1 files changed, 106 insertions, 0 deletions
diff --git a/java/com/android/dialer/about/Licenses.java b/java/com/android/dialer/about/Licenses.java
new file mode 100644
index 000000000..d90c282b6
--- /dev/null
+++ b/java/com/android/dialer/about/Licenses.java
@@ -0,0 +1,106 @@
+/*
+ * 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 com.android.dialer.about;
+
+import android.content.Context;
+import android.content.res.Resources;
+import com.android.dialer.common.Assert;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
+import java.util.ArrayList;
+import java.util.Collections;
+
+/** A helper for extracting licenses. */
+public final class Licenses {
+  private static final String TAG = "Licenses";
+  private static final String LICENSE_FILENAME = "third_party_licenses";
+  private static final String LICENSE_METADATA_FILENAME = "third_party_license_metadata";
+
+  /** Return the licenses bundled into this app. */
+  public static ArrayList<License> getLicenses(Context context) {
+    return getLicenseListFromMetadata(
+        getTextFromResource(context.getApplicationContext(), LICENSE_METADATA_FILENAME, 0, -1));
+  }
+
+  /**
+   * Returns a list of {@link License}s parsed from a license metadata file.
+   *
+   * @param metadata a {@code String} containing the contents of a license metadata file.
+   */
+  private static ArrayList<License> getLicenseListFromMetadata(String metadata) {
+    String[] entries = metadata.split("\n");
+    ArrayList<License> licenses = new ArrayList<License>(entries.length);
+    for (String entry : entries) {
+      int delimiter = entry.indexOf(' ');
+      String[] licenseLocation = entry.substring(0, delimiter).split(":");
+      Assert.checkState(
+          delimiter > 0 && licenseLocation.length == 2,
+          "Invalid license meta-data line:\n" + entry);
+      long licenseOffset = Long.parseLong(licenseLocation[0]);
+      int licenseLength = Integer.parseInt(licenseLocation[1]);
+      licenses.add(License.create(entry.substring(delimiter + 1), licenseOffset, licenseLength));
+    }
+    Collections.sort(licenses);
+    return licenses;
+  }
+
+  /** Return the text of a bundled license file. */
+  public static String getLicenseText(Context context, License license) {
+    long offset = license.getLicenseOffset();
+    int length = license.getLicenseLength();
+    return getTextFromResource(context, LICENSE_FILENAME, offset, length);
+  }
+
+  private static String getTextFromResource(
+      Context context, String filename, long offset, int length) {
+    Resources resources = context.getApplicationContext().getResources();
+    // When aapt is called with --rename-manifest-package, the package name is changed for the
+    // application, but not for the resources. This is to find the package name of a known
+    // resource to know what package to lookup the license files in.
+    String packageName = resources.getResourcePackageName(R.id.dummy_placeholder);
+    InputStream stream =
+        resources.openRawResource(resources.getIdentifier(filename, "raw", packageName));
+    return getTextFromInputStream(stream, offset, length);
+  }
+
+  private static String getTextFromInputStream(InputStream stream, long offset, int length) {
+    byte[] buffer = new byte[1024];
+    ByteArrayOutputStream textArray = new ByteArrayOutputStream();
+
+    try {
+      stream.skip(offset);
+      int bytesRemaining = length > 0 ? length : Integer.MAX_VALUE;
+      int bytes = 0;
+
+      while (bytesRemaining > 0
+          && (bytes = stream.read(buffer, 0, Math.min(bytesRemaining, buffer.length))) != -1) {
+        textArray.write(buffer, 0, bytes);
+        bytesRemaining -= bytes;
+      }
+      stream.close();
+    } catch (IOException e) {
+      throw new RuntimeException("Failed to read license or metadata text.", e);
+    }
+    try {
+      return textArray.toString("UTF-8");
+    } catch (UnsupportedEncodingException e) {
+      throw new RuntimeException("Unsupported encoding UTF8. This should always be supported.", e);
+    }
+  }
+}