cnc.cad.rxjavatestapp.AvatarImageBehavior.java Source code

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Here is the source code for cnc.cad.rxjavatestapp.AvatarImageBehavior.java

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/*
 * Copyright 2015 Yan Zhenjie
 *
 * 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 cnc.cad.rxjavatestapp;

import android.content.Context;
import android.content.res.TypedArray;
import android.support.design.widget.CoordinatorLayout;
import android.support.v4.view.ViewCompat;
import android.support.v7.widget.Toolbar;
import android.util.AttributeSet;
import android.view.View;

import de.hdodenhof.circleimageview.CircleImageView;

/**
 * Created by Yan Zhenjie on 2016/9/24.
 */
public class AvatarImageBehavior extends CoordinatorLayout.Behavior<CircleImageView> {

    private Context mContext;

    private float mCustomFinalHeight;

    private int mStartXPosition;
    private float mStartToolbarPosition;
    private int mStartYPosition;
    private int mFinalYPosition;
    private int mStartHeight;
    private int mStartWidth;
    private int mFinalXPosition;
    private float mChangeBehaviorPoint;

    public AvatarImageBehavior(Context context, AttributeSet attrs) {
        mContext = context;

        if (attrs != null) {
            TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.AvatarImageBehavior);
            mCustomFinalHeight = a.getDimension(R.styleable.AvatarImageBehavior_finalHeight, 0);
            a.recycle();
        }
    }

    @Override
    public boolean layoutDependsOn(CoordinatorLayout parent, CircleImageView child, View dependency) {
        return dependency instanceof Toolbar;
    }

    @Override
    public boolean onDependentViewChanged(CoordinatorLayout parent, CircleImageView child, View dependency) {
        maybeInitProperties(child, dependency);

        final int maxScrollDistance = (int) (mStartToolbarPosition);
        float expandedPercentageFactor = ViewCompat.getY(dependency) / maxScrollDistance;

        if (expandedPercentageFactor < mChangeBehaviorPoint) {
            float heightFactor = (mChangeBehaviorPoint - expandedPercentageFactor) / mChangeBehaviorPoint;

            float distanceXToSubtract = ((mStartXPosition - mFinalXPosition) * heightFactor)
                    + (child.getHeight() / 2);
            float distanceYToSubtract = ((mStartYPosition - mFinalYPosition) * (1f - expandedPercentageFactor))
                    + (child.getHeight() / 2);

            ViewCompat.setX(child, mStartXPosition - distanceXToSubtract);
            ViewCompat.setY(child, mStartYPosition - distanceYToSubtract);

            float heightToSubtract = ((mStartHeight - mCustomFinalHeight) * heightFactor);

            CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
            lp.width = (int) (mStartHeight - heightToSubtract);
            lp.height = (int) (mStartHeight - heightToSubtract);
            child.setLayoutParams(lp);
        } else {
            float distanceYToSubtract = ((mStartYPosition - mFinalYPosition) * (1f - expandedPercentageFactor))
                    + (mStartHeight / 2);

            ViewCompat.setX(child, mStartXPosition - child.getWidth() / 2);
            ViewCompat.setY(child, mStartYPosition - distanceYToSubtract);

            CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams) child.getLayoutParams();
            lp.width = mStartWidth;
            lp.height = mStartHeight;
            child.setLayoutParams(lp);
        }
        return true;
    }

    private void maybeInitProperties(CircleImageView child, View dependency) {
        if (mStartYPosition == 0)
            mStartYPosition = (int) (dependency.getY());

        if (mFinalYPosition == 0)
            mFinalYPosition = (dependency.getHeight() / 2);

        if (mStartHeight == 0)
            mStartWidth = mStartHeight = child.getHeight();

        if (mStartXPosition == 0)
            mStartXPosition = (int) (ViewCompat.getX(child) + (child.getWidth() / 2));

        if (mFinalXPosition == 0)
            mFinalXPosition = mContext.getResources().getDimensionPixelOffset(R.dimen.dp_25)
                    + ((int) mCustomFinalHeight / 2);

        if (mStartToolbarPosition == 0)
            mStartToolbarPosition = ViewCompat.getY(dependency);

        if (mChangeBehaviorPoint == 0) {
            mChangeBehaviorPoint = (child.getHeight() - mCustomFinalHeight)
                    / (2f * (mStartYPosition - mFinalYPosition));
        }
    }
}