How to display numbers onto a textview clicked by user?

How to display numbers onto a textview clicked by user? - java

I created a calculator but I cannot display the numbers onto the TextView like every iphone/android calculator.
For example, if the user clicks 5 + 5. I want 5 + 5 to display on the textview and once you hit equals it displays 10. I've tried different ways to figure this out but I keep getting errors.
ClearBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
TextView output = (TextView) findViewById(R.id.text_view);
output.setText("");
}
});
Button0.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "0");
}
});
Button1.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "1");
}
});
Button2.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "2");
}
});
Button3.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "3");
}
});
Button4.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "4");
}
});
Button5.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "5");
}
});
Button6.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "6");
}
});
Button7.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "7");
}
});
Button8.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "8");
}
});
Button9.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
textView.setText(textView.getText() + "9");
}
});
// Operation Buttons
addBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
if(textView == null) {
textView.setText(" ");
} else {
firstValue = Double.parseDouble(textView.getText() + " ");
addition = true;
textView.setText(null);
}
}
});
subBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
firstValue = Double.parseDouble(textView.getText() + " ");
subtract = true;
textView.setText(null);
}
});
divideBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
firstValue = Double.parseDouble(textView.getText() + " ");
divison = true;
textView.setText(null);
}
});
multiBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
firstValue = Double.parseDouble(textView.getText() + " ");
multiplication = true;
textView.setText(null);
}
});
equalBtn.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
secondValue = Double.parseDouble(textView.getText() + " ");
if(addition == true) {
textView.setText(firstValue + secondValue + " ");
addition = false;
}
if(subtract == true) {
textView.setText(firstValue - secondValue + " ");
subtract = false;
}
if(divison == true) {
textView.setText(firstValue / secondValue + " ");
divison = false;
}
if(multiplication == true) {
textView.setText(firstValue * secondValue + " ");
multiplication = false;
}
}
});

NumberFormatException is an Exception that might be thrown when you
try to convert a String into a number, where that number might be an
int , a float , or any other Java numeric type.
You can use NumberFormat and Double .
Double result = new Double(textView.getText().toString());
NumberFormat nm = NumberFormat.getNumberInstance();
textview.setText(nm.format(result)+ "3");
Hope this helps you .

Can you please try and check whether it works
firstValue = Double.parseDouble(textView.getText().toString().replaceAll(" ",""));

Just a reference since you created multiple onClick listeners which is highly repetitive in your code. I'd recommend taking a look at at Android: Use a SWITCH statement with setOnClickListener/onClick for more than 1 button? This would allow you to set a switch case for multiple buttons without making multiple onClickListeners. Good luck with your calculator!

Related

How do i remove .0 from the result if the resultant number is a full number in a calculator [duplicate]

This question already has answers here:
How to nicely format floating numbers to string without unnecessary decimal 0's
(29 answers)
Closed 2 years ago.
I am making an android calculator in android studio. But, in my calculator when the result is a full number, the number appears with decimal 0.
For example, if i add 9 and 11 the result is appearing as 20.0
So, how do i remove .0 from the result for a full number(ex:- 10,24).
This is my MainActivity.java
package com.example.calculator;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import com.faendir.rhino_android.RhinoAndroidHelper;
import org.mozilla.javascript.Context;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.ast.Scope;
public class MainActivity extends AppCompatActivity {
Button btn0,btn1,btn2,btn3,btn4,btn5,btn6,btn7,btn8,btn9,btnPercent,btnPlus,btnMinus,btnMultiply,btnDivision,btnEqual,btnClear,btnDot,btnBracket,btnBackspace;
TextView tvInput,tvOutput;
String process;
boolean checkBracket = false;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn0 = findViewById(R.id.btn0);
btn1 = findViewById(R.id.btn1);
btn2 = findViewById(R.id.btn2);
btn3 = findViewById(R.id.btn3);
btn4 = findViewById(R.id.btn4);
btn5 = findViewById(R.id.btn5);
btn6 = findViewById(R.id.btn6);
btn7 = findViewById(R.id.btn7);
btn8 = findViewById(R.id.btn8);
btn9 = findViewById(R.id.btn9);
btnPlus = findViewById(R.id.btnPlus);
btnMinus = findViewById(R.id.btnMinus);
btnDivision = findViewById(R.id.btnDivision);
btnMultiply = findViewById(R.id.btnMultiply);
btnEqual = findViewById(R.id.btnEqual);
btnClear = findViewById(R.id.btnClear);
btnDot = findViewById(R.id.btnDot);
btnPercent = findViewById(R.id.btnPercent);
btnBracket = findViewById(R.id.btnBracket);
btnBackspace = findViewById(R.id.btnBackspace);
tvInput = findViewById(R.id.tvInput);
tvOutput = findViewById(R.id.tvOutput);
btnClear.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
tvInput.setText("");
tvOutput.setText("");
}
});
btn0.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "0");
}
});
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "1");
}
});
btn2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "2");
}
});
btn3.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "3");
}
});
btn4.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "4");
}
});
btn5.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "5");
}
});
btn6.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "6");
}
});
btn6.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "6");
}
});
btn7.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "7");
}
});
btn8.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "8");
}
});
btn9.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "9");
}
});
btnPlus.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "+");
}
});
btnMinus.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "-");
}
});
btnMultiply.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "×");
}
});
btnDivision.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "÷");
}
});
btnDot.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + ".");
}
});
btnPercent.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
tvInput.setText(process + "%");
}
});
btnBracket.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (checkBracket){
process = tvInput.getText().toString();
tvInput.setText(process + ")");
checkBracket = false;
}else{
process = tvInput.getText().toString();
tvInput.setText(process + "(");
checkBracket = true;
}
}
});
btnBackspace.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
String str=tvInput.getText().toString();
if (str.length() >=1 ) {
str = str.substring(0, str.length() - 1);
tvInput.setText(str);
} else if (str.length() <=1 ) {
tvInput.setText("0");
}
}
});
btnEqual.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
process = tvInput.getText().toString();
process = process.replaceAll("×","*");
process = process.replaceAll("%","/100");
process = process.replaceAll("÷","/");
Context rhino = Context.enter();
rhino.setOptimizationLevel(-1);
String finalResult = "";
try {
Scriptable scriptable = rhino.initStandardObjects();
finalResult = rhino.evaluateString(scriptable,process,"javascript",1,null).toString();
}catch (Exception e){
finalResult="0";
}
tvOutput.setText(finalResult);
}
});
}
}
Any help would be appreciated.
Thank you.

There could be other solutions to your problem. I am proposing this one.
Put an if() condition to check if the answer is whole number or not.
if(result == (int)result){
DecimalFormat df = new DecimalFormat("0")
return df.format(result);
}
return result;

You can check if it is a whole number or not by simply doing this:
if (finalResult % 1 == 0){
//then the finalResult is a whole number.
}

when i press dot button i want that dot button press only one time in input 1?

package com.deitel.calculator;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.text.TextUtils;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Switch;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
double input1 = 0, input2 = 0d ,count=0;
Button btn0, btn1, btn2, btn3, btn4, btn5, btn6, btn7, btn8, btn9, btn_dot, btn_equal, btn_subtract, btn_multi, btn_add, btn_devision, btn_clear, btn_back;
TextView text_result;
boolean Addition, Subtraction, Multiplication, Devision, decimal;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn0 = findViewById(R.id.btn0);
btn1 = findViewById(R.id.btn1);
btn2 = findViewById(R.id.btn2);
btn3 = findViewById(R.id.btn3);
btn4 = findViewById(R.id.btn4);
btn5 = findViewById(R.id.btn5);
btn6 = findViewById(R.id.btn6);
btn7 = findViewById(R.id.btn7);
btn8 = findViewById(R.id.btn8);
btn9 = findViewById(R.id.btn9);
btn_dot = findViewById(R.id.btn_dot);
btn_equal = findViewById(R.id.btn_equal);
btn_add = findViewById(R.id.btn_add);
btn_subtract = findViewById(R.id.btn_subtract);
btn_multi = findViewById(R.id.btn_multi);
btn_devision = findViewById(R.id.btn_devision);
btn_clear = findViewById(R.id.btn_clear);
btn_back = findViewById(R.id.btn_back);
text_result = findViewById(R.id.text_result);
btn0.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "0");
}
});
btn1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "1");
}
});
btn2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "2");
}
});
btn3.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "3");
}
});
btn4.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "4");
}
});
btn5.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "5");
}
});
btn6.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "6");
}
});
btn7.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "7");
}
});
btn8.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "8");
}
});
btn9.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText(text_result.getText() + "9");
}
});
btn_add.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (text_result.getText().length() != 0) {
input1 = Float.parseFloat(text_result.getText() + "");
Addition = true;
decimal = false;
text_result.setText(null);
}
}
});
btn_subtract.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (text_result.getText().length() != 0) {
input1 = Float.parseFloat(text_result.getText() + "");
Subtraction = true;
decimal = false;
text_result.setText(null);
}
}
});
btn_multi.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (text_result.getText().length() != 0) {
input1 = Float.parseFloat(text_result.getText() + "");
Multiplication = true;
decimal = false;
text_result.setText(null);
}
}
});
btn_devision.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (text_result.getText().length() != 0) {
input1 = Float.parseFloat(text_result.getText() + "");
Devision = true;
decimal = false;
text_result.setText(null);
}
}
});
btn_clear.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
text_result.setText("");
input1 = 0.0;
input1 = 0.0;
}
});
btn_dot.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(count==0){
count=1;
text_result.setText(text_result.getText()+".");
return;
}
else{
text_result.setText(text_result.getText()+"0.");
decimal=true;
}
}
});
btn_back.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String number = text_result.getText().toString();
int input = number.length();
if (input > 0) {
text_result.setText(number.substring(0, input - 1));
}
}
});
btn_equal.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
count=0;
if ((Addition || Subtraction || Multiplication || Devision) ) {
if (text_result.getText().toString().trim().equals("")){
input2=0;
return;
}else {
input2 = Float.parseFloat(text_result.getText() + "");
}
}
if (Addition) {
text_result.setText(input1 + input2 + "");
Addition = false;
}
if (Subtraction) {
text_result.setText(input1 - input2 + "");
Subtraction = false;
}
if (Multiplication) {
text_result.setText(input1 * input2 + "");
Multiplication = false;
}
if (Devision) {
text_result.setText(input1 / input2 + "");
Devision = false;
}
}
});
}
}
When I press dot button I want that dot button press only one time in input 1 like:2.5+3.7 etc.
But this code doesn't meet that requirements - it displays 2.3.4.5 etc..but I want only one dot in one input. When I press dot button I want that dot button press only one time in input 1 like:2.5+3.7 etc.

Here you can manage that with simple flag.
public class MainActivity extends AppCompatActivity {
// IDs of all the numeric buttons
private int[] numericButtons = {R.id.btnZero, R.id.btnOne, R.id.btnTwo, R.id.btnThree, R.id.btnFour, R.id.btnFive, R.id.btnSix, R.id.btnSeven, R.id.btnEight, R.id.btnNine};
// IDs of all the operator buttons
private int[] operatorButtons = {R.id.btnAdd, R.id.btnSubtract, R.id.btnMultiply, R.id.btnDivide};
// TextView used to display the output
private TextView txtScreen;
// Represent whether the lastly pressed key is numeric or not
private boolean lastNumeric;
// Represent that current state is in error or not
private boolean stateError;
// If true, do not allow to add another DOT
private boolean lastDot;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Find the TextView
this.txtScreen = (TextView) findViewById(R.id.txtScreen);
// Find and set OnClickListener to numeric buttons
setNumericOnClickListener();
// Find and set OnClickListener to operator buttons, equal button and decimal point button
setOperatorOnClickListener();
}
/**
* Find and set OnClickListener to numeric buttons.
*/
private void setNumericOnClickListener() {
// Create a common OnClickListener
View.OnClickListener listener = new View.OnClickListener() {
#Override
public void onClick(View v) {
// Just append/set the text of clicked button
Button button = (Button) v;
if (stateError) {
// If current state is Error, replace the error message
txtScreen.setText(button.getText());
stateError = false;
} else {
// If not, already there is a valid expression so append to it
txtScreen.append(button.getText());
}
// Set the flag
lastNumeric = true;
}
};
// Assign the listener to all the numeric buttons
for (int id : numericButtons) {
findViewById(id).setOnClickListener(listener);
}
}
/**
* Find and set OnClickListener to operator buttons, equal button and decimal point button.
*/
private void setOperatorOnClickListener() {
// Create a common OnClickListener for operators
View.OnClickListener listener = new View.OnClickListener() {
#Override
public void onClick(View v) {
// If the current state is Error do not append the operator
// If the last input is number only, append the operator
if (lastNumeric && !stateError) {
Button button = (Button) v;
txtScreen.append(button.getText());
lastNumeric = false;
lastDot = false; // Reset the DOT flag
}
}
};
// Assign the listener to all the operator buttons
for (int id : operatorButtons) {
findViewById(id).setOnClickListener(listener);
}
// Decimal point
findViewById(R.id.btnDot).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (lastNumeric && !stateError && !lastDot) {
txtScreen.append(".");
lastNumeric = false;
lastDot = true;
}
}
});
// Clear button
findViewById(R.id.btnClear).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
txtScreen.setText(""); // Clear the screen
// Reset all the states and flags
lastNumeric = false;
stateError = false;
lastDot = false;
}
});
// Equal button
findViewById(R.id.btnEqual).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onEqual();
}
});
}
/**
* Logic to calculate the solution.
*/
private void onEqual() {
// If the current state is error, nothing to do.
// If the last input is a number only, solution can be found.
if (lastNumeric && !stateError) {
// Read the expression
String txt = txtScreen.getText().toString();
// Create an Expression (A class from exp4j library)
Expression expression = new ExpressionBuilder(txt).build();
try {
// Calculate the result and display
double result = expression.evaluate();
txtScreen.setText(Double.toString(result));
lastDot = true; // Result contains a dot
} catch (ArithmeticException ex) {
// Display an error message
txtScreen.setText("Error");
stateError = true;
lastNumeric = false;
}
}
}
}

How to loop in Java and Android Studio

I have made an alarm clock app however, I am trying to make a homepage where the user can see all the alarms they have set. I want to infinitely run a block of code that updates the homepage of my app, but the methods I have found have not worked (i.e using a timer loop, while, and for loop). Any suggestion would help me a lot, also any critique to the code would help to, Thanks everyone!
I have tried
Timers, Do-While, While, and For Loops
The While loop that is in there currently cause an error and the app does not even run.
All the code I need help with is in the While Loop.
I think this is the error
(I/zygote64: Rejecting re-init on previously-failed classjava.lang.Class: java.lang.NoClassDefFoundError: Failed resolution of: Landroid/view/View$OnUnhandledKeyEventListener;)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_alarms);
final Button selectAlarm1 = (Button) findViewById(R.id.selectAlarm1);
final Button selectAlarm2 = (Button) findViewById(R.id.selectAlarm2);
final Button selectAlarm3 = (Button) findViewById(R.id.selectAlarm2);
selectAlarm1.setVisibility(View.INVISIBLE);
selectAlarm2.setVisibility(View.INVISIBLE);
selectAlarm3.setVisibility(View.INVISIBLE);
final TextView textView = (TextView) findViewById(R.id.textView);
final Button createAlarm = (Button) findViewById(R.id.createAlarm);
final Button createAlarm2 = (Button) findViewById(R.id.createAlarm2);
final Button createAlarm3 = (Button) findViewById(R.id.createAlarm3);
createAlarm.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openMainActivity();
createAlarm2.bringToFront();
}
});
createAlarm2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openMainActivity2();
createAlarm3.bringToFront();
}
});
createAlarm3.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openMain3Activity();
}
});
selectAlarm1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openMainActivity();
}
});
selectAlarm2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openMainActivity2();
}
});
selectAlarm3.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openMain3Activity();
}
});
while(true){
if (Global.intHour1 != 0 && Global.intMinute1 != 0) {
textView.setVisibility(View.GONE);
selectAlarm1.setVisibility(View.VISIBLE);
//fixing minute format
if (Global.intMinute1 <= 9) {
selectAlarm1.setText("Alarm 1 is set for " +
Global.intHour1 + ":0" + Global.intMinute1);
} else {
selectAlarm1.setText("Alarm 1 is set for " +
Global.intHour1 + ":" + Global.intMinute1);
}
} else if (Global.intHour1 == 0 && Global.intMinute1 == 0) {
textView.setVisibility(View.VISIBLE);
}
if (Global.intHour2 != 0 && Global.intMinute2 != 0) {
selectAlarm2.setVisibility(View.VISIBLE);
//fixing minute format
if (Global.intMinute2 <= 9) {
selectAlarm2.setText("Alarm 1 is set for " +
Global.intHour2 + ":0" + Global.intMinute2);
} else {
selectAlarm2.setText("Alarm 1 is set for " +
Global.intHour2 + ":" + Global.intMinute2);
}
} else {
}
if (Global.intHour3 != 0 && Global.intMinute3 != 0) {
selectAlarm3.setVisibility(View.VISIBLE);
//fixing minute format
if (Global.intMinute3 <= 9) {
selectAlarm3.setText("Alarm 1 is set for " +
Global.intHour3 + ":0" + Global.intMinute3);
} else {
selectAlarm3.setText("Alarm 1 is set for " +
Global.intHour3 + ":" + Global.intMinute3);
}
}
else {
}
if (selectAlarm1.getVisibility() == View.INVISIBLE &&
selectAlarm2.getVisibility() == View.INVISIBLE &&
selectAlarm3.getVisibility() == View.INVISIBLE) {
textView.setVisibility(View.VISIBLE);
}
else
{
}
}
}
public void openMainActivity () {
Intent openAlarm = new Intent(this, MainActivity.class);
startActivity(openAlarm);
}
public void openMainActivity2 () {
Intent openAlarm2 = new Intent(this, MainActivity2.class);
startActivity(openAlarm2);
}
public void openMain3Activity () {
Intent openAlarm3 = new Intent(this, Main3Activity.class);
startActivity(openAlarm3);
}
public void makeTextVisible () {
}
}
I want the code to recognize when the intHour1-3 and intMinute1-3 are changed and change the visibility state of a button so that when the user returns to the homepage they can see which alarms are set.

Value not getting updated when making a calculator

I making a simple app in android studio. I have used a Single textview to take in both numbers. I also have buttons made, for the 10 digits, 4 operations and decimal point, and equals.
My app does not read the second number. When I press '=' button, it just displays the first number.
For example, when I put in a number 25, and I press the '+' button, the number gets stored in a float variable res, and the textview is cleared. Now if I put in a second number 11 and I press '=', the output is 25.0
Below, is my code for when I press the + button.
sum.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(result.getText()==null)
{
result.setText("");
}
else
{
num1 = Float.parseFloat(result.getText().toString());
res=res+num1;
result.setText(null);
num1=0;
}
}
});
and below is my code when I press =
equal.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(Float.toString(res));
res=0;
}
});
num1 and res, both are float, both initialized to 0.
Edit:- adding the full java code.
public class Calculator extends AppCompatActivity {
TextView result;
Button one,two,three,four,five,six,seven,eight,nine,zero,sum,sub,mul,div,decimal,equal;
float num1,num2,res=0;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_calculator);
result = findViewById(R.id.result);
one = findViewById(R.id.button_one);
two = findViewById(R.id.button_two);
three = findViewById(R.id.button_three);
four = findViewById(R.id.button_four);
five = findViewById(R.id.button_five);
six = findViewById(R.id.button_six);
seven = findViewById(R.id.button_seven);
eight = findViewById(R.id.button_eight);
nine = findViewById(R.id.button_nine);
zero = findViewById(R.id.button_zero);
sum = findViewById(R.id.button_add);
sub = findViewById(R.id.button_sub);
mul = findViewById(R.id.button_mul);
div = findViewById(R.id.button_div);
decimal = findViewById(R.id.button_decimal);
equal = findViewById(R.id.button_equal);
one.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "1");
}
});
two.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "2");
}
});
three.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "3");
}
});
four.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "4");
}
});
five.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "5");
}
});
six.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "6");
}
});
seven.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "7");
}
});
eight.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "8");
}
});
nine.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "9");
}
});
zero.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + "0");
}
});
decimal.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(result.getText() + ".");
}
});
sum.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(result.getText()==null)
{
result.setText("");
}
else
{
num1 = Float.parseFloat(result.getText().toString());
res=res+num1;
result.setText(null);
num1=0;
}
}
});
sub.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(result.getText()==null)
{
result.setText("");
}
else
{
num1 = Float.parseFloat(result.getText() + "");
res=res-num1;
result.setText(null);
}
}
});
mul.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(result.getText()==null)
{
result.setText("");
}
else
{
num1 = Float.parseFloat(result.getText() + "");
res=res/num1;
result.setText(null);
}
}
});
div.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(result.getText()==null)
{
result.setText("");
}
else
{
num1 = Float.parseFloat(result.getText() + "");
res=res/num1;
result.setText(null);
}
}
});
equal.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
result.setText(Float.toString(res));
res=0;
}
});
}
}

Your should also take the second value from the user and make the calculations in every operator function respectively.
There is logical error in your all the operators functions.
Your should add this line in all the operator whenever the specific function in called.
result.setText(num1 - num2 + "");
result.setText(num1 + num2 + "");
and so on!!!
Your are using a wrong technique by making anonymous function for the operation. Please you switch statement of nested if-else.

You are not reading in the value for the second number (right of the operator). Your OnClickListener for the = button does nothing but display res. It doesn't apply the right hand of the operator i.e. the second number
E.g. 1 + 2 = 3
Step 1 press 1
Step 2 press +, the program will get the left of the operator and load it to num1 and add it to res.
Step 3 press 2
Step 4 press =, the program will display res
If you want to see what your program is doing in real time then try using the "Debug" tool where you will be able to step through the program line by line and see what variables are being set to what extra.

use switch case for operators,
let say following are fields;
public static final int plus = 1
public static final int minus= 2
public static final int divide= 3
public static final int multiply= 4
and a variable that hold the current operation,
int currentOperation;
and when some operator button clicked then assign "currentOperation" to that operation
in listener
sum.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(result.getText()==null)
{
result.setText("");
}
else
{
num1 = Float.parseFloat(result.getText().toString());
res=res+num1;
result.setText(null);
num1=0;
currentOperation = plus //plus is public static final int plus = 1
}
}
});
and update '=' lisetener with switch statement,
equal.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
num1 = Float.parseFloat(result.getText().toString());
switch(currentOperation){
case plus:
res=res+num1;
break;
case minus:
res=res-num1;
break;
case divide:
res=res/num1;
break;
case multiply:
res=res*num1;
break;
}
result.setText(""+ res);
num1=0;
}
});

Selecting items from multiple context menus

So here is my problem, I have two context menus bound to two buttons, they take the options from db tables.
final Button bButton = (Button) findViewById(R.id.BeerButton);
bButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
registerForContextMenu(bButton);
openContextMenu(bButton);
}
});
final Button fButton = (Button) findViewById(R.id.FireButton);
fButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
registerForContextMenu(fButton);
openContextMenu(fButton);
}
});
}
#Override
public void onCreateContextMenu(ContextMenu cmenu, View v,ContextMenu.ContextMenuInfo cmenuInfo)
{
super.onCreateContextMenu(cmenu, v, cmenuInfo);
if(v.getId() == R.id.BeerButton){
ContextMenu bMenu = cmenu;
bMenu.setHeaderIcon(R.drawable.beer);
bMenu.setHeaderTitle("What's your poison?");
List<bDB> bMenuContainer = bDao.queryBuilder().list();
for (bDB item : bMenuContainer) {
bMenu.add(item.getName() + " " + item.getVolume() + "l " + "(" + item.getCost() + " Kč)");
}
}
else if(v.getId() == R.id.FireButton){
ContextMenu fMenu = cmenu;
fMenu.setHeaderIcon(R.drawable.fire);
fMenu.setHeaderTitle("What do you smoke?");
//blah blah pretty much the same thing
}
}
and now to the onContextItemSelected, could you guide me how to do this part? I just need a kick-off, the rest I will handle, the data will be then written to other table for further statistics.
#Override
public boolean onContextItemSelected(MenuItem item)
{
//somebody cast your magic here, PLEASE!
}
return super.onContextItemSelected(item);
}
thanks in advance!

Develop Reference

Java is a programming language and computing platform first released by Sun Microsystems in 1995.

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Can you please try and check whether it works firstValue = Double.parseDouble(textView.getText().toString().replaceAll(" ",""));

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