一、RotatView
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package com.sun.shine.myrotation.view;import android.content.Context;import android.graphics.Bitmap;import android.graphics.Canvas;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.drawable.BitmapDrawable;import android.os.Handler;import android.os.Message;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.SurfaceView;import android.view.View;public class RotatView extends View { float o_x; float o_y; Handler handler; int delayedTime = 20; static final int play = 0; static final int stop = 1; double currentTime = 0; int width; int height; double maxwidth; Bitmap rotatBitmap; public RotatView(Context context, AttributeSet attrs) { super(context, attrs); init(); } private void init() { vRecord = new VRecord(); handler = new Handler() { @Override public void handleMessage(Message msg) { double detaTime = System.currentTimeMillis() - currentTime; switch (msg.what) { case play: { if (isClockWise) { speed = speed - a * detaTime; if (speed <= 0) { return; } else { handler.sendEmptyMessageDelayed(play, delayedTime); } } else { speed = speed + a * detaTime; if (speed >= 0) { return; } else { handler.sendEmptyMessageDelayed(play, delayedTime); } } addDegree((float)(speed * detaTime + (a * detaTime * detaTime) / 2)); // if (a < a_max) { // a = (float)(a + a_add*detaTime); // System.out.println("a:"+a); // } currentTime = System.currentTimeMillis(); invalidate(); break; } case stop: { speed = 0; handler.removeMessages(play); } } super.handleMessage(msg); } }; initSize(); } public void setRotatBitmap(Bitmap bitmap) { rotatBitmap = bitmap; initSize(); postInvalidate(); } public void setRotatDrawableResource(int id) { BitmapDrawable drawable = (BitmapDrawable)getContext().getResources().getDrawable(id); setRotatDrawable(drawable); } public void setRotatDrawable(BitmapDrawable drawable) { rotatBitmap = drawable.getBitmap(); initSize(); postInvalidate(); } private void initSize() { if (rotatBitmap == null) { // throw new NoBitMapError("Error,No bitmap in RotatView!"); return; } width = rotatBitmap.getWidth(); height = rotatBitmap.getHeight(); maxwidth = Math.sqrt(width * width + height * height); o_x = o_y = (float)(maxwidth / 2);// ????????? } private void addDegree(float added) { deta_degree += added; if (deta_degree > 360 || deta_degree < -360) { deta_degree = deta_degree % 360; } } @Override protected void onDraw(Canvas canvas) { Matrix matrix = new Matrix(); matrix.setTranslate((float)width / 2, (float)height / 2); matrix.preRotate(deta_degree); matrix.preTranslate(-(float)width / 2, -(float)height / 2); matrix.postTranslate((float)(maxwidth - width) / 2, (float)(maxwidth - height) / 2); canvas.drawBitmap(rotatBitmap, matrix, paint); super.onDraw(canvas); } Paint paint = new Paint(); @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { // TODO Auto-generated method stub super.onMeasure(widthMeasureSpec, heightMeasureSpec); setMeasuredDimension((int)maxwidth, (int)maxwidth); } float down_x; float down_y; float target_x; float target_y; float up_x; float up_y; float current_degree; float up_degree; float deta_degree; double lastMoveTime = 0; public static final float a_min = 0.001f; public static final float a_add = 0.001f; float a = a_min; public static final float a_max = a_min * 5; double speed = 0; VRecord vRecord; boolean isClockWise; @Override public boolean onTouchEvent(MotionEvent event) { // TODO Auto-generated method stub if (rotatBitmap == null) { throw new NoBitMapError("Error,No bitmap in RotatView!"); } switch (event.getAction()) { case MotionEvent.ACTION_DOWN: { down_x = event.getX(); down_y = event.getY(); current_degree = detaDegree(o_x, o_y, down_x, down_y); vRecord.reset(); // handler.sendEmptyMessage(stop); a = a_max; break; } case MotionEvent.ACTION_MOVE: { down_x = target_x = event.getX(); down_y = target_y = event.getY(); float degree = detaDegree(o_x, o_y, target_x, target_y); float dete = degree - current_degree; if (dete < -270) { dete = dete + 360; } else if (dete > 270) { dete = dete - 360; } lastMoveTime = System.currentTimeMillis(); vRecord.add(dete, lastMoveTime); addDegree(dete); current_degree = degree; postInvalidate(); break; } case MotionEvent.ACTION_CANCEL: case MotionEvent.ACTION_UP: { a = a_min; double lastupTime = System.currentTimeMillis(); double detaTime = lastupTime - lastMoveTime; up_x = event.getX(); up_y = event.getY(); up_degree = detaDegree(o_x, o_y, up_x, up_y); speed = speed + vRecord.getSpeed(); if (speed > 0) { speed = Math.min(VRecord.max_speed, speed); } else { speed = Math.max(-VRecord.max_speed, speed); } // System.out.println("speed:" + speed); if (speed > 0) { isClockWise = true; // v = 1; } else { isClockWise = false; // v = -1; } currentTime = System.currentTimeMillis(); handler.sendEmptyMessage(0); break; } } return true; } float detaDegree(float src_x, float src_y, float target_x, float target_y) { float detaX = target_x - src_x; float detaY = target_y - src_y; double d; if (detaX != 0) { float tan = Math.abs(detaY / detaX); if (detaX > 0) { if (detaY >= 0) { d = Math.atan(tan); } else { d = 2 * Math.PI - Math.atan(tan); } } else { if (detaY >= 0) { d = Math.PI - Math.atan(tan); } else { d = Math.PI + Math.atan(tan); } } } else { if (detaY > 0) { d = Math.PI / 2; } else { d = -Math.PI / 2; } } return (float)((d * 180) / Math.PI); } static class NoBitMapError extends RuntimeException { /** * */ private static final long serialVersionUID = 1L; public NoBitMapError(String detailMessage) { super(detailMessage); } } static class VRecord { int addCount; public static final int length = 15; double[][] record = new double[length][2]; public void add(double detadegree, double time) { for (int i = length - 1; i > 0; i--) { record[i][0] = record[i - 1][0]; record[i][1] = record[i - 1][1]; } record[0][0] = detadegree; record[0][1] = time; addCount++; } public static final double max_speed = 8; public double getSpeed() { if (addCount == 0) { return 0; } int maxIndex = Math.min(addCount, length) - 1; if ((record[0][1] - record[maxIndex][1]) == 0) { return 0; } double detaTime = record[0][1] - record[maxIndex][1]; double sumdegree = 0; for (int i = 0; i < length - 1; i++) { sumdegree += record[i][0]; // System.out.println(record[i][0]); } // System.out.println("----------"); // System.out.println(sumdegree); // System.out.println(detaTime); double result = sumdegree / detaTime; if (result > 0) { return Math.min(result, max_speed); } else { return Math.max(result, -max_speed); } // System.out.println("v=" + result); } public void reset() { addCount = 0; for (int i = length - 1; i > 0; i--) { record[i][0] = 0; record[i][1] = 0; } } } @Override protected void onDetachedFromWindow() { super.onDetachedFromWindow(); if (rotatBitmap != null) { rotatBitmap.recycle(); rotatBitmap = null; } }}?
二、MainActivity
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package com.sun.shine.myrotation;import com.sun.shine.myrotation.view.RotatView;import android.os.Bundle;import android.app.Activity;public class MainActivity extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); RotatView rotatView=(RotatView)findViewById(R.id.myRotatView); rotatView.setRotatDrawableResource(R.drawable.cycle); }}?