android_view_rotate

package com.anim; import android.content.Context; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Camera; import android.graphics.Canvas; import android.graphics.Matrix; import android.view.MotionEvent; import android.view.View; public class MyView extends View { private Context context; private Bitmap showBmp; private Matrix matrix; // 作用矩阵 private Camera camera; private int deltaX, deltaY; // 翻转角度差值 private int centerX, centerY; // 图片中心点 public MyView(Context context) { super(context); this.context = context; initData(); } private void initData() { showBmp = BitmapFactory.decodeResource(context.getResources(), R.drawable.ic_launcher); centerX = showBmp.getWidth() / 2; centerY = showBmp.getHeight() / 2; matrix = new Matrix(); camera = new Camera(); } int lastMouseX; int lastMouseY; @Override public boolean dispatchTouchEvent(MotionEvent event) { int x = (int) event.getX(); int y = (int) event.getY(); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: lastMouseX = x; lastMouseY = y; break; case MotionEvent.ACTION_MOVE: int dx = x - lastMouseX; int dy = y - lastMouseY; deltaX += dx; deltaY += dy; break; } invalidate(); return true; } @Override protected void onDraw(Canvas canvas) { camera.save(); // 绕X轴翻转 camera.rotateX(-deltaY); // 绕Y轴翻转 camera.rotateY(deltaX); // 设置camera作用矩阵 camera.getMatrix(matrix); camera.restore(); // 设置翻转中心点 matrix.preTranslate(-this.centerX, -this.centerY); matrix.postTranslate(this.centerX, this.centerY); canvas.drawBitmap(showBmp, matrix, null); } }