1 files changed, 178 insertions, 0 deletions
diff --git a/main/java/com/google/android/setupcompat/logging/ScreenKey.java b/main/java/com/google/android/setupcompat/logging/ScreenKey.java
new file mode 100644
index 0000000..4fba32b
--- /dev/null
+++ b/main/java/com/google/android/setupcompat/logging/ScreenKey.java
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2022 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 com.google.android.setupcompat.logging;
+
+import static com.google.android.setupcompat.internal.Validations.assertLengthInRange;
+
+import android.content.Context;
+import android.os.Bundle;
+import android.os.Parcel;
+import android.os.Parcelable;
+import androidx.annotation.NonNull;
+import androidx.annotation.VisibleForTesting;
+import com.google.android.setupcompat.internal.Preconditions;
+import com.google.android.setupcompat.util.ObjectUtils;
+import java.util.regex.Pattern;
+
+/**
+ * A screen key represents a validated “string key” that is associated with the values reported by
+ * the API consumer.
+ */
+public class ScreenKey implements Parcelable {
+
+  @VisibleForTesting(otherwise = VisibleForTesting.PACKAGE_PRIVATE)
+  public static final String SCREEN_KEY_BUNDLE_NAME_KEY = "ScreenKey_name";
+  @VisibleForTesting(otherwise = VisibleForTesting.PACKAGE_PRIVATE)
+  public static final String SCREEN_KEY_BUNDLE_PACKAGE_KEY = "ScreenKey_package";
+  @VisibleForTesting(otherwise = VisibleForTesting.PACKAGE_PRIVATE)
+  public static final String SCREEN_KEY_BUNDLE_VERSION_KEY = "ScreenKey_version";
+  private static final int INVALID_VERSION = -1;
+  private static final int VERSION = 1;
+
+  /**
+   * Creates a new instance of {@link ScreenKey}.
+   *
+   * @param name screen name to identify what the metric belongs to. It should be in the range of
+   * 5-50 characters, only alphanumeric characters are allowed.
+   * @param context context associated to metric screen, uses to generate package name.
+   */
+  public static ScreenKey of(@NonNull String name, @NonNull Context context) {
+    Preconditions.checkNotNull(context, "Context can not be null.");
+    return ScreenKey.of(name, context.getPackageName());
+  }
+
+  private static ScreenKey of(@NonNull String name, @NonNull String packageName) {
+    Preconditions.checkArgument(
+        SCREEN_PACKAGENAME_PATTERN.matcher(packageName).matches(),
+        "Invalid ScreenKey#package, only alpha numeric characters are allowed.");
+    assertLengthInRange(
+        name, "ScreenKey.name", MIN_SCREEN_NAME_LENGTH, MAX_SCREEN_NAME_LENGTH);
+    Preconditions.checkArgument(
+        SCREEN_NAME_PATTERN.matcher(name).matches(),
+        "Invalid ScreenKey#name, only alpha numeric characters are allowed.");
+
+    return new ScreenKey(name, packageName);
+  }
+
+  /**
+   * Converts {@link ScreenKey} into {@link Bundle}.
+   * Throw {@link NullPointerException} if the screenKey is null.
+   */
+  public static Bundle toBundle(ScreenKey screenKey) {
+    Preconditions.checkNotNull(screenKey, "ScreenKey cannot be null.");
+    Bundle bundle = new Bundle();
+    bundle.putInt(SCREEN_KEY_BUNDLE_VERSION_KEY, VERSION);
+    bundle.putString(SCREEN_KEY_BUNDLE_NAME_KEY, screenKey.getName());
+    bundle.putString(SCREEN_KEY_BUNDLE_PACKAGE_KEY, screenKey.getPackageName());
+    return bundle;
+  }
+
+  /**
+   * Converts {@link Bundle} into {@link ScreenKey}.
+   * Throw {@link NullPointerException} if the bundle is null.
+   * Throw {@link IllegalArgumentException} if the bundle version is unsupported.
+   */
+  public static ScreenKey fromBundle(Bundle bundle) {
+    Preconditions.checkNotNull(bundle, "Bundle cannot be null");
+
+    int version = bundle.getInt(SCREEN_KEY_BUNDLE_VERSION_KEY, INVALID_VERSION);
+    if (version == 1) {
+      return ScreenKey.of(
+          bundle.getString(SCREEN_KEY_BUNDLE_NAME_KEY),
+          bundle.getString(SCREEN_KEY_BUNDLE_PACKAGE_KEY));
+    } else {
+      // Invalid version
+      throw new IllegalArgumentException("Unsupported version: " + version);
+    }
+  }
+
+  public static final Creator<ScreenKey> CREATOR =
+      new Creator<>() {
+        @Override
+        public ScreenKey createFromParcel(Parcel in) {
+          return new ScreenKey(in.readString(), in.readString());
+        }
+
+        @Override
+        public ScreenKey[] newArray(int size) {
+          return new ScreenKey[size];
+        }
+      };
+
+  /** Returns the name of the screen key. */
+  public String getName() {
+    return name;
+  }
+
+  /** Returns the package name of the screen key. */
+  public String getPackageName() {
+    return packageName;
+  }
+
+  @Override
+  public int describeContents() {
+    return 0;
+  }
+
+  @Override
+  public void writeToParcel(Parcel parcel, int i) {
+    parcel.writeString(name);
+    parcel.writeString(packageName);
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (!(o instanceof ScreenKey)) {
+      return false;
+    }
+    ScreenKey screenKey = (ScreenKey) o;
+    return ObjectUtils.equals(name, screenKey.name)
+        && ObjectUtils.equals(packageName, screenKey.packageName);
+  }
+
+  @Override
+  public int hashCode() {
+    return ObjectUtils.hashCode(name, packageName);
+  }
+
+  @NonNull
+  @Override
+  public String toString() {
+    return "ScreenKey {name="
+        + getName()
+        + ", package="
+        + getPackageName()
+        + "}";
+  }
+
+  private ScreenKey(String name, String packageName) {
+    this.name = name;
+    this.packageName = packageName;
+  }
+
+  private final String name;
+  private final String packageName;
+
+  private static final int MIN_SCREEN_NAME_LENGTH = 5;
+  private static final int MAX_SCREEN_NAME_LENGTH = 50;
+  private static final Pattern SCREEN_NAME_PATTERN = Pattern.compile("^[a-zA-Z][a-zA-Z0-9_]+");
+  private static final Pattern SCREEN_PACKAGENAME_PATTERN =
+      Pattern.compile("^([a-z]+[.])+[a-zA-Z][a-zA-Z0-9]+");
+}