Fix #841 - 🗑 Select neighbour list after deleting a list

Signed-off-by: Stefan Niedermann <info@niedermann.it>

4 files changed, 36 insertions, 10 deletions

diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainActivity.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainActivity.java
index f70bfbaaf..b98270c68 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainActivity.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/MainActivity.java
@@ -53,6 +53,7 @@ import com.nextcloud.android.sso.helper.SingleAccountHelper;
 import java.net.HttpURLConnection;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.NoSuchElementException;
 import java.util.Objects;
 
 import it.niedermann.android.crosstabdnd.CrossTabDragAndDrop;
@@ -771,12 +772,12 @@ public class MainActivity extends AppCompatActivity implements DeleteStackListen
             stackMoved = true;
             return true;
         } else if (itemId == R.id.delete_list) {
-            final long stackId = stackAdapter.getItem(binding.viewPager.getCurrentItem()).getLocalId();
-            mainViewModel.countCardsInStack(mainViewModel.getCurrentAccount().getId(), stackId, (numberOfCards) -> runOnUiThread(() -> {
+            final long stackLocalId = stackAdapter.getItem(binding.viewPager.getCurrentItem()).getLocalId();
+            mainViewModel.countCardsInStack(mainViewModel.getCurrentAccount().getId(), stackLocalId, (numberOfCards) -> runOnUiThread(() -> {
                 if (numberOfCards != null && numberOfCards > 0) {
-                    DeleteStackDialogFragment.newInstance(stackId, numberOfCards).show(getSupportFragmentManager(), DeleteStackDialogFragment.class.getCanonicalName());
+                    DeleteStackDialogFragment.newInstance(stackLocalId, numberOfCards).show(getSupportFragmentManager(), DeleteStackDialogFragment.class.getCanonicalName());
                 } else {
-                    onStackDeleted(stackId);
+                    onStackDeleted(stackLocalId);
                 }
             }));
             return true;
@@ -999,12 +1000,19 @@ public class MainActivity extends AppCompatActivity implements DeleteStackListen
     }
 
     @Override
-    public void onStackDeleted(Long stackLocalId) {
-        final long stackId = stackAdapter.getItem(binding.viewPager.getCurrentItem()).getLocalId();
-        mainViewModel.deleteStack(mainViewModel.getCurrentAccount().getId(), stackId, mainViewModel.getCurrentBoardLocalId(), new IResponseCallback<Void>() {
+    public void onStackDeleted(long stackLocalId) {
+        int nextStackPosition;
+        try {
+            nextStackPosition = stackAdapter.getNeighbourPosition(binding.viewPager.getCurrentItem());
+        } catch (NoSuchElementException | IndexOutOfBoundsException e) {
+            nextStackPosition = 0;
+            DeckLog.logError(e);
+        }
+        binding.viewPager.setCurrentItem(nextStackPosition);
+        mainViewModel.deleteStack(mainViewModel.getCurrentAccount().getId(), stackLocalId, mainViewModel.getCurrentBoardLocalId(), new IResponseCallback<Void>() {
             @Override
             public void onResponse(Void response) {
-                DeckLog.info("Successfully deleted stack with local id", stackLocalId, "and remote id", stackId);
+                DeckLog.info("Successfully deleted stack with local id", stackLocalId, "and remote id", stackLocalId);
             }
 
             @Override
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/DeleteStackListener.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/DeleteStackListener.java
index dfd1b4497..f0b5d68f7 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/DeleteStackListener.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/DeleteStackListener.java
@@ -1,5 +1,5 @@
 package it.niedermann.nextcloud.deck.ui.stack;
 
 public interface DeleteStackListener {
-    void onStackDeleted(Long stackLocalId);
+    void onStackDeleted(long stackLocalId);
 }
\ No newline at end of file
diff --git a/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackAdapter.java b/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackAdapter.java
index 1e0fd4e72..4867b3d85 100644
--- a/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackAdapter.java
+++ b/app/src/main/java/it/niedermann/nextcloud/deck/ui/stack/StackAdapter.java
@@ -7,6 +7,7 @@ import androidx.viewpager2.adapter.FragmentStateAdapter;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.NoSuchElementException;
 
 import it.niedermann.nextcloud.deck.model.Stack;
 
@@ -27,6 +28,22 @@ public class StackAdapter extends FragmentStateAdapter {
         return stackList.get(position);
     }
 
+    /**
+     * @return the position of the direct neighbour of the given {@param position} if available. Prefers neighbours to the start of the wanted, but might also return a neighbour to the end.
+     * @throws NoSuchElementException in case this is the only {@link Stack}.
+     */
+    public int getNeighbourPosition(int position) throws NoSuchElementException, IndexOutOfBoundsException {
+        if (position >= stackList.size()) {
+            throw new IndexOutOfBoundsException("Position " + position + " is not in the current stack list.");
+        }
+        if (stackList.size() < 2) {
+            throw new NoSuchElementException("There is no neighbour.");
+        }
+        return position > 0
+                ? position - 1
+                : position + 1;
+    }
+
     @Override
     public long getItemId(int position) {
         return stackList.get(position).getLocalId();
diff --git a/fastlane/metadata/android/en-US/changelogs/1019000.txt b/fastlane/metadata/android/en-US/changelogs/1019000.txt
index 0046030f3..2185920f3 100644
--- a/fastlane/metadata/android/en-US/changelogs/1019000.txt
+++ b/fastlane/metadata/android/en-US/changelogs/1019000.txt
@@ -1,2 +1,3 @@
 - ✏️ Remember edit / preview mode for description (#971)
-- 🖼 Support preview for images which are hosted on a Nextcloud instance (#963)
\ No newline at end of file
+- 🖼 Support preview for images which are hosted on a Nextcloud instance (#963)
+- 🗑 Select neighbour list after deleting a list (#841)
\ No newline at end of file