Android Open Source - As1-301-CounterApp Create Counter Activity

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Back to project page As1-301-CounterApp.

License

The source code is released under:

GNU General Public License

Java Source Code

package pack.as1_301;
//  w  ww .j a v a 2 s. c o  m
import java.io.BufferedReader;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;

import com.google.gson.Gson;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.view.View;
import android.widget.EditText;

public class CreateCounterActivity extends Activity {
  private static final String FILENAME = "midday.sav";
  private ArrayList<Counter> counters;
  
  // sets up the class for use
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.create_counter);
    counters = loadFromFile();
  }

  // called when the done button was clicked
  // checks that the EditText field is not empty and is not a name that is already in use
  // creates a counter and saves it into a file, appending it to the end
  public void callDone(View v) {
    EditText counterText = (EditText) findViewById(R.id.counter_name);
    if (counterText.getText().toString().isEmpty()) {
      return;
    }
    for (int i = 0; i < counters.size(); i++) {
        if (counters.get(i).getName().equals(counterText.getText().toString())) {
          return;
        }
      }
    Counter counter = new Counter(counterText.getText().toString());
    saveInFile(counter);
    finish();
  }
  
  // called when the cancel button was clicked
  // calls finish and returns to the previous activity
  public void callCancel(View v) {
    finish();
  }
  
  // loads the counter list from a file
    private ArrayList<Counter> loadFromFile() {
      ArrayList<Counter> counters = new ArrayList<Counter>();
        try {
                FileInputStream fis = openFileInput(FILENAME);
                BufferedReader in = new BufferedReader(new InputStreamReader(fis));
                String line = in.readLine();
                
                while (line != null) {
                  Counter counter = deserialization(line);
                  counters.add(counter);
                    line = in.readLine();
                }

        } catch (FileNotFoundException e) {
                e.printStackTrace();
        } catch (IOException e) {
                e.printStackTrace();
        }
        return counters;
  }
  
    // saves a counter to a file, appending it to the end
  private void saveInFile(Counter counter) {
    try {
      FileOutputStream fos = openFileOutput(FILENAME,
          Context.MODE_APPEND);
      fos.write(serialization(counter).getBytes());
      fos.close();
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
  
  // returns a counter when given a serialized text
    private Counter deserialization(String text) {
        Gson gson = new Gson();
        Counter new_counter = gson.fromJson(text, Counter.class);
        return new_counter;
    }
    
    // returns a string when given a counter
    private String serialization(Counter counter) {
        Gson gson = new Gson();
        String json = gson.toJson(counter) + "\n";
        return json;
   }
}

Java Source Code List

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