Android Coding Tips

Copy to clipboard

2017-11-21T09:15:00.001-08:00

In my upcoming app, I have codes which I display. These are some times lengthy, and I want the app to be able to copy this to clipboard. Once it is in clipboard, users can paste it anywhere.

So how do you copy some text from your app to clipboard.

You need to use clipboard manager.

Clipboard Manager

This class sets and gets data for the clipboard using Clipdata objects.

You can get the object of this class using system service. - using statement

context.getSystemService(Context.CLIPBOARD_SERVICE)

Example

I have a dummy project with a button, onclick of which copies content to clipboard.

Here is my activity file

package com.hegdeapps.testapp;

import android.content.ClipData;
import android.content.ClipboardManager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        String str = "The 7 Cs of communication provide a checklist for making sure that your meetings  , emails  , conference calls  , reports  , and presentations   are well constructed and clear – so your audience gets your message.\n" +
                "\n" +
                "According to the 7 Cs, communication needs to be:\n" +
                "\n" +
                "    Clear.\n" +
                "    Concise.\n" +
                "    Concrete.\n" +
                "    Correct.\n" +
                "    Coherent.\n" +
                "    Complete.\n" +
                "    Courteous.\n" +
                "\n" +
                "In this article, we look at each of the 7 Cs of Communication, " +
                "and we'll illustrate each element with both good and bad examples.\n" ;

        TextView tv =(TextView) findViewById(R.id.textview);
        tv.setText(str);

    }
    public void copyToClipboard(View v)
    {
        ClipboardManager manager = (ClipboardManager) getSystemService(this.CLIPBOARD_SERVICE);
        TextView tv =(TextView) findViewById(R.id.textview);
        String str = tv.getText().toString();
        ClipData data = ClipData.newPlainText("ds_soln", str);
        manager.setPrimaryClip(data);
    }
}

Now the layout file for this activity is shown below.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
  >

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="copyToClipboard"
        android:text="Copy Text"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!" 
        android:id="@+id/textview" />

</LinearLayout>

Now on click of copy button the entire string is copied to clipboard.

Selecting text and copying

Some times users find part of our code interesting. They don't want the entire text. You see this in all the browsers. You select text by long clicking on it and grabbing the two end points. And you can copy the text or share it.

How do you make your app behave like this?

Simple. Just make the textview selectable.

<TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        android:textIsSelectable="true"
        android:id="@+id/textview" />

And now your text is selectable, copyable and shareable. Great!!!.

Hundred - a number game updated

2017-11-09T21:57:00.003-08:00

Shataka - my number game which is very simple but really good, has been updated.

First of all, its name is changed to "Hundred". Because that is the aim of the game, right?

There are some UI changes too. May be for better :) :)

And I have added a how to section, which guides the user step by step.

The game has a grid of 9 cells , 3 rows and 3 columns. The aim of the game is to fill this grid with numbers so that each row and each column adds up to 100. And all the required numbers are given at the bottom of the grid.

In this version( v 3.0), in level 1, 6 numbers are already provided in the grid. (In older versions 3 numbers were filled in the grid). So user needs to fill only 3 more numbers. So level 1 is pretty easy. You can see that in the above screen shot, 2nd row and 3rd column are already filled and their sums are 100.

In level 2, 5 numbers are provided and user should fill the remaining 4. And so on.

From level 8 onwards, the game is slightly more challenging. Now the sum is different each time, its value is shown at the top of the grid.

From level 15, the sum should be 1000.

I think, better than you explaining the concepts, it is better you download it and see it for yourself.

OK, I used mockupsjar to create some nice screen frames. But you should know that, android studio provides with option of frames when you are taking screen shot. All screen shots except for first one were created using android studio.

If you are looking for a place to create feature graphic - you know that it is essential, norio site lets you create the feature graphic. But I used GIMP instead,

And do not forget to select both check boxes when you are trying to create a release version apk and studio asks you whether you want to sign jar files or entire apk.

And after you shrink the files using proguard, you may need to use few " -keep" lines in your proguard.txt file. I was unable to drop numbers into cells in my release version!

Using a list fragment with cursor adapter

2017-09-12T07:39:00.001-07:00

All these days, I avoided using fragments. But then I realized for my this particular applications fragments are ideal. I have a master - detail list in my app.
Let us say you want to have two fragments - one is a fragment which contains a list of elements and second one expands one element of the list. Both of them share the same cursor from the activity.

Let us start with list fragment.

Do not try creating list fragment using a wizard. It unnecearrily adds too many methods and classes.

Let us start writing our own fragment like this

class MyListFragment extends ListFragment{

}

Next using code menu override option, override the following method

onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)

This method should be used for inflating the layout file for the fragment. I have a framelayout in parent activity of this fragment with the id as container. So I will specify that for inflating. The framelayout will be the parent viewgroup for fragment.

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        return inflater.inflate(R.layout.listfragment,container,false);
 }

R.layout.listfragment is my layout file which for the fragment. Here it is

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:id="@android:id/list"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <TextView
        android:id="@android:id/empty"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="No items in list" />
</LinearLayout>

Note that the ids of both ListView and TextView are android ids. This is needed because we want to use listfragment methods for most of our works, instead of getting listview with the help of findviewbyid etc.

How about the adapter for the list? I am having a database cursor for my list. So I can use simple cursor adapter. The adapter should be set in onActivityCreated() method.

Where is the cursor for the adapter? Instead of trying to fetch the cursor all over again, you can access the cursor from the activity. (Make sure it is not private). Using getActivity() and typecasting it to parent activity name, you get access to parent activity. Next you access cursor from there.

@Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        MyActivity act = (MyActivity) getActivity();
        mCursor = act.mCursor;
        SimpleCursorAdapter adapter = new SimpleCursorAdapter(act,
                android.R.layout.simple_list_item_1, mCursor,
                new String[]{"name"}, new int[]{android.R.id.text1}, 0);
        setListAdapter(adapter);
        }

OK. The first parameter to SimpleCursorAdapter is context. Second parameter is the layout for each row of the list. You can use android.R.layout.simple_list_item_1. Or you can write your own layout file.

Third parameter is cursor. And fourth and fifth are mapping of columns in cursor to views in listview.

Now how do we handle item clicks?

You can write an interface in the fragment. And when item is clicked from list, call the function of this interface. Now the parent activity must implement this interface in order to listen to itemclick of this fragment.

Let us write the interface.

package your.package.name;

public interface OnListItemSelectedListener{
    public void OnItemSelected(int position);
}

Create an instance of this interface in onActivityCreated method. Developers tutorial asks you to create call back instance in onAttach() method. I faced some difficulties. So I am writing it in onActivityCreated() method like this.

public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        ........
        try {
            mCallback = (OnListItemSelectedListener) act;
        }
        catch (ClassCastException e){
            Toast.makeText(act,"Class must implement OnListItemSelectedListener",Toast.LENGTH_SHORT).show();
        }
    }

Now the thing remaining is how do we use this interface.

Override the OnListItemClick() method of ListFragment and here call the OnItemSelected method of interface.

@Override
    public void onListItemClick(ListView l, View v, int position, long id) {
        super.onListItemClick(l, v, position, id);
        if(mCallback!=null) mCallback.OnItemSelected(position);
    }

OK. Now our onclick method is ready to go to the parent activity.

Parent activity needs few lines of code.

public class MyActivity extends FragmentActivity implements OnListItemSelectedListener { 
        private MySqliteHelper mSqliteHelper;
        private int mPos;
        private MyListFragment fragment;
 
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.listact);
            mCursor=mSqliteHelper.getallrows();  
            fragment = new MyListFragment(); 
            getSupportFragmentManager().beginTransaction().add(R.id.list_container,fragment).commit(); 
        }
}

In order to use Fragments with support library, you need to extend your class from FragmentActivity.

Here is the layout file of the activity - R.layout.listact

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"> 
  
        <FrameLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginLeft="5dp"
            android:layout_marginRight="5dp"
            android:id="@+id/list_container"
            /> 
</LinearLayout>

In oncreate method of we are fetching the cursor and then creating a fragment and adding it to frame layout.

Notice that we are implementing the interface here. Android studio forces you to implement the method of the OnListItemSelectedListener interface. We complete its code.

@Override
    public void OnItemSelected(int position) {
        mPos = position;
       //do something
    }

Financial Calculator published

2017-07-21T05:00:00.002-07:00

Today I have published my 7th app Financial Calculator in google play. (you will see 8 apps in market page. But Kannada Hindi keyboard is no longer supported as Akshara keyboard is its successor.)

This app is meant for us Indians who want to save our money a little bit in FDs and RDs. Or/and pay EMI each month for housing and other loans. The app can calculate EMI amount, FD or RD maturity value. (So you can correct the bank official if they make a mistake :) )

It will also calculate how much will you pay extra for the loan. It lets you compare two loans, compare two FDs or RDs.

There are other calculations too. Gratuity calculator, loan afford
ability calculator, savings goal calculator and currency converter.

So what are you waiting for? Download app today and give me your valuable feedback.

Ratings and feedbacks

2017-07-01T20:45:00.002-07:00

Once your android project is at the finishing stage, you need to add the following extra features to your app.

Rate the app

Because rates drive app download

Other apps by you

free advertisement for your apps

Send feedback

you need them to remove bugs and improve the app

Well, I personally feel that the pop up screens which ask the user to rate the app, is not a good idea. People may get irritated by this.

But to provide the first one, you need to know the playstore page of your app. How do you get the page if you have not yet published the page?

Well, the app page always looks like this

https://play.google.com/store/apps/details?id=your_app_package_name

the last part is your package name of the app.

And to take the user to all apps by you, you need to use a url like this

https://play.google.com/store/apps/developer?id=yourdevelopername

So these two settled, let us write our xml and code

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    
    <item android:title="Rate the app"
        android:id="@+id/rateapp"/>
    <item android:title="Our other apps"
        android:id="@+id/otherapps"/>
    <item android:title="Send Feedback"
        android:id="@+id/feedback"/>


</menu>

Of course you will fill in the other menu items of your app.

In the onOptionsItemSelected method, add code for these three options.

public boolean onOptionsItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();
        if (id==R.id.rateapp){
            startPlayStore(RATE_APP);
        }else if(id==R.id.otherapps){
            startPlayStore(OTHER_APPS);
        }else if(id==R.id.feedback){
            startMailFeedback();
        }
 /* rest of the code*/ 
        
    }

Now we need to write code for viewing playstore in external browser and we also need to write code to start mail program for feedback.

private void startPlayStore(int code) {
        String url ="";
        if(code==RATE_APP) {
             url= "https://play.google.com/store/apps/details?id=your_app_package_name";
        } else if (code == OTHER_APPS ){
              url = "https://play.google.com/store/apps/developer?id=your_developer_name";
        }
        Intent intent = new  Intent(Intent.ACTION_VIEW,Uri.parse(url));
        startActivity(intent);
    }

    private void startMailFeedback() {
        Intent intent = new  Intent(Intent.ACTION_SEND);
        intent.setData(Uri.parse("mailto:"));
        intent.setType("text/plain");
        intent.putExtra(Intent.EXTRA_EMAIL,new String[]{DEV_MAIL_ID});
        intent.putExtra(Intent.EXTRA_SUBJECT,"Feedback on "+getResources().getString(R.string.app_name));
        startActivity(intent);
    }

Please fill in the values for your_app_package_name (which is of the format com.abcd.something - which is present in first line of all your activities :) ) and your_developer_name. And also provide your mail id in place of DEV_MAIL_ID

The first method shows your app in playstore. Second method takes you to email program - usually gmail with to as your mail id .

That's all.

And you are ready to get some ratings and feedbacks.

P.S. : I was wrong earlier. I had omitted details? from the url. I realized it hard way after publishing my app with wrong app link. I am sorry if I have caused any kind of problems to any of readers.

Using spinners in android

2017-07-01T19:49:00.000-07:00

Spinner in android is a view which shows you a drop down menu and lets you select one of the items.

Let us see how to use a spinner in your android program.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.hegdeapps.myapplication.MainActivity"
    tools:showIn="@layout/activity_main">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="select currency" />

    <Spinner
        android:id="@+id/spinner"
        android:layout_width="150dp"
        android:layout_height="40dp"
        android:layout_marginBottom="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="0dp"
         />
</LinearLayout>

Next you need to specify what elements should the drop down menu should display. For that you can use an adapter like the one used for listview.

protected void onCreate(Bundle savedInstanceState) {
        /********other code******/
        Spinner sp =(Spinner) findViewById(R.id.spinner);
        final String arr[] = new String[]{"Rupee","US Dollar","Euro"};/*values for drop down*/
        ArrayAdapter adapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,arr);
        sp.setAdapter( adapter);
        sp.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                Snackbar.make(view,"You selected "+arr[position],Snackbar.LENGTH_LONG).show();
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

    }

What happens when we select one of the items of the spinner? To specify that, you need to use onItemSelectedListener as shown above.

Let us look at another example. First we will see the layout file with spinner in it.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_margin="20dp"
    android:gravity="center"
    android:orientation="vertical"
    android:padding="20dp"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context="com.hegdeapps.myapplication.MainActivity">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Length of square:"
            android:textSize="18sp" />

        <EditText
            android:id="@+id/len"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:ems="10"
            android:inputType="number" />

    </LinearLayout>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/textView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Select:"
            android:textSize="18sp" />

        <Spinner
            android:id="@+id/spinner"
            android:layout_width="150dp"
            android:layout_height="40dp"
            android:layout_marginBottom="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginTop="0dp"
            android:layout_weight="1"
            android:entries="@array/type" />

    </LinearLayout>
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"

        android:text="Calculate" />
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <TextView
            android:id="@+id/textView4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="Answer is"
            android:textSize="18sp" />

        <TextView
            android:id="@+id/ans"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text=" "
            android:textSize="18sp" />
    </LinearLayout>
</LinearLayout>

In this example, we are using a spinner to select length, perimeter or area of a square. But we will not use an adapter. Instead we specify the values in xml as

android:entries = "@array/type"

where this type is a string array specified in an xml file in values folder, say strings.xml

<resources>
    <string name="app_name">My Application</string>
    <string name="action_settings">Settings</string>
    <string-array name="type">
        <item>length</item>
        <item>perimeter</item>
        <item>area</item>
    </string-array>
</resources>

So this string array type is used for populating the spinner instead of using java code.

Spinner has a method getItemSelected(), which we shall use. Please remember that the method returns an object, so we have to type cast it.

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.content_main);
        Spinner sp =(Spinner) findViewById(R.id.spinner);
        EditText etLen = (EditText) findViewById(R.id.len);
        Button btnCalculate = (Button)findViewById(R.id.button);
        btnCalculate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                calculate();
            }
        });

    }

    private void calculate() {
        Spinner sp =(Spinner) findViewById(R.id.spinner);
        EditText etLen = (EditText) findViewById(R.id.len);
        String str = (String)sp.getSelectedItem();
        String stLen = etLen.getText().toString();
        int len = Integer.valueOf(stLen);
        int ans=len;
        if(str.equals("length")){
            ans = len;
        }else if(str.equals("perimeter")){
            ans = 4*len;
        } else if(str.equals("area")){
            ans = len*len;
        }
        TextView tvAns = (TextView) findViewById(R.id.ans);
        tvAns.setText(String.valueOf(ans));
    }
}

As we can see, we are using the getSelectedItem() to extract value from spinner and using it in calculation. Also not that we are not using any kind of adapter for the spinner.

Here is the output of the program.

You can also specify whether the spinner shows values as a dropdown or a dialog using this xml attribute

android:spinnerMode =dialog

android:spinnerMode =dropdown

Actionbar and toolbar using support library

2017-06-17T23:55:00.000-07:00

Action bar has been our friend since a long time. But it has its own drawbacks. You can not change its color, or size or appearance of its elements.

So came toolbar in android Lollipop. The beauty of this is, you add a toolbar like any other item in the layout xml file, set its color, size, position. Then add a few lines of code to make it an action bar.

So let us dive straight into coding.

I am using support library for toolbar and also appcompat activity. If you do not want to bother about devices with older versions than 5.0, you can straight use toolbar.

You can find toolbar in appcompat option in Android studio design view of your xml file.

So you insert that toolbar in the layout xml file.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"

   android:layout_margin="10dp"

android:layout_height="match_parent">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme" />

 </LinearLayout>

Now you can notice that it already has background as colorPrimary. Next let us set this toolbar as actiobar writing some code in onCreate() function of our activity.

Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
        if(toolbar!=null){            
            setSupportActionBar(toolbar);

getSupportActionBar().setTitle("My activity");

Now this is how our output screen looks like

What went wrong? Why is the actionbar cropped at left and right ends? And where is the title?

The layout_margin="10dp" causes even the actionbar to have a margin. Remove that line from parent linearlayout.

Actionbar title will not be set unless we mention it before setting toolbar as action bar. We shall correct both now.

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"

android:layout_height="match_parent">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme" />

 </LinearLayout>

Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
        if(toolbar!=null){
            toolbar.setTitle("your title");
            setSupportActionBar(toolbar);           
        }

After these two corrections, our action bar is ready like this.

But if you have a theme such as

Theme.AppCompat.Light.NoActionBar

then the actionbar title will be in black. To have white text but still using them light, we need to modify the toolbar like this.

<android.support.v7.widget.Toolbar
        android:id="@+id/toolbar2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        android:minHeight="?attr/actionBarSize"
        android:theme="?attr/actionBarTheme"
        app:theme="@style/ThemeOverlay.AppCompat.Dark.ActionBar"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
          />

Next we need to add home navigation to actionbar. That is done using changes in java file as well as androidmanifest.xml file.

Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
        if(toolbar!=null){
            toolbar.setTitle("your title");
            setSupportActionBar(toolbar);
            ActionBar actionBar = getSupportActionBar();
            actionBar.setDisplayShowHomeEnabled(true);
            actionBar.setDisplayHomeAsUpEnabled(true);
            actionBar.setDisplayShowTitleEnabled(true);
            actionBar.setHomeButtonEnabled(true);
        }

And in manifest file - androidmanifest.xml add these lines to your activity

<activity 
android:name=".youractivity" 
         android:parentActivityName=".yourhomeactivity">
             <meta-data android:name="android.support.PARENT_ACTIVITY"
            android:value=".yourhomeactivity">
            </meta-data>
 </activity>

parentActivityName is used for mentioning home activity. But for sdks less than 4.0, we need to provide the metadata as shown above.

OK. Now we have a pretty actionbar plus home navigation. Now how about some menu options?

You can add menu options in two different ways. a) Add buttons to toolbar. b) use onCreateOptions menu. Let us see the second option.

   @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.mymenu,menu);
        return true;
    }

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if(id==R.id.print){
            TextView tv = new TextView(this);
            tv.setLayoutParams(

               new LinearLayoutCompat.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT));
            tv.setText("Hello world");
            LinearLayout linearLayout = (LinearLayout)findViewById(R.id.linlayout);
            linearLayout.addView(tv);
            return  true;
        }  
        return true;
    }

printhello is a dummy options menu entry which will print helloworld in a textview by creating textview dynamically.

First we use createOptionsMenu to inflate the options menu defined by menu file mymenu.xml in /res/menu folder

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
<item android:title="printHello"
    android:id="@+id/print"
    app:showAsAction="ifRoom"/>
</menu>

Next in onOptionsItemSelected we print helloworld on textview which we create and add to linearlayout.

But now a strange thing happens. The home button does not work. So home navigation is not present.

There are two ways of overcoming this.

Do not return true from onOptionsItemSelected

public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if(id==R.id.print){
            TextView tv = new TextView(this);
            tv.setLayoutParams(

               new LinearLayoutCompat.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT));
            tv.setText("Hello world");
            LinearLayout linearLayout = (LinearLayout)findViewById(R.id.linlayout);
            linearLayout.addView(tv);
            return  true;
        }  
        return false;
    }

Take home as a separate itemid and write code for that

   @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.mymenu,menu);
        return true;
    }

@Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if(id==R.id.print){
            /*write your code*/
            return  true;
        } else if (id==android.R.id.home){
            NavUtils.navigateUpFromSameTask(this);
            return true;
        }
        return true;
    }

That's it. Now you are well equipped to toolbar as actionbar to any activity in your android app.

DatePickers in Android

2017-03-13T05:30:00.000-07:00

DatePicker is a view which lets the user select a date showing a calendar or 3 spinners for dd, mm and yy.

Let us see how to use this.

Easy Method:

To use a DatePicker you can use DatePickerDialog. This can be created and shown programmatically too.

public void onCreate(Bundle b){ 
/*********/
Button btn = (Button)findViewById(R.id.btn);
 btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                showPickerDialog();
            }
        });
}

 private void showPickerDialog() {
       
        DatePickerDialog  dtPickerDlg =  new DatePickerDialog(this, this, 2017, 10, 20);
        dtPickerDialog.show();
}

In our xml file, let us have a button and in the onclick listener of the button, let us display the date picker dialog - we call showPickerDialog.

In showPickerDialog, we are using a random date to initialize.

The first parameter is the context. Second parameter is the class which implements the interface OnDateSetListener. Next three parameters are year, month (Jan is 0) and day of month.

Let us make our activity implement this interface

public class SomeActivity extends AppCompatActivity implements DatePickerDialog.OnDateSetListener{

@Override
    public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
        Calendar c = Calendar.getInstance();
        c.set(Calendar.DAY_OF_MONTH,dayOfMonth);
        c.set(Calendar.MONTH,month);
        c.set(Calendar.YEAR,year);
        mDate = DateFormat.format("dd-MM-yyyy",c).toString();
        TextView tvMessage = (TextView)findViewById(R.id.textView);
        tvMessage.setText("You have selected :"+mDate);

    }

As we can see, we modified the class header added to the phrase "implements DatePickerDialog.OnDateSetListener " to it.

The studio will prompt you to add the method onDateSet. The last 3 parameters are selected year, month and day of the Datepicker.

In this example, I am displaying this value in a textview.

Calendar.getInstance() will return a calendar object with current date and time. You can modify it as shown by setting day, month and year fields.

Note that we initialized the dialog with 2017,10,20 and the dialog shows 2017 November 20th. So keep in mind, month number starts with 0.

There is a GOTCHA

Now let us try to display the date picker as a 3 spinners. This can be done using two lines of code

dtPickerDlg.getDatePicker().setSpinnersShown(true);  
 dtPickerDlg.getDatePicker().setCalendarViewShown(false);

Studio gives you a warning that these methods are deprecated. But unlike other deprecated methods, these methods actually do not work in sdk 21- Lollipop onwards. So the dialog still shows calendar instead of spinners.

Solution

I tried various options. As far as I could find out, the only solution seems to be to use DatePicker in a normal dialog or a dialog fragment instead of a DatePickerDialog.

Let us look at that.

final Dialog  dtPickerDlg = new Dialog(this);        
       dtPickerDlg.setContentView(R.layout.picker);     
        final DatePicker picker =(DatePicker) dtPickerDlg.findViewById(R.id.datePicker);
        Button btnOk =(Button) dtPickerDlg.findViewById(R.id.okbutton);
        btnOk.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                dtPickerDlg.dismiss();
            }
        });
        Calendar c = Calendar.getInstance();
        int dd = c.get(Calendar.DAY_OF_MONTH);
        int mm = c.get(Calendar.MONTH);
        int yy = c.get(Calendar.YEAR);
        picker.init(yy,mm,dd,this);//last parameter is datechangelistener
        dtPickerDlg.show();
        dtPickerDlg.setOnDismissListener(new DialogInterface.OnDismissListener() {
            @Override
            public void onDismiss(DialogInterface dialog) {

                TextView tvMessage = (TextView)findViewById(R.id.textView);
                tvMessage.setText("You have selected :"+mDate);
            }
        });

Here is the layout xml file /res/layout/picker.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <DatePicker
        android:id="@+id/datePicker"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:calendarViewShown="false"
        android:datePickerMode="spinner" />
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:background="@android:color/transparent"
        android:text="OK"
        android:id="@+id/okbutton"/>
</LinearLayout>

Look at the two highlighted lines. You can set datePickerMode to spinner or calendar. Even when you set to spinner, a calendar is also shown. To avoid that, set calendarviewshown as false.

Now for the listeners! Funny, there is no dateset listener. Not so easily found at least.

I tried documentation and trying to use autocomplete with setOnDateSet or addOnDateSet etc. No. They are not to be found.

Finally the solution was found as init method. Datepicker should have an init method with initial values of dd, mm and yy and also the datesetlistener.

Look at the pink highlighted line again.

  picker.init(yy,mm,dd,this);//last parameter is datechangelistener

The init method takes OnDateChangeListener as fourth parameter. By adding this as fourth parameter, your activity should implement

DatePicker.OnDateChangedListener

Studio adds the interface and the method like this.

public class SomeActivity extends AppCompatActivity implements DatePicker.OnDateChangedListener{

@Override
    public void onDateChanged(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        Calendar c = Calendar.getInstance();
        c.set(year,monthOfYear,dayOfMonth);
        mDate = DateFormat.format("dd-MM-yyyy",c).toString();
    }

So that's it. Mission accomplished. We are able to show a date selector as a spinner.

You can download the complete project from here

Floating Label for EditText

2017-02-23T23:01:00.001-08:00

Because of space constraints, it is difficult to create self explanatory forms in mobile apps. Do you write a label for each field? If yes, the labels will also take half of the space in your form.

Hints solve the problem to some extent. If you add a hint for an EditText, when the field is blank, this hint is shown.

<EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/et1"

        android:hint="Name"/>

So now our hint is shown in Edit Text like this

But the moment you start entering value into the field, the hint vanishes.

To overcome this problem, support library comes to our rescue. It has a layout called TextInputLayout which places the hint as a floating label.

To use this first you need to add two lines to your build.gradle file in yourapplication/app directory.

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])

    compile 'com.android.support:appcompat-v7:25.1.1'
    compile 'com.android.support:design:25.1.0'
     
}

Next you should wrap your EditText in TextInputLayout as shown below.

<android.support.design.widget.TextInputLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content">
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/et1"
        android:hint="Name"/>
   </android.support.design.widget.TextInputLayout>

Aha! Now your hint acts as a label for input field. And it is always present. When field is empty, hint is shown inside the field. When you start typing, hint is shown as floating label in accent color. And after you finish typing, hint is shown as floating label in grey color.

So you achieved all these just by using xml files (and of course support library). Happy coding!!

You can find app folder of the application here

C++ Notes published

2017-02-11T18:24:00.000-08:00

I have published my next app - C++ Notes

The app has short notes on basic and advanced topics of C++ along with quiz and programs.

I have tried to use material design here - may not be so successful. And have used firebase ads instead of admob. Admob has now become firebase.

Be careful, when you add firebase ads, three extra permissions are added to the app - WAKELOCK and some c2d -permission-receive and c2d message. And users will wonder why the hell this app needs these permissions.

So you can add these lines in your manifest file to remove these permissions.

 <uses-permission android:name="android.permission.WAKE_LOCK" tools:node="remove" />
 <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" tools:node="remove" />
 <uses-permission android:name="your.app.package.permission.C2D_MESSAGE" tools:node="remove" />

I spent quite some time on deciding about scrolling and swiping. Notes had some formatting - colors, fonts etc. So I thought I will use HTML and webview. Questions are some what lengthy, I had to put these in a scrollview. Webview has a scroll feature automatically.

So when I tried to add swipe feature using ontouch listener, the behavior was erratic. Scroll would swipe the page. After lot of tinkering, I decided not to use swipe at all. Any views?

And it would have looked good, if the continue button was visible only when the webview scrolled to the bottom. Could not do it. :(

And I processed the html pages using Kompozer - reasonably good enough tool for HTML formatting. But even within that, code formatting was not good. So I used hilite.me site for formatting code with colors, borders etc.

Instead of actionbar I used toolbar with support library. Support library because my minimum sdk is 11. Toolbar is OK. Not as friendly as I expected it to be. But one good thing is you can add widgets in it directly and format them as you want them to be and write on click listeners to them.

One thing which I forgot was search feature. This is present in C app. But here since the topics were already highlighted in first page, I let it lapse.

Download the app and give me your feedback.

Adding depth

2016-12-04T21:21:00.001-08:00

Android sdk 5.0 - material, has a new property called elevation for views. Elevation gives z value for views. So views with higher elevation will cast a shadow.

Elevation can be set using xml
android:elevation ="somevalue"

Or using code
viewname.setElevation(5);

Let us look at how a textview uses elevation property.

<TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="#a3c6fa"
        android:elevation="5dp"
        android:text="Hello World!"/>

We are setting elevation of the textview to 5dp. We are setting light blue background color for textview.

Now our hello world textview looks like this.

Pretty simple. Isn't it?

Not quite so. Because elevation property needs sdk 21 or higher. You can not tell user to buy a new phone, just so that views will have a shadow. Can you?

The solution for older phones is layer-list. A layer-list drawable places different drawables on top of each other with given offset.

So let us write our layer-list .
shadow.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item >
        <shape>
            <solid android:color="#a3c6fa"/>

        </shape>
    </item>
    <item  android:top="0dp" android:right="2dp" android:bottom="2dp" android:left="0dp">
        <shape>
            <solid android:color="#8fd1f5"
              />

        </shape>
    </item>

</layer-list>

Each <item> in this is one layer drawable. We have two layers here. First layer is grey color rectangle. Next layer is light blue rectangle with offset of 2dp at right and bottom.

Next let us add this as background to our textview.

<TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/shadow"
     
        android:text="Hello World!"/>

After adding this code to the app, here is how our hello world looks like

Who needs to spend hours on GIMP, when we know our xml?

Using simple html in android

2016-08-17T22:18:00.000-07:00

In an app, instead of using a textview, we can use a webview. Why? Because webview is better looking. And, more importantly, we can format the text easily - specifically for long, long text. And, yes, it has an automatic scroll controls.

Now how do we display a static text in a webview?

String str="your text here";
webview.loadData(str,"text/html",null);

But your string should also have html tags in them. The simplest tags are html and body. So surround your string with these.

String str="your text here";
String str = "<html><body>"+str+"</body>";
webview.loadData(str,"text/html",null);

But if you are using for formatting the text, like bold, italic, different font etc. to be used for some parts of the text? How do you get that done?

The straight forward solution is learn html and hand code all the B 's and slash B's etc. yourself.

Of course, I am kidding. There are plenty of html editors available for automating this task. Look for a editor with WYSWIG feature. And take your text, format them using tool bar buttons and get the source html code, and paste it. I am currently using Kompozer.

OK. That task is completed. Now your webview is looking all cool and nice. But for any reason, if you want to extract plain text from this string, how do you accomplish that? You need to remove all the html tags.

Thankfully there is one line solution for this

String plainText = android.text.Html.fromHtml(strWithAllTags).toString();

This will remove all html tags from the string and give you the content.

Note: I formatted using HTML tags - but not only did my courier font did not show correctly, where ever I used a different font, there was an extra line in between. So if you face such problem, you need to use loadDataWithBaseURL as shown below.

wv.loadDataWithBaseURL(null,str,"text/html", null,null);

Adding custom view to xml

2016-06-09T06:32:00.002-07:00

You wanted to write your own custom view. You wrote it extending View class or better still TextView or ImageView class. You even added this view within your activity using Java code and tested it successfully.

But adding views with Java is a lengthy process and is cumbersome. xml makes the process easier.

So how do you add your custom view into your layout xml file?

somelayout.xml

 <?xml version="1.0" encoding="utf-8"?>  
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
        android:orientation="vertical"  
        android:layout_width="match_parent"  
        android:layout_height="match_parent">  
 <!--  Other Views -->  
     <com.some.name.CustomView  
       android:layout_width="wrap_content"  
       android:layout_height="wrap_content"  
       android:id="@+id/cell1"/>  
 <!--  Other Views -->  
 </LinearLayout>

OK, this is how you add your view in the xml file. Please note the fully qualified class name of custom view - including the package name.

After this your activity some times gives an error - error inflating the file. Why?

Two things you need to keep in mind.

You need at least two constructors for your customview class. One with Context as parameter. And second with Context and AttributeSet as parameters. You need both the constructors even if you do not use any custom attributes for your class
Both these constructors should be public.

e.g.

  class MyCustomView extends ImageView  
 {  
 /**some code here ****/  
 public MyCustomView(Context ctx)  
 {  
  /* your code **/  
 }  
 public MyCustomView(Context ctx, AttributeSet attrs)  
 {  
 /** code **/  
 }  }

Now your View will be available in the activity.

Note : My experience has been, the more code you leave to the library, better for you. Specifically measurements and layouts.

An app and a story

2016-05-02T07:45:00.000-07:00

An app and a story

I am not writing anything about coding tip here. But telling you how my app Shataka came into existence.

Few years back, I had started an app, whose idea was to find all combinations of numbers to get the required sum. Something like,

90 = 10*9

= 45*2

= 200 -110

etc.

Then the app was killed because my computer was. I did not have a single line of code remaining.

That was metamorphasized into this unique app Shataka. As far as I know, in android market there are not many number games for adults. There are few me-too versions of 2048 and few apps which ask you to type what is 10 +2 etc.

But in this app, the sum was to be 100, for rows and columns. And typing the numbers is clumsy and guessing 9 numbers to fill in 3 by 3 grid for this is too time consuming. So what if I provide the numbers after shuffling them?

Yes. I provide 9 numbers which if arranged in an order, make a grid with sum of each row as 100 and sum of each column as 100.

e.g.

81 4 15

10 73 17

9 23 68

So I generate one set of numbers - which will be one puzzle. I generate a second set, third set. How many sets should I store in the app? It should be possible to generate numbers randomly.

Generate one number randomly. Then find combinations for next 2 numbers etc. e.g. if let us say number is x1 is 10, then x2 can be 60 and x3 can be 30. Now 10+x4+x7 = 100 and 60+x5+x8 should be 100 and 30+x6+x9 should be 100. And also x4+x5+x6=100 and so on.

Few random numbers, few equations and some iterations, our puzzle set is ready. Give an empty grid, below which give 9 numbers and ask the user to fill the grid.

What I realized is, for the beginner, it is difficult to select numbers. Then I thought of hints. Providing hints for games is too complex. At least for this game it was.

If not hint, how about giving them partial solution. For the easy level, fill 3 cells of the grid, so that user needs to add only 6 numbers. That will be better and that will also make the game familiar.

That is what you see in Level 1 of the game. Level 2, gives the user 2 solved cells, level 3 gives 1 solved cell. And of course there are no solved cells in level 4.

Is that all? Will this game have only 4 levels? That will be too ridiculous. What if we add an extra number, which is not part of the solution to the game like this

We have 10 numbers given instead of 9. So makes the game little bit more challenging.

So that provided us level 5 and 6(with 2 extra numbers) and 7(3 extra numbers).

And with these features, I published the app.

But the game will become boring if it has only 7 levels. So in next version, I thought of not just shataka, but sahasraka - shataka in Sanskrit is 100 and sahasraka is 1000. So provide three numbers to add up to 1000.

And what about a sum of 77 or 92 of 66 that is some random 2 digit number. That is another set of levels

Why is there no screen shot of sahasraka - because I have not yet reached that level :)

So dear readers, what is the next feature you want me to add to this awesome game?

Shataka updated

2016-03-21T09:18:00.000-07:00

A completely original math game "Shataka" was published in Oct' 2014. The apps age faster than us:) So the design and UI were looking quite old. Hence an update has been published on March 14th

Here are the new features

Were you bored with adding to 100 always? Don't worry. In the new version you can arrange numbers so that they add to 1000. And there are also levels where sum is a random 2 digit number - different number each time. Isn't it exciting?
Believe in fast work? For you, there is timed mode. You have to finish a level in 50 seconds. And if you finish much earlier, the remaining time is added as a bonus in next level.
Do you need a hint? I do not ask you to purchase one. You can use a hint - again one hint per level which is accumulated if unused.

Does it look quite exciting? Download the game now and start playing!!!

Screen recording of your apps

2015-12-20T06:56:00.001-08:00

You want to publish your app. And you feel the app installs may improve after you add a promo video.

But you are a one-man(or woman) team. And you rarely know anything about creating a video. What do you do?

Screen recording comes to your rescue. You can record your phone screen activities into a video file. All you need is simple android adb tool.

Connect your phone to the laptop.

Go to command prompt. Locate the directory where adb command is present. Normally it is yoursdkdirectory/platform-tools.

And give the command on c
adb devices

You should be able to see your phone listed there.

Next you give command
adb shell screenrecord /sdcard/yourfilename.mp4

Now the screen record will start. End it by pressing ^c

The recorded video will be stored in your sdcard.

Copy this to your laptop and you can edit it using moviemaker software in windows

The problem with above method is audio will not be recorded and you have to add it in moviemaker. There are many screenrecording apps available in google play. I found AZ screen recorder to be good. You do not need to root the phone and it records audio as well.

Did I finally create the video for my C questions app. I did. But I realized that I have made it worse in movie maker. After spending an entire day on that.

Enabling USB debugging on your phone

2015-12-17T06:41:00.001-08:00

Coming here after a very very long time.

Today let us see how to become a developer.

I am kidding. Let us talk about how to enable your device to be connected for debugging in android studio.

You need to install a samsung adb driver for your laptop first of all. Or which phone your brand is.

Next take your phone - go to

Settings
About Device
Build Number - tap on this like 10 times. And your phone tells you now you are a developer.

Great isn't it. No studying needed.

Do you see your phone in android studio, when you connect to through usb? No, not yet.

Because there is one more step to be done.

Now settings has Developer options in it.

Goto

Settings
Developer Options
USB debugging - check on this

Done !!! Now you can debug your android app on your phone.

Indian Newspapers and magazines - new version released

2014-11-25T20:49:00.002-08:00

I have published version 2.0 of my Indian Newspapers and magazines app for android phone to google play.

I have added many more papers in regional languages and many more magazines as well. But you don't have to worry about clutter of all those papers on screen. You can select and deselect only those papers you need.

As is the new tradition, the categories are displayed as action bar tabs. So you can swipe them.

And the option to save the files for offline reading is present.

As some user had commented on advertisement filling lot of real estate on screen, I have tried reducing ad sizes on my part. But some papers publish their own huge ads which are not in my control.

The version does not support android 2.2 as google play has some problems with that. I took that risk as most of the users are having newer versions of android.

And another omission has been ability to add news papers. I will certainly add that feature in the next bug fix release within a fortnight.

So download app and give me your valuable suggestions.

Action bar menu items and Fragments

2014-11-13T22:22:00.000-08:00

How do we create menu items?
You can add menu items through code. But the easier method is writing an xml file in ../res/menu folder.

/res/menu/mymenu.xml

<menu xmlns:android="http://schemas.android.com/apk/res/android"

    >
    <item
        android:id="@+id/action_settings"
        android:icon="@android:drawable/some_icon"
        android:title="Customize"/>
     <item
         android:id="@+id/action_settings"
        android:icon="@android:drawable/some_icon"
        android:title="Customize"/>
</menu>

Next write the onCreateOptionsMenu() method of your fragment like this.

@Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        MenuInflater mnuInflater = getActivity().getMenuInflater();
        mnuInflater.inflate(R.menu.mymenu, menu);
        super.onCreateOptionsMenu(menu, inflater);
    }

Can Fragments add their own action bar menu items?

Yes, They can. To the existing items of activity, these extra menu items can be added by adding the line in the onCreate of the fragment

     setHasOptionsMenu(true);

How do we make the menu items appear on action bar always?

In the menu xml file add the option showAsAction="always"

          android:icon="..youricon"
        android:showAsAction="always"

How do we make the menu items appear on support action bar always?

In the menu xml file add the option compat:showAsAction="always"

          android:icon="..youricon"
        compat:showAsAction="always"

And also add the line
xmlns:compat="http://schemas.android.com/apk/res-auto"
to first element of xml file

That is
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:compat="http://schemas.android.com/apk/res-auto" >

What if fragment option items are not responding to click events

The onOptionItemSelected of fragment is executed after same method of parent activity and only if activity has not consumed it. So make sure you return false in your activity method if itemid does not match.

public class MyActivity extends Activity
{

.......
   @Override
    public boolean onOptionsItemSelected(MenuItem item) {
       switch (item.getItemId()) {
       case R.id.action_show_offline_pages:
            .........
           return true;
        case R.id.somethingelse: do_something_else();
            return true;
       }
       return false;
    }
}

How do I change action bar items dynamically?

Store the menuItem in the onCreateOptionsMenu() method as a global variable.

        MenuInflater inflater = this.getMenuInflater();
        inflater.inflate(R.menu.rsstitlemenu,menu);
        mCatMenuItem= menu.findItem(R.id.action_categories);

Now make changes to it when necessary.

void some_method(){
   mCatMenuItem.setVisible(false);
....
}

New puzzle "Shataka" published

2014-10-13T22:22:00.000-07:00

I have published a new math puzzle "Shataka" in google play.

This app has a 9 cell empty grid and 9 numbers. Your aim is to drag and drop these numbers into the grid so that each row adds to 100 and each column adds to 100.

e.g. In the screen shot above middle column has 87 and 9. So to make column sum 100, you need 100-(87+9). That is 4. And we do have a 4. So drag and drop this 4 in second column. Next first row will have 4 and 28. Hence it needs a 100 -(4+28) which is 68. Drop 68 in first row and first column.

So now you can see that this game is getting interesting.

The screen shot is of level 1. And as you can see, 3 numbers are already given to you. So you need to solve for remaining 6 numbers. In level 2, only 2 numbers are given.

In level 3, 1 number of solution is given. After 3rd level, solution is not given because by then you will not need it. :)

Another helpful feature is after you complete a row or a column, its sum is shown in a popup.

What are you waiting for? Download the app from google play and play non-stop.

Type in Kannada using Akshara transliteration keyboard

2014-07-24T06:05:00.000-07:00

My android app, Akshara Transliteration is now converted into a free app.

Use the app to type in Kannada or Hindi using Kannada/Hindi on screen keyboard or English QWERTY keyboard with transliteration. Type faster in Kannada. Use predictions. Use Kannada/Hindi numbers. Switch between keyboards.

Download the app at

https://play.google.com/store/apps/details?id=com.hegdeapps.aksharakeyboard

Converting String to Date and Date to String in android

2014-07-22T03:21:00.001-07:00

I struggled almost for an entire day trying to access and manipulate dates for my app. If I use date class, many of the methods show warning that they are deprecated. I took the help of simple date format and tried showing month and date. But some how the output was always wrong.

So, if you need to access dates, set a date to current date or to any other particular date and also read dates from a edit text, you should ideally use 3 classes viz Calendar, Date and SimpleDateFormat.

First create a Calendar object and initialize it with current date.

     Calendar cal = Calendar.getInstance();

Now to convert this to Date object use getTime() method.

     Date someDate = cal.getTime();//this returns a date object.

Now to get a string representation of this date use SimpleDateFormat class

        SimpleDateFormat dtFormat = new SimpleDateFormat("dd-MMMM-yyyy");
            String dtStr = dtFormat.format(someDate);

For today's date i.e. 22-7-2014, the string dtStr will be 22-July-2014.

Some points to note here

In SimpleDateFormat , d - day, M - is month , y is year
For month don't use lower m. Use M instead. (That mistake caused me hours of struggle).
If month has 3 or more, it is shown in text, else in number .

MM - 07
MMM- Jul
MMMM-July

Convert string to date

For this use parse method of SimpleDateFormat

        SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy");
        try {
            Date dt = formatter.parse(datestr);
            mCal.setTime(dt);
        } catch (ParseException e) {

            e.printStackTrace();

        }

Setting date or month or year

To set any of date, month, year or even hour, minute and second, you can use this method

calendarObject.set(Calendar.fieldname,value);
e.g.

mCal.set(Calendar.MONTH,5);
mCal.set(Calendar.DAY_OF_MONTH,4);

MemoryPro new version released

2014-07-10T02:15:00.003-07:00

If you have downloaded my "test your memory" app and had liked it, here is a new version of it.

The latest version has patterns memory which is supposedly good for spatial memory. A rectangular grid with some cells filled are shown. You have to remember them and tap the filled cells.

Also I have added sound to clicks (or taps) in each game. Good to play with some sound, right? Of course you can disable sound, if you don't like it.

So download the game and enjoy.

New Akshara keyboard

2014-04-11T00:39:00.000-07:00

If you are looking for a keyboard which lets you type in Kannada using a simple QWERTY keyboard, Akshara transliteration is your answer.

To download, click on the image below.

Main features of the app are

Supports Kannada and Hindi. And of course English
Has transliteration keyboards as well as keyboards with Kannada/ Hindi letters
Has predictions in all 3 languages
Number keyboards in Kannada, Hindi and English
4 different themes
A simple note pad to type and save your thoughts in your language. This note pad works even if your phone does not have proper font

Please note that

You should have Kannada/Hindi fonts in your phone to use the app.
Some phones like lenovo, micromax etc, do not display complex kannada fonts correctly.

R.layout.... compilation errors

2014-01-03T22:54:00.002-08:00

You are working in your android project. Everything was fine. Suddenly you start getting lot of errors. The errors are in all the lines which use R like R.layout, R.drawable etc.

Just check your import statements. Most probably there is an import which says

import android.R;

Hence all the resources are tried in android.R., Not in your R.java file.

Remove the import statements. And all these compilations errors vanish