Added patched recyclerview-selection 1.0.0

app/src/main/java/androidx/recyclerview/selection/ItemKeyProvider.java

@@ -0,0 +1,85 @@
+/*
+ * Copyright 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.recyclerview.selection;
+
+import static androidx.core.util.Preconditions.checkArgument;
+
+import androidx.annotation.IntDef;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import androidx.recyclerview.widget.RecyclerView;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+
+/**
+ * Provides selection library access to stable selection keys identifying items
+ * presented by a {@link RecyclerView RecyclerView} instance.
+ *
+ * @param <K> Selection key type. @see {@link StorageStrategy} for supported types.
+ */
+public abstract class ItemKeyProvider<K> {
+
+    /**
+     * Provides access to all data, regardless of whether it is bound to a view or not.
+     * Key providers with this access type enjoy support for enhanced features like:
+     * SHIFT+click range selection, and band selection.
+     */
+    public static final int SCOPE_MAPPED = 0;
+
+    /**
+     * Provides access to cached data based for items that were recently bound in the view.
+     * Employing this provider will result in a reduced feature-set, as some
+     * features like SHIFT+click range selection and band selection are dependent
+     * on mapped access.
+     */
+    public static final int SCOPE_CACHED = 1;
+
+    @IntDef({
+            SCOPE_MAPPED,
+            SCOPE_CACHED
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface Scope {}
+
+    private final @Scope int mScope;
+
+    /**
+     * Creates a new provider with the given scope.
+     *
+     * @param scope Scope can't be changed at runtime.
+     */
+    protected ItemKeyProvider(@Scope int scope) {
+        checkArgument(scope == SCOPE_MAPPED || scope == SCOPE_CACHED);
+
+        mScope = scope;
+    }
+
+    final boolean hasAccess(@Scope int scope) {
+        return scope == mScope;
+    }
+
+    /**
+     * @return The selection key at the given adapter position, or null.
+     */
+    public abstract @Nullable K getKey(int position);
+
+    /**
+     * @return the position corresponding to the selection key, or RecyclerView.NO_POSITION.
+     */
+    public abstract int getPosition(@NonNull K key);
+}