Add comments, deprecate Utils methods and minor fixes

Author: orbital17

androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/Utils.java

@@ -33,6 +33,62 @@
  */
 public class Utils {
 
+    /** 
+     * Sets status bar color. Makes the icons dark if necessary. 
+     * Deprecated - use EdgeToEdgeController instead.
+    */
+    @Deprecated
+    public static void setStatusBarColor(Activity activity, @ColorInt int color) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) return;
+        activity.getWindow().setStatusBarColor(color);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
+                && shouldUseDarkIconsOnBackground(color)) {
+            addSystemUiVisibilityFlag(activity, View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
+        }
+    }
+
+    /**
+     * Sets navigation bar color. Makes the icons dark if necessary.
+     * Deprecated - use EdgeToEdgeController instead.
+    */
+    @Deprecated
+    public static void setNavigationBarColor(Activity activity, @ColorInt int color) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) return;
+
+        activity.getWindow().setNavigationBarColor(color);
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O
+                && shouldUseDarkIconsOnBackground(color)) {
+            addSystemUiVisibilityFlag(activity, View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR);
+        }
+    }
+
+    private static void addSystemUiVisibilityFlag(Activity activity, int flag) {
+        View root = activity.getWindow().getDecorView().getRootView();
+        int visibility = root.getSystemUiVisibility();
+        visibility |= flag;
+        root.setSystemUiVisibility(visibility);
+    }
+
+    /**
+     * Determines whether to use dark icons on a background with given color by comparing the
+     * contrast ratio (https://www.w3.org/TR/WCAG20/#contrast-ratiodef) to a threshold.
+     * This criterion matches the one used by Chrome:
+     * https://chromium.googlesource.com/chromium/src/+/90ac05ba6cb9ab5d5df75f0cef62c950be3716c3/chrome/android/java/src/org/chromium/chrome/browser/util/ColorUtils.java#215
+     */
+    private static boolean shouldUseDarkIconsOnBackground(@ColorInt int backgroundColor) {
+        float luminance = 0.2126f * luminanceOfColorComponent(Color.red(backgroundColor))
+                + 0.7152f * luminanceOfColorComponent(Color.green(backgroundColor))
+                + 0.0722f * luminanceOfColorComponent(Color.blue(backgroundColor));
+        float contrast = Math.abs((1.05f) / (luminance + 0.05f));
+        return contrast < 3;
+    }
+
+    private static float luminanceOfColorComponent(float c) {
+        c /= 255f;
+        return (c < 0.03928f) ? c / 12.92f : (float) Math.pow((c + 0.055f) / 1.055f, 2.4f);
+    }
+
     /**
      * Converts drawable located at given resource id into a Bitmap.
      */

androidbrowserhelper/src/main/java/com/google/androidbrowserhelper/trusted/splashscreens/EdgeToEdgeController.java

@@ -35,56 +35,43 @@ public FrameLayout getWrapperView(@ColorInt int defaultColor) {
             Insets systemBarInsets = insets.getInsets(WindowInsetsCompat.Type.systemBars());
             mSystemBarBackgroundDrawable.setSystemBarPaddings(systemBarInsets.top, systemBarInsets.bottom);
             v.setPadding(0, systemBarInsets.top, 0, systemBarInsets.bottom);
-            v.invalidate();
-            return insets;
+                        return WindowInsetsCompat.CONSUMED;
         });
 
+        // This is required to make system bars transparent
         ViewCompat.setOnApplyWindowInsetsListener(mActivity.getWindow().getDecorView(), (v, insets) -> insets);
 
         return rootView;
     }
 
     public void setStatusBarColor(@ColorInt int color) {
         if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
+            // Call the old API for compatibility with older SDKs, in case edge to edge cannot be enabled
             mActivity.getWindow().setStatusBarColor(color);
         }
         mSystemBarBackgroundDrawable.setStatusBarColor(color);
-        if (shouldUseDarkIconsOnBackground(color)) {
-            addSystemUiVisibilityFlag(mActivity, View.SYSTEM_UI_FLAG_LIGHT_STATUS_BAR);
             WindowInsetsControllerCompat windowInsetsController =
                     WindowCompat.getInsetsController(mActivity.getWindow(), mActivity.getWindow().getDecorView());
             if (windowInsetsController != null) {
-                windowInsetsController.setAppearanceLightStatusBars(true);
-            }
+            boolean shouldUseDarkIcons = shouldUseDarkIconsOnBackground(color);
+            windowInsetsController.setAppearanceLightStatusBars(shouldUseDarkIcons);
         }
     }
 
     public void setNavigationBarColor(@ColorInt int color) {
         if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
+            // Call the old API for compatibility with older SDKs, in case edge to edge cannot be enabled
             mActivity.getWindow().setNavigationBarColor(color);
         }
         mSystemBarBackgroundDrawable.setNavigationBarColor(color);
-        if (shouldUseDarkIconsOnBackground(color)) {
-            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-                addSystemUiVisibilityFlag(mActivity, View.SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR);
-            }
             WindowInsetsControllerCompat windowInsetsController =
                     WindowCompat.getInsetsController(mActivity.getWindow(), mActivity.getWindow().getDecorView());
             if (windowInsetsController != null) {
-                windowInsetsController.setAppearanceLightNavigationBars(true);
-            }
+            boolean shouldUseDarkIcons = shouldUseDarkIconsOnBackground(color);
+            windowInsetsController.setAppearanceLightNavigationBars(shouldUseDarkIcons);
         }
     }
 
-    private static void addSystemUiVisibilityFlag(Activity activity, int flag) {
-        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.UPSIDE_DOWN_CAKE) return;
-
-        View root = activity.getWindow().getDecorView().getRootView();
-        int visibility = root.getSystemUiVisibility();
-        visibility |= flag;
-        root.setSystemUiVisibility(visibility);
-    }
-
     /**
      * Determines whether to use dark icons on a background with given color by comparing the
      * contrast ratio (https://www.w3.org/TR/WCAG20/#contrast-ratiodef) to a threshold.