Android Open Source - AndroidTipCalculator Main Activity

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From Project

Back to project page AndroidTipCalculator.

License

The source code is released under:

MIT License

Java Source Code

package codepath.apps.tipcalculator;
/*www  .  j  a va 2 s. c  o  m*/
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.ParseException;

import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
import android.widget.SeekBar;
import android.widget.TextView;

public class MainActivity extends Activity {

  protected EditText etCheckAmount;
  protected SeekBar sbTipPct;
  protected TextView tvTipPctVal;
  protected CheckBox cbRoundAmount;
  protected TextView tvTotalAmountVal;
  protected TextView tvTipAmountVal;
  protected TextView tvErrorMessage;
  
  final int MAX_TIP_PCT = 30;
  final int DEFAULT_TIP_PCT = 15;

  final DecimalFormat decfmt = new DecimalFormat("0.00");

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

    etCheckAmount = (EditText)findViewById(R.id.etCheckAmount);
    sbTipPct = (SeekBar)findViewById(R.id.sbTipPct);
    tvTipPctVal = (TextView)findViewById(R.id.tvTipPctVal);
    cbRoundAmount = (CheckBox)findViewById(R.id.cbRoundAmount);
    tvTotalAmountVal = (TextView)findViewById(R.id.tvTotalAmountVal);
    tvTipAmountVal = (TextView)findViewById(R.id.tvTipAmountVal);
    tvErrorMessage = (TextView)findViewById(R.id.tvErrorMessage);

    initCheckAmountTextView();
    initTipPctSeekBar();
    initRoundAmountCheckBox();
  }

  protected void initCheckAmountTextView() {
    etCheckAmount.setTextColor(Color.BLACK);

    etCheckAmount.addTextChangedListener(new TextWatcher() {

      @Override
      public void beforeTextChanged(CharSequence s, int start, int count, int after) {}

      @Override
      public void afterTextChanged(Editable s) {}

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

  protected void initTipPctSeekBar() {
    sbTipPct.setMax(MAX_TIP_PCT);
    sbTipPct.incrementProgressBy(1);
    sbTipPct.setProgress(DEFAULT_TIP_PCT);

    final NumberFormat pctfmt = NumberFormat.getPercentInstance();
    tvTipPctVal.setText(pctfmt.format((double)DEFAULT_TIP_PCT / 100));

    sbTipPct.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {

      @Override
      public void onStartTrackingTouch(SeekBar seekBar) {}

      @Override
      public void onStopTrackingTouch(SeekBar seekBar) {}

        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
          tvTipPctVal.setText(pctfmt.format((double)progress / 100));
          computeValues();
        }
    });
  }

  protected void initRoundAmountCheckBox() {
    cbRoundAmount.setOnCheckedChangeListener(new OnCheckedChangeListener() {

      @Override
      public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        computeValues();
      }
    });
  }

  protected void computeValues() {
    double checkAmount;

    etCheckAmount.setTextColor(Color.RED);
    tvTotalAmountVal.setText("");
    tvTipAmountVal.setText("");
    tvErrorMessage.setText("");

    if (etCheckAmount.getText().toString().trim().equals("")) {
      return;
    }

    try {
      checkAmount = decfmt.parse(etCheckAmount.getText().toString()).doubleValue();
    } catch (ParseException e) {
      tvErrorMessage.setText(R.string.invalid_number);
      return;
    }

    if (checkAmount <= 0) {
      tvErrorMessage.setText(R.string.negative_number);
      return;
    }

    etCheckAmount.setTextColor(Color.BLACK);
    tvErrorMessage.setText("");

    double tipPct = (double) sbTipPct.getProgress() / 100;
    double tipAmount = checkAmount * tipPct;
    double totalAmount = checkAmount + tipAmount;

    if (cbRoundAmount.isChecked()) {
      totalAmount = Math.ceil(totalAmount);
      tipAmount = totalAmount - checkAmount;
    }

    NumberFormat curfmt = NumberFormat.getCurrencyInstance();

    tvTotalAmountVal.setText(curfmt.format(totalAmount));
    tvTipAmountVal.setText(curfmt.format(tipAmount));
  }
}

Java Source Code List

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