/**
* 实现绕x或y,或z轴的旋转动画
*/
public class RotateAnimation extends Animation
{
{
// Camera实例可以用于计算三维变换并且生成可应用于，例如，画布上的矩阵(matrix)。
private Camera mCamera;
private float mCenterX;
private float mCenterY;
private Mode mMode;
public RotateAnimation( float centerX, float centerY,
Mode mode) {
Mode mode) {
mCenterX = centerX;
mCenterY = centerY;
mMode = mode;
}
/**
* initialize这是一个回调函数告诉Animation目标View的大小参数，
* 在这里可以初始化一些相关的参数，例如设置动画持续时间、设置 Interpolator、 设置动画的参考点等。
*/
@Override
public void initialize( int width, int height, int parentWidth, int parentHeight)
{
{
super.initialize(width, height, parentWidth, parentHeight);
mCamera = new Camera();
}
/**
* applyTransformation 在动画过程中 会不断的调用 每次调用参数interpolatedTime值都会变化，
* 该参数从0渐变为1，当该参数为1时表明动画结束。
*/
@Override
protected void applyTransformation( float interpolatedTime,
Transformation t) {
Transformation t) {
float deg = 0.0F + 360.0F * interpolatedTime;
// Matrix类拥有一个3x3矩阵变换坐标。(The Matrix class holds a 3x3 matrix for transforming coordinates).
Matrix matrix = t.getMatrix();
mCamera.save();
if ( mMode == Mode. X)
// 绕x轴应用旋转变换(Applies a rotation transform around the X axis)。
mCamera.rotateX(deg);
if ( mMode == Mode. Y)
mCamera.rotateY(deg);
if ( mMode == Mode. Z)
mCamera.rotateZ(deg);
// 计算当前转换(transformation)所对应的矩阵(matrix)并且把它copy到所提供的矩阵对象中(matrix object)
mCamera.getMatrix(matrix);
mCamera.restore();
// 旋转变换前平移图片使图片中心于基准点中心重合（基准点中心就是图片左上角的位置）
matrix.preTranslate(- mCenterX, - mCenterY);
// 旋转变换后将图片移回原来位置
matrix.postTranslate( mCenterX, mCenterY);
}
public enum Mode {
X, Y, Z;
}
}
运用：
public class FlippingImageView extends ImageView
{
{
private RotateAnimation mAnimation;
private boolean mIsHasAnimation;
public FlippingImageView(Context context) {
super(context);
}
public FlippingImageView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public FlippingImageView(Context context, AttributeSet attrs, int defStyle)
{
{
super(context, attrs, defStyle);
}
private void setRotateAnimation() {
if ( mIsHasAnimation == false &&
getWidth() > 0 && getVisibility() == View.VISIBLE ) {
getWidth() > 0 && getVisibility() == View.VISIBLE ) {
mIsHasAnimation = true;
mAnimation = new RotateAnimation(getWidth() / 2.0F, getHeight()
/ 2.0F, Mode.Y );
/ 2.0F, Mode.Y );
mAnimation.setDuration(1000L);
mAnimation.setInterpolator( new LinearInterpolator());
mAnimation.setRepeatCount(-1);
mAnimation.setRepeatMode(Animation. RESTART);
setAnimation( mAnimation);
}
}
private void clearRotateAnimation() {
if ( mIsHasAnimation) {
mIsHasAnimation = false;
setAnimation( null);
mAnimation = null;
}
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
setRotateAnimation();
}
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
clearRotateAnimation();
}
@Override
protected void onSizeChanged( int w, int h, int oldw, int oldh)
{
{
super.onSizeChanged(w, h, oldw, oldh);
if (w > 0) {
setRotateAnimation();
}
}
public void startAnimation() {
if ( mIsHasAnimation) {
super.startAnimation( mAnimation);
}
}
@Override
protected void onVisibilityChanged(View changedView, int visibility)
{
{
super.onVisibilityChanged(changedView, visibility);
if (visibility == View. INVISIBLE || visibility == View. GONE)
{
{
clearRotateAnimation();
} else {
setRotateAnimation();
}
}
}