背景
我一直在很多地方搜索以了解如何不为 View 设置动画并且不使用内置的可绘制对象来设置可绘制对象的动画。
原因是我需要在drawable中准备一个自定义的动画，以后可能会有不同的需求。
目前，我正在制作一个基本的动画可绘制对象，它只会在其中旋转给定的位图。
我已经在 imageView 上设置了它，但我希望能够在任何类型的 View 上使用它，甚至是覆盖了 onDraw 函数的自定义 View 。
问题
无论 View 的大小如何，我都找不到如何在不剪切的情况下显示可绘制对象。这是我看到的:
代码
代码如下:
private class CircularAnimatedDrawable extends Drawable implements Animatable {
private static final Interpolator ANGLE_INTERPOLATOR = new LinearInterpolator();
private static final int ANGLE_ANIMATOR_DURATION = 2000;
private final RectF fBounds = new RectF();
private float angle = 0;
private ObjectAnimator mObjectAnimatorAngle;
private final Paint mPaint;
private boolean mRunning;
private final Bitmap mBitmap;
public CircularAnimatedDrawable(final Bitmap bitmap) {
this.mBitmap = bitmap;
mPaint = new Paint();
setupAnimations();
}
public float getAngle() {
return this.angle;
}
public void setAngle(final float angle) {
this.angle = angle;
invalidateSelf();
}
@Override
public Callback getCallback() {
return mCallback;
}
@Override
public void draw(final Canvas canvas) {
canvas.save();
canvas.rotate(angle);
canvas.drawBitmap(mBitmap, 0, 0, mPaint);
canvas.restore();
}
@Override
public void setAlpha(final int alpha) {
mPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(final ColorFilter cf) {
mPaint.setColorFilter(cf);
}
@Override
public int getOpacity() {
return PixelFormat.TRANSPARENT;
}
@Override
protected void onBoundsChange(final Rect bounds) {
super.onBoundsChange(bounds);
fBounds.left = bounds.left;
fBounds.right = bounds.right;
fBounds.top = bounds.top;
fBounds.bottom = bounds.bottom;
}
private void setupAnimations() {
mObjectAnimatorAngle = ObjectAnimator.ofFloat(this, "angle", 360f);
mObjectAnimatorAngle.setInterpolator(ANGLE_INTERPOLATOR);
mObjectAnimatorAngle.setDuration(ANGLE_ANIMATOR_DURATION);
mObjectAnimatorAngle.setRepeatMode(ValueAnimator.RESTART);
mObjectAnimatorAngle.setRepeatCount(ValueAnimator.INFINITE);
}
@Override
public void start() {
if (isRunning())
return;
mRunning = true;
mObjectAnimatorAngle.start();
invalidateSelf();
}
@Override
public void stop() {
if (!isRunning())
return;
mRunning = false;
mObjectAnimatorAngle.cancel();
invalidateSelf();
}
@Override
public boolean isRunning() {
return mRunning;
}
}
和用法:
final ImageView imageView = (ImageView) findViewById(R.id.imageView);
final Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.spinner_76_inner_holo);
final CircularAnimatedDrawable circularAnimatedDrawable = new CircularAnimatedDrawable(bitmap);
circularAnimatedDrawable.setCallback(imageView);
circularAnimatedDrawable.start();
imageView.setImageDrawable(circularAnimatedDrawable);
问题
如何设置它使可绘制对象适合 View ？
我应该使用位图大小吗？范围？两个都？还是别的什么？
最佳答案
试试你的 Drawable 的这个修改版本:
class CircularAnimatedDrawable extends Drawable implements Animatable, TimeAnimator.TimeListener {
private static final float TURNS_PER_SECOND = 0.5f;
private Bitmap mBitmap;
private boolean mRunning;
private TimeAnimator mTimeAnimator = new TimeAnimator();
private Paint mPaint = new Paint();
private Matrix mMatrix = new Matrix();
public CircularAnimatedDrawable(final Bitmap bitmap) {
mBitmap = bitmap;
mTimeAnimator.setTimeListener(this);
}
@Override
public void draw(final Canvas canvas) {
canvas.drawBitmap(mBitmap, mMatrix, mPaint);
}
@Override
protected void onBoundsChange(Rect bounds) {
Log.d(TAG, "onBoundsChange " + bounds);
mMatrix.setRectToRect(new RectF(0, 0, mBitmap.getWidth(), mBitmap.getHeight()),
new RectF(bounds),
Matrix.ScaleToFit.CENTER);
}
@Override
public void onTimeUpdate(TimeAnimator animation, long totalTime, long deltaTime) {
Rect b = getBounds();
mMatrix.postRotate(360 * TURNS_PER_SECOND * deltaTime / 1000, b.centerX(), b.centerY());
invalidateSelf();
}
@Override
public void setAlpha(final int alpha) {
mPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(final ColorFilter cf) {
mPaint.setColorFilter(cf);
}
@Override
public int getOpacity() {
return PixelFormat.TRANSPARENT;
}
@Override
public void start() {
if (isRunning())
return;
mRunning = true;
mTimeAnimator.start();
invalidateSelf();
}
@Override
public void stop() {
if (!isRunning())
return;
mRunning = false;
mTimeAnimator.cancel();
invalidateSelf();
}
@Override
public boolean isRunning() {
return mRunning;
}
}
编辑:没有 Animator 东西的版本(使用 [un]scheduleSelf)，注意它使用 View 的 Drawable.Callback 机制，所以它通常不能直接从 onCreate 启动，其中 View 还没有附加 Handler
class CircularAnimatedDrawable extends Drawable implements Animatable, Runnable {
private static final float TURNS_PER_SECOND = 0.5f;
private static final long DELAY = 50;
private Bitmap mBitmap;
private long mLastTime;
private boolean mRunning;
private Paint mPaint = new Paint();
private Matrix mMatrix = new Matrix();
public CircularAnimatedDrawable(final Bitmap bitmap) {
mBitmap = bitmap;
}
@Override
public void draw(final Canvas canvas) {
canvas.drawBitmap(mBitmap, mMatrix, mPaint);
}
@Override
protected void onBoundsChange(Rect bounds) {
Log.d(TAG, "onBoundsChange " + bounds);
mMatrix.setRectToRect(new RectF(0, 0, mBitmap.getWidth(), mBitmap.getHeight()),
new RectF(bounds),
Matrix.ScaleToFit.CENTER);
}
@Override
public void setAlpha(final int alpha) {
mPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(final ColorFilter cf) {
mPaint.setColorFilter(cf);
}
@Override
public int getOpacity() {
return PixelFormat.TRANSPARENT;
}
@Override
public void start() {
if (isRunning())
return;
mRunning = true;
mLastTime = SystemClock.uptimeMillis();
scheduleSelf(this, 0);
invalidateSelf();
}
@Override
public void stop() {
if (!isRunning())
return;
mRunning = false;
unscheduleSelf(this);
invalidateSelf();
}
@Override
public boolean isRunning() {
return mRunning;
}
@Override
public void run() {
long now = SystemClock.uptimeMillis();
Rect b = getBounds();
long deltaTime = now - mLastTime;
mLastTime = now;
mMatrix.postRotate(360 * TURNS_PER_SECOND * deltaTime / 1000, b.centerX(), b.centerY());
scheduleSelf(this, now + DELAY);
invalidateSelf();
}
}
关于android - 如何正确创建自定义动画可绘制对象？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/25720541/