MotionHelperInterface.java
/*
* Copyright (C) 2020 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.constraintlayout.motion.widget;
import android.graphics.Canvas;
import android.view.View;
import java.util.HashMap;
/**
* This defined the interface for MotionLayout helpers
* Helpers can be used to draw motion effects or modify motions
*/
public interface MotionHelperInterface extends Animatable, MotionLayout.TransitionListener {
/**
* Notify when view is visible
* @return
*/
boolean isUsedOnShow();
/**
* Notify when views are hidden
* @return
*/
boolean isUseOnHide();
/**
* is involved in painting
* @return
*/
boolean isDecorator();
/**
* Call before views are painted
* @param canvas
*/
void onPreDraw(Canvas canvas);
/**
* Called after views are painted
* @param canvas
*/
void onPostDraw(Canvas canvas);
/**
* Called after motionController is populated with start and end and keyframes.
*
* @param motionLayout
* @param controllerMap
*/
void onPreSetup(MotionLayout motionLayout, HashMap<View, MotionController> controllerMap);
/**
* This is called after motionLayout read motionScene and assembles all constraintSets
* @param motionLayout
*/
void onFinishedMotionScene(MotionLayout motionLayout);
}