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[volttide]

Here's how you make your own calculator for android:

first make a new project

App name: Calculator
Package: com.calculator (or any)
SDK Level : 10 (if you have installed it)

1.Now open the res/layout/main.xml
modify it like this:

Code: Select all

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    
    <WebView 
        android:id="@+id/webview"
        android:layout_width="fill_parent" 
android:layout_height="50dip"/>
    
    <LinearLayout android:id="@+id/linearLayout1" 
android:layout_width="fill_parent" 
android:layout_height="wrap_content">
        <Button android:layout_height="wrap_content" 
android:id="@+id/buttonLeftParen" 
android:text="(" 
android:layout_weight="1" 
android:layout_width="fill_parent"/>

        <Button android:layout_height="wrap_content" 
android:id="@+id/buttonRightParen" 
android:text=")" 
android:layout_weight="1" 
android:layout_width="fill_parent"/>
        <Button android:layout_height="wrap_content" 
android:id="@+id/buttonBackspace" 
android:layout_weight="1" 
android:text="B" 
android:layout_width="fill_parent"/>

        <Button android:layout_height="wrap_content" 
android:id="@+id/buttonClear" 
android:text="C" 
android:layout_weight="1" 
android:layout_width="fill_parent"/>
    </LinearLayout>

    <LinearLayout android:id="@+id/linearLayout2" android:layout_width="fill_parent" android:layout_height="wrap_content">
        <Button android:layout_height="wrap_content" android:id="@+id/button7" android:text="7" android:layout_weight="1" android:layout_width="fill_parent"></Button>
        <Button android:layout_height="wrap_content" android:id="@+id/button8" android:text="8" android:layout_weight="1" android:layout_width="fill_parent"></Button>
        <Button android:layout_height="wrap_content" android:id="@+id/button9" android:text="9" android:layout_weight="1" android:layout_width="fill_parent"></Button>
        <Button android:layout_height="wrap_content" android:id="@+id/buttonPlus" android:text="+" android:layout_weight="1" android:layout_width="fill_parent"></Button>
    </LinearLayout>
    <LinearLayout android:id="@+id/linearLayout3" android:layout_width="fill_parent" android:layout_height="wrap_content">
        <Button android:layout_height="wrap_content" android:id="@+id/button4" android:text="4" android:layout_weight="1" android:layout_width="fill_parent"></Button>
        <Button android:layout_height="wrap_content" android:id="@+id/button5" android:text="5" android:layout_weight="1" android:layout_width="fill_parent"></Button>
        <Button android:layout_height="wrap_content" android:id="@+id/button6" android:text="6" android:layout_weight="1" android:layout_width="fill_parent"></Button>
        <Button android:layout_height="wrap_content" android:id="@+id/buttonMinus" android:text="-" android:layout_weight="1" android:layout_width="fill_parent"/></Button>
    </LinearLayout>

    <LinearLayout android:id="@+id/linearLayout4" 
android:layout_width="fill_parent" 
android:layout_height="wrap_content">
        <Button android:layout_height="wrap_content" 
android:id="@+id/button1" 
android:text="1" 
android:layout_weight="1"
android:layout_width="fill_parent"/>
        <Button android:layout_height="wrap_content" 
android:id="@+id/button2" 
android:text="2" 
android:layout_weight="1" 
android:layout_width="fill_parent"/>

        <Button android:layout_height="wrap_content" 
android:id="@+id/button3" 
android:text="3" 
android:layout_weight="1" 
android:layout_width="fill_parent"/>

        <Button android:layout_height="wrap_content" 
android:id="@+id/buttonTimes" 
android:text="*" 
android:layout_weight="1" 
android:layout_width="fill_parent"/>

    </LinearLayout>

    <LinearLayout android:id="@+id/linearLayout5" 
android:layout_width="fill_parent" 
android:layout_height="wrap_content">
        
<Button android:layout_height="wrap_content" 
android:layout_width="fill_parent" 
android:layout_weight="1" 
android:id="@+id/button0" 
android:text="0"/>

        <Button android:layout_height="wrap_content" 
android:layout_width="fill_parent" 
android:layout_weight="1" 
android:id="@+id/buttonDecimal" 
android:text="."/>

        <Button android:layout_height="wrap_content" 
android:layout_width="fill_parent" 
android:layout_weight="1" 
android:id="@+id/buttonEquals" 
android:text="="/>

        <Button android:layout_height="wrap_content" 
android:id="@+id/buttonDivide" 
android:text="/"
android:layout_width="fill_parent" 
android:layout_weight="1"/>
    </LinearLayout>
    
</LinearLayout>

2.Open src/com/sudoku (THIS IS THE CURRENT PROJECT PACKAGE NAME)
modify it become like this:

Code: Select all

package com.calculator;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.webkit.WebView;
import android.widget.Button;

public class CalculatorActivity extends Activity {
 
 private WebView mWebView;
 private StringBuilder mMathString;
 private ButtonClickListener mClickListener;
 
 /** Called when the activity is first created. */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
  
  // Create the math string
  mMathString = new StringBuilder();
  
  // Enable javascript for the view
  mWebView = (WebView) findViewById(R.id.webview);
  mWebView.getSettings().setJavaScriptEnabled(true);
  
  // Set the listener for all the buttons
  mClickListener = new ButtonClickListener();
  int idList[] = { R.id.button0, R.id.button1, R.id.button2,
    R.id.button3, R.id.button4, R.id.button5, R.id.button6,
    R.id.button7, R.id.button8, R.id.button9, R.id.buttonLeftParen,
    R.id.buttonRightParen, R.id.buttonPlus, R.id.buttonPlus,
    R.id.buttonMinus, R.id.buttonDivide, R.id.buttonTimes,
    R.id.buttonDecimal, R.id.buttonBackspace, R.id.buttonClear };

  for(int id : idList) {
   View v = findViewById(id);
   v.setOnClickListener(mClickListener);
  }

 }
 
 private void updateWebView() {
  
  StringBuilder builder = new StringBuilder();
  
  builder.append("<html><body>");
  builder.append("<script type=\"text/javascript\">document.write('");
  builder.append(mMathString.toString());
  builder.append("');");
  builder.append("document.write('<br />=' + eval(\"");
  builder.append(mMathString.toString());
  builder.append("\"));</script>");
  builder.append("</body></html>");

  mWebView.loadData(builder.toString(), "application/xhtml", "UTF-8");
 }

 private class ButtonClickListener implements OnClickListener {

  @Override
  public void onClick(View v) {
   switch (v.getId()) {
   case R.id.buttonBackspace:
    if(mMathString.length() > 0)
     mMathString.deleteCharAt(mMathString.length()-1);
    break;
   case R.id.buttonClear:
    if(mMathString.length() > 0)
     mMathString.delete(0, mMathString.length());
    break;
   default:
    mMathString.append(((Button) v).getText());
   }
   
   updateWebView();
  }

 }

3.Debug it and the result:

screenshot1.png

[MrAksel]

Could you explain everything? Please. A tutorial explains what code do.