[ANDROID] Cambiare colore per disegnare su schermo

[Bruce500]

Salve a tutti, non riesco a cambiare il colore per disegnare sullo schermo.
Mi potreste aiutare? Grazie.
Ho usato il color picker AmbilWarna.

Questo è il codice che ho usato:

L'Activity

import yuku.ambilwarna.AmbilWarnaDialog;
import yuku.ambilwarna.AmbilWarnaDialog.OnAmbilWarnaListener;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
import android.app.Activity;
import android.graphics.Color;

public class MainActivity extends Activity 
{
    public int initialColor = 0xffff0000;
    Button colorPicker;
    public int r = 255, g = 0, b = 0;
    
    //Identificatore delle preferenze dell'applicazione
    public static String MY_PREFERENCES = "MyPref";
    
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);        
        
        //Ottiene il riferimento al bottone
        this.colorPicker = (Button)findViewById(R.id.btnColorPicker);
        
        //Definisce il click event listener per il bottone
        OnClickListener clickListener = new OnClickListener() 
        {
            @Override
            public void onClick(View v)
            {
                colorpicker();
            }
        };
 
        //Setta il click event listener per il bottone
        this.colorPicker.setOnClickListener(clickListener);
    }
    
    public void colorpicker()
    {
        //initialColor è il colore iniziale selezionato mostrato nel rettangolo alla sinistra della freccia
        AmbilWarnaDialog dialog = new AmbilWarnaDialog(this, this.initialColor, new OnAmbilWarnaListener() 
        { 
            //Eseguita quando l'utente clicca il bottone Ok
            //color è il colore selezionato dall'utente
            @Override
            public void onOk(AmbilWarnaDialog dialog, int color) 
            {
                //Setta il colore iniziale al colore scelto dall'utente
                initialColor = color;
                
                r = Color.red(initialColor);
                g = Color.green(initialColor);
                b = Color.blue(initialColor);
                
                Toast.makeText(getBaseContext(), "Selected Color: " + Color.red(initialColor) + ", " + Color.green(initialColor) + ", " + Color.blue(initialColor), Toast.LENGTH_LONG).show();                
            }
            
            //Eseguita quando l'utente clicca il bottone Cancel
            @Override
            public void onCancel(AmbilWarnaDialog dialog)
            {
                
            }
        });
        
        //Mostra il colorpicker
        dialog.show();
    }
}

La View

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.graphics.RectF;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
 
public class MultitouchView extends View 
{   
    public static final int MAX_FINGERS = 5;
    private Path[] mFingerPaths = new Path[MAX_FINGERS];
    private Paint mFingerPaint;
    private ArrayList<Path> mCompletedPaths;
    private RectF mPathBounds = new RectF();
    
    public MultitouchView(Context context)
    {
        super(context);
    }
 
    public MultitouchView(Context context, AttributeSet attrs) 
    {
        super(context, attrs);
    }
 
    public MultitouchView(Context context, AttributeSet attrs, int defStyle) 
    {
        super(context, attrs, defStyle);
    }
 
    @Override
    protected void onAttachedToWindow() 
    {
        super.onAttachedToWindow();
        
        MainActivity color = new MainActivity();
        
        mCompletedPaths = new ArrayList<Path>();
        mFingerPaint = new Paint();
        mFingerPaint.setAntiAlias(true);
        mFingerPaint.setColor(Color.rgb(color.r, color.g, color.b));
        mFingerPaint.setStyle(Paint.Style.STROKE);
        mFingerPaint.setStrokeWidth(6);
        mFingerPaint.setStrokeCap(Paint.Cap.BUTT);
    }
 
    @Override
    protected void onDraw(Canvas canvas)
    {
        super.onDraw(canvas);
 
        for (Path completedPath : mCompletedPaths)
        {
            canvas.drawPath(completedPath, mFingerPaint);
        }
 
        for (Path fingerPath : mFingerPaths)
        {
            if (fingerPath != null) 
            {
                canvas.drawPath(fingerPath, mFingerPaint);
            }
        }
    }
 
    @Override
    public boolean onTouchEvent(MotionEvent event) 
    {
        int pointerCount = event.getPointerCount();
        int cappedPointerCount = pointerCount > MAX_FINGERS ? MAX_FINGERS : pointerCount;
        int actionIndex = event.getActionIndex();
        int action = event.getActionMasked();
        int id = event.getPointerId(actionIndex);
 
        if ((action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_POINTER_DOWN) && id < MAX_FINGERS) 
        {
            mFingerPaths[id] = new Path();
            mFingerPaths[id].moveTo(event.getX(actionIndex), event.getY(actionIndex));
        } 
        else if ((action == MotionEvent.ACTION_POINTER_UP || action == MotionEvent.ACTION_UP) && id < MAX_FINGERS) 
        {
            mFingerPaths[id].setLastPoint(event.getX(actionIndex), event.getY(actionIndex));
            mCompletedPaths.add(mFingerPaths[id]);
            mFingerPaths[id].computeBounds(mPathBounds, true);
            invalidate((int) mPathBounds.left, (int) mPathBounds.top,
                    (int) mPathBounds.right, (int) mPathBounds.bottom);
            mFingerPaths[id] = null;
        }
 
        for(int i = 0; i < cappedPointerCount; i++)
        {
            if(mFingerPaths[i] != null)
            {
                int index = event.findPointerIndex(i);
                mFingerPaths[i].lineTo(event.getX(index), event.getY(index));
                mFingerPaths[i].computeBounds(mPathBounds, true);
                invalidate((int) mPathBounds.left, (int) mPathBounds.top,
                        (int) mPathBounds.right, (int) mPathBounds.bottom);
            }
        }
 
        return true;
    }
}