custom_rules.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Copyright 2014 Google Inc. All rights reserved.

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.
-->
<project name="copy-google-play-games_lib" default="debug">

  <!-- Location of the Android SDL activity. -->
  <property name="sdlactivity" value="org/libsdl/app/SDLActivity.java" />

  <condition property="android_exe" value="android.bat" else="android">
    <os family="windows" />
  </condition>
  <condition property="ndkbuild_exe" value="ndk-build.cmd" else="ndk-build">
    <os family="windows" />
  </condition>

  <target name="initialize-google-play-games_lib"
          description="Initialize Google Play Games library in the project.">
    <!-- Copy the library to the project. -->
    <copy todir="google-play-services_lib">
      <fileset dir="${sdk.dir}/extras/google/google_play_services/libproject/google-play-services_lib"/>
    </copy>
    <!-- Create an ant project for the library. -->
    <exec executable="${android_exe}">
      <arg value="update"/>
      <arg value="project"/>
      <arg value="-p"/>
      <arg value="google-play-services_lib"/>
      <arg value="-t"/>
      <arg value="${target}"/>
    </exec>
  </target>

  <target name="get-sdl-path"
          description="Get SDL's location and save it in sdlpath.">
    <exec executable="${ndkbuild_exe}" outputproperty="sdlpath">
      <arg value="print_dependency"/>
      <arg value="DEP_DIR=SDL"/>
    </exec>
  </target>

  <target name="copy-sdl-activity"
          description="Copy SDL activity into the source directory."
          depends="get-sdl-path">
    <copy tofile="src_java/${sdlactivity}"
          file="${sdlpath}/android-project/src/${sdlactivity}"/>
  </target>

  <!-- Override the -pre-compile target in sdk/tools/ant/build.xml to copy
       the Google Play Games library and SDL Android activity to this
       directory before the build process starts. -->
  <target name="-pre-build"
          depends="initialize-google-play-games_lib, copy-sdl-activity" />
</project>