1 files changed, 146 insertions, 0 deletions
diff --git a/app/src/main/java/com/wireguard/android/activity/MainActivity.java b/app/src/main/java/com/wireguard/android/activity/MainActivity.java
new file mode 100644
index 00000000..2d06a9a9
--- /dev/null
+++ b/app/src/main/java/com/wireguard/android/activity/MainActivity.java
@@ -0,0 +1,146 @@
+package com.wireguard.android.activity;
+
+import android.app.Fragment;
+import android.app.FragmentTransaction;
+import android.content.Intent;
+import android.os.Bundle;
+import android.util.Log;
+import android.view.Menu;
+import android.view.MenuItem;
+
+import com.wireguard.android.R;
+import com.wireguard.android.fragment.ConfigEditorFragment;
+import com.wireguard.android.fragment.TunnelDetailFragment;
+import com.wireguard.android.fragment.TunnelListFragment;
+import com.wireguard.android.model.Tunnel;
+
+import java9.util.stream.Stream;
+
+/**
+ * CRUD interface for WireGuard tunnels. This activity serves as the main entry point to the
+ * WireGuard application, and contains several fragments for listing, viewing details of, and
+ * editing the configuration and interface state of WireGuard tunnels.
+ */
+
+public class MainActivity extends BaseActivity {
+    private static final String KEY_STATE = "fragment_state";
+    private static final String TAG = MainActivity.class.getSimpleName();
+    private State state = State.EMPTY;
+
+    private boolean moveToState(final State nextState) {
+        Log.i(TAG, "Moving from " + state.name() + " to " + nextState.name());
+        if (nextState == state) {
+            return false;
+        } else if (nextState.layer > state.layer + 1) {
+            moveToState(State.ofLayer(state.layer + 1));
+            moveToState(nextState);
+            return true;
+        } else if (nextState.layer == state.layer + 1) {
+            final Fragment fragment = Fragment.instantiate(this, nextState.fragment);
+            final FragmentTransaction transaction = getFragmentManager().beginTransaction()
+                    .replace(R.id.master_fragment, fragment)
+                    .setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE);
+            if (state.layer > 0)
+                transaction.addToBackStack(null);
+            transaction.commit();
+        } else if (nextState.layer == state.layer - 1) {
+            if (getFragmentManager().getBackStackEntryCount() == 0)
+                return false;
+            getFragmentManager().popBackStack();
+        } else if (nextState.layer < state.layer - 1) {
+            moveToState(State.ofLayer(state.layer - 1));
+            moveToState(nextState);
+            return true;
+        }
+        state = nextState;
+        if (state.layer > 1) {
+            if (getActionBar() != null)
+                getActionBar().setDisplayHomeAsUpEnabled(true);
+        } else {
+            if (getActionBar() != null)
+                getActionBar().setDisplayHomeAsUpEnabled(false);
+            setSelectedTunnel(null);
+        }
+        return true;
+    }
+
+    @Override
+    public void onBackPressed() {
+        if (!moveToState(State.ofLayer(state.layer - 1)))
+            super.onBackPressed();
+    }
+
+    @Override
+    protected void onCreate(final Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.main_activity);
+        if (savedInstanceState != null && savedInstanceState.getString(KEY_STATE) != null)
+            state = State.valueOf(savedInstanceState.getString(KEY_STATE));
+        if (state == State.EMPTY) {
+            State initialState = getSelectedTunnel() != null ? State.DETAIL : State.LIST;
+            if (getIntent() != null && getIntent().getStringExtra(KEY_STATE) != null)
+                initialState = State.valueOf(getIntent().getStringExtra(KEY_STATE));
+            moveToState(initialState);
+        }
+    }
+
+    @Override
+    public boolean onCreateOptionsMenu(final Menu menu) {
+        getMenuInflater().inflate(R.menu.main_activity, menu);
+        return true;
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(final MenuItem item) {
+        switch (item.getItemId()) {
+            case android.R.id.home:
+                // The back arrow in the action bar should act the same as the back button.
+                moveToState(State.ofLayer(state.layer - 1));
+                return true;
+            case R.id.menu_action_edit:
+                if (getSelectedTunnel() != null)
+                    moveToState(State.EDITOR);
+                return true;
+            case R.id.menu_action_save:
+                // This menu item is handled by the editor fragment.
+                return false;
+            case R.id.menu_settings:
+                startActivity(new Intent(this, SettingsActivity.class));
+                return true;
+            default:
+                return super.onOptionsItemSelected(item);
+        }
+    }
+
+    @Override
+    protected void onSaveInstanceState(final Bundle outState) {
+        outState.putString(KEY_STATE, state.name());
+        super.onSaveInstanceState(outState);
+    }
+
+
+    @Override
+    protected Tunnel onSelectedTunnelChanged(final Tunnel oldTunnel, final Tunnel newTunnel) {
+        moveToState(newTunnel != null ? State.DETAIL : State.LIST);
+        return newTunnel;
+    }
+
+    private enum State {
+        EMPTY(null, 0),
+        LIST(TunnelListFragment.class, 1),
+        DETAIL(TunnelDetailFragment.class, 2),
+        EDITOR(ConfigEditorFragment.class, 3);
+
+        private final String fragment;
+        private final int layer;
+
+        State(final Class<? extends Fragment> fragment, final int layer) {
+            this.fragment = fragment != null ? fragment.getName() : null;
+            this.layer = layer;
+        }
+
+        private static State ofLayer(final int layer) {
+            return Stream.of(State.values()).filter(s -> s.layer == layer).findFirst().get();
+        }
+    }
+}