User mentions in issues, prs and comments (#1418)

Closes #1394

Reviewed-on: https://codeberg.org/gitnex/GitNex/pulls/1418
Co-authored-by: M M Arif <mmarif@swatian.com>
Co-committed-by: M M Arif <mmarif@swatian.com>

app/src/main/java/org/mian/gitnex/activities/CreateIssueActivity.java

@@ -60,6 +60,7 @@ import org.mian.gitnex.helpers.AlertDialogs;
 import org.mian.gitnex.helpers.AppDatabaseSettings;
 import org.mian.gitnex.helpers.Constants;
 import org.mian.gitnex.helpers.Markdown;
+import org.mian.gitnex.helpers.MentionHelper;
 import org.mian.gitnex.helpers.SnackBar;
 import org.mian.gitnex.helpers.Toasty;
 import org.mian.gitnex.helpers.attachments.AttachmentUtils;
@@ -98,6 +99,7 @@ public class CreateIssueActivity extends BaseActivity
 	private NotesApi notesApi;
 	private List<Notes> notesList;
 	public AlertDialog dialogNotes;
+	private MentionHelper mentionHelper;
 
 	@SuppressLint("ClickableViewAccessibility")
 	@Override
@@ -152,6 +154,9 @@ public class CreateIssueActivity extends BaseActivity
 					contentUri.clear();
 				});
 
+		mentionHelper = new MentionHelper(this, viewBinding.newIssueDescription);
+		mentionHelper.setup();
+
 		viewBinding.topAppBar.setOnMenuItemClickListener(
 				menuItem -> {
 					int id = menuItem.getItemId();
@@ -280,8 +285,9 @@ public class CreateIssueActivity extends BaseActivity
 					});
 
 	public void onDestroy() {
-		AttachmentsAdapter.setAttachmentsReceiveListener(null);
 		super.onDestroy();
+		AttachmentsAdapter.setAttachmentsReceiveListener(null);
+		mentionHelper.dismissPopup();
 	}
 
 	@Override

app/src/main/java/org/mian/gitnex/activities/CreatePullRequestActivity.java

@@ -61,6 +61,7 @@ import org.mian.gitnex.helpers.AlertDialogs;
 import org.mian.gitnex.helpers.AppDatabaseSettings;
 import org.mian.gitnex.helpers.Constants;
 import org.mian.gitnex.helpers.Markdown;
+import org.mian.gitnex.helpers.MentionHelper;
 import org.mian.gitnex.helpers.SnackBar;
 import org.mian.gitnex.helpers.Toasty;
 import org.mian.gitnex.helpers.attachments.AttachmentUtils;
@@ -97,6 +98,7 @@ public class CreatePullRequestActivity extends BaseActivity
 	private NotesApi notesApi;
 	private List<Notes> notesList;
 	public AlertDialog dialogNotes;
+	private MentionHelper mentionHelper;
 
 	@SuppressLint("ClickableViewAccessibility")
 	@Override
@@ -123,6 +125,9 @@ public class CreatePullRequestActivity extends BaseActivity
 
 		int resultLimit = Constants.getCurrentResultLimit(ctx);
 
+		mentionHelper = new MentionHelper(this, viewBinding.prBody);
+		mentionHelper.setup();
+
 		viewBinding.prBody.setOnTouchListener(
 				(touchView, motionEvent) -> {
 					touchView.getParent().requestDisallowInterceptTouchEvent(true);
@@ -290,8 +295,9 @@ public class CreatePullRequestActivity extends BaseActivity
 	}
 
 	public void onDestroy() {
-		AttachmentsAdapter.setAttachmentsReceiveListener(null);
 		super.onDestroy();
+		AttachmentsAdapter.setAttachmentsReceiveListener(null);
+		mentionHelper.dismissPopup();
 	}
 
 	@Override

app/src/main/java/org/mian/gitnex/activities/EditIssueActivity.java

@@ -70,6 +70,7 @@ import org.mian.gitnex.helpers.AppDatabaseSettings;
 import org.mian.gitnex.helpers.AppUtil;
 import org.mian.gitnex.helpers.Constants;
 import org.mian.gitnex.helpers.Markdown;
+import org.mian.gitnex.helpers.MentionHelper;
 import org.mian.gitnex.helpers.SnackBar;
 import org.mian.gitnex.helpers.attachments.AttachmentUtils;
 import org.mian.gitnex.helpers.attachments.AttachmentsModel;
@@ -101,6 +102,7 @@ public class EditIssueActivity extends BaseActivity
 	private static List<AttachmentsModel> attachmentsList;
 	private static final List<Uri> contentUri = new ArrayList<>();
 	private MenuItem create;
+	private MentionHelper mentionHelper;
 
 	public ActivityResultLauncher<Intent> downloadAttachmentLauncher =
 			registerForActivityResult(
@@ -229,8 +231,9 @@ public class EditIssueActivity extends BaseActivity
 					});
 
 	public void onDestroy() {
-		AttachmentsAdapter.setAttachmentsReceiveListener(null);
 		super.onDestroy();
+		AttachmentsAdapter.setAttachmentsReceiveListener(null);
+		mentionHelper.dismissPopup();
 	}
 
 	@SuppressLint("ClickableViewAccessibility")
@@ -264,6 +267,9 @@ public class EditIssueActivity extends BaseActivity
 
 		AttachmentsAdapter.setAttachmentsReceiveListener(this);
 
+		mentionHelper = new MentionHelper(this, binding.editIssueDescription);
+		mentionHelper.setup();
+
 		create = binding.topAppBar.getMenu().getItem(2);
 		create.setTitle(getString(R.string.saveButton));
 

app/src/main/java/org/mian/gitnex/activities/IssueDetailActivity.java

@@ -103,6 +103,7 @@ import org.mian.gitnex.helpers.ColorInverter;
 import org.mian.gitnex.helpers.Constants;
 import org.mian.gitnex.helpers.LabelWidthCalculator;
 import org.mian.gitnex.helpers.Markdown;
+import org.mian.gitnex.helpers.MentionHelper;
 import org.mian.gitnex.helpers.SnackBar;
 import org.mian.gitnex.helpers.TimeHelper;
 import org.mian.gitnex.helpers.TinyDB;
@@ -167,6 +168,7 @@ public class IssueDetailActivity extends BaseActivity
 	private final float buttonAlphaStatDisabled = .5F;
 	private final float buttonAlphaStatEnabled = 1F;
 	private int loadingFinished = 0;
+	private MentionHelper mentionHelper;
 
 	private enum Mode {
 		EDIT,
@@ -411,6 +413,9 @@ public class IssueDetailActivity extends BaseActivity
 			startActivity(issue.getIntent(ctx, DiffActivity.class));
 		}
 
+		mentionHelper = new MentionHelper(this, viewBinding.commentReply);
+		mentionHelper.setup();
+
 		viewBinding.commentReply.addTextChangedListener(
 				new TextWatcher() {
 					@Override
@@ -545,8 +550,9 @@ public class IssueDetailActivity extends BaseActivity
 	}
 
 	public void onDestroy() {
-		AttachmentsAdapter.setAttachmentsReceiveListener(null);
 		super.onDestroy();
+		AttachmentsAdapter.setAttachmentsReceiveListener(null);
+		mentionHelper.dismissPopup();
 	}
 
 	@Override

app/src/main/java/org/mian/gitnex/helpers/MentionHelper.java

@@ -0,0 +1,305 @@
+package org.mian.gitnex.helpers;
+
+import android.content.Context;
+import android.text.Editable;
+import android.text.TextWatcher;
+import android.util.Log;
+import android.view.Gravity;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.EditText;
+import android.widget.ImageView;
+import android.widget.PopupWindow;
+import android.widget.TextView;
+import androidx.annotation.NonNull;
+import androidx.core.content.ContextCompat;
+import androidx.recyclerview.widget.LinearLayoutManager;
+import androidx.recyclerview.widget.RecyclerView;
+import com.bumptech.glide.Glide;
+import com.bumptech.glide.load.engine.DiskCacheStrategy;
+import java.util.ArrayList;
+import java.util.List;
+import org.gitnex.tea4j.v2.models.InlineResponse2001;
+import org.gitnex.tea4j.v2.models.User;
+import org.mian.gitnex.R;
+import org.mian.gitnex.clients.RetrofitClient;
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+
+/**
+ * @author mmarif
+ */
+public class MentionHelper {
+
+	private final PopupWindow mentionPopup = new PopupWindow();
+	private final MentionAdapter mentionAdapter;
+	private final List<User> mentionSuggestions = new ArrayList<>();
+	private final Context context;
+	private final EditText editText;
+
+	public MentionHelper(Context context, EditText editText) {
+
+		this.context = context;
+		this.editText = editText;
+
+		RecyclerView mentionRecyclerView = new RecyclerView(context);
+		mentionRecyclerView.setLayoutManager(new LinearLayoutManager(context));
+
+		mentionAdapter =
+				new MentionAdapter(
+						context,
+						mentionSuggestions,
+						user -> {
+							String mention = "@" + user.getLogin();
+							int cursorPos = editText.getSelectionStart();
+							String text = editText.getText().toString();
+							int mentionStart = text.lastIndexOf("@", cursorPos - 1);
+							if (mentionStart != -1) {
+								editText.getText().replace(mentionStart, cursorPos, mention + " ");
+								mentionPopup.dismiss();
+							}
+						});
+		mentionRecyclerView.setAdapter(mentionAdapter);
+
+		int paddingDp = 4;
+		int sidePaddingDp = 12;
+		int paddingPx = (int) (paddingDp * context.getResources().getDisplayMetrics().density);
+		int sidePaddingPx =
+				(int) (sidePaddingDp * context.getResources().getDisplayMetrics().density);
+		mentionRecyclerView.setPadding(sidePaddingPx, paddingPx, sidePaddingPx, paddingPx);
+
+		mentionPopup.setContentView(mentionRecyclerView);
+		mentionPopup.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
+		mentionPopup.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
+		mentionPopup.setFocusable(false);
+		mentionPopup.setBackgroundDrawable(
+				ContextCompat.getDrawable(context, R.drawable.shape_round_corners));
+		mentionPopup.setElevation(8f);
+	}
+
+	public void setup() {
+
+		editText.addTextChangedListener(
+				new TextWatcher() {
+					@Override
+					public void beforeTextChanged(
+							CharSequence s, int start, int count, int after) {}
+
+					@Override
+					public void onTextChanged(CharSequence s, int start, int before, int count) {
+						handleMentionInput(s);
+					}
+
+					@Override
+					public void afterTextChanged(Editable s) {}
+				});
+	}
+
+	public void dismissPopup() {
+		if (mentionPopup.isShowing()) {
+			mentionPopup.dismiss();
+		}
+	}
+
+	private void handleMentionInput(CharSequence text) {
+
+		int cursorPos = editText.getSelectionStart();
+
+		if (cursorPos > 0) {
+
+			String beforeCursor = text.subSequence(0, cursorPos).toString();
+			int atIndex = beforeCursor.lastIndexOf("@");
+
+			if (atIndex != -1
+					&& (cursorPos == atIndex + 1
+							|| !beforeCursor.substring(atIndex).contains(" "))) {
+
+				String query = beforeCursor.substring(atIndex + 1);
+				if (!query.isEmpty()) {
+					fetchUserSuggestions(query);
+				} else {
+					int oldSize = mentionSuggestions.size();
+					mentionSuggestions.clear();
+					if (oldSize > 0) {
+						mentionAdapter.notifyItemRangeRemoved(0, oldSize);
+					}
+					mentionPopup.dismiss();
+				}
+			} else {
+				int oldSize = mentionSuggestions.size();
+				mentionSuggestions.clear();
+				if (oldSize > 0) {
+					mentionAdapter.notifyItemRangeRemoved(0, oldSize);
+				}
+				mentionPopup.dismiss();
+			}
+		} else {
+			int oldSize = mentionSuggestions.size();
+			mentionSuggestions.clear();
+			if (oldSize > 0) {
+				mentionAdapter.notifyItemRangeRemoved(0, oldSize);
+			}
+			mentionPopup.dismiss();
+		}
+	}
+
+	private void fetchUserSuggestions(String query) {
+
+		Call<InlineResponse2001> call =
+				RetrofitClient.getApiInterface(context).userSearch(query, null, 1, 4);
+
+		call.enqueue(
+				new Callback<>() {
+					@Override
+					public void onResponse(
+							@NonNull Call<InlineResponse2001> call,
+							@NonNull Response<InlineResponse2001> response) {
+
+						if (response.isSuccessful()
+								&& response.body() != null
+								&& response.body().isOk()) {
+							int oldSize = mentionSuggestions.size();
+							mentionSuggestions.clear();
+							if (oldSize > 0) {
+								mentionAdapter.notifyItemRangeRemoved(0, oldSize);
+							}
+							List<User> newData = response.body().getData();
+							if (newData != null && !newData.isEmpty()) {
+								mentionSuggestions.addAll(
+										newData.subList(0, Math.min(newData.size(), 4)));
+								mentionAdapter.notifyItemRangeInserted(
+										0, mentionSuggestions.size());
+								showMentionPopup();
+							} else {
+								mentionPopup.dismiss();
+							}
+						} else {
+							int oldSize = mentionSuggestions.size();
+							mentionSuggestions.clear();
+							if (oldSize > 0) {
+								mentionAdapter.notifyItemRangeRemoved(0, oldSize);
+							}
+							mentionPopup.dismiss();
+						}
+					}
+
+					@Override
+					public void onFailure(
+							@NonNull Call<InlineResponse2001> call, @NonNull Throwable t) {
+
+						int oldSize = mentionSuggestions.size();
+						mentionSuggestions.clear();
+						if (oldSize > 0) {
+							mentionAdapter.notifyItemRangeRemoved(0, oldSize);
+						}
+						mentionPopup.dismiss();
+						Log.e("MentionHelper", "Failed to fetch users: " + t.getMessage());
+					}
+				});
+	}
+
+	private void showMentionPopup() {
+
+		int[] location = new int[2];
+		editText.getLocationOnScreen(location);
+		int x = location[0];
+		int y = location[1] - 24;
+
+		int popupWidth = editText.getWidth();
+		int popupHeight = calculatePopupHeight();
+
+		if (mentionPopup.isShowing()) {
+			mentionPopup.dismiss();
+		}
+
+		mentionPopup.setWidth(popupWidth);
+		mentionPopup.setHeight(popupHeight);
+		mentionPopup.showAtLocation(editText, Gravity.NO_GRAVITY, x, y - popupHeight);
+	}
+
+	private int calculatePopupHeight() {
+
+		int itemHeightDp = 48;
+		int paddingDp = 4;
+		int itemHeightPx =
+				(int) (itemHeightDp * context.getResources().getDisplayMetrics().density);
+		int paddingPx = (int) (paddingDp * context.getResources().getDisplayMetrics().density);
+
+		int contentHeightPx = mentionSuggestions.size() * itemHeightPx;
+		int totalPaddingPx = paddingPx * 2;
+		int popupHeight = contentHeightPx + totalPaddingPx;
+
+		int maxHeightPx = 4 * itemHeightPx + totalPaddingPx;
+		popupHeight = Math.min(popupHeight, maxHeightPx);
+
+		if (mentionSuggestions.isEmpty()) {
+			popupHeight = itemHeightPx + totalPaddingPx;
+		}
+
+		return popupHeight;
+	}
+
+	private static class MentionAdapter
+			extends RecyclerView.Adapter<MentionAdapter.MentionViewHolder> {
+		private final Context context;
+		private final List<User> users;
+		private final OnUserClickListener listener;
+
+		public MentionAdapter(Context context, List<User> users, OnUserClickListener listener) {
+			this.context = context;
+			this.users = users;
+			this.listener = listener;
+		}
+
+		@NonNull @Override
+		public MentionViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
+			View view =
+					LayoutInflater.from(context)
+							.inflate(R.layout.list_users_mention, parent, false);
+			return new MentionViewHolder(view);
+		}
+
+		@Override
+		public void onBindViewHolder(MentionViewHolder holder, int position) {
+
+			User user = users.get(position);
+			String displayName =
+					(user.getFullName() != null && !user.getFullName().isEmpty())
+							? user.getFullName() + " (" + user.getLogin() + ")"
+							: user.getLogin();
+			holder.username.setText(displayName);
+
+			Glide.with(context)
+					.load(user.getAvatarUrl())
+					.diskCacheStrategy(DiskCacheStrategy.ALL)
+					.placeholder(R.drawable.loader_animated)
+					.centerCrop()
+					.into(holder.avatar);
+
+			holder.itemView.setBackground(null);
+			holder.itemView.setOnClickListener(v -> listener.onUserClick(user));
+		}
+
+		@Override
+		public int getItemCount() {
+			return users.size();
+		}
+
+		static class MentionViewHolder extends RecyclerView.ViewHolder {
+			ImageView avatar;
+			TextView username;
+
+			MentionViewHolder(View itemView) {
+				super(itemView);
+				avatar = itemView.findViewById(R.id.avatar);
+				username = itemView.findViewById(R.id.username);
+			}
+		}
+
+		interface OnUserClickListener {
+			void onUserClick(User user);
+		}
+	}
+}

app/src/main/res/layout/list_users_mention.xml

@@ -0,0 +1,35 @@
+<?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="@dimen/dimen48dp"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:orientation="horizontal">
+
+    <com.google.android.material.card.MaterialCardView
+        android:layout_width="@dimen/dimen32dp"
+        android:layout_height="@dimen/dimen32dp"
+        style="?attr/materialCardViewElevatedStyle"
+        android:backgroundTint="@android:color/transparent"
+        android:layout_gravity="center"
+        app:cardElevation="@dimen/dimen0dp"
+        app:cardCornerRadius="@dimen/dimen12dp">
+
+        <ImageView
+            android:id="@+id/avatar"
+            android:layout_width="match_parent"
+            android:layout_height="match_parent"
+            android:contentDescription="@string/userAvatar"
+            android:src="@drawable/ic_person"/>
+
+    </com.google.android.material.card.MaterialCardView>
+
+    <TextView
+        android:id="@+id/username"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center_vertical"
+        android:layout_marginStart="@dimen/dimen12dp"
+        android:textColor="?attr/primaryTextColor"
+        android:textSize="@dimen/dimen14sp" />
+
+</LinearLayout>