Replace Listeners usages with ObservableList from Chromium

Signed-off-by: Alexey Krasilnikov <alexey@krasilnikov.me>

android/app/src/main/java/app/organicmaps/PanelAnimator.java

@@ -11,13 +11,15 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.fragment.app.Fragment;
 
-import app.organicmaps.util.Listeners;
+import org.chromium.base.ObserverList;
+
 import app.organicmaps.util.UiUtils;
 
 class PanelAnimator
 {
   private final MwmActivity mActivity;
-  private final Listeners<MwmActivity.LeftAnimationTrackListener> mAnimationTrackListeners = new Listeners<>();
+  private final ObserverList<MwmActivity.LeftAnimationTrackListener> mAnimationTrackListeners = new ObserverList<>();
+  private final ObserverList.RewindableIterator<MwmActivity.LeftAnimationTrackListener> mAnimationTrackIterator = mAnimationTrackListeners.rewindableIterator();
   private final View mPanel;
   private final int mWidth;
   @IntegerRes
@@ -33,7 +35,7 @@ class PanelAnimator
 
   void registerListener(@NonNull MwmActivity.LeftAnimationTrackListener animationTrackListener)
   {
-    mAnimationTrackListeners.register(animationTrackListener);
+    mAnimationTrackListeners.addObserver(animationTrackListener);
   }
 
   private void track(ValueAnimator animation)
@@ -42,9 +44,9 @@ class PanelAnimator
     mPanel.setTranslationX(offset);
     mPanel.setAlpha(offset / mWidth + 1.0f);
 
-    for (MwmActivity.LeftAnimationTrackListener listener: mAnimationTrackListeners)
+    mAnimationTrackIterator.rewind();
-      listener.onTrackLeftAnimation(offset + mWidth);
+    while (mAnimationTrackIterator.hasNext())
-    mAnimationTrackListeners.finishIterate();
+      mAnimationTrackIterator.next().onTrackLeftAnimation(offset + mWidth);
   }
 
   /** @param completionListener will be called before the fragment becomes actually visible */
@@ -70,9 +72,9 @@ class PanelAnimator
 
     UiUtils.show(mPanel);
 
-    for (MwmActivity.LeftAnimationTrackListener listener: mAnimationTrackListeners)
+    mAnimationTrackIterator.rewind();
-      listener.onTrackStarted(false);
+    while (mAnimationTrackIterator.hasNext())
-    mAnimationTrackListeners.finishIterate();
+      mAnimationTrackIterator.next().onTrackStarted(false);
 
     ValueAnimator animator = ValueAnimator.ofFloat(-mWidth, 0.0f);
     animator.addUpdateListener(this::track);
@@ -81,9 +83,9 @@ class PanelAnimator
       @Override
       public void onAnimationEnd(Animator animation)
       {
-        for (MwmActivity.LeftAnimationTrackListener listener: mAnimationTrackListeners)
+        mAnimationTrackIterator.rewind();
-          listener.onTrackStarted(true);
+        while (mAnimationTrackIterator.hasNext())
-        mAnimationTrackListeners.finishIterate();
+          mAnimationTrackIterator.next().onTrackStarted(true);
       }
     });
 
@@ -101,9 +103,9 @@ class PanelAnimator
       return;
     }
 
-    for (MwmActivity.LeftAnimationTrackListener listener: mAnimationTrackListeners)
+    mAnimationTrackIterator.rewind();
-      listener.onTrackStarted(true);
+    while (mAnimationTrackIterator.hasNext())
-    mAnimationTrackListeners.finishIterate();
+      mAnimationTrackIterator.next().onTrackStarted(true);
 
     ValueAnimator animator = ValueAnimator.ofFloat(0.0f, -mWidth);
     animator.addUpdateListener(this::track);
@@ -114,9 +116,9 @@ class PanelAnimator
       {
         UiUtils.hide(mPanel);
 
-        for (MwmActivity.LeftAnimationTrackListener listener: mAnimationTrackListeners)
+        mAnimationTrackIterator.rewind();
-          listener.onTrackStarted(false);
+        while (mAnimationTrackIterator.hasNext())
-        mAnimationTrackListeners.finishIterate();
+          mAnimationTrackIterator.next().onTrackStarted(false);
 
         if (completionListener != null)
           completionListener.run();

android/app/src/main/java/app/organicmaps/search/SearchEngine.java

@@ -5,9 +5,11 @@ import android.content.Context;
 import androidx.annotation.MainThread;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+
+import org.chromium.base.ObserverList;
+
 import app.organicmaps.Framework;
 import app.organicmaps.util.Language;
-import app.organicmaps.util.Listeners;
 import app.organicmaps.util.concurrency.UiThread;
 
 import java.nio.charset.StandardCharsets;
@@ -30,7 +32,6 @@ public enum SearchEngine implements NativeSearchListener,
         {
           for (NativeSearchListener listener : mListeners)
             listener.onResultsUpdate(results, timestamp);
-          mListeners.finishIterate();
         });
   }
 
@@ -42,7 +43,6 @@ public enum SearchEngine implements NativeSearchListener,
         {
           for (NativeSearchListener listener : mListeners)
             listener.onResultsEnd(timestamp);
-          mListeners.finishIterate();
         });
   }
 
@@ -54,7 +54,6 @@ public enum SearchEngine implements NativeSearchListener,
         {
           for (NativeMapSearchListener listener : mMapListeners)
             listener.onMapSearchResults(results, timestamp, isLast);
-          mMapListeners.finishIterate();
         });
   }
 
@@ -63,7 +62,6 @@ public enum SearchEngine implements NativeSearchListener,
   {
     for (NativeBookmarkSearchListener listener : mBookmarkListeners)
       listener.onBookmarkSearchResultsUpdate(bookmarkIds, timestamp);
-    mBookmarkListeners.finishIterate();
   }
 
   @Override
@@ -71,44 +69,42 @@ public enum SearchEngine implements NativeSearchListener,
   {
     for (NativeBookmarkSearchListener listener : mBookmarkListeners)
       listener.onBookmarkSearchResultsEnd(bookmarkIds, timestamp);
-    mBookmarkListeners.finishIterate();
   }
 
-  @NonNull
+  private final ObserverList<NativeSearchListener> mListeners = new ObserverList<>();
-  private final Listeners<NativeSearchListener> mListeners = new Listeners<>();
+
-  @NonNull
+  private final ObserverList<NativeMapSearchListener> mMapListeners = new ObserverList<>();
-  private final Listeners<NativeMapSearchListener> mMapListeners = new Listeners<>();
+
-  @NonNull
+  private final ObserverList<NativeBookmarkSearchListener> mBookmarkListeners = new ObserverList<>();
-  private final Listeners<NativeBookmarkSearchListener> mBookmarkListeners = new Listeners<>();
 
   public void addListener(NativeSearchListener listener)
   {
-    mListeners.register(listener);
+    mListeners.addObserver(listener);
   }
 
   public void removeListener(NativeSearchListener listener)
   {
-    mListeners.unregister(listener);
+    mListeners.removeObserver(listener);
   }
 
   public void addMapListener(NativeMapSearchListener listener)
   {
-    mMapListeners.register(listener);
+    mMapListeners.addObserver(listener);
   }
 
   public void removeMapListener(NativeMapSearchListener listener)
   {
-    mMapListeners.unregister(listener);
+    mMapListeners.removeObserver(listener);
   }
 
   public void addBookmarkListener(NativeBookmarkSearchListener listener)
   {
-    mBookmarkListeners.register(listener);
+    mBookmarkListeners.addObserver(listener);
   }
 
   public void removeBookmarkListener(NativeBookmarkSearchListener listener)
   {
-    mBookmarkListeners.unregister(listener);
+    mBookmarkListeners.removeObserver(listener);
   }
 
   private native void nativeInit();

android/app/src/main/java/app/organicmaps/util/Listeners.java

@@ -1,94 +0,0 @@
-package app.organicmaps.util;
-
-import androidx.annotation.NonNull;
-
-import java.util.Iterator;
-import java.util.LinkedHashSet;
-import java.util.Set;
-
-/**
- * `Registrator` pattern implementation which allows to maintain the list of listeners,
- * offers safe adding/removing of listeners during iteration.
- * <br/>{@link #finishIterate()} must be called after iteration is complete.
- */
-public final class Listeners<T> implements Iterable<T>
-{
-  private final Set<T> mListeners = new LinkedHashSet<>();
-  private final Set<T> mListenersToAdd = new LinkedHashSet<>();
-  private final Set<T> mListenersToRemove = new LinkedHashSet<>();
-
-  private boolean mIterating;
-
-  @Override
-  public @NonNull Iterator<T> iterator()
-  {
-    if (mIterating)
-      throw new RuntimeException("finishIterate() must be called before new iteration");
-
-    mIterating = true;
-    return mListeners.iterator();
-  }
-
-  /**
-   * Completes listeners iteration. Must be called after iteration is done.
-   */
-  public void finishIterate()
-  {
-    if (!mListenersToRemove.isEmpty())
-      mListeners.removeAll(mListenersToRemove);
-
-    if (!mListenersToAdd.isEmpty())
-      mListeners.addAll(mListenersToAdd);
-
-    mListenersToAdd.clear();
-    mListenersToRemove.clear();
-    mIterating = false;
-  }
-
-  /**
-   * Safely registers new listener. If registered during iteration, new listener will NOT be called before current iteration is complete.
-   */
-  public void register(T listener)
-  {
-    if (mIterating)
-    {
-      mListenersToRemove.remove(listener);
-      if (!mListeners.contains(listener))
-        mListenersToAdd.add(listener);
-    }
-    else
-      mListeners.add(listener);
-  }
-
-  /**
-   * Safely unregisters listener. If unregistered during iteration, old listener WILL be called in the current iteration.
-   */
-  public void unregister(T listener)
-  {
-    if (mIterating)
-    {
-      mListenersToAdd.remove(listener);
-      if (mListeners.contains(listener))
-        mListenersToRemove.add(listener);
-    }
-    else
-      mListeners.remove(listener);
-  }
-
-  public int getSize()
-  {
-    int res = mListeners.size();
-    if (mIterating)
-    {
-      res += mListenersToAdd.size();
-      res -= mListenersToRemove.size();
-    }
-
-    return res;
-  }
-
-  public boolean isEmpty()
-  {
-    return (getSize() <= 0);
-  }
-}