TunnelEditorFragment: rewrite and simplify

This should remove some null pointer dereferences and overall make the
thing more robust.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 78 insertions, 108 deletions

diff --git a/app/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.java b/app/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.java
index 0b4d74d8..e4555512 100644
--- a/app/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.java
+++ b/app/src/main/java/com/wireguard/android/fragment/TunnelEditorFragment.java
@@ -35,65 +35,50 @@ public class TunnelEditorFragment extends BaseFragment {
     private static final String TAG = "WireGuard/" + TunnelEditorFragment.class.getSimpleName();
 
     private TunnelEditorFragmentBinding binding;
-    private boolean isViewStateRestored;
-    private Config localConfig = new Config();
-    private Tunnel localTunnel;
-    private String originalName;
-
-    private static <T extends Parcelable> T copyParcelable(final T original) {
-        if (original == null)
-            return null;
-        final Parcel parcel = Parcel.obtain();
-        parcel.writeParcelable(original, 0);
-        parcel.setDataPosition(0);
-        final T copy = parcel.readParcelable(original.getClass().getClassLoader());
-        parcel.recycle();
-        return copy;
+    private Tunnel tunnel;
+
+    private void onConfigLoaded(final String name, final Config config) {
+        binding.setConfig(new Config.Observable(config, name));
     }
 
-    private void onConfigLoaded(final Config config) {
-        localConfig = copyParcelable(config);
-        if (binding != null && isViewStateRestored)
-            binding.setConfig(new Config.Observable(localConfig, originalName));
+    @Override
+    public void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setHasOptionsMenu(true);
     }
 
-    private void onConfigSaved(@SuppressWarnings("unused") final Config config,
-                               final Throwable throwable) {
-        final String message;
-        if (throwable == null) {
-            message = getString(R.string.config_save_success, localTunnel.getName());
-            Log.d(TAG, message);
-            onFinished();
-        } else {
-            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
-            message = getString(R.string.config_save_error, localTunnel.getName(), error);
-            Log.e(TAG, message, throwable);
-            if (binding != null) {
-                final CoordinatorLayout container = binding.mainContainer;
-                Snackbar.make(container, message, Snackbar.LENGTH_LONG).show();
-            }
-        }
+    @Override
+    public void onSelectedTunnelChanged(final Tunnel oldTunnel, final Tunnel newTunnel) {
+        tunnel = newTunnel;
+        if (binding == null)
+            return;
+        binding.setConfig(new Config.Observable(null, null));
+        if (tunnel != null)
+            tunnel.getConfigAsync().thenAccept(a -> onConfigLoaded(tunnel.getName(), a));
     }
 
     @Override
-    public void onCreate(final Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        if (savedInstanceState != null) {
-            localConfig = savedInstanceState.getParcelable(KEY_LOCAL_CONFIG);
-            originalName = savedInstanceState.getString(KEY_ORIGINAL_NAME);
-        }
-        // Erase the remains of creating or editing a different tunnel.
-        if (getSelectedTunnel() != null && !getSelectedTunnel().getName().equals(originalName)) {
-            // The config must be loaded asynchronously since it's not an observable property.
-            localConfig = null;
-            originalName = getSelectedTunnel().getName();
-            getSelectedTunnel().getConfigAsync().thenAccept(this::onConfigLoaded);
-        } else if (getSelectedTunnel() == null && originalName != null) {
-            localConfig = new Config();
-            originalName = null;
+    public void onSaveInstanceState(@NonNull final Bundle outState) {
+        outState.putParcelable(KEY_LOCAL_CONFIG, binding.getConfig());
+        outState.putString(KEY_ORIGINAL_NAME, tunnel == null ? null : tunnel.getName());
+        super.onSaveInstanceState(outState);
+    }
+
+    @Override
+    public void onViewStateRestored(final Bundle savedInstanceState) {
+        if (savedInstanceState == null) {
+            onSelectedTunnelChanged(null, getSelectedTunnel());
+        } else {
+            tunnel = getSelectedTunnel();
+            Config.Observable config = savedInstanceState.getParcelable(KEY_LOCAL_CONFIG);
+            String originalName = savedInstanceState.getString(KEY_ORIGINAL_NAME);
+            if (tunnel != null && !tunnel.getName().equals(originalName))
+                onSelectedTunnelChanged(null, tunnel);
+            else
+                binding.setConfig(config);
         }
-        localTunnel = getSelectedTunnel();
-        setHasOptionsMenu(true);
+
+        super.onViewStateRestored(savedInstanceState);
     }
 
     @Override
@@ -131,7 +116,7 @@ public class TunnelEditorFragment extends BaseFragment {
         // Tell the activity to finish itself or go back to the detail view.
         getActivity().runOnUiThread(() -> {
             // The selected tunnel has to actually change, but we have to remember this one.
-            final Tunnel savedTunnel = localTunnel;
+            final Tunnel savedTunnel = tunnel;
             if (savedTunnel == getSelectedTunnel())
                 setSelectedTunnel(null);
             setSelectedTunnel(savedTunnel);
@@ -142,32 +127,31 @@ public class TunnelEditorFragment extends BaseFragment {
     public boolean onOptionsItemSelected(final MenuItem item) {
         switch (item.getItemId()) {
             case R.id.menu_action_save:
-                final Tunnel selectedTunnel = getSelectedTunnel();
-                if (localConfig != null) {
-                    try {
-                        binding.getConfig().commitData(localConfig);
-                    } catch (Exception e) {
-                        final String error = ExceptionLoggers.unwrap(e).getMessage();
-                        final String message = getString(R.string.config_save_error, localTunnel.getName(), error);
-                        Log.e(TAG, message, e);
-                        final CoordinatorLayout container = binding.mainContainer;
-                        Snackbar.make(container, error, Snackbar.LENGTH_LONG).show();
-                        return false;
-                    }
+                Config newConfig = new Config();
+                try {
+                    binding.getConfig().commitData(newConfig);
+                } catch (Exception e) {
+                    final String error = ExceptionLoggers.unwrap(e).getMessage();
+                    final String tunnelName = tunnel == null ? binding.getConfig().getName() : tunnel.getName();
+                    final String message = getString(R.string.config_save_error, tunnelName, error);
+                    Log.e(TAG, message, e);
+                    final CoordinatorLayout container = binding.mainContainer;
+                    Snackbar.make(container, error, Snackbar.LENGTH_LONG).show();
+                    return false;
                 }
-                if (selectedTunnel == null) {
+                if (tunnel == null) {
                     Log.d(TAG, "Attempting to create new tunnel " + binding.getConfig().getName());
                     final TunnelManager manager = Application.getComponent().getTunnelManager();
-                    manager.create(binding.getConfig().getName(), localConfig)
+                    manager.create(binding.getConfig().getName(), newConfig)
                             .whenComplete(this::onTunnelCreated);
-                } else if (!selectedTunnel.getName().equals(binding.getConfig().getName())) {
+                } else if (!tunnel.getName().equals(binding.getConfig().getName())) {
                     Log.d(TAG, "Attempting to rename tunnel to " + binding.getConfig().getName());
-                    selectedTunnel.setName(binding.getConfig().getName())
-                            .whenComplete(this::onTunnelRenamed);
-                } else if (localConfig != null) {
-                    Log.d(TAG, "Attempting to save config of " + selectedTunnel.getName());
-                    selectedTunnel.setConfig(localConfig)
-                            .whenComplete(this::onConfigSaved);
+                    tunnel.setName(binding.getConfig().getName())
+                            .whenComplete((a, b) -> onTunnelRenamed(tunnel, newConfig, a, b));
+                } else {
+                    Log.d(TAG, "Attempting to save config of " + tunnel.getName());
+                    tunnel.setConfig(newConfig)
+                            .whenComplete((a, b) -> onConfigSaved(tunnel, a, b));
                 }
                 return true;
             default:
@@ -175,36 +159,30 @@ public class TunnelEditorFragment extends BaseFragment {
         }
     }
 
-    @Override
-    public void onSaveInstanceState(@NonNull final Bundle outState) {
-        outState.putParcelable(KEY_LOCAL_CONFIG, localConfig);
-        outState.putString(KEY_ORIGINAL_NAME, originalName);
-        super.onSaveInstanceState(outState);
-    }
-
-    @Override
-    public void onSelectedTunnelChanged(final Tunnel oldTunnel, final Tunnel newTunnel) {
-        // Erase the remains of creating or editing a different tunnel.
-        if (newTunnel != null) {
-            // The config must be loaded asynchronously since it's not an observable property.
-            localConfig = null;
-            originalName = newTunnel.getName();
-            newTunnel.getConfigAsync().thenAccept(this::onConfigLoaded);
+    private void onConfigSaved(final Tunnel savedTunnel, final Config config,
+                               final Throwable throwable) {
+        final String message;
+        if (throwable == null) {
+            message = getString(R.string.config_save_success, savedTunnel.getName());
+            Log.d(TAG, message);
+            onFinished();
         } else {
-            localConfig = new Config();
-            if (binding != null && isViewStateRestored)
-                binding.setConfig(new Config.Observable(localConfig, ""));
-            originalName = null;
+            final String error = ExceptionLoggers.unwrap(throwable).getMessage();
+            message = getString(R.string.config_save_error, savedTunnel.getName(), error);
+            Log.e(TAG, message, throwable);
+            if (binding != null) {
+                final CoordinatorLayout container = binding.mainContainer;
+                Snackbar.make(container, message, Snackbar.LENGTH_LONG).show();
+            }
         }
-        localTunnel = newTunnel;
     }
 
-    private void onTunnelCreated(final Tunnel tunnel, final Throwable throwable) {
+    private void onTunnelCreated(final Tunnel newTunnel, final Throwable throwable) {
         final String message;
         if (throwable == null) {
+            tunnel = newTunnel;
             message = getString(R.string.tunnel_create_success, tunnel.getName());
             Log.d(TAG, message);
-            localTunnel = tunnel;
             onFinished();
         } else {
             final String error = ExceptionLoggers.unwrap(throwable).getMessage();
@@ -217,14 +195,15 @@ public class TunnelEditorFragment extends BaseFragment {
         }
     }
 
-    private void onTunnelRenamed(final String name, final Throwable throwable) {
+    private void onTunnelRenamed(final Tunnel renamedTunnel, final Config newConfig,
+                                 final String name, final Throwable throwable) {
         final String message;
         if (throwable == null) {
-            message = getString(R.string.tunnel_rename_success, localTunnel.getName(), name);
+            message = getString(R.string.tunnel_rename_success, renamedTunnel.getName());
             Log.d(TAG, message);
             // Now save the rest of configuration changes.
-            Log.d(TAG, "Attempting to save config of renamed tunnel " + localTunnel.getName());
-            localTunnel.setConfig(localConfig).whenComplete(this::onConfigSaved);
+            Log.d(TAG, "Attempting to save config of renamed tunnel " + tunnel.getName());
+            renamedTunnel.setConfig(newConfig).whenComplete((a, b) -> onConfigSaved(renamedTunnel, a, b));
         } else {
             final String error = ExceptionLoggers.unwrap(throwable).getMessage();
             message = getString(R.string.tunnel_rename_error, error);
@@ -235,13 +214,4 @@ public class TunnelEditorFragment extends BaseFragment {
             }
         }
     }
-
-    @Override
-    public void onViewStateRestored(final Bundle savedInstanceState) {
-        super.onViewStateRestored(savedInstanceState);
-        if (localConfig == null)
-            localConfig = new Config();
-        binding.setConfig(new Config.Observable(localConfig, originalName));
-        isViewStateRestored = true;
-    }
 }