how to draw a line with various thickness for speed drawing

Question

I want to draw a line with various thickness on drawing application in android. when i move the finger speedy it should be some thickness and i move the finger it is some thickness

Here is my code:

public class MainActivity extends Activity implements OnClickListener {

private final String tag = "MainActivity";

private ImageView eraser;

private Button btnChooseImage;

private ImageButton btnClear, btnSave, btnShare, btnCamera;

private DrawingView drawingView;

private static final int SELECT_PHOTO = 100;

private static final int CAMERA_REQUEST = 1888;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

if (savedInstanceState == null) {

setContentView(R.layout.activity_main);

drawingView = (DrawingView) findViewById(R.id.drawing);

btnChooseImage = (Button) findViewById(R.id.btnChooseImage);

btnChooseImage.setOnClickListener(this);

btnClear = (ImageButton) findViewById(R.id.btnClear);

btnClear.setOnClickListener(this);

btnSave = (ImageButton) findViewById(R.id.btnSave);

btnSave.setOnClickListener(this);

btnShare = (ImageButton) findViewById(R.id.btnShare);

btnShare.setOnClickListener(this);

btnCamera = (ImageButton) findViewById(R.id.btnCamera);

btnCamera.setOnClickListener(this);

eraser = (ImageView) findViewById(R.id.eraser);

eraser.setOnClickListener(this);

}

}

@SuppressLint("NewApi") @Override

public void onClick(View v) {

if (v == eraser) {

if (drawingView.isEraserActive()) {

drawingView.deactivateEraser();

eraser.setImageResource(R.drawable.eraser);

} else {

drawingView.activateEraser();

eraser.setImageResource(R.drawable.pencil);

}

} else if (v == btnClear) {

drawingView.reset();

drawingView.setBackground(null);

} else if (v == btnSave) {

saveImage();

} else if (v == btnCamera) {

Intent cameraIntent = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

startActivityForResult(cameraIntent, CAMERA_REQUEST);

} else if (v == btnShare) {

Intent share = new Intent(Intent.ACTION_SEND);

share.setType("image/png");

share.putExtra(Intent.EXTRA_STREAM, Uri.parse(saveImage().getAbsolutePath())); //"file:///sdcard/temporary_file.jpg"

startActivity(Intent.createChooser(share, "Share Image"));

} else if (v == btnChooseImage) {

Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);

photoPickerIntent.setType("image/*");

startActivityForResult(photoPickerIntent, SELECT_PHOTO);

}

}

public File saveImage() {

drawingView.setDrawingCacheEnabled(true);

Bitmap bm = drawingView.getDrawingCache();

File fPath = Environment.getExternalStorageDirectory();

File f = null;

f = new File(fPath, UUID.randomUUID().toString() + ".png");

try {

FileOutputStream strm = new FileOutputStream(f);

bm.compress(Bitmap.CompressFormat.PNG, 80, strm);

strm.close();

Toast.makeText(getApplicationContext(), "Image is saved successfully.", Toast.LENGTH_SHORT).show();

} catch (IOException e) {

e.printStackTrace();

}

return f;

}

@SuppressLint("NewApi") @Override

protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {

super.onActivityResult(requestCode, resultCode, imageReturnedIntent);

switch (requestCode) {

case SELECT_PHOTO:

if (resultCode == RESULT_OK) {

Uri selectedImage = imageReturnedIntent.getData();

InputStream imageStream = null;

try {

imageStream = getContentResolver().openInputStream(selectedImage);

Bitmap bitmap = BitmapFactory.decodeStream(imageStream);

BitmapDrawable ob = new BitmapDrawable(getResources(), bitmap);

if(Build.VERSION.SDK_INT >= 16)

{

drawingView.setBackground(ob);

}else {

drawingView.setBackgroundDrawable(ob);

}

} catch (FileNotFoundException e) {

e.printStackTrace();

}

}

break;

case CAMERA_REQUEST:

if (resultCode == RESULT_OK) {

Bitmap photo = (Bitmap) imageReturnedIntent.getExtras().get("data");

BitmapDrawable ob = new BitmapDrawable(getResources(), photo);

if(Build.VERSION.SDK_INT >= 16)

{

drawingView.setBackground(ob);

}else {

drawingView.setBackgroundDrawable(ob);

}

}

}

}

}

my drawing-view code:

 

public class DrawingView extends View implements OnTouchListener {

private Canvas m_Canvas;

private Path m_Path;

private Paint m_Paint;

private ArrayList<Pair<Path, Paint>> paths = new ArrayList<Pair<Path, Paint>>();

private ArrayList<Pair<Path, Paint>> undonePaths = new ArrayList<Pair<Path, Paint>>();

private float mX, mY;

private static final float TOUCH_TOLERANCE = 0.1f;

private boolean isEraserActive = false;

private Xfermode Xfermode;

private Canvas canvas;

private ArrayList<Pair<Path, Paint>> myArrayListOfValues;

public DrawingView(Context context, AttributeSet attr) {

super(context, attr);

setFocusable(true);

setFocusableInTouchMode(true);

setBackgroundColor(Color.WHITE);

this.setOnTouchListener(this);

onCanvasInitialization();

}

public void onCanvasInitialization() {

m_Paint = new Paint();

m_Paint.setAntiAlias(true);

m_Paint.setDither(true);

m_Paint.setColor(Color.parseColor("#000000"));

m_Paint.setStyle(Paint.Style.STROKE);

m_Paint.setStrokeJoin(Paint.Join.ROUND);

m_Paint.setStrokeCap(Paint.Cap.ROUND);

m_Paint.setStrokeWidth(2);

m_Canvas = new Canvas();

m_Path = new Path();

Paint newPaint = new Paint(m_Paint);

paths.add(new Pair<Path, Paint>(m_Path, newPaint));

}

@Override

protected void onSizeChanged(int w, int h, int oldw, int oldh) {

super.onSizeChanged(w, h, oldw, oldh);

Bitmap mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);

Canvas mCanvas = new Canvas(mBitmap);

}

public boolean onTouch(View arg0, MotionEvent event) {

float x = event.getX();

float y = event.getY();

switch (event.getAction()) {

case MotionEvent.ACTION_DOWN:

touch_start(x, y);

invalidate();

break;

case MotionEvent.ACTION_MOVE:

touch_move(x, y);

invalidate();

break;

case MotionEvent.ACTION_UP:

touch_up();

invalidate();

break;

}

return true;

}

@Override

protected void onDraw(Canvas canvas) {

for (Pair<Path, Paint> p : paths) {

canvas.drawPath(p.first, p.second);

}

}

private void touch_start(float x, float y) {

if (isEraserActive) {

m_Paint.setColor(Color.WHITE);

m_Paint.setStrokeWidth(10);

Paint newPaint = new Paint(m_Paint); // Clones the mPaint object

paths.add(new Pair<Path, Paint>(m_Path, newPaint));

} else {

m_Paint.setColor(Color.BLACK);

m_Paint.setStrokeWidth(2);

//m_Paint.drawRect(0,0,100,100);

Paint newPaint = new Paint(m_Paint); // Clones the mPaint object

m_Paint.setXfermode(Xfermode);

m_Paint.setStyle(Paint.Style.STROKE);

paths.add(new Pair<Path, Paint>(m_Path, newPaint));

}

m_Path.reset();

m_Path.moveTo(x, y);

mX = x;

mY = y;

}

private void touch_move(float x, float y) {

float dx = Math.abs(x - mX);

float dy = Math.abs(y - mY);

if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {

m_Path.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);

mX = x;

mY = y;

}

}

private void touch_up() {

m_Path.lineTo(mX, mY);

// commit the path to our offscreen

m_Canvas.drawPath(m_Path, m_Paint);

// kill this so we don't double draw

m_Path = new Path();

Paint newPaint = new Paint(m_Paint); // Clones the mPaint object

paths.add(new Pair<Path, Paint>(m_Path, newPaint));

}

public void activateEraser()

{

isEraserActive = true;

}

public void deactivateEraser()

{

isEraserActive = false;

}

public boolean isEraserActive()

{

return isEraserActive;

}

public void reset()

{

paths.clear();

invalidate();

}

}