Android canvas - Drawing arc between to points and removing arc from path - android

In my android application, i want to provide tracing letter feature as shown in following image :
Here i want to provide tracing of letter-D and for that i need to draw arc between two points when user starts moving finger on arc. Here, if user starts moving finger from start point and stops at end point then only it should draw arc between those points. And it should also show arc while moving finger on arc path.For that i have written below code.The problem i am facing is that, when ACTION_UP event is fired on arc path, it still shows arc drawing on canvas. But i want to remove that drawing from path if it fires ACTION_UP event in between of arc path.
Here is my code :
public class DrawView extends View implements OnTouchListener {
List<Point> pointsD = new ArrayList<Point>();
pointsD.add(new Point(520, 70));
pointsD.add(new Point(520, 335));
pointsD.add(new Point(520, 70));
pointsD.add(new Point(520, 335));
public boolean onTouch(View view, 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(x, y);
invalidate();
break;
default:
break;
}
return true;
}
private void touch_start(float x, float y) {
if (checkPoint(x, y, mLastPointIndex)) {
mPath.reset();
isPathStarted = true;
} else {
isPathStarted = false;
}
}
private void touch_move(float x, float y) {
if (isPathStarted) {
mPath.reset();
Point p = null;
p = pointsD.get(mLastPointIndex);
mPath.moveTo(p.x, p.y);
float radius = 1;
RectF oval = new RectF();
oval.set(scalePointX((int) (486 - radius)),scalePointY(70), scalePointX((int) (686 + radius)),
scalePointY((int) (334 + radius)));
if (sweepAngelD <= 180 && startAngleD <= 360) {
mPath.arcTo(oval, startAngleD, sweepAngelD, true);
sweepAngelD += 1;
startAngleD += 2;
mCanvas.drawPath(mPath, mPaint);
}
mPath.reset();
}
private void touch_up(float x, float y) {
mPath.reset();
if (isPathStarted) {
float radius = 1;
RectF oval = new RectF();
oval.set(scalePointX((int) (486 - radius)),
scalePointY(70), scalePointX((int) (686 + radius)),
scalePointY((int) (334 + radius)));
Point p = pointsD.get(mLastPointIndex);
mPath.moveTo(p.x, p.y);
mPath.arcTo(oval, startAngleD, sweepAngelD, true);
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
++mLastPointIndex;
} else {
sweepAngelD = 1;
startAngleD = 270;
mPath.reset();
}
isPathStarted = false;
}
private boolean checkPoint(float x, float y, int pointIndex){
if (pointIndex == pointsD.size()) {
// out of bounds
return false;
}
point = pointsD.get(pointIndex);
// EDIT changed point.y to poin.x in the first if statement
if (x > (point.x - TOUCH_TOLERANCE)
&& x < (point.x + TOUCH_TOLERANCE)) {
if (y > (point.y - TOUCH_TOLERANCE)
&& y < (point.y + TOUCH_TOLERANCE)) {
return true;
}
}
return false;
}
}

I edited my code as below and now it is working..
public class DrawView extends View implements OnTouchListener {
List<Point> pointsD = new ArrayList<Point>();
pointsD.add(new Point(520, 70));
pointsD.add(new Point(520, 335));
pointsD.add(new Point(520, 70));
pointsD.add(new Point(520, 335));
public boolean onTouch(View view, 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(x, y);
invalidate();
break;
default:
break;
}
return true;
}
private void touch_start(float x, float y) {
if (checkPoint(x, y, mLastPointIndex)) {
mPath.reset();
isPathStarted = true;
} else {
isPathStarted = false;
}
}
private void touch_move(float x, float y) {
if (isPathStarted) {
mPath.reset();
Point p = null;
p = pointsD.get(mLastPointIndex);
mPath.moveTo(p.x, p.y);
float radius = 1;
RectF oval = new RectF();
oval.set(scalePointX((int) (486 - radius)),scalePointY(70), scalePointX((int) (686 + radius)),
scalePointY((int) (334 + radius)));
if (sweepAngelD <= 180 && startAngleD <= 360) {
mPath.arcTo(oval, startAngleD, sweepAngelD, true);
sweepAngelD += 1;
startAngleD += 2;
}
mPath.reset();
}
private void touch_up(float x, float y) {
mPath.reset();
if (isPathStarted) {
float radius = 1;
RectF oval = new RectF();
oval.set(scalePointX((int) (486 - radius)),
scalePointY(70), scalePointX((int) (686 + radius)),
scalePointY((int) (334 + radius)));
Point p = pointsD.get(mLastPointIndex);
mPath.moveTo(p.x, p.y);
mPath.arcTo(oval, startAngleD, sweepAngelD, true);
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
++mLastPointIndex;
} else {
sweepAngelD = 1;
startAngleD = 270;
mPath.reset();
}
isPathStarted = false;
}
private boolean checkPoint(float x, float y, int pointIndex){
if (pointIndex == pointsD.size()) {
// out of bounds
return false;
}
point = pointsD.get(pointIndex);
// EDIT changed point.y to poin.x in the first if statement
if (x > (point.x - TOUCH_TOLERANCE)
&& x < (point.x + TOUCH_TOLERANCE)) {
if (y > (point.y - TOUCH_TOLERANCE)
&& y < (point.y + TOUCH_TOLERANCE)) {
return true;
}
}
return false;
}
}

Related

How to draw a smooth path of bitmap,without any breaks

i am working on a paint application and i want to draw a path of bitmap
my code is this:
private void onCanvasInitialization() {
// Main_Activity.paintButton.setEnabled(true);
mPaint = new Paint();
BlurMaskFilter bmf = new BlurMaskFilter(2, Blur.OUTER);
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setFilterBitmap(true);
mPaint.setColor(Main_Activity.colorchanger);
mCanvas = new Canvas();
mPath = new Path();
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setMaskFilter(bmf);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setAlpha(255);
bmp = Bitmap.createScaledBitmap(bmp, 30, 30, false);
bmp = bmp.copy(Config.ARGB_8888, true);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
public boolean onTouch(View arg0, MotionEvent event) {
float x = event.getX();
float y = event.getY();
if (true)
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;
}
private void touch_start(float x, float y) {
Random rand = new Random();
float r = rand.nextFloat();
float g = rand.nextFloat();
float b = rand.nextFloat();
Random rnd = new Random();
mPaint.setColor(Color.rgb(rnd.nextInt(256), rnd.nextInt(256),
rnd.nextInt(256)));
mPath.reset();
mPath.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) {
// mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
arrX[i] = mX;
arrY[i] = mY;
i++;
}
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
for (int k = 0; k < i; k++) {
canvas.drawBitmap(bmp, arrX[k], arrY[k], mPaint);
}
}
by this i am able to draw bitmap on canvas but the flow is not smooth it is not looks like a line .there is a gap between the two successive bitmaps.i want it to look like a path .
Why are you calling invalidate() method in every case: , try to call it out ot switch.
For Ex.
public boolean onTouch(View arg0, MotionEvent event) {
float x = event.getX();
float y = event.getY();
if (true)
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
break;
case MotionEvent.ACTION_UP:
touch_up();
break;
}
invalidate();
return true;
}

Curves are broken while drawing path in canvas

I am using the following code to draw a path based on variable width changes on a Canvas, So far everything works fine and i can easily draw path using this code.
But the path drawn is not smooth, Especially when i draw a curved path all the lines look broken, Why does this happen? Is anything wrong in my code?
public class FingerPaint extends GraphicsActivity
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(new MyView(this));
}
public void colorChanged(int color)
{
}
public class MyView extends View implements OnTouchListener
{
private static final float STROKE_WIDTH = 3f;
private Paint paint = new Paint();
private Path mPath = new Path();
ArrayList<Path> mPaths = new ArrayList<Path>();
private Canvas m_CanvasView;
private Bitmap m_CanvasBitmap;
int variableWidthDelta = 1;
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
ArrayList<Point> points = new ArrayList<Point>(64);
public MyView(Context context)
{
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
this.setOnTouchListener(this);
paint.setAntiAlias(true);
paint.setDither(true);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeJoin(Paint.Join.ROUND);
paint.setStrokeCap(Paint.Cap.ROUND);
paint.setStrokeWidth(STROKE_WIDTH);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh)
{
super.onSizeChanged(w, h, oldw, oldh);
m_CanvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
m_CanvasView = new Canvas(m_CanvasBitmap);
}
#Override
protected void onDraw(Canvas canvas)
{
canvas.drawBitmap(m_CanvasBitmap, 0f, 0f, null);
m_CanvasView.drawPath(mPath, paint);
}
public boolean onTouch(View arg0, MotionEvent event)
{
float x = event.getX();
float y = event.getY();
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
{
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
break;
}
case MotionEvent.ACTION_MOVE:
{
if (event.getPressure()>=0.00 && event.getPressure()<0.05)
{
variableWidthDelta = 1;
}
else if (event.getPressure()>=0.05 && event.getPressure()<0.10)
{
variableWidthDelta = 1;
}
else if (event.getPressure()>=0.10 && event.getPressure()<0.15)
{
variableWidthDelta = 2;
}
else if (event.getPressure()>=0.15 && event.getPressure()<0.20)
{
variableWidthDelta = 2;
}
else if (event.getPressure()>=0.20 && event.getPressure()<0.25)
{
variableWidthDelta = 1;
}
else if (event.getPressure() >= 0.25 && event.getPressure()<0.30)
{
variableWidthDelta = 1;
}
else if (event.getPressure() >= 0.30 && event.getPressure()<0.35)
{
variableWidthDelta = 2;
}
else if (event.getPressure() >= 0.35 && event.getPressure()<0.40)
{
variableWidthDelta = 2;
}
else if (event.getPressure() >= 0.40 && event.getPressure()<0.45)
{
variableWidthDelta = 3;
}
else if (event.getPressure() >= 0.45 && event.getPressure()<0.50)
{
variableWidthDelta = 4;
}
paint.setStrokeWidth(STROKE_WIDTH + variableWidthDelta);
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE)
{
points.add(new Point(event.getX(), event.getY()));
mPath = new Path();
mPath = generatePath();
}
break;
}
case MotionEvent.ACTION_UP:
{
break;
}
}
invalidate();
return true;
}
class Point
{
public final float x;
public final float y;
public Point(float x, float y)
{
this.x = x;
this.y = y;
}
}
public Path generatePath()
{
final float tangentScale = 0.3F;
int pointcount = points.size();
mPath.moveTo(points.get(0).x, points.get(0).y);
mPath.cubicTo(
points.get(0).x + (points.get(1).x - points.get(0).x)*tangentScale,
points.get(0).y + (points.get(1).y - points.get(0).y)*tangentScale,
points.get(1).x - (points.get(2).x - points.get(0).x)*tangentScale,
points.get(1).y - (points.get(2).y - points.get(0).y)*tangentScale,
points.get(1).x, points.get(1).y
);
for(int p=2; p<pointcount-1; p++)
{
mPath.cubicTo(
points.get(p-1).x + (points.get(p).x - points.get(p-2).x)*tangentScale,
points.get(p-1).y + (points.get(p).y - points.get(p-2).y)*tangentScale,
points.get(p).x - (points.get(p+1).x - points.get(p-1).x)*tangentScale,
points.get(p ).y - (points.get(p+1).y - points.get(p-1).y)*tangentScale,
points.get(p).x, points.get(p).y
);
}
mPath.cubicTo(
points.get(pointcount-2).x + (points.get(pointcount-1).x - points.get(pointcount-3).x)*tangentScale,
points.get(pointcount-2).y + (points.get(pointcount-1).y - points.get(pointcount-3).y)*tangentScale,
points.get(pointcount-1).x - (points.get(pointcount-1).x - points.get(pointcount-2).x)*tangentScale,
points.get(pointcount-1).y - (points.get(pointcount-1).y - points.get(pointcount-2).y)*tangentScale,
points.get(pointcount-1).x, points.get(pointcount-1).y
);
return mPath;
}
}
}
The onTouch event is not fired fast enough, so if you draw curves fast enough you will see this happening.
You can improve the point resolution by getting all recorded points between this onTouch event and the last one. Use event.getHistorySize() to get the amount of available points, and get their positions with event.getHistoricalX(int) and event.getHistoricalY(int).
If you still have problems, you would probably have to implement some sort of interpolation of the points.
Here is a simple example using cubicTo() to get a smooth path:
points is an array of all points that are to be drawn.
pointcount is the amount of points
//This code is untested
public Path generatePath(){
Path path = new Path();
if( points.size() < 3 ) return path;
final float tangentScale = 0.3;
path.moveTo(points[0].x, points[0].y);
path.cubicTo(
points[0].x + (points[1].x - points[0].x)*tangentScale,
points[0].y + (points[1].y - points[0].y)*tangentScale,
points[1].x - (points[2].x - points[0].x)*tangentScale,
points[1].y - (points[2].y - points[0].y)*tangentScale,
points[1].x, points[1].y
);
for(int p=2; p<pointcount-1; p++){
path.cubicTo(
points[p-1].x + (points[p].x - points[p-2].x)*tangentScale,
points[p-1].y + (points[p].y - points[p-2].y)*tangentScale,
points[p ].x - (points[p+1].x - points[p-1].x)*tangentScale,
points[p ].y - (points[p+1].y - points[p-1].y)*tangentScale,
points[p].x, points[p].y
);
}
path.cubicTo(
points[pointcount-2].x + (points[pointcount-1].x - points[pointcount-3].x)*tangentScale,
points[pointcount-2].y + (points[pointcount-1].y - points[pointcount-3].y)*tangentScale,
points[pointcount-1].x - (points[pointcount-1].x - points[pointcount-2].x)*tangentScale,
points[pointcount-1].y - (points[pointcount-1].y - points[pointcount-2].y)*tangentScale,
points[pointcount-1].x, points[pointcount-1].y
);
return path;
}
Adapting this for your specific case:
(You will have to modify the above method to use .get() instead of array accessors, since I am using a list here)
//A class for holding x and y values:
class Point{
public final float x;
public final float y;
public Point(float x, float y){
this.x = x;
this.y = y;
}
}
//In your View:
ArrayList<Point> points = new ArrayList<Points>(64);
//In the onTouch-method if the tolerance is ok:
points.add(new Point(event.getX(), event.GetY());
mPath = generatePath();
The above will generate a rounded path that you can draw. Note that it uses all points, so they will all be redrawn every time (you might have to clear the canvas to avoid some artiefacts). You might want to move the generatePath-call to when you lift the finger, so you get a faster, but jagged preview path while drawing.

Paint Xfermode draws black line on andorid 2.2---->again

I want to erase a part of image and I setting XferMode to clear image. but when i testing on android >3.0 it works fine and it draws black line on android < 3.0 (2.2). I can't find solution for this problem. Can anyone explain me why ?
this is TouchView method:
public TouchView(Context context) {
super(context);
mPath = new Path();
Display display = getWindowManager().getDefaultDisplay();
#SuppressWarnings("deprecation")
int dWidth = display.getWidth();
#SuppressWarnings("deprecation")
int dHeight = display.getHeight();
int id = getIntent().getIntExtra("id", -1);
bgr1 = BitmapFactory.decodeResource(getResources(),BackgroundAdapter.mThumbIds[id]);
bgr = Bitmap.createScaledBitmap(bgr1, dWidth, dHeight, true);
overlay1 = BitmapFactory.decodeResource(getResources(),OverlayAdapter.mThumbIds[id]).copy(Config.ARGB_8888, true);
overlay = Bitmap.createScaledBitmap(overlay1, dWidth, dHeight, true);
c2 = new Canvas(
pTouch = new Paint(/*Paint.ANTI_ALIAS_FLAG*/);
pTouch.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
pTouch.setColor(Color.TRANSPARENT);
pTouch.setDither(true);
pTouch.setStrokeWidth(20);
pTouch.setAntiAlias(true);
pTouch.setFilterBitmap(true);
pTouch.setStyle(Paint.Style.STROKE);
pTouch.setMaskFilter(new BlurMaskFilter(10, Blur.
}
this sets paint to TouchView:
private void touch_start(float x, float y){
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
mDrawPoint = true;
mPath.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) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mPath.lineTo(mX, mY);
c2.drawPath(mPath, pTouch);
mPath.reset();
mPath.moveTo(mX, mY);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.reset();
}
public boolean onTouchEvent(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;
}
and onDraw:
public void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(bgr, 0, 0, null);
Paint new_paint = new Paint();
new_paint.setXfermode(new PorterDuffXfermode(Mode.SRC_ATOP));
new_paint.setStyle(Paint.Style.STROKE );
new_paint.setFilterBitmap(true);
canvas.drawBitmap(overlay, 0, 0, new_paint);
canvas.drawColor(Color.TRANSPARENT);
canvas.isHardwareAccelerated();
c2.drawPath(mPath, pTouch);
}
i
This is an issue with hardware acceleration. Try doing this in your custom view's constructor:
if (android.os.Build.VERSION.SDK_INT >= 11)
{
setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}

erasing from canvas, last canvas.drawPath()

this is the code i made:
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
undoPath = new Path();
undoPath.moveTo(x, y);
canvas.drawPoint(x, y, paint);
mX = x;
mY = y;
if (bitmaps.size() > 0) {
for (int i = 0; i < (bitmaps.size()); i++) {
System.out.println("CustomImage.touch_start(): " + i + "||" + bitmaps.get(i).rect + "ZZ: " + x + "|| " + y);
if (bitmaps.get(i).rect.contains((int) x, (int) y)) {
System.out.println("CustomImage.touch_start()2");
contains = true;
lastBitmap = i;
}
}
}
private void touch_move(float x, float y) {
float dx, dy;
dx = Math.abs(x - mX);
dy = Math.abs(y - mY);
if ((dx >= TOUCH_TOLERANCE) || (dy >= TOUCH_TOLERANCE)) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
undoPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
mPath.moveTo(mX, mY);
undoPath.lineTo(mX, mY);
undoPath.moveTo(mX, mY);
canvas.drawPath(mPath, paint);
mPath.reset();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
When i press the undo button i do this:
public void setPaint2(Paint paint2) {
canvas.drawPath(undoPath, paint2);
invalidate();
}
where paint2 is:
paint2= new Paint();
paint2.setStrokeWidth(paint.getStrokeWidth()+5);
paint2.setColor(0x00000000);
paint2.setXfermode(clear);
paint2.setAlpha(0x00);
paint is the Paint() that i use to draw, paint2 is the one i use to erase(paints with alpha = 0 (transparent) over the first one.
The problem is that, even if it erases a part, it does not erase everything, what can I do?
This resolved my issues:
delPaint = new Paint();
delPaint.setColor(0x00000000);
delPaint.setXfermode(clear);
delPaint.setAlpha(0x00);
delPaint.setAntiAlias(true);
delPaint.setDither(true);
delPaint.setStyle(Paint.Style.STROKE);
delPaint.setStrokeJoin(Paint.Join.ROUND);
delPaint.setStrokeCap(Paint.Cap.ROUND);

How to get X and Y coordinates of a signature drawn in a bitmap canvas

Given below is my Java code. I want to capture the signature drawn in the bitmap and store it in a string array (X and Y coordinates of the signature).
package com.ust.mobile.android.jnj;
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.view.MotionEvent;
import android.view.View;
public class SignatureFieldClass extends View{
private int nBitmapWidth = 700;
private int nBitmapHeight = 220;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
private Paint mPaint = new Paint();
private ArrayList<String> signature=new ArrayList<String>();
public SignatureFieldClass(Context c) {
super(c);
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xFFFF0000);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(4);
mBitmap = Bitmap.createBitmap(nBitmapWidth, nBitmapHeight, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(0xFF6386AD);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath.reset();
mPath.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) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
#Override
public boolean onTouchEvent(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;
}
public void ClearPath(){
mPath.reset();
invalidate();
}
}
we can store the X and Y coordinates of the bitmap to a string array.for dat we can use below code.
private int mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(int x, int y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
s=Integer.toString(mX);
//signatures=s;
sb.append(s);
sb.append(",");
//signature[0]=s;
mY = y;
s=Integer.toString(mY);
sb.append(s);
//signature[1]=s;
}
private void touch_move(int x, int y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
s=Integer.toString(mX);
sb.append(",");
sb.append(s);
sb.append(",");
/* int l=signature.length;
signature[l]=s;*/
mY = y;
s=Integer.toString(mY);
sb.append(s);
/*l=signature.length;
signature[l]=s;*/
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
s=Integer.toString(mX);
sb.append(",");
sb.append(s);
s=Integer.toString(mY);
sb.append(",");
sb.append(s);
sb.append(",");
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
int x = (int)event.getX();
int y = (int)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;
}
This is not full code.it s d part f code dat captures x and y coordinates.sb is a string buffer.we can copy d values in d string buffer to a string.

Categories

Resources