1 files changed, 153 insertions, 0 deletions
diff --git a/integration_tests/nativegraphics/src/test/java/org/robolectric/integrationtests/nativegraphics/ColorUtils.java b/integration_tests/nativegraphics/src/test/java/org/robolectric/integrationtests/nativegraphics/ColorUtils.java
new file mode 100644
index 000000000..9a116a16f
--- /dev/null
+++ b/integration_tests/nativegraphics/src/test/java/org/robolectric/integrationtests/nativegraphics/ColorUtils.java
@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package org.robolectric.integrationtests.nativegraphics;
+
+import static org.junit.Assert.fail;
+
+import android.graphics.Color;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import java.util.function.Function;
+import java.util.function.IntUnaryOperator;
+
+public final class ColorUtils {
+  public static void verifyColor(int expected, int observed) {
+    verifyColor(expected, observed, 0);
+  }
+
+  public static void verifyColor(int expected, int observed, int tolerance) {
+    verifyColor("", expected, observed, tolerance);
+  }
+
+  /**
+   * Verify that two colors match within a per-channel tolerance.
+   *
+   * @param s String with extra information about the test with an error.
+   * @param expected Expected color.
+   * @param observed Observed color.
+   * @param tolerance Per-channel tolerance by which the color can mismatch.
+   */
+  public static void verifyColor(@NonNull String s, int expected, int observed, int tolerance) {
+    s +=
+        " expected 0x"
+            + Integer.toHexString(expected)
+            + ", observed 0x"
+            + Integer.toHexString(observed)
+            + ", tolerated channel error 0x"
+            + tolerance;
+    String red = verifyChannel("red", expected, observed, tolerance, (i) -> Color.red(i));
+    String green = verifyChannel("green", expected, observed, tolerance, (i) -> Color.green(i));
+    String blue = verifyChannel("blue", expected, observed, tolerance, (i) -> Color.blue(i));
+    String alpha = verifyChannel("alpha", expected, observed, tolerance, (i) -> Color.alpha(i));
+
+    buildErrorString(s, red, green, blue, alpha);
+  }
+
+  /**
+   * Verify that two colors match within a per-channel tolerance.
+   *
+   * @param msg String with extra information about the test with an error.
+   * @param expected Expected color.
+   * @param observed Observed color.
+   * @param tolerance Per-channel tolerance by which the color can mismatch.
+   */
+  public static void verifyColor(
+      @NonNull String msg, Color expected, Color observed, float tolerance) {
+    if (!expected.getColorSpace().equals(observed.getColorSpace())) {
+      fail(
+          "Cannot compare Colors with different color spaces! expected: "
+              + expected
+              + "\tobserved: "
+              + observed);
+    }
+    msg +=
+        " expected "
+            + expected
+            + ", observed "
+            + observed
+            + ", tolerated channel error "
+            + tolerance;
+    String red = verifyChannel("red", expected, observed, tolerance, (c) -> c.red());
+    String green = verifyChannel("green", expected, observed, tolerance, (c) -> c.green());
+    String blue = verifyChannel("blue", expected, observed, tolerance, (c) -> c.blue());
+    String alpha = verifyChannel("alpha", expected, observed, tolerance, (c) -> c.alpha());
+
+    buildErrorString(msg, red, green, blue, alpha);
+  }
+
+  private static void buildErrorString(
+      @NonNull String s,
+      @Nullable String red,
+      @Nullable String green,
+      @Nullable String blue,
+      @Nullable String alpha) {
+    String err = null;
+    for (String channel : new String[] {red, green, blue, alpha}) {
+      if (channel == null) {
+        continue;
+      }
+      if (err == null) {
+        err = s;
+      }
+      err += "\n\t\t" + channel;
+    }
+    if (err != null) {
+      fail(err);
+    }
+  }
+
+  private static String verifyChannel(
+      String channelName, int expected, int observed, int tolerance, IntUnaryOperator f) {
+    int e = f.applyAsInt(expected);
+    int o = f.applyAsInt(observed);
+    if (Math.abs(e - o) <= tolerance) {
+      return null;
+    }
+    return "Channel "
+        + channelName
+        + " mismatch: expected<0x"
+        + Integer.toHexString(e)
+        + ">, observed: <0x"
+        + Integer.toHexString(o)
+        + ">";
+  }
+
+  private static String verifyChannel(
+      String channelName,
+      Color expected,
+      Color observed,
+      float tolerance,
+      Function<Color, Float> f) {
+    float e = f.apply(expected);
+    float o = f.apply(observed);
+    float diff = Math.abs(e - o);
+    if (diff <= tolerance) {
+      return null;
+    }
+    return "Channel "
+        + channelName
+        + " mismatch: expected<"
+        + e
+        + ">, observed: <"
+        + o
+        + ">, difference: <"
+        + diff
+        + ">";
+  }
+
+  private ColorUtils() {}
+}