I'm writing a calculator app for android using android studio. I want to used 4 buttons for inputting values and functions. However the way I am currently doing it takes the input from the text written on the button. So for my button 1/2/3 when this is pressed 1/2/3 is passed to the textView.
Below is my MainActivity:
package com.example.myfirstapp;
import android.media.MediaPlayer;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.MediaController;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
private int[] operatorButtons = {R.id.operators};
private int[] numericButtons = {R.id.onetwothree, R.id.fourfivesix, R.id.seveneightninezero};
private boolean lastNumeric, stateError;
private TextView txtScreen;
@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();
}
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);
}
}
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;
}
}
};
// Assign the listener to all the operator buttons
for (int id : operatorButtons) {
findViewById(id).setOnClickListener(listener);
}
// Equal button
/*findViewById(R.id.btnEqual).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
onEqual();
}
});*/
}
}
and my activity_main:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="@+id/txtScreen"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:gravity="right|center_vertical"
android:maxLength="16"
android:padding="10dp"
android:textAppearance="?android:attr/textAppearanceLarge"
android:textSize="30sp"
android:typeface="serif" />
<!--<Button-->
<!--android:id="@+id/equal1"-->
<!--android:layout_width="match_parent"-->
<!--android:layout_height="100dp"-->
<!--android:text="="-->
<!--/>-->
<Button
android:id="@+id/equal2"
android:layout_width="match_parent"
android:layout_height="100dp"
android:text="="
android:layout_alignParentBottom="true"
/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/txtScreen"
android:orientation="vertical"
android:layout_above="@id/equal2">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
<Button
android:id="@+id/onetwothree"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="1/2/3"/>
<Button
android:id="@+id/fourfivesix"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="4/5/6"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
<Button
android:id="@+id/seveneightninezero"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="7/8/9/0"/>
<Button
android:id="@+id/operators"
android:layout_width="0dp"
android:layout_height="match_parent"
android:layout_weight="1"
android:text="+-*/"/>
</LinearLayout>
</LinearLayout>
</RelativeLayout>
Will it be possible for me to get the input of 1, 2 or 3 from my first button for example? So on 1 press you get 1, 2 press gives 2 etc.
Any suggestions/ ideas on how I can move forward with this are greatly appreciated.
Kind Regards, Ben
