Android: Add simple launcher

This adds a minimal launcher activity for the android app, which does
the followings:

- Opens a file chooser to let user select a zip file
- Extracts the zip into the app's internal storage
- Launches the SDL activity

android/app/build.gradle

@@ -11,7 +11,7 @@ android {
     compileSdkVersion 26
     defaultConfig {
         if (buildAsApplication) {
-            applicationId "org.libsdl.app"
+            applicationId "io.github.kichikuou.system3"
         }
         minSdkVersion 16
         targetSdkVersion 26

android/app/src/main/AndroidManifest.xml

@@ -3,7 +3,7 @@
      com.gamemaker.game
 -->
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
-    package="org.libsdl.app"
+    package="io.github.kichikuou.system3"
     android:versionCode="1"
     android:versionName="1.0"
     android:installLocation="auto">
@@ -51,17 +51,21 @@
         <!-- Example of setting SDL hints from AndroidManifest.xml:
         <meta-data android:name="SDL_ENV.SDL_ACCELEROMETER_AS_JOYSTICK" android:value="0"/>
          -->
-     
-        <activity android:name="SDLActivity"
+
+        <activity android:name=".LauncherActivity">
+            <intent-filter>
+                <action android:name="android.intent.action.MAIN" />
+                <category android:name="android.intent.category.LAUNCHER" />
+            </intent-filter>
+        </activity>
+
+        <activity android:name=".GameActivity"
             android:label="@string/app_name"
             android:alwaysRetainTaskState="true"
             android:launchMode="singleInstance"
             android:configChanges="orientation|uiMode|screenLayout|screenSize|smallestScreenSize|keyboard|keyboardHidden|navigation"
             >
-            <intent-filter>
-                <action android:name="android.intent.action.MAIN" />
-                <category android:name="android.intent.category.LAUNCHER" />
-            </intent-filter>
+
             <!-- Drop file event -->
             <!--
             <intent-filter>

android/app/src/main/java/io/github/kichikuou/system3/GameActivity.java

@@ -0,0 +1,35 @@
+/* Copyright (C) 2019 <KichikuouChrome@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+*/
+package io.github.kichikuou.system3;
+
+import org.libsdl.app.SDLActivity;
+
+public class GameActivity extends SDLActivity {
+    @Override
+    protected String[] getLibraries() {
+        return new String[] {
+            "hidapi",
+            "SDL2",
+            // "SDL2_image",
+            // "SDL2_mixer",
+            // "SDL2_net",
+            // "SDL2_ttf",
+            "system3"
+        };
+    }
+}

android/app/src/main/java/io/github/kichikuou/system3/LauncherActivity.java

@@ -0,0 +1,91 @@
+/* Copyright (C) 2019 <KichikuouChrome@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+*/
+package io.github.kichikuou.system3;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Build;
+import android.os.Bundle;
+import android.util.Log;
+
+import java.io.BufferedInputStream;
+import java.io.BufferedOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+public class LauncherActivity extends Activity {
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
+        i.setType("application/zip");
+        startActivityForResult(Intent.createChooser(i, "Choose a file"), 0);
+    }
+
+    @Override
+    public void onActivityResult(int requestCode, int resultCode, Intent data) {
+        if (resultCode == RESULT_OK)
+            extractFiles(data.getData(), getApplicationContext().getFilesDir());
+        startGame();
+    }
+
+    boolean extractFiles(Uri zipUri, File outDir) {
+        try {
+            InputStream input = getContentResolver().openInputStream(zipUri);
+            if (input == null)
+                return false;
+            ZipInputStream zip;
+            if (Build.VERSION.SDK_INT >= 24)
+                zip = new ZipInputStream(new BufferedInputStream(input), Charset.forName("Shift_JIS"));
+            else
+                zip = new ZipInputStream(new BufferedInputStream(input));
+            byte[] buffer = new byte[4096];
+            ZipEntry zipEntry;
+            while ((zipEntry = zip.getNextEntry()) != null) {
+                File entryName = new File(zipEntry.getName());
+                if (zipEntry.isDirectory())
+                    continue;
+                Log.d("Extracting", entryName.toString());
+                File outFile = new File(outDir, entryName.getName());
+                BufferedOutputStream output = new BufferedOutputStream(new FileOutputStream(outFile));
+                int size;
+                while ((size = zip.read(buffer)) > 0) {
+                    output.write(buffer, 0, size);
+                }
+                output.close();
+            }
+            zip.close();
+            return true;
+        } catch (IOException e) {
+            Log.e("launcher", "Error while extracting zip", e);
+            return false;
+        }
+    }
+
+    void startGame() {
+        Intent i = new Intent();
+        i.setClass(getApplicationContext(), GameActivity.class);
+        startActivity(i);
+    }
+}

android/app/src/main/res/values/strings.xml

@@ -1,3 +1,3 @@
 <resources>
-    <string name="app_name">Game</string>
+    <string name="app_name">system3</string>
 </resources>

src/sdlmain.cpp

@@ -1,6 +1,7 @@
 #include "common.h"
 #include "fileio.h"
 #include "sys/nact.h"
+#include <unistd.h>
 #ifdef __EMSCRIPTEN__
 #include <emscripten.h>
 #include <emscripten/html5.h>
@@ -14,6 +15,12 @@ SDL_Window* g_window;
 
 int main(int argc, char *argv[])
 {
+#ifdef __ANDROID__
+	// Chdir to the internal storage path where the launcher should have placed
+	// game files.
+	chdir(SDL_AndroidGetInternalStoragePath());
+#endif
+
 	SDL_Init(SDL_INIT_VIDEO);
 
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