package com.anlia.pageturn.view;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.drawable.GradientDrawable;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewTreeObserver;
import android.view.animation.LinearInterpolator;
import android.widget.Scroller;
import com.anlia.pageturn.bean.MyPoint;
import com.anlia.pageturn.factory.PageFactory;
import com.anlia.pageturn.utils.ViewUtils;
/**
* Created by anlia on 2017/12/11.
*/
public class CoverPageView extends View {
private int defaultWidth;//默认宽度
private int defaultHeight;//默认高度
private int viewWidth;
private int viewHeight;
private int pageNum;//当前页数
private float xDown;//记录初始触摸的x坐标
private float scrollPageLeft;//滑动页左边界
private int scrollTime;//滑动动画时间
private PageFactory pageFactory;
private MyPoint touchPoint;//触摸点
private Scroller mScroller;
private GradientDrawable shadowDrawable;
private Bitmap previousPage;//上一页bitmap
private Bitmap currentPage;//当前页bitmap
private Bitmap nextPage;//下一页bitmap
private int touchStyle;//触摸类型
public static final int TOUCH_MIDDLE = 0;//点击中间区域
public static final int TOUCH_LEFT = 1;//点击左边区域
public static final int TOUCH_RIGHT = 2;//点击右边区域
private int pageState;//翻页状态，用于限制翻页动画结束前的触摸操作
public static final int PAGE_STAY = 0;//处于静止状态
public static final int PAGE_NEXT = 1;//翻至下一页
public static final int PAGE_PREVIOUS = 2;//翻至上一页
public CoverPageView(Context context) {
super(context);
init(context);
}
public CoverPageView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
init(context);
}
private void init(Context context){
defaultWidth = 600;
defaultHeight = 1000;
pageNum = 1;
scrollPageLeft = 0;
scrollTime = 300;
touchStyle = TOUCH_RIGHT;
pageState = PAGE_STAY;
touchPoint = new MyPoint(-1,-1);
mScroller = new Scroller(context,new LinearInterpolator());
int[] mBackShadowColors = new int[] { 0x66000000,0x00000000};
shadowDrawable = new GradientDrawable(GradientDrawable.Orientation.LEFT_RIGHT, mBackShadowColors);
shadowDrawable.setGradientType(GradientDrawable.LINEAR_GRADIENT);
}
/**
* 设置工厂类
* @param factory
*/
public void setPageFactory(final PageFactory factory){
//保证View已经完成了测量工作，各页bitmap已初始化
getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
@Override
public boolean onPreDraw() {
getViewTreeObserver().removeOnPreDrawListener(this);
if(factory.hasData){
pageFactory = factory;
pageFactory.drawCurrentBitmap(currentPage,pageNum);
postInvalidate();
}
return true;
}
});
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int height = ViewUtils.measureSize(defaultHeight, heightMeasureSpec);
int width = ViewUtils.measureSize(defaultWidth, widthMeasureSpec);
setMeasuredDimension(width, height);
viewWidth = width;
viewHeight = height;
previousPage = Bitmap.createBitmap(viewWidth, viewHeight, Bitmap.Config.RGB_565);
currentPage = Bitmap.createBitmap(viewWidth, viewHeight, Bitmap.Config.RGB_565);
nextPage = Bitmap.createBitmap(viewWidth, viewHeight, Bitmap.Config.RGB_565);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
if(pageFactory !=null){
if(touchPoint.x ==-1 && touchPoint.y ==-1){
drawCurrentPage(canvas);
pageState = PAGE_STAY;
}else{
if(touchStyle == TOUCH_RIGHT){
drawCurrentPage(canvas);
drawPreviousPage(canvas);
drawShadow(canvas);
}else {
drawNextPage(canvas);
drawCurrentPage(canvas);
drawShadow(canvas);
}
}
}
}
/**
* 绘制上一页
* @param canvas
*/
private void drawPreviousPage(Canvas canvas){
canvas.drawBitmap(previousPage, scrollPageLeft, 0,null);
}
/**
* 绘制当前页
* @param canvas
*/
private void drawCurrentPage(Canvas canvas){
if(touchStyle == TOUCH_RIGHT){
canvas.drawBitmap(currentPage, 0, 0,null);
}else if(touchStyle == TOUCH_LEFT){
canvas.drawBitmap(currentPage, scrollPageLeft, 0,null);
}
}
/**
* 绘制下一页
* @param canvas
*/
private void drawNextPage(Canvas canvas){
canvas.drawBitmap(nextPage, 0, 0, null);
}
/**
* 绘制阴影
* @param canvas
*/
private void drawShadow(Canvas canvas){
int left = (int)(viewWidth + scrollPageLeft);
shadowDrawable.setBounds(left, 0, left + 30 , viewHeight);
shadowDrawable.draw(canvas);
}
@Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
float x = event.getX();
float y = event.getY();
if(pageState == PAGE_STAY){
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
xDown = x;
if(x<=viewWidth/3){//左
touchStyle = TOUCH_LEFT;
if(pageNum>1){
pageNum--;
pageFactory.drawCurrentBitmap(currentPage,pageNum);
pageFactory.drawNextBitmap(nextPage,pageNum);
pageNum++;
}
}else if(x>viewWidth*2/3){//右
touchStyle = TOUCH_RIGHT;
if(pageNum<pageFactory.pageTotal){
pageNum++;
pageFactory.drawPreviousBitmap(previousPage,pageNum);
pageFactory.drawCurrentBitmap(currentPage,pageNum);
pageNum--;
}
}else if(x>viewWidth/3 && x<viewWidth*2/3){//中
touchStyle = TOUCH_MIDDLE;
}
break;
case MotionEvent.ACTION_MOVE:
if(touchStyle == TOUCH_LEFT){
if(pageNum>1){
scrollPage(x,y);
}
}else if(touchStyle == TOUCH_RIGHT){
if(pageNum<pageFactory.pageTotal){
scrollPage(x,y);
}
}
break;
case MotionEvent.ACTION_UP:
autoScroll();
break;
}
}
return true;
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
float x = mScroller.getCurrX();
float y = mScroller.getCurrY();
scrollPageLeft = 0 - (viewWidth - x);
if (mScroller.getFinalX() == x && mScroller.getFinalY() == y){
if(touchStyle == TOUCH_RIGHT){
pageNum++;
}else if(touchStyle == TOUCH_LEFT){
pageNum--;
}
resetView();
}
postInvalidate();
}
}
/**
* 计算滑动页面左边界位置，实现滑动当前页效果
* @param x
* @param y
*/
private void scrollPage(float x, float y){
touchPoint.x = x;
touchPoint.y = y;
if(touchStyle == TOUCH_RIGHT){
scrollPageLeft = touchPoint.x - xDown;
}else if(touchStyle == TOUCH_LEFT){
scrollPageLeft =touchPoint.x - xDown - viewWidth;
}
if(scrollPageLeft > 0){
scrollPageLeft = 0;
}
postInvalidate();
}
/**
* 自动完成滑动操作
*/
private void autoScroll(){
switch (touchStyle){
case TOUCH_LEFT:
if(pageNum>1){
autoScrollToPreviousPage();
}
break;
case TOUCH_RIGHT:
if(pageNum<pageFactory.pageTotal){
autoScrollToNextPage();
}
break;
}
}
/**
* 自动完成翻到下一页操作
*/
private void autoScrollToNextPage(){
pageState = PAGE_NEXT;
int dx,dy;
dx = (int) -(viewWidth+scrollPageLeft);
dy = (int) (touchPoint.y);
int time =(int) ((1+scrollPageLeft/viewWidth) * scrollTime);
mScroller.startScroll((int) (viewWidth+scrollPageLeft), (int) touchPoint.y, dx, dy, time);
}
/**
* 自动完成返回上一页操作
*/
private void autoScrollToPreviousPage(){
pageState = PAGE_PREVIOUS;
int dx,dy;
dx = (int) -scrollPageLeft;
dy = (int) (touchPoint.y);
int time =(int) (-scrollPageLeft/viewWidth * scrollTime);
mScroller.startScroll((int) (viewWidth+scrollPageLeft), (int) touchPoint.y, dx, dy, time);
}
/**
* 取消翻页动画,计算滑动位置与时间
*/
private void startCancelAnim(){
int dx,dy;
dx = (int) (viewWidth-1-touchPoint.x);
dy = (int) (touchPoint.y);
mScroller.startScroll((int) touchPoint.x, (int) touchPoint.y, dx, dy, scrollTime);
}
/**
* 重置操作
*/
private void resetView(){
scrollPageLeft = 0;
touchPoint.x = -1;
touchPoint.y = -1;
}
}
