mirror of https://github.com/M66B/FairEmail.git
73 lines
2.6 KiB
Java
73 lines
2.6 KiB
Java
/*
|
|
* 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 static androidx.core.util.Preconditions.checkState;
|
|
|
|
import android.view.MotionEvent;
|
|
|
|
import androidx.annotation.NonNull;
|
|
import androidx.annotation.Nullable;
|
|
|
|
import java.util.Arrays;
|
|
import java.util.List;
|
|
|
|
/**
|
|
* Registry for tool specific event handler. This provides map like functionality,
|
|
* along with fallback to a default handler, while avoiding auto-boxing of tool
|
|
* type values that would be necessitated were a Map used.k
|
|
*
|
|
* <p>ToolHandlerRegistry guarantees that it will never return a null handler ensuring
|
|
* client code isn't peppered with null checks. To that end a default handler
|
|
* is required. This default handler will be returned when a handler matching
|
|
* the event tooltype has not be registered using {@link #set(int, T)}.
|
|
*
|
|
* @param <T> type of item being registered.
|
|
*/
|
|
final class ToolHandlerRegistry<T> {
|
|
|
|
// list with one null entry for each known tooltype (0-4).
|
|
// See MotionEvent.TOOL_TYPE_ERASER for details. We're using a list here because
|
|
// it is parameterized type friendly, and a natural container given that
|
|
// the index values are 0-based ints.
|
|
private final List<T> mHandlers = Arrays.asList(null, null, null, null, null);
|
|
private final T mDefault;
|
|
|
|
ToolHandlerRegistry(@NonNull T defaultDelegate) {
|
|
checkArgument(defaultDelegate != null);
|
|
mDefault = defaultDelegate;
|
|
}
|
|
|
|
/**
|
|
* @param toolType
|
|
* @param delegate the delegate, or null to unregister.
|
|
* @throws IllegalStateException if an tooltype handler is already registered.
|
|
*/
|
|
void set(int toolType, @Nullable T delegate) {
|
|
checkArgument(toolType >= 0 && toolType <= MotionEvent.TOOL_TYPE_ERASER);
|
|
checkState(mHandlers.get(toolType) == null);
|
|
|
|
mHandlers.set(toolType, delegate);
|
|
}
|
|
|
|
T get(@NonNull MotionEvent e) {
|
|
T d = mHandlers.get(e.getToolType(0));
|
|
return d != null ? d : mDefault;
|
|
}
|
|
}
|