ToolsInstaller: Extract to its own classes

Signed-off-by: Samuel Holland <samuel@sholland.org>

4 files changed, 164 insertions, 72 deletions

diff --git a/app/src/main/java/com/wireguard/android/Application.java b/app/src/main/java/com/wireguard/android/Application.java
index e8d0d7db..8a46a8f6 100644
--- a/app/src/main/java/com/wireguard/android/Application.java
+++ b/app/src/main/java/com/wireguard/android/Application.java
@@ -15,6 +15,7 @@ import com.wireguard.android.configStore.FileConfigStore;
 import com.wireguard.android.model.TunnelManager;
 import com.wireguard.android.util.AsyncWorker;
 import com.wireguard.android.util.RootShell;
+import com.wireguard.android.util.ToolsInstaller;
 
 import java.util.concurrent.Executor;
 
@@ -56,6 +57,8 @@ public class Application extends android.app.Application {
 
         SharedPreferences getPreferences();
 
+        ToolsInstaller getToolsInstaller();
+
         TunnelManager getTunnelManager();
     }
 
diff --git a/app/src/main/java/com/wireguard/android/activity/SettingsActivity.java b/app/src/main/java/com/wireguard/android/activity/SettingsActivity.java
index 06d40ad5..3eb633ff 100644
--- a/app/src/main/java/com/wireguard/android/activity/SettingsActivity.java
+++ b/app/src/main/java/com/wireguard/android/activity/SettingsActivity.java
@@ -1,14 +1,10 @@
 package com.wireguard.android.activity;
 
 import android.app.Activity;
-import android.content.Context;
-import android.os.AsyncTask;
 import android.os.Bundle;
-import android.preference.Preference;
 import android.preference.PreferenceFragment;
 
 import com.wireguard.android.R;
-import com.wireguard.android.util.RootShell;
 
 /**
  * Interface for changing application-global persistent settings.
@@ -30,74 +26,6 @@ public class SettingsActivity extends Activity {
         public void onCreate(final Bundle savedInstanceState) {
             super.onCreate(savedInstanceState);
             addPreferencesFromResource(R.xml.preferences);
-            final Preference installTools = findPreference("install_cmd_line_tools");
-            installTools.setOnPreferenceClickListener(preference -> {
-                new ToolsInstaller(preference).execute();
-                return true;
-            });
-        }
-    }
-
-    private static final class ToolsInstaller extends AsyncTask<Void, Void, Integer> {
-        private static final String[][] LIBRARY_NAMED_EXECUTABLES = {
-                {"libwg.so", "wg"},
-                {"libwg-quick.so", "wg-quick"}
-        };
-
-        private final Context context;
-        private final Preference preference;
-
-        private ToolsInstaller(final Preference preference) {
-            context = preference.getContext();
-            this.preference = preference;
-            preference.setEnabled(false);
-            preference.setSummary(context.getString(R.string.install_cmd_line_tools_progress));
-        }
-
-        @Override
-        protected Integer doInBackground(final Void... voids) {
-            final String libDir = context.getApplicationInfo().nativeLibraryDir;
-            final StringBuilder cmd = new StringBuilder();
-
-            cmd.append("set -ex;");
-
-            for (final String[] libraryNamedExecutable : LIBRARY_NAMED_EXECUTABLES) {
-                final String arg1 = '\'' + libDir + '/' + libraryNamedExecutable[0] + '\'';
-                final String arg2 = "'/system/xbin/" + libraryNamedExecutable[1] + '\'';
-
-                cmd.append(String.format("cmp -s %s %s && ", arg1, arg2));
-            }
-            cmd.append("exit 114;");
-
-            cmd.append("trap 'mount -o ro,remount /system' EXIT;");
-            cmd.append("mount -o rw,remount /system;");
-
-            for (final String[] libraryNamedExecutable : LIBRARY_NAMED_EXECUTABLES) {
-                final String arg1 = '\'' + libDir + '/' + libraryNamedExecutable[0] + '\'';
-                final String arg2 = "'/system/xbin/" + libraryNamedExecutable[1] + '\'';
-                cmd.append(String.format("cp %s %s; chmod 755 %s;", arg1, arg2, arg2));
-            }
-
-            return new RootShell(context).run(null, cmd.toString());
-        }
-
-        @Override
-        protected void onPostExecute(final Integer ret) {
-            final String status;
-
-            switch (ret) {
-                case 0:
-                    status = context.getString(R.string.install_cmd_line_tools_success);
-                    break;
-                case 114 /* OsConstants.EALREADY */:
-                    status = context.getString(R.string.install_cmd_line_tools_already);
-                    break;
-                default:
-                    status = context.getString(R.string.install_cmd_line_tools_failure);
-                    break;
-            }
-            preference.setSummary(status);
-            preference.setEnabled(true);
         }
     }
 }
diff --git a/app/src/main/java/com/wireguard/android/preference/ToolsInstallerPreference.java b/app/src/main/java/com/wireguard/android/preference/ToolsInstallerPreference.java
new file mode 100644
index 00000000..c9dfa7b7
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/preference/ToolsInstallerPreference.java
@@ -0,0 +1,91 @@
+package com.wireguard.android.preference;
+
+import android.content.Context;
+import android.preference.Preference;
+import android.system.OsConstants;
+import android.util.AttributeSet;
+
+import com.wireguard.android.Application;
+import com.wireguard.android.Application.ApplicationComponent;
+import com.wireguard.android.R;
+import com.wireguard.android.util.AsyncWorker;
+import com.wireguard.android.util.ToolsInstaller;
+
+/**
+ * Preference implementing a button that asynchronously runs {@code ToolsInstaller} and displays the
+ * result as the preference summary.
+ */
+
+public class ToolsInstallerPreference extends Preference {
+    private final AsyncWorker asyncWorker;
+    private final ToolsInstaller toolsInstaller;
+    private State state = State.INITIAL;
+
+    public ToolsInstallerPreference(final Context context, final AttributeSet attrs) {
+        super(context, attrs);
+        final ApplicationComponent applicationComponent = Application.getComponent();
+        asyncWorker = applicationComponent.getAsyncWorker();
+        toolsInstaller = applicationComponent.getToolsInstaller();
+    }
+
+    public ToolsInstallerPreference(final Context context) {
+        this(context, null);
+    }
+
+    private static State mapResultToState(final int scriptResult) {
+        if (scriptResult == OsConstants.EXIT_SUCCESS)
+            return State.SUCCESS;
+        else if (scriptResult == OsConstants.EALREADY)
+            return State.ALREADY;
+        else
+            return State.FAILURE;
+    }
+
+    @Override
+    public CharSequence getSummary() {
+        return getContext().getString(state.messageResourceId);
+    }
+
+    @Override
+    public CharSequence getTitle() {
+        return getContext().getString(getTitleRes());
+    }
+
+    @Override
+    public int getTitleRes() {
+        return R.string.tools_installer_title;
+    }
+
+    @Override
+    protected void onClick() {
+        setState(State.WORKING);
+        asyncWorker.supplyAsync(toolsInstaller::install)
+                .thenApply(ToolsInstallerPreference::mapResultToState)
+                .thenAccept(this::setState);
+    }
+
+    private void setState(final State state) {
+        if (this.state == state)
+            return;
+        this.state = state;
+        if (isEnabled() != state.shouldEnableView)
+            setEnabled(state.shouldEnableView);
+        notifyChanged();
+    }
+
+    private enum State {
+        ALREADY(R.string.tools_installer_already, false),
+        FAILURE(R.string.tools_installer_failure, true),
+        INITIAL(R.string.tools_installer_initial, true),
+        SUCCESS(R.string.tools_installer_success, false),
+        WORKING(R.string.tools_installer_working, false);
+
+        private final int messageResourceId;
+        private final boolean shouldEnableView;
+
+        State(final int messageResourceId, final boolean shouldEnableView) {
+            this.messageResourceId = messageResourceId;
+            this.shouldEnableView = shouldEnableView;
+        }
+    }
+}
diff --git a/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
new file mode 100644
index 00000000..8496a310
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/util/ToolsInstaller.java
@@ -0,0 +1,70 @@
+package com.wireguard.android.util;
+
+import android.content.Context;
+import android.system.OsConstants;
+
+import com.wireguard.android.Application.ApplicationContext;
+import com.wireguard.android.Application.ApplicationScope;
+
+import java.io.File;
+import java.util.Arrays;
+import java.util.List;
+
+import javax.inject.Inject;
+
+/**
+ * Helper to install WireGuard tools to the system partition.
+ */
+
+@ApplicationScope
+public final class ToolsInstaller {
+    private static final String[][] EXECUTABLES = {
+            {"libwg.so", "wg"},
+            {"libwg-quick.so", "wg-quick"},
+    };
+    private static final File[] INSTALL_DIRS = {
+            new File("/system/xbin"),
+            new File("/system/bin"),
+    };
+
+    private final String nativeLibraryDir;
+    private final RootShell rootShell;
+
+    @Inject
+    public ToolsInstaller(@ApplicationContext final Context context, final RootShell rootShell) {
+        nativeLibraryDir = context.getApplicationInfo().nativeLibraryDir;
+        this.rootShell = rootShell;
+    }
+
+    private static File getInstallDir() {
+        final String path = System.getenv("PATH");
+        if (path == null)
+            return INSTALL_DIRS[0];
+        final List<String> paths = Arrays.asList(path.split(":"));
+        for (final File dir : INSTALL_DIRS)
+            if (paths.contains(dir.getPath()) && dir.isDirectory())
+                return dir;
+        return null;
+    }
+
+    public int install() {
+        final File installDir = getInstallDir();
+        if (installDir == null)
+            return OsConstants.ENOENT;
+        final StringBuilder script = new StringBuilder("set -ex; ");
+        for (final String[] names : EXECUTABLES) {
+            script.append(String.format("cmp -s '%s' '%s' && ",
+                    new File(nativeLibraryDir, names[0]),
+                    new File(installDir, names[1])));
+        }
+        script.append("exit ").append(OsConstants.EALREADY).append("; ");
+        script.append("trap 'mount -o ro,remount /system' EXIT; mount -o rw,remount /system; ");
+        for (final String[] names : EXECUTABLES) {
+            script.append(String.format("cp %s %s; chmod 755 %s; ",
+                    new File(nativeLibraryDir, names[0]),
+                    new File(installDir, names[1]),
+                    new File(installDir, names[1])));
+        }
+        return rootShell.run(null, script.toString());
+    }
+}