Android Open Source - loancalc Main Activity

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From Project

Back to project page loancalc.

License

The source code is released under:

Apache License

Java Source Code

/**
 *    Copyright 2014 Xavier Delaunay/* w  w w.j  a  v  a2 s .c  o  m*/
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

package com.dxav.loancalc;

import java.util.Locale;

import com.dxav.loancalc.Loan;
import com.dxav.loancalc.R;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

  public static final String EXTRA_BORROWED_CAPITAL = "com.dxav.loancalculator.BORROWED_CAPITAL";
  public static final String EXTRA_ANNUAL_RATE_PERCENTAGE = "com.dxav.loancalculator.ANNUAL_RATE_PERCENTAGE";
  public static final String EXTRA_NUMBER_OF_INSTALLMENTS = "com.dxav.loancalculator.NUMBER_OF_INSTALLMENTS";

  private static Intent intent = null;

  private double mCapital = 0;
  private double mAnnualRatePercentage = 0;
  private int mNumberOfInstallments = 0;

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

    setContentView(R.layout.activity_main);
    
    // Restore the data saved during the previous session
    restoreData();
    
    // Fill the editText boxes with the data saved during the previous session
    setBorrowedCapitalText();
    setInterestRateText();
    setNumberOfInstallmentsText();
  }


  public void enterButtonProcess(View v) {
    // Action when the user clicks on the "Enter" button

    // Create an intent
    intent = new Intent(this, DisplayInstallmentsListActivity.class);

    // Get the borrowed capital
    String capitalStr = getBorrowedCapitalText();
    try {
      //mCapital = stringToDouble(capitalStr);
      mCapital = Double.parseDouble(capitalStr);
    } catch (NumberFormatException e) {
      // If the rate has not been entered
      // Raise the helper message read from the resources strings
      Toast.makeText(
          MainActivity.this,
          getResources().getString(
              R.string.borrowed_capital_error_message),
          Toast.LENGTH_SHORT).show();
      e.printStackTrace();
      return;
    }
    // Add it to the intent
    intent.putExtra(EXTRA_BORROWED_CAPITAL, mCapital);

    // Get the interest rate (in percentage)
    String annualRatePercentageStr = getInterestRateText();
    try {
      mAnnualRatePercentage = Double.parseDouble(annualRatePercentageStr);
    } catch (NumberFormatException e) {
      // If the rate has not been entered
      // Raise the helper message read from the resources strings
      Toast.makeText(
          MainActivity.this,
          getResources().getString(
              R.string.interest_rate_error_message),
          Toast.LENGTH_SHORT).show();
      e.printStackTrace();
      return;
    }
    // Add it to the intent
    intent.putExtra(EXTRA_ANNUAL_RATE_PERCENTAGE, mAnnualRatePercentage);

    // Get the number of installments
    String numberOfInstallmentsStr = getNumberOfInstallmentsText();
    try {
      mNumberOfInstallments = Integer.valueOf(numberOfInstallmentsStr);
    } catch (NumberFormatException e) {
      // If the rate has not been entered
      // Raise the helper message read from the resources strings
      Toast.makeText(
          MainActivity.this,
          getResources().getString(
              R.string.number_of_installments_error_message),
          Toast.LENGTH_SHORT).show();
      e.printStackTrace();
      return;
    }
    // Add it to the intent
    intent.putExtra(EXTRA_NUMBER_OF_INSTALLMENTS, mNumberOfInstallments);

    saveData();
    startComputation();
  }
  
  public void resetButtonProcess(View v) {
    mCapital = 0;
    mAnnualRatePercentage = 0;
    mNumberOfInstallments = 0;
    
    // Reset the editText boxes hints
    EditText borrowedCapital = (EditText) findViewById(R.id.borrowedCapital);
    borrowedCapital.setText("");
    EditText interestRate = (EditText) findViewById(R.id.interestRate);
    interestRate.setText("");
    EditText numberOfInstallments = (EditText) findViewById(R.id.numberOfInstallments);
    numberOfInstallments.setText("");

    // Reset the result of the computation
    TextView amountOfInstallments = (TextView) findViewById(R.id.amountOfInstallments);
    amountOfInstallments.setText("");
    TextView loanCost = (TextView) findViewById(R.id.loanCost);
    loanCost.setText("");
    
    // Make invisible the loan table button
    Button displayLoanTableButton = (Button) findViewById(R.id.displayInstallmentsTableButton);
    displayLoanTableButton.setVisibility(Button.INVISIBLE);
  }

  public void displayInstallmentsTable(View v) {
    // Update the computation in case the user
    // has changed something in the text boxes
    enterButtonProcess(v);
    // Start the activity
    startActivity(intent);
  }
  

  private String getBorrowedCapitalText() {
    // Get the borrowed capital
    EditText borrowedCapital = (EditText) findViewById(R.id.borrowedCapital);
    String capitalStr = borrowedCapital.getText().toString();
    return capitalStr;
  }

  private void setBorrowedCapitalText() {
    // Set the borrowed capital in the edit text
    if (mCapital > 0) {
      EditText borrowedCapital = (EditText) findViewById(R.id.borrowedCapital);
      String capitalStr = String.format(Locale.ENGLISH, "%.2f", mCapital);
      borrowedCapital.setText(capitalStr, TextView.BufferType.EDITABLE);
    }
  }

  private String getInterestRateText() {
    // Get the interest rate (in percentage)
    EditText interestRate = (EditText) findViewById(R.id.interestRate);
    String annualRatePercentageStr = interestRate.getText().toString();
    return annualRatePercentageStr;
  }

  private void setInterestRateText() {
    // Set the interest rate in the edit text
    if (mAnnualRatePercentage > 0) {
      EditText interestRate = (EditText) findViewById(R.id.interestRate);
      String annualRatePercentageStr = String.format(Locale.ENGLISH, "%.2f",
          mAnnualRatePercentage);
      interestRate.setText(annualRatePercentageStr);
    }
  }

  private String getNumberOfInstallmentsText() {
    // Get the number of installments
    EditText numberOfInstallments = (EditText) findViewById(R.id.numberOfInstallments);
    String numberOfInstallmentsStr = numberOfInstallments.getText()
        .toString();
    return numberOfInstallmentsStr;
  }

  private void setNumberOfInstallmentsText() {
    // Set the number of installments in the edit text
    if (mNumberOfInstallments > 0) {
      EditText numberOfInstallments = (EditText) findViewById(R.id.numberOfInstallments);
      String numberOfInstallmentsStr = String.valueOf(mNumberOfInstallments);
      numberOfInstallments.setText(numberOfInstallmentsStr);
    }
  }

  private void saveData() {
    // Save user data
    SharedPreferences sharedPref = getSharedPreferences(
        getString(R.string.preference_file_key), Context.MODE_PRIVATE);
    SharedPreferences.Editor editor = sharedPref.edit();
    editor.putFloat(getString(R.string.saved_borrowed_capital), (float) mCapital);
    editor.putFloat(getString(R.string.saved_annual_percentage_rate),
         (float) mAnnualRatePercentage);
    editor.putInt(getString(R.string.saved_number_of_installments),
        mNumberOfInstallments);
    editor.commit();
  }

  private void restoreData() {
    // Restore the data saved
    SharedPreferences sharedPref = getSharedPreferences(
        getString(R.string.preference_file_key), Context.MODE_PRIVATE);
    mCapital = sharedPref.getFloat(
        getString(R.string.saved_borrowed_capital), (float) 0.0);
    mAnnualRatePercentage = sharedPref.getFloat(
        getString(R.string.saved_annual_percentage_rate), (float) 0.0);
    mNumberOfInstallments = sharedPref.getInt(
        getString(R.string.saved_number_of_installments), 0);
  }

  private void startComputation() {

    // Create the loan object
    Loan loan = new Loan(mCapital, mAnnualRatePercentage, mNumberOfInstallments);
    // Compute the amounts of the monthly installments
    double amount = loan.getInstallmentAmount(1);

    // Write the result into the amountOfInstallments TextView
    TextView amountOfInstallments = (TextView) findViewById(R.id.amountOfInstallments);
    amountOfInstallments.setText(String.format(Locale.ENGLISH, "%.2f", amount));

    // Compute the cost of the loan
    double cost = loan.computeLoanCost();

    // Write the result into the amountOfInstallments TextView
    TextView loanCost = (TextView) findViewById(R.id.loanCost);
    loanCost.setText(String.format(Locale.ENGLISH, "%.2f", cost));

    // Make visible the loan table button
    Button displayLoanTableButton = (Button) findViewById(R.id.displayInstallmentsTableButton);
    displayLoanTableButton.setVisibility(Button.VISIBLE);
  }
}

Java Source Code List

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