RevealLayout.java

package com.cusnews.widgets;

import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Path;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
import android.view.View;
import android.widget.FrameLayout;

import com.nineoldandroids.animation.Animator;
import com.nineoldandroids.animation.AnimatorListenerAdapter;
import com.nineoldandroids.animation.ObjectAnimator;

/**
 * Created by yugy on 14/11/21.
 * <p/>
 * Support material-design feeling.
 * <p/>
 * <a href="https://github.com/kyze8439690/RevealLayout">RevealLayout</a>
 */
public class RevealLayout extends FrameLayout {

	private Path mClipPath;
	private float mClipRadius                = 0;
	private int   mClipCenterX, mClipCenterY = 0;
	private Animator mAnimator;
	private static final int     DEFAULT_DURATION = 600;
	private              boolean mIsContentShown  = true;

	public RevealLayout( Context context ) {
		this( context, null );
	}

	public RevealLayout( Context context, AttributeSet attrs ) {
		this( context, attrs, 0 );
	}

	@TargetApi(Build.VERSION_CODES.HONEYCOMB)
	public RevealLayout( Context context, AttributeSet attrs, int defStyleAttr ) {
		super( context, attrs, defStyleAttr );
		mClipPath = new Path();
		if( Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR2 && Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB ) {
			setLayerType( View.LAYER_TYPE_SOFTWARE, null );
		}
	}

	@Override
	protected void onSizeChanged( int w, int h, int oldw, int oldh ) {
		mClipCenterX = w / 2;
		mClipCenterY = h / 2;
		if( !mIsContentShown ) {
			mClipRadius = 0;
		} else {
			mClipRadius = (float) ( Math.sqrt( w * w + h * h ) / 2 );
		}

		super.onSizeChanged( w, h, oldw, oldh );
	}

	public float getClipRadius() {
		return mClipRadius;
	}

	public void setClipRadius( float clipRadius ) {
		mClipRadius = clipRadius;
		invalidate();
	}

	public boolean isContentShown() {
		return mIsContentShown;
	}

	public void setContentShown( boolean isContentShown ) {
		mIsContentShown = isContentShown;
		if( mIsContentShown ) {
			mClipRadius = 0;
		} else {
			mClipRadius = getMaxRadius( mClipCenterX, mClipCenterY );
		}
		invalidate();
	}

	public void show() {
		show( DEFAULT_DURATION );
	}

	public void hide() {
		hide( DEFAULT_DURATION );
	}

	public void next() {
		next( DEFAULT_DURATION );
	}

	public void show( int duration ) {
		show( getWidth() / 2, getHeight() / 2, duration );
	}

	public void hide( int duration ) {
		hide( getWidth() / 2, getHeight() / 2, duration );
	}

	public void next( int duration ) {
		next( getWidth() / 2, getHeight() / 2, duration );
	}

	public void show( int x, int y ) {
		show( x, y, DEFAULT_DURATION );
	}

	public void hide( int x, int y ) {
		hide( x, y, DEFAULT_DURATION );
	}

	public void next( int x, int y ) {
		next( x, y, DEFAULT_DURATION );
	}

	public void show( int x, int y, int duration ) {
		if( x < 0 || x > getWidth() || y < 0 || y > getHeight() ) {
			throw new RuntimeException( "Center point out of range or call method when View is not initialed yet." );
		}

		mClipCenterX = x;
		mClipCenterY = y;
		float maxRadius = getMaxRadius( x, y );

		if( mAnimator != null && mAnimator.isRunning() ) {
			mAnimator.cancel();
		}

		mAnimator = ObjectAnimator.ofFloat( this, "clipRadius", 0f, maxRadius );
		mAnimator.setInterpolator( new BakedBezierInterpolator() );
		mAnimator.setDuration( duration );
		mAnimator.addListener( new AnimatorListenerAdapter() {
			@Override
			public void onAnimationEnd( Animator animation ) {
				super.onAnimationEnd( animation );
				mIsContentShown = true;
			}
		} );
		mAnimator.start();
	}

	public void hide( int x, int y, int duration ) {
		if( x < 0 || x > getWidth() || y < 0 || y > getHeight() ) {
			throw new RuntimeException( "Center point out of range or call method when View is not initialed yet." );
		}

		if( x != mClipCenterX || y != mClipCenterY ) {
			mClipCenterX = x;
			mClipCenterY = y;
			mClipRadius = getMaxRadius( x, y );
		}

		if( mAnimator != null && mAnimator.isRunning() ) {
			mAnimator.cancel();
		}

		mAnimator = ObjectAnimator.ofFloat( this, "clipRadius", 0f );
		mAnimator.setInterpolator( new BakedBezierInterpolator() );
		mAnimator.setDuration( duration );
		mAnimator.addListener( new AnimatorListenerAdapter() {
			@Override
			public void onAnimationEnd( Animator animation ) {
				super.onAnimationEnd( animation );
				mIsContentShown = false;
			}
		} );
		mAnimator.start();
	}

	public void next( int x, int y, int duration ) {
		final int childCount = getChildCount();
		if( childCount > 1 ) {
			for( int i = 0; i < childCount; i++ ) {
				View child = getChildAt( i );
				if( i == 0 ) {
					bringChildToFront( child );
				}
			}
			show( x, y, duration );
		}
	}

	private float getMaxRadius( int x, int y ) {
		int h = Math.max( x, getWidth() - x );
		int v = Math.max( y, getHeight() - y );
		return (float) Math.sqrt( h * h + v * v );
	}

	@Override
	protected boolean drawChild( Canvas canvas, View child, long drawingTime ) {
		if( indexOfChild( child ) == getChildCount() - 1 ) {
			boolean result;
			mClipPath.reset();
			mClipPath.addCircle( mClipCenterX, mClipCenterY, mClipRadius, Path.Direction.CW );

			Log.d( "RevealLayout", "ClipRadius: " + mClipRadius );
			canvas.save();
			canvas.clipPath( mClipPath );
			result = super.drawChild( canvas, child, drawingTime );
			canvas.restore();
			return result;
		} else {
			return super.drawChild( canvas, child, drawingTime );
		}
	}

}