return (int) (rgb[0] * rgb[0] * .241 + rgb[1] * rgb[1] * .691 + rgb[2] * rgb[2] * .068);
     }
 
+    @ColorInt
+    public static int brighten(@ColorInt int color) {
+        float[] hsl = new float[3];
+        ColorUtils.colorToHSL(color, hsl);
+        hsl[2] += 0.05f;
+        return ColorUtils.HSLToColor(hsl);
+    }
+
+    @ColorInt
+    public static int darken(@ColorInt int color) {
+        float[] hsl = new float[3];
+        ColorUtils.colorToHSL(color, hsl);
+        hsl[2] -= 0.05f;
+        return ColorUtils.HSLToColor(hsl);
+    }
+
 }