Clean code

app/src/leanback/java/com/fongmi/android/tv/ui/custom/CustomSelector.java

@@ -1,66 +1,72 @@
 package com.fongmi.android.tv.ui.custom;
 
+import androidx.annotation.NonNull;
 import androidx.collection.ArrayMap;
 import androidx.leanback.widget.ListRow;
 import androidx.leanback.widget.Presenter;
 import androidx.leanback.widget.PresenterSelector;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.LinkedHashSet;
+import java.util.Set;
 
 public class CustomSelector extends PresenterSelector {
 
-    private final List<Presenter> mPresenters;
-    private final ArrayMap<Class<?>, Presenter> mSingleMap;
-    private final ArrayMap<Class<?>, ArrayMap<Class<?>, Presenter>> mClassMap;
-
-    public CustomSelector() {
-        super();
-        mPresenters = new ArrayList<>();
-        mSingleMap = new ArrayMap<>();
-        mClassMap = new ArrayMap<>();
-    }
+    private final Set<Presenter> presenters = new LinkedHashSet<>();
+    private final ArrayMap<Key, Presenter> cacheMap = new ArrayMap<>();
+    private final ArrayMap<Class<?>, Presenter> singleMap = new ArrayMap<>();
+    private final ArrayMap<Class<?>, ArrayMap<Class<? extends Presenter>, Presenter>> nestedMap = new ArrayMap<>();
 
     public void addPresenter(Class<?> cls, Presenter presenter) {
-        mSingleMap.put(cls, presenter);
-        if (!mPresenters.contains(presenter)) {
-            mPresenters.add(presenter);
-        }
+        singleMap.put(cls, presenter);
+        presenters.add(presenter);
+        cacheMap.clear();
     }
 
-    public void addPresenter(Class<?> cls, Presenter presenter, Class<?> childType) {
-        ArrayMap<Class<?>, Presenter> classPresenterArrayMap = mClassMap.get(cls);
-        if (classPresenterArrayMap == null) classPresenterArrayMap = new ArrayMap<>();
-        classPresenterArrayMap.put(childType, presenter);
-        mClassMap.put(cls, classPresenterArrayMap);
-        if (!mPresenters.contains(presenter)) {
-            mPresenters.add(presenter);
-        }
+    public void addPresenter(Class<?> cls, Presenter presenter, Class<? extends Presenter> childType) {
+        nestedMap.computeIfAbsent(cls, k -> new ArrayMap<>()).put(childType, presenter);
+        presenters.add(presenter);
+        cacheMap.clear();
     }
 
     @Override
     public Presenter getPresenter(Object item) {
+        if (item == null) return null;
         Class<?> cls = item.getClass();
-        Presenter presenter;
-        presenter = mSingleMap.get(cls);
+        Presenter presenter = singleMap.get(cls);
         if (presenter != null) return presenter;
-        ArrayMap<Class<?>, Presenter> presenters = mClassMap.get(cls);
-        assert presenters != null;
-        if (presenters.size() == 1) return presenters.valueAt(0);
-        if (item instanceof ListRow) {
-            ListRow listRow = (ListRow) item;
-            Presenter childPresenter = listRow.getAdapter().getPresenter(listRow);
-            Class<?> childCls = childPresenter.getClass();
-            do {
-                presenter = presenters.get(childCls);
-                childCls = childCls.getSuperclass();
-            } while (presenter == null && childCls != null);
+        ArrayMap<Class<? extends Presenter>, Presenter> map = nestedMap.get(cls);
+        if (map == null || map.isEmpty()) return null;
+        if (map.size() == 1) {
+            Presenter only = map.valueAt(0);
+            Class<? extends Presenter> childType = map.keyAt(0);
+            cacheMap.put(new Key(cls, childType), only);
+            return only;
         }
-        return presenter;
+        if (item instanceof ListRow row) {
+            if (row.getAdapter() == null) return null;
+            Presenter child = row.getAdapter().getPresenter(row);
+            if (child == null) return null;
+            Class<?> childCls = child.getClass();
+            Key key = new Key(cls, childCls);
+            Presenter cached = cacheMap.get(key);
+            if (cached != null) return cached;
+            for (Class<?> type = childCls; type != null && type != Object.class; type = type.getSuperclass()) {
+                Presenter found = map.get(type);
+                if (found != null) {
+                    cacheMap.put(key, found);
+                    return found;
+                }
+            }
+        }
+        return null;
     }
 
+    @NonNull
     @Override
     public Presenter[] getPresenters() {
-        return mPresenters.toArray(new Presenter[]{});
+        return presenters.toArray(new Presenter[0]);
+    }
+
+    private record Key(Class<?> parent, Class<?> child) {
     }
 }

app/src/leanback/java/com/fongmi/android/tv/ui/custom/CustomTextListener.java

@@ -41,7 +41,7 @@ public abstract class CustomTextListener implements TextWatcher, RecognitionList
         List<String> texts = results.getStringArrayList(SpeechRecognizer.RESULTS_RECOGNITION);
         for (String text : texts) sb.append(text).append("\n");
         String result = sb.toString().trim();
-        if (result.length() > 0) onResults(result);
+        if (!result.isEmpty()) onResults(result);
     }
 
     @Override