Have the engine access weights from external storage

LeelaChessEngine/gradle.properties

@@ -0,0 +1,2 @@
+android.enableJetifier=true
+android.useAndroidX=true

LeelaChessEngine/leelaChessEngine/build.gradle

@@ -19,4 +19,5 @@ android {
 
 dependencies {
     implementation project(':chessEngineSupportLibrary')
+    implementation 'androidx.core:core:1.2.0'
 }

LeelaChessEngine/leelaChessEngine/src/main/AndroidManifest.xml

@@ -3,6 +3,7 @@
     package="com.kalab.chess.leelaengine"
     android:versionCode="1"
     android:versionName="0.25dev">
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
     <application
         android:allowBackup="true"
         android:icon="@drawable/ic_launcher"

LeelaChessEngine/leelaChessEngine/src/main/java/com/kalab/chess/leelaengine/MainActivity.java

@@ -1,16 +1,21 @@
 package com.kalab.chess.leelaengine;
 
+import android.Manifest;
 import android.app.Activity;
 import android.content.Context;
 import android.content.Intent;
 import android.content.pm.PackageManager;
+import android.content.res.AssetFileDescriptor;
+import android.content.res.AssetManager;
 import android.graphics.Typeface;
 import android.net.Uri;
 import android.os.Bundle;
+import android.os.Environment;
 import android.text.SpannableStringBuilder;
 import android.text.method.LinkMovementMethod;
 import android.text.style.ClickableSpan;
 import android.util.AttributeSet;
+import android.util.Log;
 import android.view.Gravity;
 import android.view.View;
 import android.view.ViewGroup;
@@ -21,12 +26,20 @@
 import android.text.style.RelativeSizeSpan;
 import android.text.style.ForegroundColorSpan;
 
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
 public class MainActivity extends Activity {
 
 	private class HeaderView extends LinearLayout {
 		public HeaderView(Context context) {
 			super(context);
-
 			ImageView icon = new ImageView(context);
 			icon.setImageResource(R.drawable.ic_launcher);
 			int iconSize = getRawPixels(48f);
@@ -35,7 +48,6 @@ public HeaderView(Context context) {
 			iconParams.height = iconSize;
 			iconParams.gravity = Gravity.CENTER_VERTICAL;
 			addView(icon, iconParams);
-
 			TextView text = new TextView(context);
 			text.setGravity(Gravity.CENTER);
 			text.setText(R.string.app_name);
@@ -61,22 +73,26 @@ public void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
 		}
 	}
 
+	private static String baseDirPath = "lc0";
+	private static String weightsDirPath = "networks";
+
 	@Override
 	public void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
+		createDirectories();
+		createLayout();
+	}
 
+	void createLayout() {
 		LinearLayout layout = new LinearLayout(this);
 		layout.setOrientation(LinearLayout.VERTICAL);
 		int spacing = getRawPixels(12f);
 		layout.setPadding(spacing, spacing, spacing, spacing);
-
 		HeaderView header = new HeaderView(this);
 		LinearLayout.LayoutParams headerParams = LinearLayoutParams();
 		headerParams.gravity = Gravity.CENTER_HORIZONTAL;
 		layout.addView(header, headerParams);
-
 		layout.addView(new VerticalSeparator(this));
-
 		TextView label = new TextView(this);
 		label.setMovementMethod(LinkMovementMethod.getInstance());
 		label.setText(getLabel());
@@ -85,7 +101,9 @@ public void onCreate(Bundle savedInstanceState) {
 		labelParams.weight = 1.0f;
 		labelParams.topMargin = spacing;
 		layout.addView(label, labelParams);
-
+		TextView notice = new TextView(this);
+		notice.setText(getNotice());
+		layout.addView(notice);
 		setContentView(layout);
 	}
 
@@ -104,57 +122,50 @@ String getNetworkWeights() {
 
 	private CharSequence getLabel()  {
 		SpannableStringBuilder b = new SpannableStringBuilder();
-
 		appendLine(b, getText(R.string.includes_the_following_engines));
-
 		appendDetail(b, "Chess Engine Version", getVersionName());
-
 		appendDetail(b, "Network Weights File", getNetworkWeights());
-
 		appendLine(b, getText(R.string.to_use_them));
-
 		appendLink(b, getText(R.string.released_under), getText(R.string.source_code));
-
 		return b;
 	}
 
+	private CharSequence getNotice()  {
+		if (!getPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE))
+			return getText(R.string.storage_permission);
+		else
+			return null;
+	}
+
 	private static void appendLine(SpannableStringBuilder b, CharSequence line) {
 		b.append(line);
 		b.append("\n\n");
 	}
 
 	private static void appendDetail(SpannableStringBuilder b, String title, String subtitle) {
 		b.append("    ");
-
 		int nameStart = b.length();
 		b.append(title);
 		b.setSpan(new StyleSpan(Typeface.BOLD), nameStart, b.length(), 0);
-
 		b.append("\n    ");
-
 		int subtitleStart = b.length();
 		b.append(subtitle);
-
 		b.setSpan(new RelativeSizeSpan(0.8f), subtitleStart, b.length(), 0);
 		b.setSpan(new ForegroundColorSpan(0xff808080), subtitleStart, b.length(), 0);
-
 		b.append("\n\n");
 	}
 
 	private void appendLink(SpannableStringBuilder b, CharSequence line, final CharSequence link) {
 		b.append(line);
 		b.append(" (");
-
 		int downloadLinkStart = b.length();
-
 		b.append("source code");
 		b.setSpan(new ClickableSpan() {
 			@Override
 			public void onClick(View widget) {
 				launchUri(link);
 			}
 		}, downloadLinkStart, b.length(), 0);
-
 		b.append(").");
 	}
 
@@ -173,4 +184,86 @@ private int getRawPixels(float dp) {
 	private LinearLayout.LayoutParams LinearLayoutParams() {
 		return new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT);
 	}
+
+	/** Create directory structure on external storage. */
+	private void createDirectories() {
+		if (!getPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE))
+			return;
+		copyAssets(baseDirPath, weightsDirPath);
+	}
+
+	boolean getPermission(String permission) {
+		if (ContextCompat.checkSelfPermission(this, permission) ==
+				PackageManager.PERMISSION_GRANTED) {
+			return true;
+		} else {
+			ActivityCompat.requestPermissions(this, new String[]{permission}, 0);
+			return false;
+		}
+	}
+
+	@Override
+	public void onRequestPermissionsResult(int code, String[] permissions, int[] results) {
+		for (int i = 0; i < permissions.length; ++i) {
+			if (results[i] == PackageManager.PERMISSION_GRANTED) {
+				if (permissions[i].equals(Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
+					createDirectories();
+				}
+			}
+		}
+	}
+
+	/** Copy assets to external storage. */
+	private void copyAssets(String base, String dir) {
+		AssetManager assetManager = getAssets();
+		String[] files = null;
+		try {
+			files = assetManager.list(dir);
+		} catch (IOException e) {
+			Log.e("tag", "Failed to get asset file list.", e);
+		}
+		if (files != null) {
+			for (String filename : files) {
+				InputStream in = null;
+				OutputStream out = null;
+				try {
+					File outDir = new File(Environment.getExternalStorageDirectory() + File.separator + base + File.separator + dir);
+					outDir.mkdirs();
+					File outFile = new File(outDir,  filename);
+
+					AssetFileDescriptor asset = assetManager.openFd(dir + File.separator + filename);
+					if (asset.getLength() != outFile.length()) {
+						in = asset.createInputStream();
+						out = new FileOutputStream(outFile);
+						copyFile(in, out);
+					}
+				} catch (IOException e) {
+					Log.e("tag", "Failed to copy asset file: " + filename, e);
+				} finally {
+					if (in != null) {
+						try {
+							in.close();
+						} catch (IOException e) {
+							// NOOP
+						}
+					}
+					if (out != null) {
+						try {
+							out.close();
+						} catch (IOException e) {
+							// NOOP
+						}
+					}
+				}
+			}
+		}
+	}
+
+	private void copyFile(InputStream in, OutputStream out) throws IOException {
+		byte[] buffer = new byte[1024];
+		int read;
+		while((read = in.read(buffer)) != -1){
+			out.write(buffer, 0, read);
+		}
+	}
 }

LeelaChessEngine/leelaChessEngine/src/main/res/values/strings.xml

@@ -1,10 +1,11 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <string name="app_name">Leela Chess Zero Engine</string>
+    <string name="app_name">Leela Chess Zero</string>
     <string name="network_weights">591226</string>
     <string name="includes_the_following_engines">This package provides the Leela Chess Zero engine.</string>
     <string name="to_use_them">To use it, you need a chess application compatible with the Open Exchange protocol.</string>
     <string name="released_under">Leela Chess Zero is released under the terms of the GNU General Public License v3</string>
     <string name="build">Build</string>
-    <string name="source_code">https://github.com/LeelaChessZero/lc0</string>
+    <string name="source_code">https://github.com/LeelaChessZero</string>
+    <string name="storage_permission">To function properly, the engine needs to access its network weights file from the local storage. Please give storage permission to this application.</string>
 </resources>

LeelaChessEngine/leelaChessEngine/src/main/res/xml/enginelist.xml

@@ -4,6 +4,6 @@
     <engine
         name="Leela Chess Zero"
         filename="liblc0.so"
-        target="armeabi-v7a|arm64-v8a" />
+        target="armeabi-v7a|arm64-v8a|x86" />
 
 </enginelist>