単純な描画可能なビューを実装しようとしています。現在、PathのquadToメソッドを使用して滑らかな線を描画しています。
そしてこのような結果：
ユーザーが指を速く動かしたときに、どのようにして徐々に小さな線を引くことができるのかわかりません。この例と同じです：
この結果をどのように取得できるか知っていますか？（とにかく、エンジンまたはオープンソース）。今、私は自分の「quadTo」メソッドを実装することを考えています。しかし、私はそれが遅くなるだろうと思います（またはそれは私の能力を超えています）。これはAndroidSDKのネイティブメソッドだからです。
助けてくれてありがとう。
これは、それを必要とする人のための私の単純な描画可能なビューのための私の実装です：
public class TestView extends LinearLayout{
private static final String TAG = "TestView";
private PointF previousPoint;
private PointF startPoint;
private PointF currentPoint;
private static final float STROKE_WIDTH = 5f;
private static final float HALF_STROKE_WIDTH = STROKE_WIDTH / 2;
private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
private Paint paintBm = new Paint(Paint.ANTI_ALIAS_FLAG);
private Bitmap bmp;
private Canvas canvasBmp;
private Path path;
private int paintSize = 25;
public TestView(Context context, AttributeSet attrs) {
super(context, attrs);
this.setWillNotDraw(false);
paint.setAntiAlias(true);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
paint.setColor(Color.BLACK);
//paint.setAlpha(100);
paintBm.setAntiAlias(true);
paintBm.setStyle(Paint.Style.STROKE);
paintBm.setStrokeJoin(Paint.Join.ROUND);
paintBm.setStrokeCap(Paint.Cap.ROUND);
paintBm.setStrokeWidth(STROKE_WIDTH);
paintBm.setColor(Color.BLACK);
paintBm.setAlpha(100);
path = new Path();
//paint.setPathEffect(new CornerPathEffect(2));
}
public TestView(Context context) {
super(context);
// TODO Auto-generated constructor stub
paint.setAntiAlias(true);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
paint.setColor(Color.BLACK);
path = new Path();
//paint.setPathEffect(new CornerPathEffect(2));
}
@Override
protected void onLayout(boolean changed, int left, int top, int right,
int bottom) {
// TODO Auto-generated method stub
super.onLayout(changed, left, top, right, bottom);
if(bmp == null){
bmp = Bitmap.createBitmap(right-left,bottom-top,Bitmap.Config.ARGB_8888);
canvasBmp = new Canvas(bmp);
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
//printSamples(event);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
currentPoint = new PointF(event.getX(), event.getY());
previousPoint = currentPoint;
startPoint = previousPoint;
path.reset();
break;
case MotionEvent.ACTION_MOVE:
startPoint = previousPoint;
previousPoint = currentPoint;
currentPoint = new PointF(event.getX(), event.getY());
int historySize = event.getHistorySize();
for(int i = 0; i < historySize; i++){
}
drawLine(canvasBmp, path, paint, previousPoint, currentPoint);
//path.moveTo(currentPoint.x, currentPoint.y);
break;
case MotionEvent.ACTION_UP:
startPoint = previousPoint;
previousPoint = currentPoint;
currentPoint = new PointF(event.getX(), event.getY());
drawLine(canvasBmp, path, paint, previousPoint, currentPoint);
paintSize = 25;
break;
default:
break;
}
invalidate();
return true;// super.onTouchEvent(event);
}
@Override
protected void onDraw(Canvas canvas) {
Log.v("pichan", "dasd");
//canvas.drawBitmap(bmp, 0,0, null);
//canvas.drawColor(Color.BLUE);
//canvas.drawPath(path, paint);
canvas.drawBitmap(bmp, 0, 0, paintBm);
}
private void drawLine(Canvas canvas, Path path, Paint paint, PointF start, PointF end)
{
PointF mid1 = midPoint(previousPoint, startPoint);
PointF mid2 = midPoint(end, start);
path.reset();
paint.setStrokeWidth(paintSize);
path.moveTo(mid1.x, mid1.y);
path.quadTo(previousPoint.x, previousPoint.y, mid2.x, mid2.y);
canvas.drawPath(path, paint);
//canvas.
//paintSize -= 1;
}
private PointF midPoint(PointF p1, PointF p2)
{
return new PointF((p1.x + p2.x) / 2.0f , (p1.y + p2.y) * 0.5f);
}
}