ColorShadesUsage.java

package com.cooltechworks.materialcolorshades;

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.TextView;


public class MainActivity extends ActionBarActivity {

    private float mRange;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        TextWatcher watcher = new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {

            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {

            }

            @Override
            public void afterTextChanged(Editable s) {

                refresh();
            }
        };
        ((EditText)findViewById(R.id.from_color_et)).addTextChangedListener(watcher);
        ((EditText)findViewById(R.id.to_color_et)).addTextChangedListener(watcher);

        SeekBar seekbar = (SeekBar) findViewById(R.id.seek_bar);
        seekbar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {

                mRange = (progress/100f);

                ((TextView) findViewById(R.id.seek_bar_label)).setText(getString(R.string.seek, mRange));
                refresh();

            }

            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {

            }

            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {

            }
        });

        refresh();

    }

    private void refresh() {


        String fromColor = ((EditText)findViewById(R.id.from_color_et)).getText().toString();
        String toColor = ((EditText)findViewById(R.id.to_color_et)).getText().toString();

        int fromColorLength = fromColor.length();
        int toColorLength = toColor.length();



        if(((fromColorLength == 6 && !fromColor.startsWith("#")) || (fromColorLength == 7 && fromColor.startsWith("#"))) &&
                ((toColorLength == 6 && !toColor.startsWith("#")) || (toColorLength == 7 && toColor.startsWith("#")))) {
            if (!fromColor.startsWith("#")) {
                fromColor = "#" + fromColor;
            }

            if (!toColor.startsWith("#")) {
                toColor = "#" + toColor;
            }

            // replace any other '#' char in the string.
            fromColor = "#" + fromColor.substring(1).replace("#", "");
            toColor = "#" + toColor.substring(1).replace("#", "");

            ColorShades colorShades = new ColorShades();
            colorShades.
                    setFromColor(fromColor)
                    .setToColor(toColor);

            int outputColor = colorShades.generateColor(mRange);
            int outputColorInverted = colorShades.generateColorInverted(mRange);

            String outputColorString = colorShades.generateColorString(mRange);

            TextView outputView = (TextView) findViewById(R.id.output_color_code);

            outputView.setBackgroundColor(outputColor);
            outputView.setTextColor(outputColorInverted);
            outputView.setText(outputColorString);
        }



    }
}