Android翻页动画效果完整实例代码

package pro.wizardroid.firebird; import android.graphics.*; import android.view.*; import android.content.*; import android.widget.*; public class FireView extends View { private Path preVisibleArea = null; /* 非当前页可见区域的区域，包括当前页的背面可见区域和下一页的可见区域 */ private Path currPageBackVisibleArea = null; /* 当前页的背面可见区域 */ private Path nextPageVisibleArea = null; /* 下一页的可见区域 */ Bitmap currPageBitmap = null; Bitmap nextPageBitmap = null; PointF touchPoint = new PointF(); /* 屏幕触点 */ PointF cornerPoint = new PointF(); /* 触点对应的页角点 */ PointF Bezier1StartPoint = new PointF(); /* 第一条贝塞尔曲线的起点 */ PointF Bezier1EndPoint = new PointF(); /* 第一条贝塞尔曲线的终点 */ PointF Bezier1CtrlPoint = new PointF(); /* 第一条贝塞尔曲线的控制点 */ PointF Bezier1TangentPoint = new PointF(); /* 第一条贝塞尔曲线上的切点 */ PointF Bezier2StartPoint = new PointF(); /* 第二条贝塞尔曲线的起点 */ PointF Bezier2EndPoint = new PointF(); /* 第二条贝塞尔曲线的终点 */ PointF Bezier2CtrlPoint = new PointF(); /* 第二条贝塞尔曲线的控制点 */ PointF Bezier2TangentPoint = new PointF(); /* 第二条贝塞尔曲线上的切点 */ /* begin:绘制翻起页背面所需的对象 */ ColorMatrix colormatrix = null; ColorMatrixColorFilter colorFilter = null; Paint paint = null; Matrix matrix = null; /* end:绘制翻起页背面所需的对象 */ Context toastCtx = null; private int viewWidth; private int viewHeight; Scroller scroller = null; public FireView(Context context) { super(context); toastCtx = context; scroller = new Scroller(context); preVisibleArea = new Path(); currPageBackVisibleArea = new Path(); nextPageVisibleArea = new Path(); float array[] = { 0.55f, 0, 0, 0, 80.0f, 0, 0.55f, 0, 0, 80.0f, 0, 0,0.55f, 0, 80.0f, 0, 0, 0, 0.2f, 0 }; colormatrix = new ColorMatrix(); colormatrix.set(array); colorFilter = new ColorMatrixColorFilter(colormatrix); matrix = new Matrix(); paint = new Paint(); paint.setStyle(Paint.Style.FILL); touchPoint.x = 0.1f; touchPoint.y = 0.1f; cornerPoint.x = 0; cornerPoint.y = 0; } @Override protected void onDraw(Canvas canvas) { canvas.drawColor(0xFFAAAAAA); setBezierCurvePoints(); drawCurrPageVisibleArea(canvas, currPageBitmap); drawNextPageVisibleArea(canvas, nextPageBitmap); drawCurrPageBackVisibleArea(canvas, currPageBitmap); } /* 已知触点和页角点，设置二阶贝塞尔曲线相关的点 */ public void setBezierCurvePoints() { /* 令两条贝塞尔曲线的控制点的连线，是触点与页角之间的线段的垂直平分线 */ float midX = (touchPoint.x + cornerPoint.x) / 2; float midY = (touchPoint.y + cornerPoint.y) / 2; /* 根据相似三角形边长的比例关系 */ Bezier1CtrlPoint.x = midX - (cornerPoint.y - midY) * (cornerPoint.y - midY) / (cornerPoint.x - midX); Bezier1CtrlPoint.y = cornerPoint.y; Bezier2CtrlPoint.x = cornerPoint.x; Bezier2CtrlPoint.y = midY - (cornerPoint.x - midX) * (cornerPoint.x - midX) / (cornerPoint.y - midY); /* 令两条贝塞尔曲线的起点的连线，是控制点连线的平行线；且触点与其的距离，是触点到控制点连线距离的一半 */ /* 根据相似三角形边长的比例关系 */ Bezier1StartPoint.x = Bezier1CtrlPoint.x - (cornerPoint.x - Bezier1CtrlPoint.x) / 2; Bezier1StartPoint.y = cornerPoint.y; Bezier2StartPoint.x = cornerPoint.x; Bezier2StartPoint.y = Bezier2CtrlPoint.y - (cornerPoint.y - Bezier2CtrlPoint.y) / 2; /* 令两条贝塞尔曲线的终点，是起点的连线与两条控制点和触点的连线的交点 */ Bezier1EndPoint = getCrossPoint(touchPoint, Bezier1CtrlPoint, Bezier1StartPoint, Bezier2StartPoint); Bezier2EndPoint = getCrossPoint(touchPoint, Bezier2CtrlPoint, Bezier1StartPoint, Bezier2StartPoint); /* 上面形成的贝塞尔曲线的起点、终点、控制点构成等腰三角形 */ /* 同时与两条贝塞尔曲线相切的直线，切点为等腰三角形底边中线的中点 */ Bezier1TangentPoint.x = (Bezier1StartPoint.x + Bezier1EndPoint.x + 2 * Bezier1CtrlPoint.x) / 4; Bezier1TangentPoint.y = (Bezier1StartPoint.y + Bezier1EndPoint.y + 2 * Bezier1CtrlPoint.y) / 4; Bezier2TangentPoint.x = (Bezier2StartPoint.x + Bezier2EndPoint.x + 2 * Bezier2CtrlPoint.x) / 4; Bezier2TangentPoint.y = (Bezier2StartPoint.y + Bezier2EndPoint.y + 2 * Bezier2CtrlPoint.y) / 4; } /* 已知两条直线上的各两个点，获得两线的交点——保证有交点 */ public PointF getCrossPoint(PointF p1ofl1, PointF p2ofl1, PointF p1ofl2, PointF p2ofl2) { PointF crossPoint = new PointF(); float aofl1; float bofl1; float aofl2; float bofl2; /* begin:斜率不存在的特殊情况处理 */ if (p2ofl1.x == p1ofl1.x) { crossPoint.x = p1ofl1.x; aofl2 = (p2ofl2.y - p1ofl2.y) / (p2ofl2.x - p1ofl2.x); bofl2 = (p1ofl2.y * p2ofl2.x - p1ofl2.x * p2ofl2.y) / (p2ofl2.x - p1ofl2.x); crossPoint.y = aofl2 * crossPoint.x + bofl2; return crossPoint; } if (p2ofl2.x == p1ofl2.x) { crossPoint.x = p1ofl2.x; aofl1 = (p2ofl1.y - p1ofl1.y) / (p2ofl1.x - p1ofl1.x); bofl1 = (p1ofl1.y * p2ofl1.x - p1ofl1.x * p2ofl1.y) / (p2ofl1.x - p1ofl1.x); crossPoint.y = aofl1 * crossPoint.x + bofl1; return crossPoint; } /* end:斜率不存在的特殊情况处理 */ /* y = ax + b，a和b未知 */ aofl1 = (p2ofl1.y - p1ofl1.y) / (p2ofl1.x - p1ofl1.x); bofl1 = (p1ofl1.y * p2ofl1.x - p1ofl1.x * p2ofl1.y) / (p2ofl1.x - p1ofl1.x); aofl2 = (p2ofl2.y - p1ofl2.y) / (p2ofl2.x - p1ofl2.x); bofl2 = (p1ofl2.y * p2ofl2.x - p1ofl2.x * p2ofl2.y) / (p2ofl2.x - p1ofl2.x); /* y = ax + b，x和y未知 */ crossPoint.x = (bofl2 - bofl1) / (aofl1 - aofl2); crossPoint.y = aofl1 * crossPoint.x + bofl1; return crossPoint; } private void drawCurrPageVisibleArea(Canvas canvas, Bitmap bitmap) { preVisibleArea.reset(); preVisibleArea.moveTo(Bezier1StartPoint.x, Bezier1StartPoint.y); preVisibleArea.quadTo(Bezier1CtrlPoint.x, Bezier1CtrlPoint.y, Bezier1EndPoint.x, Bezier1EndPoint.y); preVisibleArea.lineTo(touchPoint.x, touchPoint.y); preVisibleArea.lineTo(Bezier2EndPoint.x, Bezier2EndPoint.y); preVisibleArea.quadTo(Bezier2CtrlPoint.x, Bezier2CtrlPoint.y, Bezier2StartPoint.x, Bezier2StartPoint.y); preVisibleArea.lineTo(cornerPoint.x, cornerPoint.y); preVisibleArea.close(); canvas.save(); canvas.clipPath(preVisibleArea, Region.Op.XOR); /* 补集 */ canvas.drawBitmap(bitmap, 0, 0, null); canvas.restore(); } private void drawNextPageVisibleArea(Canvas canvas, Bitmap bitmap) { nextPageVisibleArea.reset(); nextPageVisibleArea.moveTo(Bezier1StartPoint.x, Bezier1StartPoint.y); nextPageVisibleArea.lineTo(Bezier1TangentPoint.x, Bezier1TangentPoint.y); nextPageVisibleArea.lineTo(Bezier2TangentPoint.x, Bezier2TangentPoint.y); nextPageVisibleArea.lineTo(Bezier2StartPoint.x, Bezier2StartPoint.y); nextPageVisibleArea.lineTo(cornerPoint.x, cornerPoint.y); nextPageVisibleArea.close(); canvas.save(); canvas.clipPath(preVisibleArea); canvas.clipPath(nextPageVisibleArea, Region.Op.INTERSECT); /* 交集 */ canvas.drawBitmap(bitmap, 0, 0, null); canvas.restore(); } private void drawCurrPageBackVisibleArea(Canvas canvas, Bitmap bitmap) { currPageBackVisibleArea.reset(); currPageBackVisibleArea.moveTo(Bezier1TangentPoint.x, Bezier1TangentPoint.y); currPageBackVisibleArea.lineTo(Bezier2TangentPoint.x, Bezier2TangentPoint.y); currPageBackVisibleArea.lineTo(Bezier2EndPoint.x, Bezier2EndPoint.y); currPageBackVisibleArea.lineTo(touchPoint.x, touchPoint.y); currPageBackVisibleArea.lineTo(Bezier1EndPoint.x, Bezier1EndPoint.y); currPageBackVisibleArea.close(); canvas.save(); canvas.clipPath(preVisibleArea); canvas.clipPath(currPageBackVisibleArea, Reg