Как я могу нарисовать текст с линией на холсте?

Question

** Как я могу нарисовать линию с текстом на холсте.Текст, который показывает, это длина строки, которая отображается вместе со строкой, когда он рисует на холсте.Пожалуйста, помогите мне в этой ситуации.

Вот выходные изображения, которые я пробовал.Токовый выход: **

и вот выход, который мне нужен.Требуемый вывод:

Вот код вида чертежа, который я пробовал.

    class Line {
    float startX, startY, stopX, stopY;
    public Line(float startX, float startY, float stopX, float stopY) {
        this.startX = startX;
        this.startY = startY;
        this.stopX = stopX;
        this.stopY = stopY;
    }
    public Line(float startX, float startY) { // for convenience
        this(startX, startY, startX, startY);
    }
}

public class DrawView extends View {

    Paint paint = new Paint();
    Paint paint1 = new Paint();
    ArrayList<Line> lines = new ArrayList<Line>();
    Path path = new Path();
    private void init() {
        paint.setColor(Color.BLACK);
        paint.setStrokeWidth(5);
        paint.setStyle(Paint.Style.FILL);
        paint.setStrokeJoin(Paint.Join.MITER);
    }

    private void drawArrow1(float startX, float startY, float stopX, float stopY, Canvas canvas, Paint paint1) {
        double degree = calculateDegree(startX, stopX, startY, stopY);

        float endX1 = (float) (stopX + ((20) * Math.cos(Math.toRadians((degree-30)+90))));
        float endY1 = (float) (stopY + ((20) * Math.sin(Math.toRadians(((degree-30)+90)))));

        float endX2 = (float) (stopX + ((20) * Math.cos(Math.toRadians((degree-60)+180))));
        float endY2 = (float) (stopY + ((20) * Math.sin(Math.toRadians(((degree-60)+180)))));

        canvas.drawLine(stopX,stopY,endX1,endY1,paint1);
        canvas.drawLine(stopX, stopY, endX2,endY2,paint1);
    }

    private void drawArrow(float startX, float startY, float stopX, float stopY, Canvas canvas, Paint paint1) {

        double degree1 = calculateDegree(stopX, startX, stopY, startY);
        float endX11 = (float) (startX + ((20) * Math.cos(Math.toRadians((degree1-30)+90))));
        float endY11 = (float) (startY + ((20) * Math.sin(Math.toRadians(((degree1-30)+90)))));

        float endX22 = (float) (startX + ((20) * Math.cos(Math.toRadians((degree1-60)+180))));
        float endY22 = (float) (startY + ((20) * Math.sin(Math.toRadians(((degree1-60)+180)))));

        canvas.drawLine(startX,startY,endX11,endY11,paint1);
        canvas.drawLine(startX,startY,endX22,endY22,paint1);

    }

    public double calculateDegree(float x1, float x2, float y1, float y2) {
        float startRadians = (float) Math.atan((y2 - y1) / (x2 - x1));
        System.out.println("radian=====" + Math.toDegrees(startRadians));
        startRadians += ((x2 >= x1) ? 90 : -90) * Math.PI / 180;
        return Math.toDegrees(startRadians);
    }

    public DrawView(Context context) {
        super(context);
        init();
    }

    public DrawView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public DrawView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    @Override
    public void onDraw(Canvas canvas) {
        for (Line l : lines) {
            canvas.drawLine(l.startX, l.startY, l.stopX, l.stopY, paint);
            drawArrow(l.startX, l.startY, l.stopX, l.stopY,canvas,paint);
            drawArrow1(l.startX, l.startY, l.stopX, l.stopY,canvas,paint);
        }
    }

    float first_x, first_y, last_x, last_y, line_lenght;
    @Override
    public boolean onTouchEvent(MotionEvent event) {

        float x = event.getX();
        float y = event.getY();

        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            first_x = x;
            first_y = y;

            lines.add(new Line(event.getX(), event.getY()));
            return true;
        }
        else if ((event.getAction() == MotionEvent.ACTION_MOVE ||
                event.getAction() == MotionEvent.ACTION_UP) &&
                lines.size() > 0) {
            Line current = lines.get(lines.size() - 1);
            current.stopX = event.getX();
            current.stopY = event.getY();
            last_x = x;
            last_y = y;
            line_lenght = (float) Math.pow(Math.abs(first_x-last_x),2) + (float) Math.pow(Math.abs(first_y-last_y),2);
            line_lenght = (float) Math.sqrt(line_lenght);
            Log.i("lenght", String.valueOf(line_lenght));
            invalidate();
            return true;
        }
        else {
            return false;
        }
    }
}

Answer 1

У меня есть немного решения моего собственного вопроса. Вот решение, которое я получил.

class Line {
    float startX, startY, stopX, stopY;
    public Line(float startX, float startY, float stopX, float stopY) {
        this.startX = startX;
        this.startY = startY;
        this.stopX = stopX;
        this.stopY = stopY;
    }
    public Line(float startX, float startY) { // for convenience
        this(startX, startY, startX, startY);
    }
}

public class DrawView extends View {

    Paint paint = new Paint();
    ArrayList<Line> lines = new ArrayList<Line>();
    TextPaint textPaint = new TextPaint();
    private void init() {
        paint.setColor(Color.BLUE);
        paint.setStrokeWidth(5);
        paint.setStyle(Paint.Style.FILL);
        paint.setStrokeJoin(Paint.Join.MITER);

        textPaint.setAntiAlias(true);
        textPaint.setTypeface(Typeface.create("Arial", Typeface.BOLD));
        textPaint.setTextSize(18 * getResources().getDisplayMetrics().density);
        textPaint.setColor(Color.BLACK);
    }

    private void drawArrow1(float startX, float startY, float stopX, float stopY, Canvas canvas, Paint paint1) {
        double degree = calculateDegree(startX, stopX, startY, stopY, canvas);
        float line_lenghtt = (float) Math.pow(Math.abs(startX-stopX),2) + (float) Math.pow(Math.abs(startY-stopY),2);
        line_lenghtt = (float) Math.sqrt(line_lenghtt);
        float inch = (float) (line_lenghtt / 95.999999998601);

        float m = (startX+stopX)/2;
        float m1 = (startY+stopY)/2;
        canvas.drawText(String.format("%.2f", inch)+"″",m,m1,textPaint);

        float endX1 = (float) (stopX + ((20) * Math.cos(Math.toRadians((degree-30)+90))));
        float endY1 = (float) (stopY + ((20) * Math.sin(Math.toRadians(((degree-30)+90)))));

        float endX2 = (float) (stopX + ((20) * Math.cos(Math.toRadians((degree-60)+180))));
        float endY2 = (float) (stopY + ((20) * Math.sin(Math.toRadians(((degree-60)+180)))));

        canvas.drawLine(stopX,stopY,endX1,endY1,paint1);
        canvas.drawLine(stopX, stopY, endX2,endY2,paint1);

    }

    private void drawArrow(float startX, float startY, float stopX, float stopY, Canvas canvas, Paint paint1) {

        double degree1 = calculateDegree(stopX, startX, stopY, startY,canvas);
        float endX11 = (float) (startX + ((20) * Math.cos(Math.toRadians((degree1-30)+90))));
        float endY11 = (float) (startY + ((20) * Math.sin(Math.toRadians(((degree1-30)+90)))));

        float endX22 = (float) (startX + ((20) * Math.cos(Math.toRadians((degree1-60)+180))));
        float endY22 = (float) (startY + ((20) * Math.sin(Math.toRadians(((degree1-60)+180)))));

        canvas.drawLine(startX,startY,endX11,endY11,paint1);
        canvas.drawLine(startX,startY,endX22,endY22,paint1);
    }

    public double calculateDegree(float x1, float x2, float y1, float y2, Canvas canvas) {
        float startRadians = (float) Math.atan((y2 - y1) / (x2 - x1));
        System.out.println("radian=====" + Math.toDegrees(startRadians));
        startRadians += ((x2 >= x1) ? 90 : -90) * Math.PI / 180;
        return Math.toDegrees(startRadians);
    }

    public DrawView(Context context) {
        super(context);
        init();
    }

    public DrawView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public DrawView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    @Override
    public void onDraw(Canvas canvas) {
        for (Line l : lines) {
            canvas.drawLine(l.startX, l.startY, l.stopX, l.stopY, paint);
            drawArrow(l.startX, l.startY, l.stopX, l.stopY,canvas,paint);
            drawArrow1(l.startX, l.startY, l.stopX, l.stopY,canvas,paint);
        }
    }

    float first_x, first_y, last_x, last_y, line_lenght;
    @Override
    public boolean onTouchEvent(MotionEvent event) {

        float x = event.getX();
        float y = event.getY();

        if (event.getAction() == MotionEvent.ACTION_DOWN) {
            first_x = x;
            first_y = y;

            lines.add(new Line(event.getX(), event.getY()));
            return true;
        }
        else if ((event.getAction() == MotionEvent.ACTION_MOVE || event.getAction() == MotionEvent.ACTION_UP) &&
                lines.size() > 0) {
            Line current = lines.get(lines.size() - 1);
            current.stopX = event.getX();
            current.stopY = event.getY();
            last_x = x;
            last_y = y;
            line_lenght = (float) Math.pow(Math.abs(first_x-last_x),2) + (float) Math.pow(Math.abs(first_y-last_y),2);
            line_lenght = (float) Math.sqrt(line_lenght);
            Log.i("lenght", String.valueOf(line_lenght));

            invalidate();
            return true;
        }
        else {
            return false;
        }
    }
}