guard against ncurrent navigation controller destination being null

diff --git a/app/src/main/java/net/ktnx/mobileledger/ui/patterns/PatternsActivity.java b/app/src/main/java/net/ktnx/mobileledger/ui/patterns/PatternsActivity.java
deleted file mode 100644 (file)
index 945123d..0000000
--- a/app/src/main/java/net/ktnx/mobileledger/ui/patterns/PatternsActivity.java
+++ /dev/null
@@ -1,123 +0,0 @@
-/*
- * Copyright © 2021 Damyan Ivanov.
- * This file is part of MoLe.
- * MoLe is free software: you can distribute it and/or modify it
- * under the term of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your opinion), any later version.
- *
- * MoLe 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 terms for details.
- *
- * You should have received a copy of the GNU General Public License
- * along with MoLe. If not, see <https://www.gnu.org/licenses/>.
- */
-
-package net.ktnx.mobileledger.ui.patterns;
-
-import android.os.Bundle;
-import android.view.Menu;
-import android.view.MenuItem;
-
-import androidx.appcompat.app.ActionBar;
-import androidx.lifecycle.ViewModelProvider;
-import androidx.lifecycle.ViewModelStoreOwner;
-import androidx.navigation.NavController;
-import androidx.navigation.fragment.NavHostFragment;
-
-import net.ktnx.mobileledger.R;
-import net.ktnx.mobileledger.databinding.ActivityPatternsBinding;
-import net.ktnx.mobileledger.ui.activity.CrashReportingActivity;
-import net.ktnx.mobileledger.utils.Logger;
-
-import java.util.Objects;
-
-public class PatternsActivity extends CrashReportingActivity
-        implements PatternListFragment.OnPatternListFragmentInteractionListener {
-    public static final String ARG_ADD_PATTERN = "add-pattern";
-    private ActivityPatternsBinding b;
-    private NavController navController;
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        super.onCreateOptionsMenu(menu);
-        getMenuInflater().inflate(R.menu.pattern_list_menu, menu);
-
-        return true;
-    }
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        b = ActivityPatternsBinding.inflate(getLayoutInflater());
-        setContentView(b.getRoot());
-        setSupportActionBar(b.toolbar);
-        // Show the Up button in the action bar.
-        ActionBar actionBar = getSupportActionBar();
-        if (actionBar != null) {
-            actionBar.setDisplayHomeAsUpEnabled(true);
-        }
-
-        NavHostFragment navHostFragment = (NavHostFragment) Objects.requireNonNull(
-                getSupportFragmentManager().findFragmentById(R.id.fragment_container));
-        navController = navHostFragment.getNavController();
-
-        navController.addOnDestinationChangedListener((controller, destination, arguments) -> {
-            if (destination.getId() == R.id.patternListFragment) {
-                b.fabAdd.show();
-                b.fabSave.hide();
-                b.toolbarLayout.setTitle(getString(R.string.title_activity_patterns));
-            }
-            if (destination.getId() == R.id.patternDetailsFragment) {
-                b.fabAdd.hide();
-                b.fabSave.show();
-            }
-        });
-
-        b.toolbarLayout.setTitle(getString(R.string.title_activity_patterns));
-
-        b.fabAdd.setOnClickListener(v -> onEditPattern(null));
-        b.fabSave.setOnClickListener(v -> onSavePattern());
-    }
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        if (item.getItemId() == android.R.id.home) {
-            if (navController.getCurrentDestination()
-                             .getId() == R.id.patternDetailsFragment)
-                navController.popBackStack();
-            else
-                finish();
-
-            return true;
-        }
-        return super.onOptionsItemSelected(item);
-    }
-
-    @Override
-    public void onEditPattern(Long id) {
-        if (id == null) {
-            navController.navigate(R.id.action_patternListFragment_to_patternDetailsFragment);
-            b.toolbarLayout.setTitle(getString(R.string.title_new_pattern));
-        }
-        else {
-            Bundle bundle = new Bundle();
-            bundle.putLong(PatternDetailsFragment.ARG_PATTERN_ID, id);
-            navController.navigate(R.id.action_patternListFragment_to_patternDetailsFragment,
-                    bundle);
-            b.toolbarLayout.setTitle(getString(R.string.title_edit_pattern));
-        }
-    }
-    @Override
-    public void onSavePattern() {
-        final ViewModelStoreOwner viewModelStoreOwner =
-                navController.getViewModelStoreOwner(R.id.pattern_list_navigation);
-        PatternDetailsViewModel model =
-                new ViewModelProvider(viewModelStoreOwner).get(PatternDetailsViewModel.class);
-        Logger.debug("flow", "PatternsActivity.onSavePattern(): model=" + model);
-        model.onSavePattern();
-        navController.navigateUp();
-    }
-    public NavController getNavController() {
-        return navController;
-    }
-}
\ No newline at end of file

diff --git a/app/src/main/java/net/ktnx/mobileledger/ui/templates/TemplatesActivity.java b/app/src/main/java/net/ktnx/mobileledger/ui/templates/TemplatesActivity.java
new file mode 100644 (file)
index 0000000..0f1d20f
--- /dev/null
+++ b/app/src/main/java/net/ktnx/mobileledger/ui/templates/TemplatesActivity.java
@@ -0,0 +1,124 @@
+/*
+ * Copyright © 2021 Damyan Ivanov.
+ * This file is part of MoLe.
+ * MoLe is free software: you can distribute it and/or modify it
+ * under the term of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your opinion), any later version.
+ *
+ * MoLe 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 terms for details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MoLe. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package net.ktnx.mobileledger.ui.patterns;
+
+import android.os.Bundle;
+import android.view.Menu;
+import android.view.MenuItem;
+
+import androidx.appcompat.app.ActionBar;
+import androidx.lifecycle.ViewModelProvider;
+import androidx.lifecycle.ViewModelStoreOwner;
+import androidx.navigation.NavController;
+import androidx.navigation.fragment.NavHostFragment;
+
+import net.ktnx.mobileledger.R;
+import net.ktnx.mobileledger.databinding.ActivityPatternsBinding;
+import net.ktnx.mobileledger.ui.activity.CrashReportingActivity;
+import net.ktnx.mobileledger.utils.Logger;
+
+import java.util.Objects;
+
+public class PatternsActivity extends CrashReportingActivity
+        implements PatternListFragment.OnPatternListFragmentInteractionListener {
+    public static final String ARG_ADD_PATTERN = "add-pattern";
+    private ActivityPatternsBinding b;
+    private NavController navController;
+    @Override
+    public boolean onCreateOptionsMenu(Menu menu) {
+        super.onCreateOptionsMenu(menu);
+        getMenuInflater().inflate(R.menu.pattern_list_menu, menu);
+
+        return true;
+    }
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        b = ActivityPatternsBinding.inflate(getLayoutInflater());
+        setContentView(b.getRoot());
+        setSupportActionBar(b.toolbar);
+        // Show the Up button in the action bar.
+        ActionBar actionBar = getSupportActionBar();
+        if (actionBar != null) {
+            actionBar.setDisplayHomeAsUpEnabled(true);
+        }
+
+        NavHostFragment navHostFragment = (NavHostFragment) Objects.requireNonNull(
+                getSupportFragmentManager().findFragmentById(R.id.fragment_container));
+        navController = navHostFragment.getNavController();
+
+        navController.addOnDestinationChangedListener((controller, destination, arguments) -> {
+            if (destination.getId() == R.id.patternListFragment) {
+                b.fabAdd.show();
+                b.fabSave.hide();
+                b.toolbarLayout.setTitle(getString(R.string.title_activity_patterns));
+            }
+            if (destination.getId() == R.id.patternDetailsFragment) {
+                b.fabAdd.hide();
+                b.fabSave.show();
+            }
+        });
+
+        b.toolbarLayout.setTitle(getString(R.string.title_activity_patterns));
+
+        b.fabAdd.setOnClickListener(v -> onEditPattern(null));
+        b.fabSave.setOnClickListener(v -> onSavePattern());
+    }
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        if (item.getItemId() == android.R.id.home) {
+            final NavDestination currentDestination = navController.getCurrentDestination();
+            if (currentDestination != null &&
+                currentDestination.getId() == R.id.patternDetailsFragment)
+                navController.popBackStack();
+            else
+                finish();
+
+            return true;
+        }
+        return super.onOptionsItemSelected(item);
+    }
+
+    @Override
+    public void onEditPattern(Long id) {
+        if (id == null) {
+            navController.navigate(R.id.action_patternListFragment_to_patternDetailsFragment);
+            b.toolbarLayout.setTitle(getString(R.string.title_new_pattern));
+        }
+        else {
+            Bundle bundle = new Bundle();
+            bundle.putLong(PatternDetailsFragment.ARG_PATTERN_ID, id);
+            navController.navigate(R.id.action_patternListFragment_to_patternDetailsFragment,
+                    bundle);
+            b.toolbarLayout.setTitle(getString(R.string.title_edit_pattern));
+        }
+    }
+    @Override
+    public void onSavePattern() {
+        final ViewModelStoreOwner viewModelStoreOwner =
+                navController.getViewModelStoreOwner(R.id.pattern_list_navigation);
+        PatternDetailsViewModel model =
+                new ViewModelProvider(viewModelStoreOwner).get(PatternDetailsViewModel.class);
+        Logger.debug("flow", "PatternsActivity.onSavePattern(): model=" + model);
+        model.onSavePattern();
+        navController.navigateUp();
+    }
+    public NavController getNavController() {
+        return navController;
+    }
+}
\ No newline at end of file