Question

how to draw a path in android on canvas from stored coordinates in database..

i had tried fingerpaint but when i am fetching the co-ordinates
from the database its drawing a path from a different location and if i had put a single dot to draw it draws a line from last drawing to this dot..

the following is code to read the coordinates from the database….

public Cursor read() {
    Cursor cur = db.query("path_new", null, null, null, null, null, null);
    StringBuffer sbx_read, sby_read;

    cur.moveToFirst();
    float x1 = 0, y1 = 0;
    int pid_read = 1;
    int cur_pid;
    float mX1 = 0, mY1 = 0;
    do {

        sbx_read = new StringBuffer();
        sbx_read.append(cur.getString(0));
        sby_read = new StringBuffer();
        sby_read.append(cur.getString(1));
        cur.moveToNext();
        Log.d("X", sbx_read.toString());
        Log.d("Y", sby_read.toString());
        Path mPath1 = new Path();

        String[] sbx_read_array = sbx_read.toString().trim().split(",");
        String[] sby_read_array = sby_read.toString().trim().split(",");
        // mPath.moveTo(x1, y1);
        for (int i = 0; i < sbx_read_array.length; i++) {

            x1 = Float.parseFloat(sbx_read_array[i].toString());
            y1 = Float.parseFloat(sby_read_array[i].toString());

            mPath1.moveTo(x1, y1);
            // mPath.reset();

            // mX1 = x1;
            // mY1 = y1;

            float dx = Math.abs(x1 - mX1);
            float dy = Math.abs(y1 - mY1);
            if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
                mPath.reset();
                mPath1.quadTo(mX1, mY1, (x1 + mX1) / 2, (y1 + mY1) / 2);
                mX1 = x1;
                mY1 = y1;
                // Log.d("X1", String.valueOf(x1));
                // Log.d("mX1", String.valueOf(mX1));
                // Log.d("Y1", String.valueOf(y1));
                // Log.d("mY1", String.valueOf(mY1));

                mPath1.lineTo(mX1, mY1);
                mCanvas.drawPath(mPath1, mPaint);

            }
        }
    } while (cur.moveToNext());
    cur.close();
    return cur;
}

here i am getting the path from database into stringbuffer & convert it into String array so the different paths can be store in different records..

my table is…

X-cordinatrs TEXT, Y-cordinatrs TEXT, Path_id INTEGER, PAGE_NO INTEGER

Answer 1

here is the answer..

    do {

        sbx_read = new StringBuffer();
        sbx_read.append(cur.getString(0));
        sby_read = new StringBuffer();
        sby_read.append(cur.getString(1));

        String[] sbx_read_array = sbx_read.toString().trim().split(",");
        String[] sby_read_array = sby_read.toString().trim().split(",");

        for (int i = 0; i < sbx_read_array.length; i++) {

            x1 = Float.parseFloat(sbx_read_array[i].toString());
            y1 = Float.parseFloat(sby_read_array[i].toString());

            if (pid != cur.getInt(2)) {
                pid = cur.getInt(2);
                mPath1.reset();
                mPath1.moveTo(x1, y1);
            }
            mPath1.lineTo(x1, y1);
            mCanvas.drawPath(mPath1, mPaint);
        }
    } while (cur.moveToNext());
    cur.close();

this is the Do..While loop of your code just replace it with your code..
it will work as u want……..