Android Color Picker SeekBar

Color picker seekBar

                                                             
Here is Code for Color Picker SeekBar


Define SeekBar in activity_main.xml. Just Like normal SeekBar.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    tools:context="techamongus.com.testapplication.MainActivity">
   <SeekBar
       android:id="@+id/colorSeekbar"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:layout_centerInParent="true"
       android:maxHeight="10dp"
       />

</RelativeLayout>

Define MainActivity.java

Here define LinearGradient and shader.

package techamongus.com.testapplication;

import android.app.Activity;
import android.app.Dialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import android.graphics.LinearGradient;
import android.graphics.Shader;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.ShapeDrawable;
import android.graphics.drawable.shapes.RectShape;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SeekBar;

public class MainActivity extends Activity {
Dialog customDialog;
    Button ok,cancel;
     int width;
//    Button showDialog;
    CustomView customView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);
        width=getWindowManager().getDefaultDisplay().getWidth();
        LinearGradient test = new LinearGradient(0.f, 0.f, width, 0.0f,
                new int[] { 0xFF000000, 0xFF0000FF, 0xFF00FF00, 0xFF00FFFF,
                        0xFFFF0000, 0xFFFF00FF, 0xFFFFFF00, 0xFFFFFFFF},
                null, Shader.TileMode.CLAMP);
        ShapeDrawable shape = new ShapeDrawable(new RectShape());
        shape.getPaint().setShader(test);

        SeekBar seekBarFont = (SeekBar)findViewById(R.id.colorSeekbar);
        seekBarFont.setProgressDrawable( (Drawable)shape );
        seekBarFont.setMax(256*7-1);
        seekBarFont.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                if(fromUser){
                    int r = 0;
                    int g = 0;
                    int b = 0;

                    if(progress < 256){
                        b = progress;
                    } else if(progress < 256*2) {
                        g = progress%256;
                        b = 256 - progress%256;
                    } else if(progress < 256*3) {
                        g = 255;
                        b = progress%256;
                    } else if(progress < 256*4) {
                        r = progress%256;
                        g = 256 - progress%256;
                        b = 256 - progress%256;
                    } else if(progress < 256*5) {
                        r = 255;
                        g = 0;
                        b = progress%256;
                    } else if(progress < 256*6) {
                        r = 255;
                        g = progress%256;
                        b = 256 - progress%256;
                    } else if(progress < 256*7) {
                        r = 255;
                        g = 255;
                        b = progress%256;
                    }

//                    seekBarFont.setBackgroundColor(Color.argb(255, r, g, b));

                }
            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

            }
        });
    }


}