我受到新材料设计动画的启发，我努力创建一个类似的drawable，用于新的支持v7 Action Bar Drawer Toggle。
我创建了一个CustomDrawable。我实际上做的就是我在画布上创建了一个Play三角形，并在可见画布的左边缘左侧暂停了徽标。我根据进度旋转画布并恢复它。然后我使用Xfermode将旋转的结果裁剪成圆圈。
我无法找到解决问题的方法。
问题是xFermode不适用于180度旋转结果（在调用canvas.restore（）之后）。
以下是活动代码。
public class MainActivity extends Activity{
ImageView iv;
CustomDrawable drawable = new CustomDrawable();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
iv = (ImageView) findViewById(R.id.button);
iv.setLayerType(View.LAYER_TYPE_HARDWARE, null);
iv.setBackgroundDrawable(drawable);
iv.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
float[] values = { 0, 1 };
if (drawable.getProgress() != 0) {
values[0] = drawable.getProgress();
values[1] = 0;
}
ObjectAnimator animator = ObjectAnimator.ofFloat(drawable,
"progress", values);
animator.setDuration(2000);
animator.start();
}
});
}
}
CustomDrawable的代码
public class CustomDrawable extends Drawable {
private float mProgress = 0;
private Paint mPaint = new Paint();
private Path mPath = new Path();
private final float rootTwo = (float) Math.sqrt(2);
private final float rootThree = (float) Math.sqrt(3);
private float radius = 0;
private float side = 0;
private Point[] triangle = new Point[3];
Paint xferpaint = new Paint();
Canvas cropper;
Bitmap bitmap;
Interpolator interpolator = new AnticipateOvershootInterpolator();
private float width;
Rect rec1, rec2;
public CustomDrawable() {
mPaint.setAntiAlias(true);
mPaint.setStyle(Style.FILL);
xferpaint.setColor(Color.RED);
xferpaint.setStyle(Style.FILL);
xferpaint.setAntiAlias(true);
}
@Override
public void draw(Canvas canvas) {
canvas.getClipBounds(bound);
boundsf.set(bound);
if (radius == 0) {
radius = Math.min(bound.centerX(), bound.centerY());
radius -= 5;
bitmap = Bitmap.createBitmap(bound.width(), bound.height(),
Config.ARGB_8888);
cropper = new Canvas(bitmap);
cropper.drawCircle(bound.centerX(), bound.centerY(), radius,
xferpaint);
xferpaint.setXfermode(new PorterDuffXfermode(Mode.DST_IN));
side = rootTwo * radius;
triangle[0] = new Point(
(int) (bound.centerX() + (side / rootThree)),
bound.centerY());
triangle[1] = new Point(bound.centerX()
- (int) (side / (2 * rootThree)), bound.centerY()
- (int) (side / 2));
triangle[2] = new Point(bound.centerX()
- (int) (side / (2 * rootThree)), bound.centerY()
+ (int) (side / 2));
width = side / 4;
rec1 = new Rect((int) (-bound.centerX() - (3 * width / 2)),
(int) (bound.centerY() - (side / 2)),
(int) (-bound.centerX() - (width / 2)),
(int) (bound.centerY() + (side / 2)));
rec2 = new Rect((int) (-bound.centerX() + (width / 2)),
(int) (bound.centerY() - (side / 2)),
(int) (-bound.centerX() + (3 * width / 2)),
(int) (bound.centerY() + (side / 2)));
}
mPath.rewind();
mPath.moveTo(triangle[0].x, triangle[0].y);
mPath.lineTo(triangle[1].x, triangle[1].y);
mPath.lineTo(triangle[2].x, triangle[2].y);
mPath.close();
mPaint.setColor(Color.parseColor("#378585"));
canvas.drawPaint(mPaint);
mPaint.setColor(Color.parseColor("#FF0400"));
canvas.rotate(180 * interpolator.getInterpolation(mProgress), 0,
bound.centerY());
canvas.drawPath(mPath, mPaint);
canvas.drawRect(rec1, mPaint);
canvas.drawRect(rec2, mPaint);
canvas.restore();
canvas.drawBitmap(bitmap, 0, 0, xferpaint);
}
@Override
public int getOpacity() {
return mPaint.getAlpha();
}
@Override
public void setAlpha(int alpha) {
mPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(ColorFilter filter) {
mPaint.setColorFilter(filter);
}
public float getProgress() {
return mProgress;
}
public void setProgress(float progress) {
mProgress = progress;
invalidateSelf();
}
}
答案 0 :(得分：0)
这是您简化的Drawable：
class CustomDrawable extends Drawable implements ValueAnimator.AnimatorUpdateListener {
private float mProgress = 0;
private Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
private Path mPath;
private Path mClipPath;
public CustomDrawable() {
mPaint.setStyle(Paint.Style.FILL);
mPaint.setColor(0xffFF0400);
}
@Override
protected void onBoundsChange(Rect bounds) {
mClipPath = new Path();
int cx = bounds.centerX();
int cy = bounds.centerY();
int radius = Math.min(cx, cy) - 5;
mClipPath.addCircle(cx, cy, radius, Path.Direction.CCW);
final float rootTwo = (float) Math.sqrt(2);
final float rootThree = (float) Math.sqrt(3);
float side = rootTwo * radius;
mPath = new Path();
mPath.moveTo(cx + (side / rootThree), cy);
mPath.lineTo(cx - side / (2 * rootThree), cy - side / 2);
mPath.lineTo(cx - side / (2 * rootThree), cy + side / 2);
mPath.close();
float width = side / 4;
addRect(-cx - (3 * width / 2), cy - (side / 2), width, side);
addRect(-cx + (width / 2), cy - (side / 2), width, side);
}
private void addRect(float l, float t, float dx, float dy) {
mPath.addRect(l, t, l + dx, t + dy, Path.Direction.CCW);
}
@Override
public void draw(Canvas canvas) {
canvas.clipPath(mClipPath);
canvas.drawColor(0xff378585);
Rect bounds = getBounds();
canvas.rotate(mProgress, 0, bounds.centerY());
canvas.drawPath(mPath, mPaint);
}
public void switchIcons() {
float[] values = { 0, 180 };
if (mProgress != 0) {
values[0] = mProgress;
values[1] = 0;
}
ValueAnimator animator = ValueAnimator.ofFloat(values).setDuration(2000);
animator.setInterpolator(new AnticipateOvershootInterpolator());
animator.addUpdateListener(this);
animator.start();
}
@Override
public void onAnimationUpdate(ValueAnimator animation) {
mProgress = (Float) animation.getAnimatedValue();
invalidateSelf();
}
@Override
public int getOpacity() {
return mPaint.getAlpha();
}
@Override
public void setAlpha(int alpha) {
mPaint.setAlpha(alpha);
}
@Override
public void setColorFilter(ColorFilter filter) {
mPaint.setColorFilter(filter);
}
}
编辑：这是draw()方法，没有Canvas.clipPath而没有创建“掩码”Bitmap：
@Override
public void draw(Canvas canvas) {
canvas.drawColor(0xff378585);
canvas.save();
canvas.rotate(mProgress, 0, cy);
canvas.drawPath(mPath, mPaint);
canvas.restore();
canvas.saveLayer(null, mDstInPaint, 0);
canvas.drawCircle(cx, cy, radius, mPaint);
canvas.restore();
}
其中：mDstInPaint是一个Paint对象，在Drawable的构造函数中设置了xfermode：
mDstInPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));