android翻页效果（阅读器）

package sf.hmg.turntest; import android.content.Context; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.ColorMatrix; import android.graphics.ColorMatrixColorFilter; import android.graphics.Matrix; import android.graphics.Paint; import android.graphics.Path; import android.graphics.PointF; import android.graphics.Region; import android.graphics.drawable.GradientDrawable; import android.view.MotionEvent; import android.view.View; import android.widget.Scroller; public class PageWidget extends View { private static final String TAG = "hmg"; private int mWidth = 480; private int mHeight = 800; private int mCornerX = 0; // 拖拽点对应的页脚 private int mCornerY = 0; private Path mPath0; private Path mPath1; Bitmap mCurPageBitmap = null; // 当前页 Bitmap mNextPageBitmap = null; PointF mTouch = new PointF(); // 拖拽点 PointF mBezierStart1 = new PointF(); // 贝塞尔曲线起始点 PointF mBezierControl1 = new PointF(); // 贝塞尔曲线控制点 PointF mBeziervertex1 = new PointF(); // 贝塞尔曲线顶点 PointF mBezierEnd1 = new PointF(); // 贝塞尔曲线结束点 PointF mBezierStart2 = new PointF(); // 另一条贝塞尔曲线 PointF mBezierControl2 = new PointF(); PointF mBeziervertex2 = new PointF(); PointF mBezierEnd2 = new PointF(); float mMiddleX; float mMiddleY; float mDegrees; float mTouchToCornerDis; ColorMatrixColorFilter mColorMatrixFilter; Matrix mMatrix; float[] mMatrixArray = { 0, 0, 0, 0, 0, 0, 0, 0, 1.0f }; boolean mIsRTandLB; // 是否属于右上左下 float mMaxLength = (float) Math.hypot(mWidth, mHeight); int[] mBackShadowColors; int[] mFrontShadowColors; GradientDrawable mBackShadowDrawableLR; GradientDrawable mBackShadowDrawableRL; GradientDrawable mFolderShadowDrawableLR; GradientDrawable mFolderShadowDrawableRL; GradientDrawable mFrontShadowDrawableHBT; GradientDrawable mFrontShadowDrawableHTB; GradientDrawable mFrontShadowDrawableVLR; GradientDrawable mFrontShadowDrawableVRL; Paint mPaint; Scroller mScroller; public PageWidget(Context context) { super(context); // TODO Auto-generated constructor stub mPath0 = new Path(); mPath1 = new Path(); createDrawable(); mPaint = new Paint(); mPaint.setStyle(Paint.Style.FILL); ColorMatrix cm = new ColorMatrix(); 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 }; cm.set(array); mColorMatrixFilter = new ColorMatrixColorFilter(cm); mMatrix = new Matrix(); mScroller = new Scroller(getContext()); mTouch.x = 0.01f; // 不让x,y为0,否则在点计算时会有问题 mTouch.y = 0.01f; } /** * Author : hmg25 Version: 1.0 Description : 计算拖拽点对应的拖拽脚 */ public void calcCornerXY(float x, float y) { if (x <= mWidth / 2) mCornerX = 0; else mCornerX = mWidth; if (y <= mHeight / 2) mCornerY = 0; else mCornerY = mHeight; if ((mCornerX == 0 && mCornerY == mHeight) || (mCornerX == mWidth && mCornerY == 0)) mIsRTandLB = true; else mIsRTandLB = false; } public boolean doTouchEvent(MotionEvent event) { // TODO Auto-generated method stub if (event.getAction() == MotionEvent.ACTION_MOVE) { mTouch.x = event.getX(); mTouch.y = event.getY(); this.postInvalidate(); } if (event.getAction() == MotionEvent.ACTION_DOWN) { mTouch.x = event.getX(); mTouch.y = event.getY(); // calcCornerXY(mTouch.x, mTouch.y); // this.postInvalidate(); } if (event.getAction() == MotionEvent.ACTION_UP) { if (canDragOver()) { startAnimation(1200); } else { mTouch.x = mCornerX - 0.09f; mTouch.y = mCornerY - 0.09f; } this.postInvalidate(); } // return super.onTouchEvent(event); return true; } /** * Author : hmg25 Version: 1.0 Description : 求解直线P1P2和直线P3P4的交点坐标 */ public PointF getCross(PointF P1, PointF P2, PointF P3, PointF P4) { PointF CrossP = new PointF(); // 二元函数通式： y=ax+b float a1 = (P2.y - P1.y) / (P2.x - P1.x); float b1 = ((P1.x * P2.y) - (P2.x * P1.y)) / (P1.x - P2.x); float a2 = (P4.y - P3.y) / (P4.x - P3.x); float b2 = ((P3.x * P4.y) - (P4.x * P3.y)) / (P3.x - P4.x); CrossP.x = (b2 - b1) / (a1 - a2); CrossP.y = a1 * CrossP.x + b1; return CrossP; } private void calcPoints() { mMiddleX = (mTouch.x + mCornerX) / 2; mMiddleY = (mTouch.y + mCornerY) / 2; mBezierControl1.x = mMiddleX - (mCornerY - mMiddleY) * (mCornerY - mMiddleY) / (mCornerX - mMiddleX); mBezierControl1.y = mCornerY; mBezierControl2.x = mCornerX; mBezierControl2.y = mMiddleY - (mCornerX - mMiddleX) * (mCornerX - mMiddleX) / (mCornerY - mMiddleY); // Log.i("hmg", "mTouchX " + mTouch.x + " mTouchY " + mTouch.y); // Log.i("hmg", "mBezierControl1.x " + mBezierControl1.x // + " mBezierControl1.y " + mBezierControl1.y); // Log.i("hmg", "mBezierControl2.x " + mBezierControl2.x // + " mBezierControl2.y " + mBezierControl2.y); mBezierStart1.x = mBezierControl1.x - (mCornerX - mBezierControl1.x) / 2; mBezierStart1.y = mCornerY; // 当mBezierStart1.x < 0或者mBezierStart1.x > 480时 // 如果继续翻页，会出现BUG故在此限制 if (mTouch.x > 0 && mTouch.x < mWidth) { if (mBezierStart1.x < 0 || mBezierStart1.x > mWidth) { if (mBezierStart1.x < 0) mBezierStart1.x = mWidth - mBezierStart1.x; float f1 = Math.abs(mCornerX - mTouch.x); float f2 = mWidth * f1 / mBezierStart1.x; mTouch.x = Math.abs(mCornerX - f2); float f3 = Math.abs(mCornerX - mTouch.x) * Math.abs(mCornerY - mTouch.y) / f1; mTouch.y = Math.abs(mCornerY - f3); mMiddleX = (mTouch.x + mCornerX) / 2; mMiddleY = (mTouch.y + mCornerY) / 2; mBezierControl1.x = mMiddleX - (mCornerY - mMiddleY) * (mCornerY - mMiddleY) / (mCornerX - mMiddleX); mBezierControl1.y = mCornerY; mBezierControl2.x = mCornerX; mBezierControl2.y = mMiddleY - (mCornerX - mMiddleX) * (mCornerX - mMiddleX) / (mCornerY - mMiddleY); // Log.i("hmg", "mTouchX --> " + mTouch.x + " mTouchY--> " // + mTouch.y); // Log.i("hmg", "mBezierControl1.x-- " + mBezierControl1.x // + " mBezierControl1.y -- " + mBezierControl1.y); // Log.i("hmg", "mBezierControl2.x -- " + mBezierControl2.x // + " mBezierControl2.y -- " + mBezierControl2.y); mBezierStart1.x = mBezierControl1.x - (mCornerX - mBezierControl1.x) / 2; } } mBezierStart2.x = mCornerX; mBezierStart2.y = mBezierControl2.y - (mCornerY - mBezierControl2.y) / 2; mTouchToCornerDis = (float) Math.hypot((mTouch.x - mCornerX), (mTouch.y - mCornerY)); mBezierEnd1 = getCross(mTouch, mBezierControl1, mBezierStart1, mBezierStart2); mBezierEnd2 = getCross(mTouch, mBezierControl2, mBezierStart1, mBezierStart2); // Log.i("hmg", "mBezierEnd1.x " + mBezierEnd1.x + " mBezierEnd1.y " // + mBezierEnd1.y); // Log.i("hmg", "mBezierEnd2.x " + mBezierEnd2.x + " mBezierEnd2.y " // + mBezierEnd2.y); /* * mBeziervertex1.x 推导 * ((mBezierStart1.x+mBezierEnd1.x)/2+mBezierControl1.x)/2 化简等价于 * (mBezierStart1.x+ 2*mBezierControl1.x+mBezierEnd1.x) / 4 */ mBeziervertex1.x = (mBezierStart1.x + 2 * mBezierControl1.x + mBezierEnd1.x) / 4; mBeziervertex1.y = (2 * mBezierControl1.y + mBezierStart1.y + mBezierEnd1.y) / 4; mBeziervertex2.x = (mBezierStart2.x + 2 * mBezierControl2.x + mBezierEnd2.x) / 4; mBeziervertex2.y = (2 * mBezierControl2.y + mBezierStart2.y + mBezierEnd2.y) / 4; } private void drawCurrentPageArea(Canvas canvas, Bitmap bitmap, Path path) { mPath0.reset(); mPath0.moveTo(mBezierStart1.x, mBezierStart1.y); mPath0.quadTo(mBezierControl1.x, mBezierControl1.y, mBezierEnd1.x, mBezierEnd1.y); mPath0.lineTo(mTouch.x, mTouch.y); mPath0.lineTo(mBezierEnd2.x, mBezierEnd2.y);