Color selection does not work with undo and redo

Question

This is the code to perform undo and redo in Android Canvas and works fine.

package com.example.canva; import java.util.ArrayList; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Path; import android.view.MotionEvent; import android.view.View; public class MainView extends View { private Canvas mCanvas; private Path mPath; private Paint mPaint; private ArrayList<Path> paths = new ArrayList<Path>(); private ArrayList<Path> undonePaths = new ArrayList<Path>(); public MainView(Context context) { super(context); setFocusable(true); setFocusableInTouchMode(true); mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setDither(true); mPaint.setColor(0xFFFFFFFF); mPaint.setStyle(Paint.Style.STROKE); mPaint.setStrokeJoin(Paint.Join.ROUND); mPaint.setStrokeCap(Paint.Cap.ROUND); mPaint.setStrokeWidth(6); mCanvas = new Canvas(); mPath = new Path(); } // im=BitmapFactory.decodeResource(context.getResources(),R.drawable.ic_launcher); @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); } @Override protected void onDraw(Canvas canvas) { //mPath = new Path(); //canvas.drawPath(mPath, mPaint); for (Path p : paths){ canvas.drawPath(p, mPaint); } canvas.drawPath(mPath, mPaint); } private float mX, mY; private static final float TOUCH_TOLERANCE = 4; private void touch_start(float x, float y) { undonePaths.clear(); 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 paths.add(mPath); mPath = new Path(); } 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 } @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; } } 

But in my application I need to change the color, stroke width, style, etc., when I try to change the color using the following method, the whole thing in the canvas changes to that color.

 public void setColor(int color){ mPaint.setColor(color);} 

Answer 1

Save the paths in the array and perform operations on this array to cancel or redo.