Develop Reference

How to draw Canvas Points paths into another Canvas in Android?

What actually I want, whenever I draw or write in 1st canvas then at same time it would be show in 2nd canvas with points not bitmap.
The reason is 2nd user will aware with that another one is working on same screen.
I have done with store points and paths in first canvas but when i show that path in another canvas it show me only line not proper canvas.
Let me show you an image how it look likes.
My First Canvas
My first canvas:
public class CanvasView extends View {
private Path mDrawPath;
private Paint mBackgroundPaint;
private Paint mDrawPaint;
private Canvas mDrawCanvas;
private Bitmap mCanvasBitmap, mBitmap;
public static String XVALUE = "";
public static String YVALUE = "";
private static final float TOUCH_TOLERANCE = 5;
public static ArrayList<String> mXPaths = new ArrayList<>();
public static ArrayList<String> mYPaths = new ArrayList<>();
private ArrayList<String> mUnXPaths = new ArrayList<>();
private ArrayList<String> mUnYPaths = new ArrayList<>();
private ArrayList<Path> mPaths = new ArrayList<>();
public static ArrayList<Path> mPaths1 = new ArrayList<>();
private ArrayList<Paint> mPaints = new ArrayList<>();
private ArrayList<Path> mUndonePaths = new ArrayList<>();
private ArrayList<Paint> mUndonePaints = new ArrayList<>();
public static ArrayList<Point> mPoints = new ArrayList<>();
private float mX, mY;
private int mBackgroundColor = 0xFFFFFFFF;
private int mPaintColor = 0xFF660000;
private int mStrokeWidth = 4;
public CanvasView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.img1);
mDrawPath = new Path();
mBackgroundPaint = new Paint();
initPaint();
}
private void initPaint() {
mDrawPaint = new Paint();
mDrawPaint.setColor(mPaintColor);
mDrawPaint.setAntiAlias(true);
mDrawPaint.setStrokeWidth(mStrokeWidth);
mDrawPaint.setStyle(Paint.Style.STROKE);
mDrawPaint.setStrokeJoin(Paint.Join.ROUND);
mDrawPaint.setStrokeCap(Paint.Cap.ROUND);
mDrawPaint.setDither(true);
}
private void drawBackground(Canvas canvas) {
mBackgroundPaint.setColor(mBackgroundColor);
mBackgroundPaint.setStyle(Paint.Style.FILL);
canvas.drawRect(0, 0, this.getWidth(), this.getHeight(), mBackgroundPaint);
}
private void drawPaths(Canvas canvas) {
int i = 0;
for (Path p : mPaths) {
canvas.drawPath(p, mPaints.get(i));
i++;
}
}
#Override
protected void onDraw(Canvas canvas) {
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.img1);
Rect source = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
Rect bitmapRect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
canvas.drawBitmap(bitmap, source, bitmapRect, new Paint());
drawPaths(canvas);
canvas.drawPath(mDrawPath, mDrawPaint);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mCanvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mDrawCanvas = new Canvas(mCanvasBitmap);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float touchX = event.getX();
float touchY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mDrawPath.moveTo(touchX, touchY);
mX = touchX;
mY = touchY;
Log.e("Location", String.valueOf("x : "+ event.getX()+ "y : " +event.getY()));
break;
case MotionEvent.ACTION_MOVE:
float dx = Math.abs(touchX - mX);
float dy = Math.abs(touchY - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mDrawPath.quadTo(mX, mY, (touchX + mX) / 2, (touchY + mY) / 2);
mX = touchX;
mY = touchY;
Point point = new Point();
point.x = (int) event.getX();
point.y = (int)event.getY();
mPoints.add(point);
mPaths1.add(mDrawPath);
Log.d("Ponts Values", mPoints.toString());
}
break;
case MotionEvent.ACTION_UP:
mDrawPath.lineTo(mX, mY);
mXPaths.add(String.valueOf(touchX));
mYPaths.add(String.valueOf(touchY));
mPaths.add(mDrawPath);
mPaints.add(mDrawPaint);
XVALUE = mXPaths.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
YVALUE = mYPaths.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
mDrawPath = new Path();
initPaint();
break;
default:
return false;
}
invalidate();
return true;
}
public void clearCanvas() {
mXPaths.clear();
mYPaths.clear();
mPaths.clear();
mPaints.clear();
mUndonePaths.clear();
mUndonePaints.clear();
XVALUE = "";
YVALUE = "";
System.out.println("Cordinates X: "+XVALUE);
System.out.println("Cordinates Y:"+YVALUE);
mDrawCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
invalidate();
}
public void setPaintColor(int color) {
mPaintColor = color;
mDrawPaint.setColor(mPaintColor);
}
public void setPaintStrokeWidth(int strokeWidth) {
mStrokeWidth = strokeWidth;
mDrawPaint.setStrokeWidth(mStrokeWidth);
}
public void setBackgroundColor(int color) {
mBackgroundColor = color;
mBackgroundPaint.setColor(mBackgroundColor);
invalidate();
}
public Bitmap getBitmap() {
drawBackground(mDrawCanvas);
drawPaths(mDrawCanvas);
this.setDrawingCacheEnabled(false);
this.setDrawingCacheEnabled(true);
return Bitmap.createBitmap(this.getDrawingCache());
}
public void undo() {
if (mPaths.size() > 0) {
mUnXPaths.add(mXPaths.remove(mPaths.size() - 1));
mUnYPaths.add(mYPaths.remove(mPaths.size() - 1));
mUndonePaths.add(mPaths.remove(mPaths.size() - 1));
mUndonePaints.add(mPaints.remove(mPaints.size() - 1));
Log.d("X Cordinates", mXPaths.toString());
Log.d("Y Cordinates", mYPaths.toString());
XVALUE = mXPaths.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
YVALUE = mYPaths.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
System.out.println("Cordinates X: "+XVALUE);
System.out.println("Cordinates Y:"+YVALUE);
invalidate();
}
}
public void redo() {
if (mUndonePaths.size() > 0) {
mXPaths.add(mUnXPaths.remove(mUnXPaths.size() - 1));
mYPaths.add(mUnYPaths.remove(mUnYPaths.size() - 1));
mPaths.add(mUndonePaths.remove(mUndonePaths.size() - 1));
mPaints.add(mUndonePaints.remove(mUndonePaints.size() - 1));
Log.d("X Cordinates", mXPaths.toString());
Log.d("Y Cordinates", mYPaths.toString());
XVALUE = mXPaths.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
YVALUE = mYPaths.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
System.out.println("Cordinates X: "+XVALUE);
System.out.println("Cordinates Y:"+YVALUE);
invalidate();
}
}
}
My Second Canvas Code:
public class CanvasView_New extends View {
private Path mDrawPath;
private Paint mBackgroundPaint;
private Paint mDrawPaint;
private Canvas mDrawCanvas;
private Bitmap mCanvasBitmap, mBitmap;
public static String XVALUE = "";
public static String YVALUE = "";
private static final float TOUCH_TOLERANCE = 5;
public static ArrayList<String> mXPathsNew = new ArrayList<>();
public static ArrayList<String> mYPathsNew = new ArrayList<>();
private ArrayList<String> mUnXPathsNew = new ArrayList<>();
private ArrayList<String> mUnYPathsNew = new ArrayList<>();
private ArrayList<Path> mPathsNew = new ArrayList<>();
private ArrayList<Paint> mPaintsNew = new ArrayList<>();
private ArrayList<Path> mUndonePathsNew = new ArrayList<>();
private ArrayList<Paint> mUndonePaintsNew = new ArrayList<>();
private float mX, mY;
private int mBackgroundColor = 0xFFFFFFFF;
private int mPaintColor = 0xFF660000;
private int mStrokeWidth = 4;
private ArrayDeque<Point> mPoints1 = new ArrayDeque<>();
public CanvasView_New(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
private void init() {
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.img1);
mDrawPath = new Path();
mBackgroundPaint = new Paint();
initPaint();
}
private void initPaint() {
mDrawPaint = new Paint();
mDrawPaint.setColor(mPaintColor);
mDrawPaint.setAntiAlias(true);
mDrawPaint.setStrokeWidth(mStrokeWidth);
mDrawPaint.setStyle(Paint.Style.STROKE);
mDrawPaint.setStrokeJoin(Paint.Join.ROUND);
mDrawPaint.setStrokeCap(Paint.Cap.ROUND);
mDrawPaint.setDither(true);
}
private void drawBackground(Canvas canvas) {
mBackgroundPaint.setColor(mBackgroundColor);
mBackgroundPaint.setStyle(Paint.Style.FILL);
canvas.drawRect(0, 0, this.getWidth(), this.getHeight(), mBackgroundPaint);
}
private void drawPaths(Canvas canvas) {
int i = 0;
for (Path p : mPathsNew) {
canvas.drawPath(p, mPaintsNew.get(i));
i++;
}
}
#Override
protected void onDraw(Canvas canvas) {
Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.img1);
Rect source = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
Rect bitmapRect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
canvas.drawBitmap(bitmap, source, bitmapRect, new Paint());
canvas.drawPath(mDrawPath, mDrawPaint);
for(int i = 0; i< mPoints.size(); i++) {
mDrawPath.moveTo(mPoints.get(i).x, mPoints.get(i).x);
mDrawPath.quadTo(mPoints.get(i).x, mPoints.get(i).y, (mPoints.get(i).x + mPoints.get(i).x) / 2, (mPoints.get(i).y + mPoints.get(i).y) / 2);
mPathsNew.add(mDrawPath);
mPaintsNew.add(mDrawPaint);
}
drawPaths(canvas);
canvas.drawPath(mDrawPath, mDrawPaint);
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mCanvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mDrawCanvas = new Canvas(mCanvasBitmap);
}
#Override
public boolean onTouchEvent(MotionEvent event) {
float touchX = event.getX();
float touchY = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
mDrawPath.moveTo(touchX, touchY);
mX = touchX;
mY = touchY;
break;
case MotionEvent.ACTION_MOVE:
float dx = Math.abs(touchX - mX);
float dy = Math.abs(touchY - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mDrawPath.quadTo(mX, mY, (touchX + mX) / 2, (touchY + mY) / 2);
mX = touchX;
mY = touchY;
}
break;
case MotionEvent.ACTION_UP:
mDrawPath.lineTo(mX, mY);
Log.d("Path Values", touchX + " " + touchY);
mXPathsNew.add(String.valueOf(touchX));
mYPathsNew.add(String.valueOf(touchY));
mPathsNew.add(mDrawPath);
mPaintsNew.add(mDrawPaint);
Log.d("X Cordinates", mXPathsNew.toString());
Log.d("Y Cordinates", mYPathsNew.toString());
XVALUE = mXPathsNew.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
YVALUE = mYPathsNew.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
System.out.println("Cordinates X: "+XVALUE);
System.out.println("Cordinates Y:"+YVALUE);
mDrawPath = new Path();
initPaint();
break;
default:
return false;
}
invalidate();
return true;
}
public void clearCanvas() {
mXPathsNew.clear();
mYPathsNew.clear();
mPathsNew.clear();
mPaintsNew.clear();
mUndonePathsNew.clear();
mUndonePaintsNew.clear();
XVALUE = "";
YVALUE = "";
System.out.println("Cordinates X: "+XVALUE);
System.out.println("Cordinates Y:"+YVALUE);
mDrawCanvas.drawColor(0, PorterDuff.Mode.CLEAR);
invalidate();
}
public void setPaintColor(int color) {
mPaintColor = color;
mDrawPaint.setColor(mPaintColor);
}
public void setPaintStrokeWidth(int strokeWidth) {
mStrokeWidth = strokeWidth;
mDrawPaint.setStrokeWidth(mStrokeWidth);
}
public void setBackgroundColor(int color) {
mBackgroundColor = color;
mBackgroundPaint.setColor(mBackgroundColor);
invalidate();
}
public Bitmap getBitmap() {
drawBackground(mDrawCanvas);
drawPaths(mDrawCanvas);
this.setDrawingCacheEnabled(false);
this.setDrawingCacheEnabled(true);
return Bitmap.createBitmap(this.getDrawingCache());
}
public void undo() {
if (mPathsNew.size() > 0) {
mUnXPathsNew.add(mXPathsNew.remove(mPathsNew.size() - 1));
mUnYPathsNew.add(mYPathsNew.remove(mPathsNew.size() - 1));
mUndonePathsNew.add(mPathsNew.remove(mPathsNew.size() - 1));
mUndonePaintsNew.add(mPaintsNew.remove(mPaintsNew.size() - 1));
Log.d("X Cordinates", mXPathsNew.toString());
Log.d("Y Cordinates", mYPathsNew.toString());
XVALUE = mXPathsNew.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
YVALUE = mYPathsNew.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
System.out.println("Cordinates X: "+XVALUE);
System.out.println("Cordinates Y:"+YVALUE);
invalidate();
}
}
public void redo() {
if (mUndonePathsNew.size() > 0) {
mXPathsNew.add(mUnXPathsNew.remove(mUnXPathsNew.size() - 1));
mYPathsNew.add(mUnYPathsNew.remove(mUnYPathsNew.size() - 1));
mPathsNew.add(mUndonePathsNew.remove(mUndonePathsNew.size() - 1));
mPaintsNew.add(mUndonePaintsNew.remove(mUndonePaintsNew.size() - 1));
Log.d("X Cordinates", mXPathsNew.toString());
Log.d("Y Cordinates", mYPathsNew.toString());
XVALUE = mXPathsNew.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
YVALUE = mYPathsNew.toString().replaceAll("\\[|\\]", "").replaceAll(", ",",");
System.out.println("Cordinates X: "+XVALUE);
System.out.println("Cordinates Y:"+YVALUE);
invalidate();
}
}
}

Drag a rectangle on Canvas Android

I'm drawing a rectangle on a Canvas in Android. How do I drag it around on the screen? I have an onTouchEvent() method in my class that listens to MotionEvent(s). How do I use this to drag my rectangle around while preserving it's size.
My code is as follows:
public class CustomSquareView3 extends View {
private Rect rect;
private Paint paint;
public static int rotation = 45;
Canvas canvas;
int x1 = 200;
int x2 = 400;
int y1 = 200;
int y2 = 400;
public CustomSquareView3(Context context){
super(context);
int x = 50;
int y = 50;
int sideLength = 200;
rect = new Rect(x1,y1, x2, y2);
paint = new Paint();
paint.setColor(Color.GRAY);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawColor(Color.WHITE);
canvas.save();
canvas.rotate(rotation, (x1+x2)/2, (y1+y2)/2);
canvas.drawRect(rect, paint);
Paint paint2 = new Paint();
paint2.setColor(Color.WHITE);
paint2.setTextSize(50);
canvas.drawText("Hi", (x1+x2)/2, (y1+y2)/2, paint2);
canvas.restore();
}
#Override
public boolean onTouchEvent(MotionEvent event) {
int motionEvent = event.getAction();
float xMove = event.getX();
float yMove = event.getY();
switch (motionEvent){
case MotionEvent.ACTION_DOWN : {
x1 = (int) event.getX();
y1 = (int) event.getY();
rect = new Rect(x1, y1, x2, y2);
break;
}
case MotionEvent.ACTION_MOVE : {
x1 = (int) event.getX();
y1 = (int) event.getY();
rect = new Rect(x1, y1, x2, y2);
break;
}
case MotionEvent.ACTION_UP : {
x1 = (int) event.getX();
y1 = (int) event.getY();
rect = new Rect(x1, y1, x2, y2);
break;
}
default:
return false;
}
invalidate();
return true;
}
}
The above code resizes the rectangle every time I touch the screen. How do I get a smooth drag gesture in the code such that the size of the rectangle is maintained when it is dragged around the screen?

See this example:
class ViewPort extends View {
List<Layer> layers = new LinkedList<Layer>();
int[] ids = {R.drawable.layer0, R.drawable.layer1, R.drawable.layer2};
public ViewPort(Context context) {
super(context);
Resources res = getResources();
for (int i = 0; i < ids.length; i++) {
Layer l = new Layer(context, this, BitmapFactory.decodeResource(res, ids[i]));
layers.add(l);
}
}
#Override
protected void onDraw(Canvas canvas) {
for (Layer l : layers) {
l.draw(canvas);
}
}
private Layer target;
#Override
public boolean onTouchEvent(MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_DOWN) {
target = null;
for (int i = layers.size() - 1; i >= 0; i--) {
Layer l = layers.get(i);
if (l.contains(event)) {
target = l;
layers.remove(l);
layers.add(l);
invalidate();
break;
}
}
}
if (target == null) {
return false;
}
return target.onTouchEvent(event);
}
}
class Layer implements MatrixGestureDetector.OnMatrixChangeListener {
Matrix matrix = new Matrix();
Matrix inverse = new Matrix();
RectF bounds;
View parent;
Bitmap bitmap;
MatrixGestureDetector mgd = new MatrixGestureDetector(matrix, this);
public Layer(Context ctx, View p, Bitmap b) {
parent = p;
bitmap = b;
bounds = new RectF(0, 0, b.getWidth(), b.getHeight());
matrix.postTranslate(50 + (float) Math.random() * 50, 50 + (float) Math.random() * 50);
}
public boolean contains(MotionEvent event) {
matrix.invert(inverse);
float[] pts = {event.getX(), event.getY()};
inverse.mapPoints(pts);
if (!bounds.contains(pts[0], pts[1])) {
return false;
}
return Color.alpha(bitmap.getPixel((int) pts[0], (int) pts[1])) != 0;
}
public boolean onTouchEvent(MotionEvent event) {
mgd.onTouchEvent(event);
return true;
}
#Override
public void onChange(Matrix matrix) {
parent.invalidate();
}
public void draw(Canvas canvas) {
canvas.drawBitmap(bitmap, matrix, null);
}
}
class MatrixGestureDetector {
private static final String TAG = "MatrixGestureDetector";
private int ptpIdx = 0;
private Matrix mTempMatrix = new Matrix();
private Matrix mMatrix;
private OnMatrixChangeListener mListener;
private float[] mSrc = new float[4];
private float[] mDst = new float[4];
private int mCount;
interface OnMatrixChangeListener {
void onChange(Matrix matrix);
}
public MatrixGestureDetector(Matrix matrix, MatrixGestureDetector.OnMatrixChangeListener listener) {
this.mMatrix = matrix;
this.mListener = listener;
}
public void onTouchEvent(MotionEvent event) {
if (event.getPointerCount() > 2) {
return;
}
int action = event.getActionMasked();
int index = event.getActionIndex();
switch (action) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_POINTER_DOWN:
int idx = index * 2;
mSrc[idx] = event.getX(index);
mSrc[idx + 1] = event.getY(index);
mCount++;
ptpIdx = 0;
break;
case MotionEvent.ACTION_MOVE:
for (int i = 0; i < mCount; i++) {
idx = ptpIdx + i * 2;
mDst[idx] = event.getX(i);
mDst[idx + 1] = event.getY(i);
}
mTempMatrix.setPolyToPoly(mSrc, ptpIdx, mDst, ptpIdx, mCount);
mMatrix.postConcat(mTempMatrix);
if(mListener != null) {
mListener.onChange(mMatrix);
}
System.arraycopy(mDst, 0, mSrc, 0, mDst.length);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
if (event.getPointerId(index) == 0) ptpIdx = 2;
mCount--;
break;
}
}
}
You have to redo it a little. Use your rectangle instead of bitmaps.

Android - How to change color in setColor

I want to create a drawing app, and it works clearly but it is still far away from my goal.
Here's my code:
public class MainActivity extends Activity {
DrawingView dv;
private Paint mPaint;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
dv = new DrawingView(this);
setContentView(dv);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLUE);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(5);
}
public class DrawingView extends View {
public int width;
public int height;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
Context context;
private Paint circlePaint;
private Path circlePath;
public DrawingView(Context c) {
super(c);
context = c;
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
circlePaint = new Paint();
circlePath = new Path();
circlePaint.setAntiAlias(true);
circlePaint.setColor(Color.RED);
circlePaint.setStyle(Paint.Style.STROKE);
circlePaint.setStrokeJoin(Paint.Join.MITER);
circlePaint.setStrokeWidth(4f);
}
#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);
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.asd) //-->here load your image
.copy(Bitmap.Config.ARGB_8888, true);
mCanvas = new Canvas(mBitmap);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
canvas.drawPath(circlePath, circlePaint);
}
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;
circlePath.reset();
circlePath.addCircle(mX, mY, 30, Path.Direction.CW);
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
circlePath.reset();
// 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 class FingerPaintActivity extends Activity
implements ColorPickerDialog.OnColorChangedListener{
MyView mv;
AlertDialog dialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mv= new MyView(this);
mv.setDrawingCacheEnabled(true);
mv.setBackgroundResource(R.drawable.afor);//set the back ground if you wish to
setContentView(mv);
mPaint = new Paint();
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(20);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },
0.4f, 6, 3.5f);
mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
}
private Paint mPaint;
private MaskFilter mEmboss;
private MaskFilter mBlur;
public void colorChanged(int color) {
mPaint.setColor(color);
}
public class MyView extends View {
private static final float MINP = 0.25f;
private static final float MAXP = 0.75f;
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
Context context;
public MyView(Context c) {
super(c);
context=c;
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);
//mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
mBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.asd) //-->here load your image
.copy(Bitmap.Config.ARGB_8888, true);
mCanvas = new Canvas(mBitmap);
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
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) {
//showDialog();
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();
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SCREEN));
//mPaint.setMaskFilter(null);
}
#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;
}
}
}
This is what my app looks like:
I want to change color draw from blue to brown. I changed mPaint.setColor(Color.BROWN); and it failed.
If you check my preview app, you'll see that I want to create a business logic where: If user is drawing and it's not completed, the app will show a message like "sorry you have not finished the drawing" and I still look for the way to do it. I don't know if it's possible, is it?

Try using the following line:
mPaint.setColor(ContextCompat.getColor(context, R.color.your_color));

I presume that your main question is how to change color programmatically, right?
just change:
mPaint.setColor(Color.BROWN);
to:
mPaint.setColor(getResources().getColor(R.color.Brown));
I think it can help you

Daw line between 2 points

I am trying to draw a line between 2 points. I can draw a line between 2 points like: A to B to C. But I want to draw lines between them like A to C or C to A.
Also I wanted to draw those lines on a image background. I have a background there, but when i draw a line with background my app is lagging.
Here's the code:
package com.example.grzegorz.kropy;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Point;
import android.graphics.drawable.*;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.View;
import android.graphics.BitmapFactory;
import java.util.ArrayList;
import java.util.List;
public class PaintView extends View {
private Bitmap mBitmap;
private Canvas mCanvas; // holds the "draw" calls
private Path mPath; //Create an empty path
private Paint mPaint; // the style and color information about how to draw geometries, text and bitmaps.
private static final int TOUCH_TOLERANCE_DP = 24;
private static final int BACKGROUND =0xFFCC00 ;
private List<Point> mPoints = new ArrayList<Point>();
private int mLastPointIndex = 0;
private int mTouchTolerance;
private boolean isPathStarted = false;
public PaintView(Context context) {
super(context);
mCanvas = new Canvas();
mPath = new Path();
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(12);
mTouchTolerance = dp2px(TOUCH_TOLERANCE_DP);
// TODO just test points
Point p1 = new Point(20, 20);
Point p2 = new Point(100, 100);
Point p3 = new Point(200, 250);
Point p4 = new Point(280, 400);
Point p5 = new Point(350, 600);
Point p6 = new Point(400, 500);
Point p7 = new Point(450, 500);
mPoints.add(p1);
mPoints.add(p2);
mPoints.add(p3);
mPoints.add(p4);
mPoints.add(p5);
mPoints.add(p6);
mPoints.add(p7);
}
public PaintView(Context context, AttributeSet attrs) {
super(context, attrs);
mBitmap = BitmapFactory.decodeResource(getResources(),R.drawable.polacz);
mCanvas = new Canvas();
mPath = new Path();
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(12);
mTouchTolerance = dp2px(TOUCH_TOLERANCE_DP);
// TODO just test points
Point p1 = new Point(20, 20);
Point p2 = new Point(100, 100);
Point p3 = new Point(200, 250);
Point p4 = new Point(280, 400);
Point p5 = new Point(350, 600);
Point p6 = new Point(400, 500);
Point p7 = new Point(450, 500);
mPoints.add(p1);
mPoints.add(p2);
mPoints.add(p3);
mPoints.add(p4);
mPoints.add(p5);
mPoints.add(p6);
mPoints.add(p7);
}
public PaintView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
mCanvas = new Canvas();
mPath = new Path();
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(12);
mTouchTolerance = dp2px(TOUCH_TOLERANCE_DP);
}
#Override
protected void onSizeChanged(int width, int height, int oldWidth, int oldHeight) {
super.onSizeChanged(width, height, oldWidth, oldHeight);
clear();
}
#Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//canvas.drawColor(BACKGROUND);
Drawable d = getResources().getDrawable(R.drawable.polacz);
d.setBounds(canvas.getClipBounds());
d.draw(canvas);
// mCustomImage.setBounds(canvas.getClipBounds());
// mCustomImage.draw(canvas);
canvas.drawBitmap(mBitmap, 0, 0, null);
// canvas.drawBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.polacz1), 0, 0, null);
canvas.drawPath(mPath, mPaint);
// TODO remove if you dont want points to be drawn
for (Point point : mPoints) {
canvas.drawPoint(point.x, point.y, mPaint);
}
}
#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(x, y);
invalidate();
break;
}
return true;
}
private void touch_start(float x, float y) {
if (checkPoint(x, y, mLastPointIndex)) {
mPath.reset();
// user starts from given point so path can beis started
isPathStarted = true;
} else {
// user starts move from point which doen's belongs to mPinst list
isPathStarted = false;
}
}
private void touch_move(float x, float y) {
// draw line with finger move
if (isPathStarted) {
mPath.reset();
Point p = mPoints.get(mLastPointIndex);
mPath.moveTo(p.x, p.y);
if (checkPoint(x, y, mLastPointIndex + 1)) {
p = mPoints.get(mLastPointIndex + 1);
mPath.lineTo(p.x, p.y);
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
++mLastPointIndex;
} else {
mPath.lineTo(x, y);
}
}
}
/**
* Draws line.
*/
private void touch_up(float x, float y) {
mPath.reset();
if (checkPoint(x, y, mLastPointIndex + 1) && isPathStarted) {
// move finished at valid point so draw whole line
// start point
Point p = mPoints.get(mLastPointIndex);
mPath.moveTo(p.x, p.y);
// end point
p = mPoints.get(mLastPointIndex + 1);
mPath.lineTo(p.x, p.y);
mCanvas.drawPath(mPath, mPaint);
mPath.reset();
// increment point index
++mLastPointIndex;
isPathStarted = false;
}
}
/**
* Sets paint
*
* #param paint
*/
public void setPaint(Paint paint) {
this.mPaint = paint;
}
/**
* Returns image as bitmap
*
* #return
*/
public Bitmap getBitmap() {
return mBitmap;
}
/**
* Clears canvas
*/
public void clear() {
mBitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888);
mBitmap.eraseColor(BACKGROUND);
mCanvas.setBitmap(mBitmap);
invalidate();
}
/**
* Checks if user touch point with some tolerance
*/
private boolean checkPoint(float x, float y, int pointIndex) {
if (pointIndex == mPoints.size()) {
// out of bounds
return false;
}
Point point = mPoints.get(pointIndex);
//EDIT changed point.y to poin.x in the first if statement
if (x > (point.x - mTouchTolerance) && x < (point.x + mTouchTolerance)) {
if (y > (point.y - mTouchTolerance) && y < (point.y + mTouchTolerance)) {
return true;
}
}
return false;
}
public List<Point> getPoints() {
return mPoints;
}
public void setPoints(List<Point> points) {
this.mPoints = points;
}
private int dp2px(int dp) {
Resources r = getContext().getResources();
float px = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, r.getDisplayMetrics());
return (int) px;
}
}
XML:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:focusableInTouchMode="false">
<com.example.grzegorz.kropy.PaintView
android:layout_width="670dp"
android:layout_height="820dp"
/>
<!--<Button-->
<!--android:layout_width="wrap_content"-->
<!--android:layout_height="wrap_content"-->
<!--android:text="graj"-->
<!--android:id="#+id/button"-->
<!--android:layout_alignParentTop="true"-->
<!--android:layout_alignParentLeft="true"-->
<!--android:onClick="gra"-->
<!--android:layout_alignParentStart="true" />-->
</RelativeLayout>

Try solution works for me
public class DrawView extends View {
Paint paint = new Paint();
View startView1;
View endView1;
int myToken;
float sX,sY,eX,eY;
public DrawView(Context context,View startView ,View endView) {
super(context);
paint.reset();
myToken=token;
paint.setStrokeWidth(3);
this.startView1 = startView;
this.endView1 = endView;
}
public void onDraw(Canvas canvas) {
paint.setColor(Color.GREEN);
canvas.drawLine(startView1.getX()+startView1.getWidth() / 2.F, startView1.getY()+startView1.getHeight()/ 2.F, endView1.getX()+endView1.getWidth() / 2.F, endView1.getY()+endView1.getHeight() / 2.F, paint);
}
}
and call this DrawView class as :
Button btn1=(Button) findViewById(id1);
Button btn2=(Button) findViewById(id2);
DrawView drawView = new DrawView(RoasterScreen.this,btn1,btn2);
rootLayout.addView(drawView);

public class DrawingPanel extends View implements OnTouchListener {
private Canvas mCanvas;
private Path mPath;
private Paint mPaint, mBitmapPaint;
private ArrayList<PathPoints> paths = new ArrayList<PathPoints>();
private ArrayList<PathPoints> undonePaths = new ArrayList<PathPoints>();
private Bitmap mBitmap;
private int color;
public int SSL = Color.WHITE;
private int x, y;
private int strockWidth = 3;
private String textToDraw = null;
public static boolean isTextModeOn = false;
//public static boolean flag = true;
//public static int angle = 0;
public DrawingPanel(Context context, int color, Bitmap bitmap) {
super(context);
this.color = color;
System.out.println("---> Drawing pannel Construction <--- ");
setFocusable(true);
setFocusableInTouchMode(true);
this.setOnTouchListener(this);
mBitmap = bitmap;
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(color);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(strockWidth);
mPaint.setTextSize(30);
mPath = new Path();
paths.add(new PathPoints(mPath, color,strockWidth, false));
mCanvas = new Canvas();
}
public void colorChanged(int color) {
this.color = color;
mPaint.setColor(color);
//invalidate();
}
public void changeWidthOfStrock(int strockWidth) {
this.strockWidth = strockWidth;
mPaint.setStrokeWidth(strockWidth);
//invalidate();
}
#Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
// mBitmap = AddReportItemActivity.mPhoto;
//mBitmap = getIntent().getExtras().getParcelable("Bitmap");
System.out.println("mBitmap"+mBitmap);
if(mBitmap != null) {
float xscale = (float) w / (float) mBitmap.getWidth();
float yscale = (float) h / (float) mBitmap.getHeight();
if (xscale > yscale) // make sure both dimensions fit (use the
xscale = yscale;
float newx = (float) w * xscale;
float newy = (float) h * xscale; // use the same scale for both
// dimensions
}
// if you want it centered on the display (black borders)
mBitmap = Bitmap.createScaledBitmap(mBitmap, this.getWidth(),this.getHeight(), true);
// mCanvas = new Canvas(mBitmap);
}
#Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
for (PathPoints p : paths) {
mPaint.setColor(p.getColor());
mPaint.setStrokeWidth(p.getStrockWidth());
if (p.isTextToDraw()) {
//canvas.drawText(p.textToDraw, p.x, p.y, mPaint);
} else {
canvas.drawPath(p.getPath(), mPaint);
}
}
mPaint.setColor(SSL);
mPaint.setStrokeWidth(strockWidth);
canvas.drawPath(mPath, mPaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 0;
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 = new Path();
paths.add(new PathPoints(mPath, SSL,strockWidth ,false));
mPath = new Path();
}
private void drawText(int x, int y) {
//Log.v(TAG, "Here");
//Log.v(TAG, "X " + x + " Y " + y);
this.x = x;
this.y = y;
paths.add(new PathPoints(color, textToDraw, true, x, y));
// mCanvas.drawText(textToDraw, x, y, mPaint);
}
#Override
public boolean onTouch(View arg0, MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
if (!isTextModeOn) {
touch_start(x, y);
invalidate();
}
break;
case MotionEvent.ACTION_MOVE:
if (!isTextModeOn) {
touch_move(x, y);
invalidate();
}
break;
case MotionEvent.ACTION_UP:
if (isTextModeOn) {
drawText((int) x, (int) y);
invalidate();
} else {
touch_up();
invalidate();
}
break;
}
return true;
}
public void onClickUndo() {
if (paths.size() > 0) {
undonePaths.add(paths.remove(paths.size() - 1));
invalidate();
} else {
}
// toast the user
}
public void onClickRedo() {
if (undonePaths.size() > 0) {
paths.add(undonePaths.remove(undonePaths.size() - 1));
invalidate();
} else {
}
// toast the user
}
class PathPoints {
private Path path;
// private Paint mPaint;
private int color;
private int strockW;
private String textToDraw;
private boolean isTextToDraw;
private int x, y;
public PathPoints(Path path, int color,int strockWidth ,boolean isTextToDraw) {
this.path = path;
this.color = color;
this.strockW = strockWidth;
this.isTextToDraw = isTextToDraw;
}
public PathPoints(int color, String textToDraw, boolean isTextToDraw,int x, int y) {
this.color = color;
this.textToDraw = textToDraw;
this.isTextToDraw = isTextToDraw;
this.x = x;
this.y = y;
}
public Path getPath() {
return path;
}
public void setPath(Path path) {
this.path = path;
}
/*
* private Paint getPaint() { mPaint = new Paint();
* mPaint.setAntiAlias(true); mPaint.setColor(color);
* mPaint.setStyle(Paint.Style.STROKE);
* mPaint.setStrokeJoin(Paint.Join.ROUND);
* mPaint.setStrokeCap(Paint.Cap.ROUND); mPaint.setStrokeWidth(6);
* return mPaint; }
*/
public int getColor() {
return color;
}
public void setColor(int color) {
this.color = color;
}
public int getStrockWidth() {
return strockW;
}
public void setStrokWidth(int color) {
this.strockW = color;
}
public String getTextToDraw() {
return textToDraw;
}
public void setTextToDraw(String textToDraw) {
this.textToDraw = textToDraw;
}
public boolean isTextToDraw() {
return isTextToDraw;
}
public void setTextToDraw(boolean isTextToDraw) {
this.isTextToDraw = isTextToDraw;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
}
}
Add this view into your layout
DrawingPanel drawingPanel = new DrawingPanel(getApplicationContext(), color, bitmap);
rl_layout.addView(drawingPanel);

How to draw the multiple lines with different color and undo,redo the paths in android?

I want to draw multiple lines on the view with different colors and undo,redo the paths in android.
I use the bitmap paint option, each path has a unique color but undo,redo is not working.
Here is my code of bitmappaint:
public MyView(Context context, Object object) {
super(context);
setFocusable(true);
setFocusableInTouchMode(true);
mPath = new Path();
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setColor(0xFFFFFF00);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(3);
mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
}
protected void onSizeChanged(int w, int h, int oldw, int oldh)
{
super.onSizeChanged(w, h, oldw, oldh);
}
protected void onDraw(Canvas canvas)
{
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
for (Path p : paths)
{
canvas.drawPath(p, mPaint);
}
canvas.drawPath(mPath, mPaint);
}
public boolean onTouchEvent(MotionEvent event)
{
float x = event.getX();
float y = event.getY();
int action = event.getAction();
int action1=event.getAction();
switch (event.getAction())
{
case MotionEvent.ACTION_DOWN:
undonePaths.clear();
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
startPoint = new PointF(event.getX(), event.getY());
endPoint = new PointF();
invalidate();
// isDrawing = true;
break;
case MotionEvent.ACTION_MOVE:
float dx = Math.abs(x - mX);
System.out.println("action move");
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE)
{
// currentDrawingPath.path.quadTo(mX,mY,(x + mX)/2, (y + mY)/2);
}
mX = x;
mY = y;
endPoint.x = event.getX();
endPoint.y = event.getY();
isDrawing = true;
invalidate();
break;
case MotionEvent.ACTION_UP:
mPath.lineTo(mX, mY);
paths.add(mPath);
mPath = new Path();
// mCanvas.drawPath(mPath, ppaint);
endPoint.x = event.getX();
endPoint.y = event.getY();
isDrawing = false;
invalidate();
break;
default:
break;
}
}
without bitmap using i faced the color problem if i select a blue color for a path means all the previous paths will be changed to blue color;
Here is my code
protected void onDraw(Canvas canvas)
{
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
for (Path p : paths)
{
canvas.drawPath(p, mPaint);
}
canvas.drawPath(mPath, mPaint);
}
Can anyone help me to draw multiple paths with different color of unique paths in android?

When you handle the MotionEvent.ACTION_UP : you need to save the color used to draw the path with something like this :
case MotionEvent.ACTION_UP:
paths.add(mPath);
colorsMap.put(mPath,selectedColor); // store the color of mPath
...
Before drawing a path, you need to set the paint color:
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
for (Path p : paths)
{
mPaint.setColor(colorsMap.get(p));
canvas.drawPath(p, mPaint);
}
mPaint.setColor(selectedColor);
canvas.drawPath(mPath, mPaint);
}
And the colorsMap is a simple instance variable:
private Map<Path, Integer> colorsMap = new HashMap<Path, Integer>();
To implement the Undo/Redo feature, you just have to remove the last element from paths (and store it in a undoneList so that on redo can restore it). see Android Canvas Redo and Undo Operation

this working code .I test it on my own app and it is working very good.
May be it help u.Please comment on it.
public class Main extends Activity implements OnColorChangedListener {
//public static int selectedColor = Color.BLACK;
public static ArrayList<Path> mMaindialog;
// private ArrayList<Path> undonePaths;
// public int selectedcolor;
private static final String COLOR_PREFERENCE_KEY = "color";
private FrameLayout relativelayout;
static String sdpath,location;
Boolean i;
// Instance variables
private Bitmap mBitmap=null;
Bitmap bitmap;
private Paint mPaint, mBitmapPaint, mPaint1;
private MyView mView;
ImageView idd;
// private Path mPath;
int slll = Color.BLACK;
Bitmap map=ListView5.bMap;
private Button ClearPaint, Colorpaint;
Ghostdatabase gost;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
idd=(ImageView)findViewById(R.id.imageView1);
relativelayout = (FrameLayout) findViewById(R.id.frameLayout);
DisplayMetrics metrics = getBaseContext().getResources()
.getDisplayMetrics();
int w = metrics.widthPixels;
int h = metrics.heightPixels;
System.out.println(" width " + w);
System.out.println(" height " + h);
mView = new MyView(this, w, h);
mView.setDrawingCacheEnabled(true);
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(4);
ClearPaint = (Button) findViewById(R.id.ne);
ClearPaint.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
// mBitmap.eraseColor(Color.TRANSPARENT);
// mPath.reset();
// mView.invalidate();
mView.onClickUndo();
}
});
Button save22 = (Button) findViewById(R.id.save);
save22.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
File cacheDir;
Toast.makeText(Main.this, "Photo", 500).show();
Bitmap icon;
relativelayout.setDrawingCacheEnabled(true);
icon = Bitmap.createBitmap(relativelayout.getDrawingCache());
Bitmap bitmap = icon;
relativelayout.setDrawingCacheEnabled(false);
// File mFile1 = Environment.getExternalStorageDirectory();
Date d = new Date();
String fileName = d.getTime() + "mg1.jpg";
File storagePath = (Environment.getExternalStorageDirectory());
File dest = new File(storagePath + "/CityAppImages");
if (!dest.exists()) {
dest.mkdirs();
}
File mFile2 = new File(dest, fileName);
sdpath = mFile2.getAbsolutePath();
Log.d("qqqqqqqqqqqqqqqqqqqqqqq", "zzzzzzzz" + sdpath);
try {
FileOutputStream outStream;
outStream = new FileOutputStream(mFile2);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outStream);
outStream.flush();
outStream.close();
Toast.makeText(Main.this, "Photo Saved Sucessfully", 500)
.show();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Toast.makeText(Main.this, "Photo Not Saved Sucessfully",
500).show();
}
gost = new Ghostdatabase(Main.this);
gost.open();
gost.insertTitle(sdpath);
}
});
Button view = (Button) findViewById(R.id.listtt);
view.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent ii = new Intent(Main.this, ListView5.class);
startActivity(ii);
}
});
Button Colorpaint = (Button) findViewById(R.id.Color);
Colorpaint.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
int color = PreferenceManager.getDefaultSharedPreferences(
Main.this).getInt(COLOR_PREFERENCE_KEY, Color.WHITE);
// int _color = R.color.red;
new ColorPickerDialog(v.getContext(),
new OnColorChangedListener() {
public void colorChanged(int color) {
mPaint.setColor(color);
slll = color;
Log.i("TAG", "mpaint one" + mPaint);
}
}, mPaint.getColor()).show();
Log.i("TAG", "mpaint two" + mPaint);
}
});
relativelayout.addView(mView);
}
// //////////******************* Pinting view
// *******************///////////////////
public class MyView extends View implements OnTouchListener {
private Map<Path, Integer> colorsMap = new HashMap<Path, Integer>();
private ArrayList<Path> mMaindialog = new ArrayList<Path>();
private ArrayList<Path> undonePaths = new ArrayList<Path>();
int colorPicked = slll;
// Paint mPaint1;
private Canvas mCanvas;
private Path mPath;
public MyView(Context c, int w, int h) {
super(c);
if(GlobalVariable.impath==1)
{
Log.d("","111111"+GlobalVariable.impath);
System.out.println(GlobalVariable.impath);
Intent ii = getIntent();
location = ii.getStringExtra("IMAGE");
// bitmap.recycle();
Log.d("","location"+location);
bitmap = BitmapFactory.decodeFile(location);
mBitmap = Bitmap.createScaledBitmap(bitmap,300, 300,false);
Log.d("hhhhhhhhhhhhhhhssssssss","mBitmap"+mBitmap);
//mBitmap = Bitmap.createBitmap(100, 100, Bitmap.Config.ARGB_8888);
// idd.setImageBitmap(mBitmap);
Log.d("hhhhhhhhhhhhhhhssssssss","GlobalVariable.impath"+GlobalVariable.impath);
}
else if(GlobalVariable.impath==2){
//bitmap.recycle();
Log.d("","22222222222222222222222"+GlobalVariable.impath);
bitmap=BitmapFactory.decodeResource(getResources(),R.drawable.base);
mBitmap = Bitmap.createScaledBitmap(bitmap,100, 100, false);
//mBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Log.d("hhhhhhhhhhhhhhhssssssss1111111","mBitmap"+mBitmap);
}
//
mCanvas = new Canvas(mBitmap);
mPath = new Path();
}
#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.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
for (Path p : mMaindialog) {
mPaint.setColor(colorsMap.get(p));
canvas.drawPath(p, mPaint);
}
mPaint.setColor(slll);
canvas.drawPath(mPath, mPaint);
}
// //////************touching evants for painting**************///////
private float mX, mY;
private static final float TOUCH_TOLERANCE = 0;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
undonePaths.clear();
}
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 = new Path();
mPath.reset();
mMaindialog.add(mPath);
}
#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();
undonePaths.clear();
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
invalidate();
break;
case MotionEvent.ACTION_MOVE:
// touch_move(x, y);
// invalidate();
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;
}
invalidate();
break;
case MotionEvent.ACTION_UP:
// touch_up();
// invalidate();
mPath.lineTo(mX, mY);
mMaindialog.add(mPath);
colorsMap.put(mPath, slll);
mPath = new Path();
mPath.reset();
invalidate();
break;
}
return true;
} // end of touch events for image
private Paint createPen(int colorPicked) {
// TODO Auto-generated method stub
mPaint1 = new Paint();
mPaint1.setColor(colorPicked);
mPaint1.setAntiAlias(true);
mPaint1.setDither(true);
mPaint1.setStyle(Paint.Style.STROKE);
mPaint1.setStrokeJoin(Paint.Join.ROUND);
mPaint1.setStrokeCap(Paint.Cap.ROUND);
// mPaint1.setStrokeWidth(3);
return mPaint1;
}
public void onClickRedo() {
if (undonePaths.size() > 0) {
mMaindialog.add(undonePaths.remove(undonePaths.size() - 1));
mView.invalidate();
} else {
}
// toast the user
}
public void onClickUndo() {
if (mMaindialog.size() > 0) {
undonePaths.add(mView.mMaindialog.remove(mView.mMaindialog
.size() - 1));
mView.invalidate();
}
else {
}
}
#Override
public boolean onTouch(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
}// end MyView
#Override
public void colorChanged(int color) {
// TODO Auto-generated method stub
PreferenceManager.getDefaultSharedPreferences(this).edit()
.putInt(COLOR_PREFERENCE_KEY, color).commit();
slll = color;
}
}