Setting the application on the Android¶
Introduction¶
Devolping an application on Aakash, the basic software platform utilised was Eclipse (Indigo). The Android Version 2.2 was the supporting version to devlop and implement an application on AAKASH. The objective to port the programming languages C, C++,Python and Scilab needed an interface on android, thus Android application package file (APK) was devloped on Eclipse and was tested rigorously to achieve the perfect version.
Setting up the Android Envionment¶
Android SDK
- Download the android SDK from the official website developer.android.com
Software platform- Eclipse(Indigo)
- The basic software platform to devlop an application for
that need to install Eclipse.
- The official website to eclipse.
The basic command for ubuntu users to check their configured version is uname -a. Type the command on the terminal and check for the system is 64 or 32 bit.
- The linux users should install the proper version, as their
is availabilty of two versions 64 and 32 bit.
Installing the Packages in SDK Manager
- Configure the SDK manager and download tools and packages for different Android versions.
- For example the Android 2.2 (froyo), Android 2.3 (ginerbread), Android 3.0 or 3.1 (honeycomb), Android 4.0 (ice cream sandwich)
Adding and Configuring the ADT plugin
- Android offers a custom plugin for the Eclipse IDE, called Android Development Tools (ADT). This plugin is designed to give you a powerful, integrated environment in which to develop Android apps. It extends the capabilites of Eclipse to let you quickly set up new Android projects, build an app UI, debug your app, and export signed (or unsigned) app packages (APKs) for distribution.
Setups for configuring :
- NOTE : before starting the ADT plugin process (if installing from
the internet), apply net settings in the Eclipse, select Windows > Preferences . On General option , click on Network and configure the internet settings.
- Start Eclipse, then select Help > Install New Software....
- Click Add, in the top-right corner.
- In the Add Repository dialog that appears, enter “ADT Plugin” for the Name and the following URL for the location https://dl-ssl.google.com/android/eclipse/
- Click OK. Note, If you have trouble acquiring the plugin, try using http in the Location URL, instead of https (https is preferred for security reasons).
- In the Available Software dialog, select the checkbox next to Developer Tools and click Next.
- In the next window, you’ll see a list of the tools to be downloaded. Click Next.
- Read and accept the license agreements, then click Finish.
- When the installation completes, restart Eclipse.
- Configure the ADT Plugin
- After you’ve installed ADT and restarted Eclipse, you must specify the location of your Android SDK directory.
- Select Window > Preferences... to open the Preferences panel (on Mac OS X, select Eclipse > Preferences).
- Select Android from the left panel.
- For the SDK Location in the main panel, click Browse... and locate your downloaded Android SDK directory (such as android-sdk-windows).
- Click Apply, then OK.
- Create new AVD
- Create a new avd in AVD manager and mention proper memory size of the SDcard and launch the emulator.
- Create your new project
- The android environment is set , create new projects and enjoy the android versions.
Developing the APK for the Porting of the Programming Languages¶
- The project was entiltled as Aakash Programming Lab (APL)
- The package name : com.aakash.lab
- In the android project mainly the editing part was in layout,Activity(java class) and in AndroidManifest.xml
- Designing the Layout for the application
- The layout of the android APK consists of three xml files namely as main.xml, main1.xml, and main2.
- main.xml contains the features for the first screen that displays the four main icons of the programming languages C, C++, Python and Scilab, besides the main heading Aakash Programming Lab (APL).
- The icons were padded properly to fit according to tablet screen size and resolution
- The icons were polished and scaled for glossy display of the application on the tablet screen.
<TableRow
android:id="@+id/tableRow1"
android:layout_width="wrap_content"
android:layout_height="wrap_content" >
<ImageButton
android:id="@+id/imageButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/c_back"
android:padding="54dip"/>
<ImageButton
android:id="@+id/imageButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/cpp_back"
android:padding="54dip"/>
<ImageButton
android:id="@+id/imageButton3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/python_back"
android:padding="54dip"/>
<ImageButton
android:id="@+id/imageButton4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/scilab"
android:padding="54dip"/>
</TableRow>
- In order to display the web page of the each programming language main1.xml was created.
- The webview feature was added in the xml file, which will be utilised by the each webpage of programming language to display the its key features and functionality.
<WebView android:id="@+id/webView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent" />
- In order to display the web page for Help and About main2.xml was created.
- The webview feature and Button was added in the xml file, the webview for webpage of help and options , and a close button to take back the user back to the previous state.
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Close" />
WebView
android:id="@+id/webView1"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
- The APL activity
- The main activity was entiltled as APL Activity.
- The activity contains the essential and required import like
import com.aakash.lab.R;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageButton;
import android.widget.TextView;
The activity intializes all the essential parameters and variables.
ImageButton rd1, rd2, rd4, rd5;
TextView tv1,tv2;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// parameters initialisation for image buttons
rd1 = (ImageButton)findViewById(R.id.imageButton1);
rd2 = (ImageButton)findViewById(R.id.imageButton2);
rd3 = (ImageButton)findViewById(R.id.imageButton3);
rd4 = (ImageButton)findViewById(R.id.imageButton4);
tv1 = (TextView)findViewById(R.id.textView1);
tv2 = (TextView)findViewById(R.id.textView2);
rd1.setOnClickListener(this);
rd2.setOnClickListener(this);
rd3.setOnClickListener(this);
rd5.setOnClickListener(this);
}
Synchronises the four subclasses created mainly for C, C++, Python and Scilab.
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.imageButton1:
Intent myIntent = new Intent(v.getContext(),
c.class);
startActivityForResult(myIntent, 0);
break;
case R.id.imageButton2:
Intent myIntent1 = new Intent(v.getContext(),
cp.class);
startActivityForResult(myIntent1, 0);
break;
case R.id.imageButton3:
Intent myIntent2 = new Intent(v.getContext(),
py.class);
startActivityForResult(myIntent2, 0);
break;
case R.id.imageButton4:
ntent myIntent3 = new Intent(v.getContext(),
sci.class);
startActivityForResult(myIntent3, 0);
break;
default:
break;
}
}
Contains the code for user to quit and switch to another programming language.
public void onBackPressed() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Are you sure you want to exit?")
.setCancelable(false)
.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
finish();
android.os.Process
.killProcess(android.os.Process.myPid());
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}
The Sub Classes
- c.java
- The sub class for programming language C.
- The subclass contains the essential and required import like
import android.app.ActivityGroup;
import android.app.AlertDialog;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import com.aakash.lab.R;
import android.webkit.JsResult;
import android.app.AlertDialog.Builder;
import android.app.Dialog;
import android.content.DialogInterface;
import java.io.*;
- Webview feature implementation- the java script is enabled,
- the scrollbars are disabled to avoid the screen shift,
- the cache problem is resolved,
- the pop ups in the webview are enabled to take the arguments.
// web view for c class
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
// java script enabled
webSettings.setJavaScriptEnabled(true);
// js interface for reload
engine.addJavascriptInterface(new JsInterface(), "android");
// cache problem removed
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
// scroll bars disabled
engine.setVerticalScrollBarEnabled(false);
engine.setHorizontalScrollBarEnabled(false);
// focused the web page
engine.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
if (!v.hasFocus()) {
v.requestFocus();
}
break;
}
return false;
}
public boolean onTouch1(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
});
engine.loadUrl("http://127.0.0.1/html/c/index.html");
engine.setWebChromeClient(new WebChromeClient()
{
@Override
public void onConsoleMessage(String message, int lineNumber,
String sourceID) {
Log.d("MyApplication", message + " -- From line " + lineNumber
+ " of " + sourceID);
super.onConsoleMessage(message, lineNumber, sourceID);
}
});
- Menu implementation for options like Save, Open and Example, Help and About.
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu1, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.savecode1:
save();
return true;
case R.id.open:
oe_path = Environment.getExternalStorageDirectory() + "/APL/c/code/";
mPath = new File(oe_path);
loadFileList();
return true;
case R.id.example:
oe_path = "/data/local/linux/var/www/html/c/example/";
mPath = new File(oe_path);
loadFileList();
return true;
case R.id.help:
Intent myIntent = new Intent(c.this, help.class);
startActivityForResult(myIntent, 0);
return true;
case R.id.about:
Intent myIntent1 = new Intent(c.this, about.class);
startActivityForResult(myIntent1, 0);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
- Save feature to save the code in sdcard.
public void save()
{
// TODO Auto-generated method stub
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
webSettings.setJavaScriptEnabled(true);
engine.getSettings().setJavaScriptEnabled(true);
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
engine.setWebChromeClient(new MyWebChromeClientsci());
engine.loadUrl("javascript:savecode()");
}
- Open feature to display the list of files saved in sdcard and display the file in codemirror of the webpage using javascript.
private void loadFileList() {
try {
mPath.mkdirs();
} catch (SecurityException e) {
System.out.println("unable to write on the sd card ");
}
if (mPath.exists()) {
FilenameFilter filter = new FilenameFilter() {
public boolean accept(File dir, String filename) {
File sel = new File(dir, filename);
return filename.contains(FTYPE) || sel.isDirectory();
}
};
mFileList = mPath.list(filter);
onCreateDialog(DIALOG_LOAD_FILE);
} else {
mFileList = new String[0];
}
}
protected Dialog onCreateDialog(int id) {
Dialog dialog = null;
AlertDialog.Builder builder = new Builder(this);
switch (id) {
case DIALOG_LOAD_FILE:
builder.setTitle("Choose your file");
if (mFileList == null) {
System.out.println("Showing file picker before loading the file list ");
dialog = builder.create();
return dialog;
}
builder.setItems(mFileList, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
mChosenFile = mFileList[which];
InputStream inStream = null;
OutputStream outStream = null;
try {
File bfile = new File(
"/data/local/linux/var/www/html/scilab/code/.open_file.cde");
inStream = new FileInputStream(oe_path + mChosenFile);
outStream = new FileOutputStream(bfile);
byte[] buffer = new byte[1024];
int length;
while ((length = inStream.read(buffer)) > 0) {
outStream.write(buffer, 0, length);
}
inStream.close();
outStream.close();
openFile();
} catch (IOException e) {
e.printStackTrace();
}
}
});
break;
}
dialog = builder.show();
return dialog;
}
- Examples for the demo part was also added in the simlar fashion as open was implemented .
- For implementing the Help and Options , two new sub classes were created namely help.class and options.class which are explained in detail after sci.class.
- Similar process was repeated in cpp.java for C++ and in py.java for Python creating the web view, implementing the menu and additional features like Open, Save, Example, Help and About to increase the functionality of the programming language so ported on the tablet.
- sci.java
- In Scilab along with the output, the garpical output (plot) is also displayed , so additional feature like Save Figure was implemented.
public void savefig() {
// TODO Auto-generated method stub
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
webSettings.setJavaScriptEnabled(true);
engine.getSettings().setJavaScriptEnabled(true);
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
engine.setWebChromeClient(new MyWebChromeClientsci());
engine.loadUrl("javascript:saveImg()");
}
help.java
- Help is implemented to provide the guidance to the user. To enrich this feature a new sub class is created and whenevr the user opts for Help in menu, it directs him to the new webview that displays the contents of help.html.
CODE
//button for close
Button btnOpenNewActivity = (Button) findViewById(R.id.button1);
btnOpenNewActivity .setOnClickListener(new View.OnClickListener() {
// close this class and bring to same state
public void onClick(View v) {
finish();
}
});
// webview for help
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
//java script enabled
webSettings.setJavaScriptEnabled(true);
// cache problem removed
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
//scroll bars disabled in webview
engine.setVerticalScrollBarEnabled(false);
engine.setHorizontalScrollBarEnabled(false);
// focus on web page
engine.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
if (!v.hasFocus()) {
v.requestFocus();
}
break; }
return false;
}
public boolean onTouch1(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
});
// address of html file in ch root
engine.loadUrl("http://127.0.0.1/html/help.html");
// enabling all pop ups in web view
engine.setWebChromeClient(new WebChromeClient()
{
@Override
public void onConsoleMessage(String message, int lineNumber,String sourceID) {
Log.d("MyApplication", message + " -- From line "+ lineNumber + " of " + sourceID);
super.onConsoleMessage(message, lineNumber, sourceID);
}
}); }
- options.java
- To make the user compatible with different layout, icons and their functionality, the options was added in the menu.
- Whenever the user opts for the options in menu, the class directs the user to new screen displaying the required important content.
CODE NOT FOUND
//button for close
Button btnOpenNewActivity = (Button) findViewById(R.id.button1);
btnOpenNewActivity .setOnClickListener(new View.OnClickListener() {
// close this class and bring to same state
public void onClick(View v) {
finish(); }
});
// webview for help
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
//java script enabled
webSettings.setJavaScriptEnabled(true);
// cache problem removed
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
//scroll bars disabled in webview
engine.setVerticalScrollBarEnabled(false);
engine.setHorizontalScrollBarEnabled(false);
// focus on web page
engine.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
if (!v.hasFocus()) {
v.requestFocus();
}
break; }
return false;
}
public boolean onTouch1(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
});
// address of html file in ch root
engine.loadUrl("http://127.0.0.1/html/help.html");
// enabling all pop ups in web view
engine.setWebChromeClient(new WebChromeClient()
{ @Override
public void onConsoleMessage(String message, int lineNumber,String sourceID) {
Log.d("MyApplication", message + " -- From line "+ lineNumber + " of " + sourceID);
super.onConsoleMessage(message, lineNumber, sourceID);
}
}); }
The Android Manifest.xml¶
- The most important part for a project to execute, lies in its manifest.xml file.
- The manifest contains the permission for the webview enability, for the webview feature.
- The permission to read and write from the External Source, handling the sdcard.
<uses-sdk android:minSdkVersion="8" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
- The application intilaization and icon and its label information.
<application
android:icon="@drawable/apl"
android:label="@string/app_name9"
android:background="@null"
>
- The main activity APL and its sub classes intilaization,name, label and name information.
<activity
android:name=".APLActivity"
android:configChanges="keyboardHidden|orientation"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.aakash.lab.sci"
android:label="@string/app_name1" >
</activity>
<activity
android:name="com.aakash.lab.c"
android:label="@string/app_name2" >
</activity>
<activity
android:name="com.aakash.lab.cp"
android:label="@string/app_name3" >
</activity>
<activity
android:name="com.aakash.lab.py"
android:label="@string/app_name4" >
</activity>
<activity
android:name=".OnlyExt"
android:label="@string/app_name4" >
</activity>
<activity
android:name=".chelp"
android:label="@string/app_name7" >
</activity>
<activity
android:name=".cphelp"
android:label="@string/app_name7" >
</activity>
<activity
android:name=".pyhelp"
android:label="@string/app_name7" >
</activity>
<activity
android:name=".scihelp"
android:label="@string/app_name7" >
</activity>
<activity
android:name="com.aakash.lab.about"
android:label="@string/app_name8" >
</activity>
Need of another version¶
- The previous version so implemented was incapable to take input from the user hence a robust version need to develop to make the application more interactive with user, giving the user a chance to code and enhance further the concepts and deepen its roots in the programming language.
- Developing the APK for the next version for the Porting of the Programming Languages
- The project was entiltled as Aakash Programming Lab (APL)
- The package name : com.aakash.lab
- Designing the Layout for the application
- The layout of the android APK consists of four xml files namely as main.xml, main1.xml, main2.xml, main3.xml.
Xml files¶
- main.xml contains the features for the first screen that displays the four main icons of the programming languages C, C++, Python and Scilab, besides the main heading Aakash Programming Lab (APL).
- In order to display the web page of the each programming language main1.xml was created.
- The webview feature was added in the xml file, which will be utilised by the each webpage of programming language to display the its key features and functionality.
<WebView android:id="@+id/webView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
- To display the graphical output of the scilab on a two column web page format, we need an image view and close button thus the layout was sketched at main3.xml.
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Close" />
<ImageView
android:id="@+id/imageView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"/>
- In order to display the web page for Help and About main3.xml was created. The webview feature and Button was added in the xml file, the webview for webpage of help and options , and a close button to take back the user back to the previous state.
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Close" />
<WebView
android:id="@+id/webView1"
android:layout_width="match_parent"
android:layout_height="match_parent" />
- The APL activity
- The main activity was entiltled as APL Activity.
- The activity contains the essential and required import like,
import com.aakash.lab.R;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageButton;
import android.widget.TextView;
The activity intializes all the essential parameters and variables.
ImageButton rd1, rd2, rd4, rd5;
TextView tv1,tv2;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// parameters initialisation for image buttons
rd1 = (ImageButton)findViewById(R.id.imageButton1);
rd2 = (ImageButton)findViewById(R.id.imageButton2);
rd3 = (ImageButton)findViewById(R.id.imageButton3);
rd4 = (ImageButton)findViewById(R.id.imageButton4);
tv1 = (TextView)findViewById(R.id.textView1);
tv2 = (TextView)findViewById(R.id.textView2);
rd1.setOnClickListener(this);
rd2.setOnClickListener(this);
rd3.setOnClickListener(this);
rd5.setOnClickListener(this);
}
Synchronises the four subclasses created mainly for C, C++, Python and Scilab.
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.imageButton1:
Intent myIntent = new Intent(v.getContext(), c.class);
startActivityForResult(myIntent, 0);
break;
case R.id.imageButton2:
Intent myIntent1 = new Intent(v.getContext(), cp.class);
startActivityForResult(myIntent1, 0);
break;
case R.id.imageButton3:
Intent myIntent3 = new Intent(v.getContext(), py.class);
startActivityForResult(myIntent3, 0);
break;
case R.id.imageButton4:
Intent myIntent4 = new Intent(v.getContext(), sci.class);
startActivityForResult(myIntent4, 0);
break;
default:
break;
}
}
Contains the code for user to quit and switch to another programming language.
CODE
// implemented application exit for the user
public void onBackPressed() {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("Are you sure you want to exit?")
.setCancelable(false)
.setPositiveButton("Yes",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
finish();
android.os.Process.killProcess(android.os.Process.myPid());
}
})
.setNegativeButton("No", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();
}
});
AlertDialog alert = builder.create();
alert.show();
}
The Sub Classes
c.java
- The sub class for programming language C.
- The subclass contains the essential and required import.
- Webview feature implementation-
- The java script is enabled,
- The scrollbars are disabled to avoid the screen shift,
- The cache problem is resolved,
- The pop ups in the webview are enabled to take the arguments.
- The feature to focus the both web pages, links simultaneously was also added
- Two web views are implemented, one for code mirror and another for shell in a box
- For the first web view
// web view for c class
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
// java script enabled
webSettings.setJavaScriptEnabled(true);
// js interface for reload
engine.addJavascriptInterface(new JsInterface(), "android");
// cache problem removed
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
// scroll bars disabled
engine.setVerticalScrollBarEnabled(false);
engine.setHorizontalScrollBarEnabled(false);
// focused the web page
engine.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
if (!v.hasFocus()) {
v.requestFocus();
}
break;
}
return false;
}
public boolean onTouch1(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
});
engine.loadUrl("http://127.0.0.1/html/c/index.html");
engine.setWebChromeClient(new WebChromeClient()
{
@Override
public void onConsoleMessage(String message, int lineNumber,
String sourceID) {
Log.d("MyApplication", message + " -- From line " + lineNumber
+ " of " + sourceID);
super.onConsoleMessage(message, lineNumber, sourceID);
}
});
For the second web view
// web view for shell in a box
WebView engine1 = (WebView) findViewById(R.id.webView2);
WebSettings webSettings1 = engine1.getSettings();
// java script enabled
webSettings1.setJavaScriptEnabled(true);
// scroll bars disabled
engine1.setVerticalScrollBarEnabled(false);
engine1.setHorizontalScrollBarEnabled(false);
// web page focused
engine1.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
if (!v.hasFocus()) {
v.requestFocus();
}
break;
}
return false;
}
public boolean onTouch1(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
});
// address of page for shell in a box
engine1.loadUrl("http://127.0.0.1:4200");
engine1 = new WebView(this);
engine1.reload();
engine1.setWebChromeClient(new WebChromeClient()
{
@Override
public void onConsoleMessage(String message, int lineNumber,
String sourceID) {
Log.d("MyApplication", message + " -- From line " + lineNumber
+ " of " + sourceID);
super.onConsoleMessage(message, lineNumber, sourceID);
}
});
}
Menu implementation for options like Save, Open and Example, Help and About.
// menu options by switch case
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle item selection
switch (item.getItemId()) {
case R.id.open:
ex_flag = "open";
write_path = "/data/local/linux/var/www/html/c/code/.open_file.c";
oe_path = Environment.getExternalStorageDirectory()
+ "/APL/c/code/";
mPath = new File(oe_path);
loadFileList();
return true;
case R.id.savecode1:
test();
return true;
case R.id.example:
ex_flag = "example";
write_path = "/data/example/c/.open_file.c";
oe_path = "/data/local/linux/var/www/html/c/example/";
mPath = new File(oe_path);
loadFileList();
return true;
case R.id.help:
Intent myIntent = new Intent(c.this, chelp.class);
startActivityForResult(myIntent, 0);
return true;
case R.id.about:
Intent myIntent1 = new Intent(c.this, about.class);
startActivityForResult(myIntent1, 0);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
Save feature to save the code in sdcard
public void save()
{
// TODO Auto-generated method stub
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
webSettings.setJavaScriptEnabled(true);
engine.getSettings().setJavaScriptEnabled(true);
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
engine.setWebChromeClient(new
MyWebChromeClientsci());
engine.loadUrl("javascript:savecode()");
Open feature to display the list of files saved in sdcard and display the file in codemirror of the webpage using javascript
// function for open
public void openFile() {
// TODO Auto-generated method stub
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
webSettings.setJavaScriptEnabled(true);
engine.getSettings().setJavaScriptEnabled(true);
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
engine.setWebChromeClient(new MyWebChromeClient());
if (ex_flag == "open")
engine.loadUrl("javascript:submit_file()");
else if (ex_flag == "example")
engine.loadUrl("javascript:example_file()");
}
// android file explorer
private void loadFileList() {
try {
mPath.mkdirs();
} catch (SecurityException e) {
System.out.println("unable to write on the sd card ");
}
if (mPath.exists()) {
FilenameFilter filter = new FilenameFilter() {
public boolean accept(File dir, String filename) {
File sel = new File(dir, filename);
return filename.contains(FTYPE) || sel.isDirectory();
}
};
mFileList = mPath.list(filter);
onCreateDialog(DIALOG_LOAD_FILE);
} else {
mFileList = new String[0];
}
}
protected Dialog onCreateDialog(int id) {
Dialog dialog = null;
AlertDialog.Builder builder = new Builder(this);
switch (id) {
case DIALOG_LOAD_FILE:
builder.setTitle("Choose your file");
if (mFileList == null) {
System.out
.println("Showing file picker before loading the file list ");
dialog = builder.create();
return dialog;
}
builder.setItems(mFileList, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
mChosenFile = mFileList[which];
InputStream inStream = null;
OutputStream outStream = null;
try {
File bfile = new File(write_path);
inStream = new FileInputStream(oe_path + mChosenFile);
outStream = new FileOutputStream(bfile);
byte[] buffer = new byte[1024];
int length;
// copy the file content in bytes
while ((length = inStream.read(buffer)) > 0) {
outStream.write(buffer, 0, length);
}
inStream.close();
outStream.close();
openFile();
} catch (IOException e) {
e.printStackTrace();
}
}
});
break;
}
dialog = builder.show();
return dialog;
}
- Examples for the demo part was also added in the simlar fashion as open was implemented.
- For implementing the Help and Options , two new sub classes were created namely help.class and options.class which are explained in detail after sci.class.
- A function Android js interface is also implemented so that web page for the shell in a box is reloaded whenever the execute button is pressed.
// js interface to establish communication between the android and
// javascript for reloading the webpage for shell in a box
private class JsInterface {
public void reloadConsole() {
/* below put id of second webview which has shell in a box */
WebView engine1 = (WebView) findViewById(R.id.webView2);
WebSettings webSettings1 = engine1.getSettings();
webSettings1.setJavaScriptEnabled(true);
engine1.reload();
}
}
Similar process was repeated in cpp.java for C++ and in py.java for Python creating the web view, implementing the menu and additional features like Open, Save, Example, Help and About to increase the functionality of the programming language so ported on the tablet.
- sci.java
- In Scilab along with the output, the graphical output (plot) is also displayed , so additional feature like Save Figure was implemented:
- sci.java
public void savefig()
{
// TODO Auto-generated method stub
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
webSettings.setJavaScriptEnabled(true);
engine.getSettings().setJavaScriptEnabled(true);
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
engine.setWebChromeClient(new
MyWebChromeClientsci());
engine.loadUrl("javascript:saveImg()");
}
Since for implementing the shell in a box, we are utilising the two web view format, so it was difficult to manage the image plot in Scilab, thus for smooth working of the application, we created two new subclasses, ImagePlotActivity and SimpleGestureFilter.
- ImagePlotActivity.java
- The subclass was created to display the graphical output in the image view.
- On press of Execute button in the web page, a call from the javascript to android is made and ImagePlotActivity is called.
- The user is directed to new screen containing the image view and the closeButton.
- The class utilises the SimpleGestureFilter.java to add the feature of Swipe so that user can return back to the previous screen and cross check the output and the graphical output.
- Whenever the image file exits, the swipe feature would be enabled and user can swipe between the two screens.
- ImagePlotActivity.java
public class ImagePlotActivity extends Activity implements SimpleGestureListener {
private SimpleGestureFilter detector;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main2);
detector = new SimpleGestureFilter(this, this);
Button btnOpenNewActivity = (Button) findViewById(R.id.button1);
btnOpenNewActivity.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent myIntent = new Intent();
sci.clearFlag();
finish();
}
});
ImageView img = (ImageView) findViewById(R.id.imageView1);
/* give path of actual image file generated by cgi script below */
Bitmap bmp = BitmapFactory.decodeFile("/data/local/linux/var/www/html/scilab/tmp/1.gif");
img.setImageBitmap(bmp);
}
public boolean dispatchTouchEvent(MotionEvent me) {
this.detector.onTouchEvent(me);
return super.dispatchTouchEvent(me);
}
public void onSwipe(int direction) {
switch (direction) {
case SimpleGestureFilter.SWIPE_RIGHT:
finish();
break;
}
}
public void onDoubleTap() {
}
}
- SimpleGestureFilter.java
- The sub class was added to implement the feature of the Swipe between the screens.
- Whenever the image file would exist the swipe feature is enabled and output and image plot and image view screens can be swipped between. The swipe right function is utilized to swipe from two webview format to image view screen.
- And the swipe left is used to come back from the image view to two column web page format.
- SimpleGestureFilter.java
public class SimpleGestureFilter extends SimpleOnGestureListener{
public final static int SWIPE_RIGHT = 4;
public final static int MODE_TRANSPARENT = 0;
public final static int MODE_SOLID = 1;
public final static int MODE_DYNAMIC = 2;
private final static int ACTION_FAKE = -13;
private int swipe_Min_Distance = 100;
private int swipe_Max_Distance = 350;
private int swipe_Min_Velocity = 100;
private int mode = MODE_DYNAMIC;
private boolean running = true;
private boolean tapIndicator = false;
private Activity context;
private GestureDetector detector;
private SimpleGestureListener listener;
public SimpleGestureFilter(Activity context,SimpleGestureListener sgl) {
this.context = context;
this.detector = new GestureDetector(context, this);
this.listener = sgl;
}
public void onTouchEvent(MotionEvent event){
if(!this.running)
return;
boolean result = this.detector.onTouchEvent(event);
if(this.mode == MODE_SOLID)
event.setAction(MotionEvent.ACTION_CANCEL);
else if (this.mode == MODE_DYNAMIC) {
if(event.getAction() == ACTION_FAKE)
event.setAction(MotionEvent.ACTION_UP);
else if (result)
event.setAction(MotionEvent.ACTION_CANCEL);
else if(this.tapIndicator){
event.setAction(MotionEvent.ACTION_DOWN);
this.tapIndicator = false;
}
}
//else just do nothing, it's Transparent
}
- help.java
- Help is implemented to provide the guidance to the user . To enrich this feature a new sub class is created and whenever the user opts for Help in menu, it directs him to the new webview that displays the contents of help.html.
- help.java
// button for close
Button btnOpenNewActivity = (Button) findViewById(R.id.button1);
btnOpenNewActivity.setOnClickListener(new View.OnClickListener() {
// close this class and bring to same state
public void onClick(View v) {
finish();
}
});
// webview for chelp
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
// java script enabled
webSettings.setJavaScriptEnabled(true);
// cache problem removed
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
// scroll bars disabled in webview
engine.setVerticalScrollBarEnabled(false);
engine.setHorizontalScrollBarEnabled(false);
// focus on web page
engine.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
if (!v.hasFocus()) {
v.requestFocus();
}
break;
}
return false;
}
public boolean onTouch1(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
});
// address of html file in ch root
engine.loadUrl("file:///data/local/linux/var/www/html/c/chelp.html");
// enabling all pop ups in web view
engine.setWebChromeClient(new WebChromeClient()
{
@Override
public void onConsoleMessage(String message, int lineNumber,
String sourceID) {
Log.d("MyApplication", message + " -- From line " + lineNumber
+ " of " + sourceID);
super.onConsoleMessage(message, lineNumber, sourceID);
}
});
}
- options.java
- To make the user compatible with different layout, icons and their functionality, the options was added in the menu. Whenever the user opts for the options in menu, the class directs the user to new screen displaying the required important content.
- options.java
// button for close
Button btnOpenNewActivity = (Button) findViewById(R.id.button1);
btnOpenNewActivity.setOnClickListener(new View.OnClickListener() {
// close this class and bring to same state
public void onClick(View v) {
finish();
}
});
// webview for chelp
WebView engine = (WebView) findViewById(R.id.webView1);
WebSettings webSettings = engine.getSettings();
// java script enabled
webSettings.setJavaScriptEnabled(true);
// cache problem removed
webSettings.setCacheMode(WebSettings.LOAD_NO_CACHE);
webSettings.setAppCacheEnabled(false);
// scroll bars disabled in webview
engine.setVerticalScrollBarEnabled(false);
engine.setHorizontalScrollBarEnabled(false);
// focus on web page
engine.setOnTouchListener(new View.OnTouchListener() {
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
case MotionEvent.ACTION_UP:
if (!v.hasFocus()) {
v.requestFocus();
}
break;
}
return false;
}
public boolean onTouch1(View arg0, MotionEvent arg1) {
// TODO Auto-generated method stub
return false;
}
});
// address of html file in ch root
engine.loadUrl("file:///data/local/linux/var/www/html/c/chelp.html");
// enabling all pop ups in web view
engine.setWebChromeClient(new WebChromeClient()
{
@Override
public void onConsoleMessage(String message, int lineNumber,
String sourceID) {
Log.d("MyApplication", message + " -- From line " + lineNumber
+ " of " + sourceID);
super.onConsoleMessage(message, lineNumber, sourceID);
}
});
}
The Android Manifest.xml¶
- The most important part for a project to execute, lies in its manifest.xml file.
- The manifest contains the permission for the webview enability, for the webview feature.
- The permission to read and write from the External Source, handling the sdcard.
<uses-sdk android:minSdkVersion="8" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
The application intilaization and icon and its label information.
<application
android:icon="@drawable/apl"
android:label="@string/app_name9"
android:background="@null"
>
The main activity APL and its sub classes intilaization, name, label and name information.
<activity
android:name=".APLActivity"
android:configChanges="keyboardHidden|orientation"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.aakash.lab.sci"
android:label="@string/app_name1" >
</activity>
<activity
android:name="com.aakash.lab.c"
android:label="@string/app_name2" >
</activity>
<activity
android:name="com.aakash.lab.cp"
android:label="@string/app_name3" >
</activity>
<activity
android:name="com.aakash.lab.py"
android:label="@string/app_name4" >
</activity>
<activity
android:name=".OnlyExt"
android:label="@string/app_name4" >
</activity>
<activity
android:name="com.aakash.lab.ImagePlotActivity"
android:label="@string/app_name6" >
</activity>
<activity
android:name=".chelp"
android:label="@string/app_name7" >
</activity>
<activity
android:name=".cphelp"
android:label="@string/app_name7" >
</activity>
<activity
android:name=".pyhelp"
android:label="@string/app_name7" >
</activity>
<activity
android:name=".scihelp"
android:label="@string/app_name7" >
</activity>
<activity
android:name="com.aakash.lab.about"
android:label="@string/app_name8" >
</activity>
