Don't use too much bright or dark feeds colors

app/src/main/java/com/readrops/app/utils/Utils.java

@@ -117,4 +117,20 @@ public final class Utils {
         return bitmap;
 
     }
+
+    public static boolean isColorTooBright(@ColorInt int color) {
+        return getColorLuma(color) > 210;
+    }
+
+    public static boolean isColorTooDark(@ColorInt int color) {
+        return getColorLuma(color) < 40;
+    }
+
+    private static double getColorLuma(@ColorInt int color) {
+        int r = (color >> 16) & 0xff;
+        int g = (color >>  8) & 0xff;
+        int b = (color >>  0) & 0xff;
+
+        return 0.2126 * r + 0.7152 * g + 0.0722 * b;
+    }
 }

app/src/main/java/com/readrops/app/utils/feedscolors/FeedColors.kt

@@ -1,9 +1,9 @@
 package com.readrops.app.utils.feedscolors
 
 import androidx.palette.graphics.Palette
-import com.readrops.db.entities.Feed
 import com.readrops.app.utils.HtmlParser
 import com.readrops.app.utils.Utils
+import com.readrops.db.entities.Feed
 
 fun setFeedColors(feed: Feed) {
     getFaviconLink(feed)
@@ -13,12 +13,17 @@ fun setFeedColors(feed: Feed) {
         val palette = Palette.from(bitmap).generate()
 
         val dominantSwatch = palette.dominantSwatch
-        if (dominantSwatch != null)
-            feed.textColor = dominantSwatch.rgb
+        feed.textColor = if (dominantSwatch != null && !Utils.isColorTooBright(dominantSwatch.rgb)
+                && !Utils.isColorTooDark(dominantSwatch.rgb)) {
+            dominantSwatch.rgb
+        } else 0
+
 
         val mutedSwatch = palette.mutedSwatch
-        if (mutedSwatch != null)
-            feed.backgroundColor = mutedSwatch.rgb
+        feed.backgroundColor = if (mutedSwatch != null && !Utils.isColorTooBright(mutedSwatch.rgb)
+                && !Utils.isColorTooDark(mutedSwatch.rgb)) {
+            mutedSwatch.rgb
+        } else 0
     }
 }
 

app/src/test/java/com/readrops/app/UtilsTest.java

@@ -1,9 +1,12 @@
 package com.readrops.app;
 
+import android.graphics.Color;
+
 import com.readrops.app.utils.Utils;
 
 import org.junit.Test;
 
+import static junit.framework.Assert.assertTrue;
 import static junit.framework.TestCase.assertEquals;
 
 public class UtilsTest {
@@ -14,4 +17,14 @@ public class UtilsTest {
 
         assertEquals("This is a text to clean", Utils.cleanText(text));
     }
+
+    @Test
+    public void colorTooBrightTest() {
+        assertTrue(Utils.isColorTooBright(-986896));
+    }
+
+    @Test
+    public void colorTooDarkTest() {
+        assertTrue(Utils.isColorTooDark(Color.parseColor("#1a1a1a")));
+    }
 }