How to initiate a color picket dialog?

I have followed a tutorial over at http://www.yougli.net/android/a-photoshop-like-color-picker-for-your-android-application/

But couldn't find a way of how to create/initiate this dialog... any ideas?

Class's code below.

Thanks! :)

import android.app.Dialog;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Paint;
import android.graphics.Shader;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;

public class ColorPickerDialog extends Dialog {
    public interface OnColorChangedListener {
        void colorChanged(String key, int color);
    }

    private OnColorChangedListener mListener;
    private int mInitialColor, mDefaultColor;
    private String mKey;

    private static class ColorPickerView extends View {
        private Paint mPaint;
        private float mCurrentHue = 0;
        private int mCurrentX = 0, mCurrentY = 0;
        private int mCurrentColor, mDefaultColor;
        private final int[] mHueBarColors = new int[258];
        private int[] mMainColors = new int[65536];
        private OnColorChangedListener mListener;

        ColorPickerView(Context c, OnColorChangedListener l, int color, int defaultColor) {
            super(c);
            mListener = l;
            mDefaultColor = defaultColor;

            // Get the current hue from the current color and update the main color field
            float[] hsv = new float[3];
            Color.colorToHSV(color, hsv);
            mCurrentHue = hsv[0];
            updateMainColors();

            mCurrentColor = color;

            // Initialize the colors of the hue slider bar
            int index = 0;
            for (float i=0; i<256; i += 256/42) // Red (#f00) to pink (#f0f)
            {
                mHueBarColors[index] = Color.rgb(255, 0, (int) i);
                index++;
            }
            for (float i=0; i<256; i += 256/42) // Pink (#f0f) to blue (#00f)
            {
                mHueBarColors[index] = Color.rgb(255-(int) i, 0, 255);
                index++;
            }
            for (float i=0; i<256; i += 256/42) // Blue (#00f) to light blue (#0ff)
            {
                mHueBarColors[index] = Color.rgb(0, (int) i, 255);
                index++;
            }
            for (float i=0; i<256; i += 256/42) // Light blue (#0ff) to green (#0f0)
            {
                mHueBarColors[index] = Color.rgb(0, 255, 255-(int) i);
                index++;
            }
            for (float i=0; i<256; i += 256/42) // Green (#0f0) to yellow (#ff0)
            {
                mHueBarColors[index] = Color.rgb((int) i, 255, 0);
                index++;
            }
            for (float i=0; i<256; i += 256/42) // Yellow (#ff0) to red (#f00)
            {
                mHueBarColors[index] = Color.rgb(255, 255-(int) i, 0);
                index++;
            }

            // Initializes the Paint that will draw the View
            mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
            mPaint.setTextAlign(Paint.Align.CENTER);
            mPaint.setTextSize(12);
        }

        // Get the current selected color from the hue bar
        private int getCurrentMainColor()
        {
            int translatedHue = 255-(int)(mCurrentHue*255/360);
            int index = 0;
            for (float i=0; i<256; i += 256/42)
            {
                if (index == translatedHue)
                    return Color.rgb(255, 0, (int) i);
                index++;
            }
            for (float i=0; i<256; i += 256/42)
            {
                if (index == translatedHue)
                    return Color.rgb(255-(int) i, 0, 255);
                index++;
            }
            for (float i=0; i<256; i += 256/42)
            {
                if (index == translatedHue)
                    return Color.rgb(0, (int) i, 255);
                index++;
            }
            for (float i=0; i<256; i += 256/42)
            {
                if (index == translatedHue)
                    return Color.rgb(0, 255, 255-(int) i);
                index++;
            }
            for (float i=0; i<256; i += 256/42)
            {
                if (index == translatedHue)
                    return Color.rgb((int) i, 255, 0);
                index++;
            }
            for (float i=0; i<256; i += 256/42)
            {
                if (index == translatedHue)
                    return Color.rgb(255, 255-(int) i, 0);
                index++;
            }
            return Color.RED;
        }

        // Update the main field colors depending on the current selected hue
        private void updateMainColors()
        {
            int mainColor = getCurrentMainColor();
            int index = 0;
            int[] topColors = new int[256];
            for (int y=0; y<256; y++)
            {
                for (int x=0; x<256; x++)
                {
                    if (y == 0)
                    {
                        mMainColors[index] = Color.rgb(255-(255-Color.red(mainColor))*x/255, 255-(255-Color.green(mainColor))*x/255, 255-(255-Color.blue(mainColor))*x/255);
                        topColors[x] = mMainColors[index];
                    }
                    else
                        mMainColors[index] = Color.rgb((255-y)*Color.red(topColors[x])/255, (255-y)*Color.green(topColors[x])/255, (255-y)*Color.blue(topColors[x])/255);
                    index++;
                }
            }
        }

        @Override
        protected void onDraw(Canvas canvas) {
            int translatedHue = 255-(int)(mCurrentHue*255/360);
            // Display all the colors of the hue bar with lines
            for (int x=0; x<256; x++)
            {
                // If this is not the current selected hue, display the actual color
                if (translatedHue != x)
                {
                    mPaint.setColor(mHueBarColors[x]);
                    mPaint.setStrokeWidth(1);
                }
                else // else display a slightly larger black line
                {
                    mPaint.setColor(Color.BLACK);
                    mPaint.setStrokeWidth(3);
                }
                canvas.drawLine(x+10, 0, x+10, 40, mPaint);
            }

            // Display the main field colors using LinearGradient
            for (int x=0; x<256; x++)
            {
                int[] colors = new int[2];
                colors[0] = mMainColors[x];
                colors[1] = Color.BLACK;
                Shader shader = new LinearGradient(0, 50, 0, 306, colors, null, Shader.TileMode.REPEAT);
                mPaint.setShader(shader);
                canvas.drawLine(x+10, 50, x+10, 306, mPaint);
            }
            mPaint.setShader(null);

            // Display the circle around the currently selected color in the main field
            if (mCurrentX != 0 && mCurrentY != 0)
            {
                mPaint.setStyle(Paint.Style.STROKE);
                mPaint.setColor(Color.BLACK);
                canvas.drawCircle(mCurrentX, mCurrentY, 10, mPaint);
            }

            // Draw a 'button' with the currently selected color
            mPaint.setStyle(Paint.Style.FILL);
            mPaint.setColor(mCurrentColor);
            canvas.drawRect(10, 316, 138, 356, mPaint);

            // Set the text color according to the brightness of the color
            if (Color.red(mCurrentColor)+Color.green(mCurrentColor)+Color.blue(mCurrentColor) < 384)
                mPaint.setColor(Color.WHITE);
            else
                mPaint.setColor(Color.BLACK);
            canvas.drawText(getResources().getString(R.string.settings_bg_color_confirm), 74, 340, mPaint);

            // Draw a 'button' with the default color
            mPaint.setStyle(Paint.Style.FILL);
            mPaint.setColor(mDefaultColor);
            canvas.drawRect(138, 316, 266, 356, mPaint);

            // Set the text color according to the brightness of the color
            if (Color.red(mDefaultColor)+Color.green(mDefaultColor)+Color.blue(mDefaultColor) < 384)
                mPaint.setColor(Color.WHITE);
            else
                mPaint.setColor(Color.BLACK);
            canvas.drawText(getResources().getString(R.string.settings_default_color_confirm), 202, 340, mPaint);
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            setMeasuredDimension(276, 366);
        }

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            if (event.getAction() != MotionEvent.ACTION_DOWN) return true;
            float x = event.getX();
            float y = event.getY();

            // If the touch event is located in the hue bar
            if (x > 10 && x < 266 && y > 0 && y < 40)
            {
                // Update the main field colors
                mCurrentHue = (255-x)*360/255;
                updateMainColors();

                // Update the current selected color
                int transX = mCurrentX-10;
                int transY = mCurrentY-60;
                int index = 256*(transY-1)+transX;
                if (index > 0 && index < mMainColors.length)
                    mCurrentColor = mMainColors[256*(transY-1)+transX];

                // Force the redraw of the dialog
                invalidate();
            }

            // If the touch event is located in the main field
            if (x > 10 && x < 266 && y > 50 && y < 306)
            {
                mCurrentX = (int) x;
                mCurrentY = (int) y;
                int transX = mCurrentX-10;
                int transY = mCurrentY-60;
                int index = 256*(transY-1)+transX;
                if (index > 0 && index < mMainColors.length)
                {
                    // Update the current color
                    mCurrentColor = mMainColors[index];
                    // Force the redraw of the dialog
                    invalidate();
                }
            }

            // If the touch event is located in the left button, notify the listener with the current color
            if (x > 10 && x < 138 && y > 316 && y < 356)
                mListener.colorChanged("", mCurrentColor);

            // If the touch event is located in the right button, notify the listener with the default color
            if (x > 138 && x < 266 && y > 316 && y < 356)
                mListener.colorChanged("", mDefaultColor);

     开发者_如何学C       return true;
        }
    }

    public ColorPickerDialog(Context context, OnColorChangedListener listener, String key, int initialColor, int defaultColor) {
        super(context);

        mListener = listener;
        mKey = key;
        mInitialColor = initialColor;
        mDefaultColor = defaultColor;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        OnColorChangedListener l = new OnColorChangedListener() {
            public void colorChanged(String key, int color) {
                mListener.colorChanged(mKey, color);
                dismiss();
            }
        };

        setContentView(new ColorPickerView(getContext(), l, mInitialColor, mDefaultColor));
        setTitle(R.string.settings_bg_color_dialog);
    }
}

The code to show it should be something like this:

ColorPickerDialog dialog = new ColorPickerDialog(context, this, 0);
dialog.show();

Edit: I used this in a class which was used to choose preferences. The class extended Preference and implemented OnClickListener and OnColorChangedListener, so the ColorPickerDialog constructor parameters are context - the application context which you must pass to it (there are a few ways to get your applications context e.g. getApplicationContext() in an activity); 'this' is a reference to the OnColorChangedListener (because the class where the ColorPickerDialog is being called implements this interface, but it could be a separate class) and finally, 0 is the value of the initial color.

new ColorPickerDialog(
    this,
    new ColorPickerDialog.OnColorChangedListener() {
            @Override
            public void colorChanged(int color) {
                //you change your color when the color is changed in the dialog
                myColor = color;
            }
        },
    Color.BLACK).show();