FlipCards.java

package com.aincc.lib.ui.widget.flip;

import javax.microedition.khronos.opengles.GL10;

import android.graphics.Bitmap;
import android.view.MotionEvent;
import android.view.View;

import com.aincc.lib.util.Logger;
import com.aincc.lib.util.Utils;

/*
 Copyright 2012 Aphid Mobile

 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.

 */

/**
 * 
 * <h3><b>FlipCards</b></h3></br>
 * 
 * 플립카드 관리 (front/current/back pages)
 * 
 * @author aincc@barusoft.com
 * @version 1.0.0
 * @since 1.0.0
 */
public class FlipCards
{
	private static final float ACCELERATION = 0.618f;
	private static final float TIP_SPEED = 1f;
	private static final float MOVEMENT_RATE = 1.5f;
	private static final int MAX_TIP_ANGLE = 60;

	private static final int STATE_TIP = 0;
	private static final int STATE_TOUCH = 1;
	private static final int STATE_AUTO_ROTATE = 2;
	private static final int STATE_STOP = 3;

	private Texture frontTexture;
	private Bitmap frontBitmap;

	private Texture backTexture;
	private Bitmap backBitmap;

	private Card frontTopCard;
	private Card frontBottomCard;

	private Card backTopCard;
	private Card backBottomCard;

	private float angle = 0f;
	private boolean forward = true;
	// private boolean animating = false;
	private int animatedFrame = 0;
	private int state = STATE_TIP;

	public FlipCards()
	{
		frontTopCard = new Card();
		frontBottomCard = new Card();

		backTopCard = new Card();
		backBottomCard = new Card();

		frontBottomCard.setAxis(Card.AXIS_TOP);
		backTopCard.setAxis(Card.AXIS_BOTTOM);
	}

	public void reloadTexture(View frontView, View backView)
	{
		frontBitmap = Utils.takeScreenShot(frontView);
		backBitmap = Utils.takeScreenShot(backView);
	}

	public void rotateBy(float delta)
	{
		angle += delta;
		if (angle > 180)
			angle = 180;
		else if (angle < 0)
			angle = 0;
	}

	public void setState(int state)
	{
		if (this.state != state)
		{
			this.state = state;
			animatedFrame = 0;
		}
	}

	public void draw(GL10 gl)
	{
		applyTexture(gl);

		if (frontTexture == null)
			return;

		switch (state)
		{
		case STATE_TIP:
		{
			if (angle >= 180)
				forward = false;
			else if (angle <= 0)
				forward = true;

			rotateBy((forward ? TIP_SPEED : -TIP_SPEED));
			if (angle > 90 && angle <= 180 - MAX_TIP_ANGLE)
			{
				forward = true;
			}
			else if (angle < 90 && angle >= MAX_TIP_ANGLE)
			{
				forward = false;
			}
		}
			break;
		case STATE_TOUCH:
			break;
		case STATE_AUTO_ROTATE:
		{
			animatedFrame++;
			rotateBy((forward ? ACCELERATION : -ACCELERATION) * animatedFrame);
			if (angle >= 180 || angle <= 0)
			{
				// setState(STATE_TIP); // 2012.08.28 aincc : 애니메이션 효과 유지 해제로 변경.
				setState(STATE_STOP);
			}
		}
			break;
		default:
			Logger.e("Invalid state: " + state);
			break;
		}

		if (angle < 90)
		{
			frontTopCard.draw(gl);
			backBottomCard.draw(gl);
			frontBottomCard.setAngle(angle);
			frontBottomCard.draw(gl);
		}
		else
		{
			frontTopCard.draw(gl);
			backTopCard.setAngle(180 - angle);
			backTopCard.draw(gl);
			backBottomCard.draw(gl);
		}
	}

	private void applyTexture(GL10 gl)
	{
		if (frontBitmap != null)
		{
			if (frontTexture != null)
				frontTexture.destroy(gl);

			frontTexture = Texture.createTexture(frontBitmap, gl);

			frontTopCard.setTexture(frontTexture);
			frontBottomCard.setTexture(frontTexture);

			frontTopCard.setCardVertices(new float[]
			{ 0f, frontBitmap.getHeight(), 0f, // top left
			0f, frontBitmap.getHeight() / 2.0f, 0f, // bottom left
			frontBitmap.getWidth(), frontBitmap.getHeight() / 2f, 0f, // bottom right
			frontBitmap.getWidth(), frontBitmap.getHeight(), 0f // top right
			});

			frontTopCard.setTextureCoordinates(new float[]
			{ 0f, 0f, 0f, frontBitmap.getHeight() / 2f / (float) frontTexture.getHeight(), frontBitmap.getWidth() / (float) frontTexture.getWidth(), frontBitmap.getHeight() / 2f / (float) frontTexture.getHeight(), frontBitmap.getWidth() / (float) frontTexture.getWidth(), 0f });

			frontBottomCard.setCardVertices(new float[]
			{ 0f, frontBitmap.getHeight() / 2f, 0f, // top left
			0f, 0f, 0f, // bottom left
			frontBitmap.getWidth(), 0f, 0f, // bottom right
			frontBitmap.getWidth(), frontBitmap.getHeight() / 2f, 0f // top right
			});

			frontBottomCard.setTextureCoordinates(new float[]
			{ 0f, frontBitmap.getHeight() / 2f / (float) frontTexture.getHeight(), 0f, frontBitmap.getHeight() / (float) frontTexture.getHeight(), frontBitmap.getWidth() / (float) frontTexture.getWidth(), frontBitmap.getHeight() / (float) frontTexture.getHeight(), frontBitmap.getWidth() / (float) frontTexture.getWidth(), frontBitmap.getHeight() / 2f / (float) frontTexture.getHeight() });

			FlipRenderer.checkError(gl);

			frontBitmap.recycle();
			frontBitmap = null;
		}

		if (backBitmap != null)
		{
			if (backTexture != null)
				backTexture.destroy(gl);

			backTexture = Texture.createTexture(backBitmap, gl);

			backTopCard.setTexture(backTexture);
			backBottomCard.setTexture(backTexture);

			backTopCard.setCardVertices(new float[]
			{ 0f, backBitmap.getHeight(), 0f, // top left
			0f, backBitmap.getHeight() / 2.0f, 0f, // bottom left
			backBitmap.getWidth(), backBitmap.getHeight() / 2f, 0f, // bottom right
			backBitmap.getWidth(), backBitmap.getHeight(), 0f // top right
			});

			backTopCard.setTextureCoordinates(new float[]
			{ 0f, 0f, 0f, backBitmap.getHeight() / 2f / (float) backTexture.getHeight(), backBitmap.getWidth() / (float) backTexture.getWidth(), backBitmap.getHeight() / 2f / (float) backTexture.getHeight(), backBitmap.getWidth() / (float) backTexture.getWidth(), 0f });

			backBottomCard.setCardVertices(new float[]
			{ 0f, backBitmap.getHeight() / 2f, 0f, // top left
			0f, 0f, 0f, // bottom left
			backBitmap.getWidth(), 0f, 0f, // bottom right
			backBitmap.getWidth(), backBitmap.getHeight() / 2f, 0f // top right
			});

			backBottomCard.setTextureCoordinates(new float[]
			{ 0f, backBitmap.getHeight() / 2f / (float) backTexture.getHeight(), 0f, backBitmap.getHeight() / (float) backTexture.getHeight(), backBitmap.getWidth() / (float) backTexture.getWidth(), backBitmap.getHeight() / (float) backTexture.getHeight(), backBitmap.getWidth() / (float) backTexture.getWidth(), backBitmap.getHeight() / 2f / (float) backTexture.getHeight() });

			FlipRenderer.checkError(gl);

			backBitmap.recycle();
			backBitmap = null;
		}
	}

	public void invalidateTexture()
	{
		// Texture is vanished when the gl context is gone, no need to delete it explicitly
		frontTexture = null;
		backTexture = null;
	}

	private float lastY = -1;

	public boolean handleTouchEvent(MotionEvent event)
	{
		if (frontTexture == null)
			return false;

		float delta;

		switch (event.getAction())
		{
		case MotionEvent.ACTION_DOWN:
			lastY = event.getY();
			setState(STATE_TOUCH);
			return true;
		case MotionEvent.ACTION_MOVE:
			delta = lastY - event.getY();
			rotateBy(180 * delta / frontTexture.getContentHeight() * MOVEMENT_RATE);
			lastY = event.getY();
			return true;
		case MotionEvent.ACTION_UP:
		case MotionEvent.ACTION_CANCEL:
			delta = lastY - event.getY();
			rotateBy(180 * delta / frontTexture.getContentHeight() * MOVEMENT_RATE);
			if (angle < 90)
				forward = false;
			else
				forward = true;

			setState(STATE_AUTO_ROTATE);
			return true;
		}

		return false;
	}
}