Show contact avatar in @mention suggestion list items

Co-authored-by: adbenitez <24558636+adbenitez@users.noreply.github.com>

.github/copilot-instructions.md

@@ -8,7 +8,7 @@ ArcaneChat is a Delta Chat Android client built on top of the official Delta Cha
 - **Language:** Java (Java 8 compatibility)
 - **Build System:** Gradle with Android Gradle Plugin 8.11.1
 - **Min SDK:** 21 (Android 5.0)
-- **Target SDK:** 35 (Android 15)
+- **Target SDK:** 36 (Android 16)
 - **NDK Version:** 27.0.12077973
 - **Native Components:** Rust (deltachat-core-rust submodule)
 - **UI Framework:** Android SDK, Material Design Components
@@ -17,13 +17,23 @@ ArcaneChat is a Delta Chat Android client built on top of the official Delta Cha
 ## Repository Structure
 
 - `src/main/` - Main application source code
+  - `src/main/java/org/thoughtcrime/securesms/` - Main UI components
+  - `src/main/java/com/b44t/messenger/` - Delta Chat core integration
+  - `src/main/java/chat/delta/rpc/` - JSON-RPC bindings (generated, don't edit manually)
+  - `src/main/res/` - Android resources (layouts, strings, drawables)
 - `src/androidTest/` - Instrumented tests (UI tests, benchmarks)
+  - `src/androidTest/java/com/b44t/messenger/uitests/` - UI tests
+  - `src/androidTest/java/com/b44t/messenger/uibenchmarks/` - Performance benchmarks
 - `src/gplay/` - Google Play flavor-specific code
 - `src/foss/` - F-Droid/FOSS flavor-specific code
-- `jni/deltachat-core-rust/` - Native Rust core library (submodule)
+- `jni/deltachat-core-rust/` - Native Rust core library (submodule, **don't edit directly**)
 - `scripts/` - Build and helper scripts
+  - `scripts/ndk-make.sh` - Build native libraries
+  - `scripts/install-toolchains.sh` - Install Rust cross-compilation toolchains
+  - `scripts/generate-rpc-bindings.sh` - Generate JSON-RPC bindings
 - `docs/` - Documentation
 - `fastlane/` - App store metadata and screenshots
+- `.github/workflows/` - CI/CD workflows (GitHub Actions)
 
 ## Build Instructions
 
@@ -33,17 +43,36 @@ ArcaneChat is a Delta Chat Android client built on top of the official Delta Cha
    ```bash
    git submodule update --init --recursive
    ```
+   This MUST be done first before any build attempts.
 
-2. **Build native libraries:**
+2. **Set up environment variables:**
+   ```bash
+   export ANDROID_NDK_ROOT=/path/to/ndk/27.0.12077973
+   export PATH=${PATH}:${ANDROID_NDK_ROOT}/toolchains/llvm/prebuilt/linux-x86_64/bin/:${ANDROID_NDK_ROOT}
+   ```
+   Note: Path format varies by OS (linux-x86_64, darwin-x86_64, etc.)
+
+3. **Install Rust toolchains:**
+   ```bash
+   scripts/install-toolchains.sh
+   ```
+   Required for building the native Rust components.
+
+4. **Build native libraries:**
    ```bash
    scripts/ndk-make.sh
    ```
-   Note: First run may take significant time as it builds for all architectures (armeabi-v7a, arm64-v8a, x86, x86_64)
+   **IMPORTANT:** First run takes 30-60 minutes as it builds for all architectures (armeabi-v7a, arm64-v8a, x86, x86_64).
+   For faster development builds, build for a single architecture:
+   ```bash
+   scripts/ndk-make.sh armeabi-v7a
+   ```
 
-3. **Build APK:**
+5. **Build APK:**
    ```bash
    ./gradlew assembleDebug
    ```
+   Build time: ~2-5 minutes after native libraries are built.
 
 ### Build Flavors
 
@@ -55,6 +84,24 @@ ArcaneChat is a Delta Chat Android client built on top of the official Delta Cha
 - Debug APKs: `build/outputs/apk/gplay/debug/` and `build/outputs/apk/fat/debug/`
 - Release APKs require signing configuration in `~/.gradle/gradle.properties`
 
+### Common Build Issues
+
+1. **Missing NDK or incorrect version:**
+   - Error: `ANDROID_NDK_ROOT not set` or native library missing
+   - Solution: Install NDK 27.0.12077973 and set ANDROID_NDK_ROOT environment variable
+
+2. **Submodules not initialized:**
+   - Error: Missing deltachat-core-rust files
+   - Solution: Run `git submodule update --init --recursive`
+
+3. **Gradle wrapper validation:**
+   - Always validate gradle wrapper before building: `./gradlew wrapper --gradle-version=current`
+   - Wrapper is validated in CI via `gradle/actions/wrapper-validation@v4`
+
+4. **Clean build issues:**
+   - If build fails, try: `./gradlew clean && scripts/ndk-make.sh && ./gradlew assembleDebug`
+   - Remove `build/` directory if clean doesn't work
+
 ## Testing
 
 ### Running Unit Tests
@@ -62,16 +109,19 @@ ArcaneChat is a Delta Chat Android client built on top of the official Delta Cha
 ```bash
 ./gradlew test
 ```
+Expected duration: 1-3 minutes
 
 ### Running Instrumented Tests
 
 1. **Disable animations** on your device/emulator:
    - Developer Options → Set "Window animation scale", "Transition animation scale", and "Animator duration scale" to 0x
+   - **CRITICAL:** Tests will fail if animations are enabled
 
 2. **Run tests:**
    ```bash
    ./gradlew connectedAndroidTest
    ```
+   Expected duration: 10-30 minutes depending on device/emulator
 
 ### Online Tests
 
@@ -129,6 +179,14 @@ TEST_MAIL_PW=yourpassword
 - Java bindings are in `src/main/java/com/b44t/messenger/Dc*.java`
 - JSON-RPC bindings in `chat.delta.rpc.*` package (generated via dcrpcgen)
 
+### Generating JSON-RPC Bindings
+
+To regenerate JSON-RPC bindings after core changes:
+```bash
+./scripts/generate-rpc-bindings.sh
+```
+**Note:** Requires Rust tooling and [dcrpcgen tool](https://github.com/chatmail/dcrpcgen) installed
+
 ### Working with Translations
 
 - Translations managed via Transifex (not in repository)
@@ -142,6 +200,43 @@ Decode crash symbols:
 $ANDROID_NDK_ROOT/ndk-stack --sym obj/local/armeabi-v7a --dump crash.txt > decoded.txt
 ```
 
+## Validation and Quality Checks
+
+### Pre-commit Checks
+
+Before committing changes, always run:
+
+1. **Gradle wrapper validation:**
+   ```bash
+   ./gradlew wrapper --gradle-version=current
+   ```
+
+2. **Build verification:**
+   ```bash
+   ./gradlew assembleDebug
+   ```
+
+3. **Unit tests:**
+   ```bash
+   ./gradlew test
+   ```
+
+4. **Code style:** Match existing code style in modified files (no automatic formatter configured)
+
+### When to Rebuild Native Libraries
+
+Rebuild native libraries (`scripts/ndk-make.sh`) when:
+- Updating deltachat-core-rust submodule
+- Modifying anything in `jni/` directory
+- Changing NDK version
+- After `git clean -fdx` or fresh clone
+
+**DO NOT** rebuild native libraries for:
+- Pure Java/Kotlin code changes
+- Resource file changes
+- Gradle configuration changes (unless changing native library linking)
+- Documentation updates
+
 ## WebXDC Support
 
 ArcaneChat has extended WebXDC support:
@@ -152,12 +247,24 @@ ArcaneChat has extended WebXDC support:
 
 ## Important Files
 
-- `build.gradle` - Main build configuration
+- `build.gradle` - Main build configuration (Android Gradle Plugin 8.11.1, Java 8 compatibility)
 - `CONTRIBUTING.md` - Contribution guidelines
-- `BUILDING.md` - Detailed build setup
+- `BUILDING.md` - Detailed build setup instructions
 - `RELEASE.md` - Release process
-- `proguard-rules.pro` - ProGuard configuration
-- `google-services.json` - Firebase configuration (gplay flavor)
+- `proguard-rules.pro` - ProGuard configuration (enabled for both debug and release)
+- `google-services.json` - Firebase configuration (gplay flavor only)
+- `settings.gradle` - Gradle settings
+- `.github/workflows/` - CI/CD configuration
+
+## Dependencies and Constraints
+
+- **Java Version:** Java 8 compatibility (do not use Java 9+ features)
+- **Gradle:** Use wrapper (`./gradlew`) to ensure correct Gradle version
+- **NDK:** Must use version 27.0.12077973 (specified in build.gradle)
+- **Min SDK:** 21 (Android 5.0) - code must be compatible
+- **Target SDK:** 36 (Android 16) - test on this API level when possible
+- **ProGuard:** Always enabled - ensure ProGuard rules are correct for new dependencies
+- **Multi-dex:** Enabled - app exceeds 65k method limit
 
 ## Package Structure
 
@@ -173,3 +280,35 @@ ArcaneChat has extended WebXDC support:
 - Native library must be rebuilt after core changes
 - ProGuard is enabled in both debug and release builds
 - Multi-dex is enabled due to app size
+
+## CI/CD Workflows
+
+### Preview APK Workflow (.github/workflows/preview-apk.yml)
+
+Runs on every pull request to build and upload a preview APK:
+
+1. **Setup steps:**
+   - Checks out repository with submodules
+   - Validates Fastlane metadata
+   - Sets up Rust cache (working-directory: jni/deltachat-core-rust)
+   - Sets up Java 17 (Temurin distribution)
+   - Sets up Android SDK
+   - Caches Gradle dependencies
+   - Sets up NDK r27
+
+2. **Build process:**
+   ```bash
+   scripts/install-toolchains.sh && scripts/ndk-make.sh armeabi-v7a
+   ./gradlew --no-daemon -PABI_FILTER=armeabi-v7a assembleFossDebug
+   ```
+   Note: Builds only armeabi-v7a for faster CI builds
+
+3. **Output:** Uploads APK artifact to GitHub Actions
+
+### Important CI Considerations
+
+- Always validate Gradle wrapper before committing changes
+- Fastlane metadata must be valid (validated in CI)
+- Use `--no-daemon` flag for Gradle in CI environments
+- CI builds use FOSS flavor to avoid Google Services dependencies
+- Expected CI build time: 15-25 minutes for full workflow

src/main/java/org/thoughtcrime/securesms/ConversationActivity.java

@@ -72,6 +72,8 @@ import androidx.lifecycle.ViewModelProvider;
 import androidx.media3.session.MediaController;
 import androidx.media3.session.SessionCommand;
 import androidx.media3.session.SessionToken;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
 
 import com.b44t.messenger.DcChat;
 import com.b44t.messenger.DcContact;
@@ -90,6 +92,7 @@ import org.thoughtcrime.securesms.components.HidingLinearLayout;
 import org.thoughtcrime.securesms.components.InputAwareLayout;
 import org.thoughtcrime.securesms.components.InputPanel;
 import org.thoughtcrime.securesms.components.KeyboardAwareLinearLayout.OnKeyboardShownListener;
+import org.thoughtcrime.securesms.components.MentionAdapter;
 import org.thoughtcrime.securesms.components.ScaleStableImageView;
 import org.thoughtcrime.securesms.components.SendButton;
 import org.thoughtcrime.securesms.components.audioplay.AudioPlaybackViewModel;
@@ -208,6 +211,9 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
   private boolean isEditing = false;
   private boolean switchedProfile = false;
 
+  private RecyclerView   mentionSuggestions;
+  private MentionAdapter mentionAdapter;
+
   @Override
   protected void onCreate(Bundle state, boolean ready) {
     this.context = ApplicationContext.getInstance(getApplicationContext());
@@ -956,6 +962,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     inputPanel            = ViewUtil.findById(this, R.id.bottom_panel);
     backgroundView        = ViewUtil.findById(this, R.id.conversation_background);
     messageRequestBottomView = ViewUtil.findById(this, R.id.conversation_activity_message_request_bottom_bar);
+    mentionSuggestions    = ViewUtil.findById(this, R.id.mention_suggestions);
 
     ImageButton quickCameraToggle = ViewUtil.findById(this, R.id.quick_camera_toggle);
 
@@ -1057,6 +1064,11 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     recipient        = new Recipient(this, dcChat);
     glideRequests    = GlideApp.with(this);
 
+    mentionAdapter = new MentionAdapter(glideRequests);
+    mentionSuggestions.setLayoutManager(new LinearLayoutManager(this));
+    mentionSuggestions.setAdapter(mentionAdapter);
+    mentionAdapter.setOnMentionClickListener(contact -> insertMention(contact));
+
     setComposePanelVisibility(true);
     initializeContactRequest();
   }
@@ -1560,6 +1572,77 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
     }
   }
 
+  private void updateMentionSuggestions() {
+    if (!dcChat.isMultiUser()) {
+      mentionSuggestions.setVisibility(View.GONE);
+      return;
+    }
+
+    Editable text = composeText.getText();
+    if (text == null) {
+      mentionSuggestions.setVisibility(View.GONE);
+      return;
+    }
+
+    int cursorPos = composeText.getSelectionStart();
+    if (cursorPos <= 0) {
+      mentionSuggestions.setVisibility(View.GONE);
+      return;
+    }
+
+    String textBeforeCursor = text.toString().substring(0, cursorPos);
+    int atIndex = textBeforeCursor.lastIndexOf('@');
+    if (atIndex < 0) {
+      mentionSuggestions.setVisibility(View.GONE);
+      return;
+    }
+
+    // Check that there's no space between "@" and the cursor
+    String query = textBeforeCursor.substring(atIndex + 1);
+    if (query.contains(" ") || query.contains("\n")) {
+      mentionSuggestions.setVisibility(View.GONE);
+      return;
+    }
+
+    DcContext dcContext = DcHelper.getContext(context);
+    int[] contactIds = dcContext.getChatContacts(chatId);
+    List<DcContact> matched = new ArrayList<>();
+    String lowerQuery = query.toLowerCase();
+    for (int id : contactIds) {
+      if (id <= DcContact.DC_CONTACT_ID_LAST_SPECIAL) continue;
+      DcContact contact = dcContext.getContact(id);
+      String displayName = contact.getDisplayName().toLowerCase();
+      String addr = contact.getAddr().toLowerCase();
+      if (displayName.contains(lowerQuery) || addr.contains(lowerQuery)) {
+        matched.add(contact);
+      }
+    }
+
+    if (matched.isEmpty()) {
+      mentionSuggestions.setVisibility(View.GONE);
+    } else {
+      mentionAdapter.setContacts(matched);
+      mentionSuggestions.setVisibility(View.VISIBLE);
+    }
+  }
+
+  private void insertMention(DcContact contact) {
+    Editable text = composeText.getText();
+    if (text == null) return;
+
+    int cursorPos = composeText.getSelectionStart();
+    if (cursorPos <= 0) return;
+
+    String textBeforeCursor = text.toString().substring(0, cursorPos);
+    int atIndex = textBeforeCursor.lastIndexOf('@');
+    if (atIndex < 0) return;
+
+    String mention = "@" + contact.getDisplayName() + " ";
+    text.replace(atIndex, cursorPos, mention);
+    composeText.setSelection(atIndex + mention.length());
+    mentionSuggestions.setVisibility(View.GONE);
+  }
+
   private class ComposeKeyPressedListener implements OnKeyListener, OnClickListener, TextWatcher, OnFocusChangeListener {
 
     int beforeLength;
@@ -1593,6 +1676,7 @@ public class ConversationActivity extends PassphraseRequiredActionBarActivity
       if (composeText.getTextTrimmed().length() == 0 || beforeLength == 0) {
         composeText.postDelayed(ConversationActivity.this::updateToggleButtonState, 50);
       }
+      updateMentionSuggestions();
     }
 
     @Override

src/main/java/org/thoughtcrime/securesms/components/MentionAdapter.java

@@ -0,0 +1,94 @@
+package org.thoughtcrime.securesms.components;
+
+import android.content.Context;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import androidx.annotation.NonNull;
+import androidx.recyclerview.widget.RecyclerView;
+
+import com.b44t.messenger.DcContact;
+
+import org.thoughtcrime.securesms.R;
+import org.thoughtcrime.securesms.mms.GlideRequests;
+import org.thoughtcrime.securesms.recipients.Recipient;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class MentionAdapter extends RecyclerView.Adapter<MentionAdapter.ViewHolder> {
+
+    public interface OnMentionClickListener {
+        void onMentionClicked(DcContact contact);
+    }
+
+    private final List<DcContact> contacts = new ArrayList<>();
+    private final GlideRequests glideRequests;
+    private OnMentionClickListener listener;
+
+    public MentionAdapter(@NonNull GlideRequests glideRequests) {
+        this.glideRequests = glideRequests;
+    }
+
+    public void setContacts(List<DcContact> newContacts) {
+        contacts.clear();
+        contacts.addAll(newContacts);
+        notifyDataSetChanged();
+    }
+
+    public void setOnMentionClickListener(OnMentionClickListener listener) {
+        this.listener = listener;
+    }
+
+    @NonNull
+    @Override
+    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+        View view = LayoutInflater.from(parent.getContext())
+                .inflate(R.layout.mention_list_item, parent, false);
+        return new ViewHolder(view);
+    }
+
+    @Override
+    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
+        DcContact contact = contacts.get(position);
+        Context context = holder.itemView.getContext();
+
+        holder.displayName.setText(contact.getDisplayName());
+        String addr = contact.getAddr();
+        String name = contact.getName();
+        if (!name.isEmpty() && !name.equals(addr)) {
+            holder.address.setText(addr);
+            holder.address.setVisibility(View.VISIBLE);
+        } else {
+            holder.address.setVisibility(View.GONE);
+        }
+
+        holder.avatar.setAvatar(glideRequests, new Recipient(context, contact), false);
+
+        holder.itemView.setOnClickListener(v -> {
+            if (listener != null) {
+                listener.onMentionClicked(contact);
+            }
+        });
+    }
+
+    @Override
+    public int getItemCount() {
+        return contacts.size();
+    }
+
+    static class ViewHolder extends RecyclerView.ViewHolder {
+        final AvatarImageView avatar;
+        final TextView displayName;
+        final TextView address;
+
+        ViewHolder(@NonNull View itemView) {
+            super(itemView);
+            avatar = itemView.findViewById(R.id.mention_avatar);
+            displayName = itemView.findViewById(R.id.mention_display_name);
+            address = itemView.findViewById(R.id.mention_address);
+        }
+    }
+}

src/main/res/layout/conversation_activity.xml

@@ -53,6 +53,14 @@
                 android:paddingEnd="16dp"
                 android:focusable="true" />
 
+            <androidx.recyclerview.widget.RecyclerView
+                android:id="@+id/mention_suggestions"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:visibility="gone"
+                android:background="?attr/input_panel_bg_color"
+                android:elevation="4dp" />
+
             <include layout="@layout/conversation_input_panel"/>
 
             <FrameLayout

src/main/res/layout/mention_list_item.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="match_parent"
+    android:layout_height="48dp"
+    android:orientation="horizontal"
+    android:gravity="center_vertical"
+    android:background="?attr/conversation_list_item_background"
+    android:paddingStart="12dp"
+    android:paddingEnd="12dp">
+
+    <org.thoughtcrime.securesms.components.AvatarImageView
+        android:id="@+id/mention_avatar"
+        android:layout_width="32dp"
+        android:layout_height="32dp"
+        android:layout_marginEnd="10dp" />
+
+    <TextView
+        android:id="@+id/mention_display_name"
+        android:layout_width="0dp"
+        android:layout_height="wrap_content"
+        android:layout_weight="1"
+        android:singleLine="true"
+        android:ellipsize="end"
+        android:textSize="15sp" />
+
+    <TextView
+        android:id="@+id/mention_address"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:singleLine="true"
+        android:ellipsize="end"
+        android:textSize="13sp"
+        android:paddingStart="8dp"
+        android:textAppearance="?android:attr/textAppearanceSmall" />
+
+</LinearLayout>