Android alkalmazásfejlesztés 1. rész: számológép

Hirdetés

Kód

package hu.example.divinity.simplecalculator;

import java.util.HashSet;
import java.util.Set;
import java.util.regex.Pattern;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {

private TextView result;

private String operator;

private Set<String> numbers;

private Set<String> operators;

private String[] valueArray;

private Boolean operatorClicked = false;

private Boolean negativeNum = false;

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

result = (TextView) findViewById(R.id.result);
}


private void initNumbers() {
numbers = new HashSet<String>();
for (int i = 0; i < 10; i++) {
numbers.add(Integer.toString(i));
}
}

private void initOperators() {
operators = new HashSet<String>();
String[] ops = { "+", "-", "*", "/" };
for (String operator : ops) {
operators.add(operator);
}
}

public void handleClick(View view) {
Button clicked = (Button) view;
String value = clicked.getText().toString();
String operator = containOperator(result.getText().toString());

Log.d("##### operatorClicked: ", operatorClicked.toString());
Log.d("##### clicked: ", value);

if (operatorClicked && !isNumerical(value)) {
value = result.getText().toString().substring(0,result.getText().toString().length()-1) + value;
} else if (isNumerical(value)) {
if (!isDefaultResult(result.getText().toString())) {
value = result.getText().toString() + value;
operatorClicked = false;
}
} else if (isOperator(value)) {
operatorClicked = true;
if (!isDefaultResult(result.getText().toString())) {
if (operator == null) {
operator = value;
value = result.getText().toString() + value;
} else {
Log.d("##### RESULT after ", result.getText().toString());
if (negativeNum) {
valueArray = result.getText().toString().substring(1,result.getText().toString().length()).split((Pattern.quote(operator)));
double a = Double.parseDouble("-" +valueArray[0]), b = Double.parseDouble(valueArray[1]);
value = calculate(a,b,operator) + value;
} else {
valueArray = result.getText().toString().split((Pattern.quote(operator)));
double a = Double.parseDouble(valueArray[0]), b = Double.parseDouble(valueArray[1]);
value = calculate(a,b,operator) + value;
}

operator = null;
valueArray = null;
}
}
} else if (isClear(value)) {
value = "Eredmény";
} else {
if (!isDefaultResult(result.getText().toString())) {
if (operator != null) {
if (negativeNum) {
valueArray = result.getText().toString().substring(1,result.getText().toString().length()).split((Pattern.quote(operator)));
double a = Double.parseDouble("-" + valueArray[0]), b = Double.parseDouble(valueArray[1]);
value = calculate(a,b,operator);
} else {
valueArray = result.getText().toString().split((Pattern.quote(operator)));
double a = Double.parseDouble(valueArray[0]), b = Double.parseDouble(valueArray[1]);
value = calculate(a,b,operator);
}

} else value = result.getText().toString();
operator = null;
valueArray = null;
} else value = "Eredmény";
}
result.setText(value);
}

private boolean isClear(String value) {
return value.equals("CE");
}


private boolean isOperator(String value) {
if (operators == null) {
initOperators();
}
return operators.contains(value);
}
private String containOperator(String value) {
if (operators == null) {
initOperators();
}

if (Character.toString(value.charAt(0)).equals("-")) {
negativeNum = true;
for(int i = 1; i < value.length(); i++) {
if(operators.contains(Character.toString(value.charAt(i)))) {
Log.d("##### containOperator: ", Character.toString(value.charAt(i)));
return Character.toString(value.charAt(i));

}
}
} else {
negativeNum = false;
for(int i = 0; i < value.length(); i++) {
if(operators.contains(Character.toString(value.charAt(i)))) {
Log.d("##### containOperator: ", Character.toString(value.charAt(i)));
return Character.toString(value.charAt(i));

}
}
}


return null;
}
private boolean isDefaultResult(String value) {
return value.equals("Eredmény");
}

private boolean isNumerical(String value) {
if (numbers == null) {
initNumbers();
}
return numbers.contains(value);
}

private String calculate( double a, double b, String operator) {
String value = null;
Log.d("a: ", String.valueOf(a));
Log.d("b: ", String.valueOf(b));
Log.d("Operator: ", operator);
if (operator.equals("+")) {
value = Double.toString(a + b);
} else if (operator.equals("-")) {
value = Double.toString(a - b);
} else if (operator.equals("*")) {
value = Double.toString(a * b);
} else if (operator.equals("/")) {
value = Double.toString(a / b);
}
return value;
}
}