Android and Java Codings

Hi,

Gallery Images using dots in Android :

        This is an Example how to create dots while scrolling the images in Android


1. Create a Android Application project

2.After that create drawable folder under res and put all the images

3.create the ImageAdapter class that extends the BaseAdapter that implements all predefined methods and also create an constructor array of integers which storing imageids

ImageAdapter.java:

package com.example.galleryimage;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ImageView.ScaleType;

public class ImageAdapter extends BaseAdapter {
    private Context context;

    public IamgeAdapter(Context c) {
    // TODO Auto-generated constructor stub
    this.context = c;
    }
    public int getCount() {
    // TODO Auto-generated method stub
    return flowers.length;
    }
    public Object getItem(int position) {
    // TODO Auto-generated method stub
    return position;
    }
    public long getItemId(int position) {
    // TODO Auto-generated method stub
    return position;
    }
    public View getView(int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    ImageView image = new ImageView(context);
    image.setImageResource(flowers[position]);
    image.setScaleType(ScaleType.FIT_XY);
    // image.setLayoutParams(new Gallery.LayoutParams(400, 400));
    return image;
    }
    int[] flowers = { R.drawable.images2, R.drawable.img1, R.drawable.img2};
    }

4.Then put these codings in MainActivity.java

MainActivity.java :

package com.example.galleryimage;

import android.app.Activity;
import android.graphics.Typeface;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MainActivity extends Activity {
Gallery gallery;
   IamgeAdapter imageAdapter;
   LinearLayout count_layout;
   int count = 0;
   static TextView page_text[];

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);


        count_layout = (LinearLayout) findViewById(R.id.image_count);
        gallery = (Gallery) findViewById(R.id.mygallery01);
        imageAdapter = new IamgeAdapter(this);
        gallery.setAdapter(imageAdapter);
        count=gallery.getAdapter().getCount();
        page_text = new TextView[count];
        for (int i = 0; i < count; i++) {
            page_text[i] = new TextView(this);
            page_text[i].setText(".");
            page_text[i].setTextSize(45);
            page_text[i].setTypeface(null, Typeface.BOLD);
            page_text[i].setTextColor(android.graphics.Color.GRAY);
            count_layout.addView(page_text[i]);
        }
        gallery.setOnItemSelectedListener(new OnItemSelectedListener() {

            public void onItemSelected(AdapterView<?> arg0, View arg1,
                    int position, long arg3) {
                // TODO Auto-generated method stub
                 for (int i = 0; i < count; i++) {
                   MainActivity.page_text[i].setTextColor(android.graphics.Color.GRAY);
                    }
                 MainActivity.page_text[position].setTextColor(android.graphics.Color.WHITE);
               
            }

            public void onNothingSelected(AdapterView<?> arg0) {
                // TODO Auto-generated method stub
               
            }
        });
       
       }

}


5.put these code in activity_main.xml

activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/gallery_paging"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="#000000"
    android:orientation="vertical" >

    <Gallery
        android:id="@+id/mygallery01"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"/>

    <LinearLayout
        android:id="@+id/image_count"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:orientation="horizontal"
        android:gravity="center" >
    </LinearLayout>

</RelativeLayout>


Screenshots:







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Hi,

This is an Example for Custom toast and Alert Dialog in Android Example. We can use this Alert and Custom Toast Project in Android Example.

Using handler that receives messages from the thread and update the progress.

we can create that show Toast and show Dialog method in Main Activity class.


// sending error message to handler
public void showToast(int show_toast, int error, int error_layout,
String message) {
Message msg = handler.obtainMessage();
msg.what = show_toast;
msg.arg1 = error;
msg.arg2 = error_layout;
msg.obj = message;
msg.sendToTarget();

}

// sending success message to handler
public void showAlert(int show_alert, String message2) {
Message msg = handler.obtainMessage();
msg.what = show_alert;
msg.obj = message2;
msg.sendToTarget();
}
 Output is shown below






Download this project

Here we can create SQLite database is created at runtime. we can use this an existing database in Android App

Creating the Pre-Populated Database :
 
     To create a Separate database using SQLite Database Browser we can download the SQLManager
addon on Firefox

       Using this SQLite Manager create a sample.sqlite3 file with one table called friends. which shows list of friends and has two fields: id and name

 To make your database work correctly  on a device  you have to included  two modifications.

    1. Rename the id field of your own table to "_id"  you can done this with modify the table and then choosing the necessary table and field names.

2. Add the android_metadata table.To do that open the Execute SQL tab and run this both command
    into the SQL String field:

      CREATE TABLE android_metadata (locale_TEXT);
      INSERT INTO android_metadata VALUES ('en_US');

click the execute query button and now you can export the database and located in assests folder in Android Project.

Implementing the ExternalDbOpenHelper class
   
 
         This class is inherited from SOLiteOpenHelper. The application database are stored in the data/data/<name of your package>/databases/ folder on your device.

Note:  Export the database from SQLManager and put in assests folder in Android Project.

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Hi,

  This is an example for swipe the image in android using pager adapter

1. create a xml file called activity_main.xml

activity_main.xml:

 <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

     <android.support.v4.view.ViewPager
          android:id="@+id/view_pager"
          android:layout_width="match_parent"
          android:layout_height="match_parent" />

</RelativeLayout>


2. create  a Java class called MainActivity.class

using Imageadapter class create view for page adapter and override a method called instantiateItem

MainActivity.class :

package com.example.imageswipe;
import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
public class MainActivity extends Activity {
 @Override
 public void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);

   ViewPager viewPager = (ViewPager) findViewById(R.id.view_pager);
   ImageAdapter adapter = new ImageAdapter(this);
   viewPager.setAdapter(adapter);
 }
 public class ImageAdapter extends PagerAdapter {
 Context context;
 private int[] GalImages = new int[] {
 R.drawable.img1,
 R.drawable.img2,
 R.drawable.img3,
 R.drawable.img4,
 R.drawable.img5,
 R.drawable.img6,
 R.drawable.img7
 };
                ImageAdapter(Context context)
 {
 this.context=context;
 }
 @Override
 public int getCount() {
 return GalImages.length;
 }

 @Override
 public boolean isViewFromObject(View view, Object object) {
 return view == ((ImageView) object);
 }

 @Override
 public Object instantiateItem(ViewGroup container, int position) {
 ImageView imageView = new ImageView(context);
 int padding = context.getResources().getDimensionPixelSize(R.dimen.activity_horizontal_margin);
 imageView.setPadding(padding, padding, padding, padding);
 imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
 imageView.setImageResource(GalImages[position]);
 ((ViewPager) container).addView(imageView, 0);
 return imageView;
 }

 @Override
 public void destroyItem(ViewGroup container, int position, Object object) {
 ((ViewPager) container).removeView((ImageView) object);
 }
 }
}

3. Here the output is shown below

           
       

Hi,

    This is an Example for creating DatePickerDialog  Example in Android

   DatePicker Dialog is child class for AlertDialog.It is used to select Date.And the benefits of DatePickerDialog is appears as pre user request and after setting the date it automatically disappears.And it does not occupy any space in Activity.

Syntax for Create DatePickerDialog :

      Create a DatePickerDailog class and the parameter of DatePickerDialog is Activity Context,Callback Listener,year,month,day.

 Dialog dialog=new DatePickerDialog(context,callback,year,month,dayofMonth);

activity_main.xml:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="19dp"
        android:layout_marginTop="142dp"
        android:text="StartDate"
        android:textStyle="bold"/>

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/textView1"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="42dp"
        android:text="EndDate"
        android:textStyle="bold"/>

    <EditText
        android:id="@+id/editText1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/textView1"
        android:layout_alignBottom="@+id/textView1"
        android:layout_toLeftOf="@+id/startdate"
        android:layout_toRightOf="@+id/textView1"
        android:ems="10"
        android:hint="Startdate" />

    <EditText
        android:id="@+id/editText2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/editText1"
        android:layout_alignTop="@+id/textView2"
        android:layout_toLeftOf="@+id/startdate"
        android:hint="Enddate"
        android:ems="10" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/startdate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/editText1"
        android:layout_alignBottom="@+id/editText1"
        android:layout_alignParentRight="true"
        android:background="@drawable/img" />

    <Button
        android:id="@+id/enddate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/editText2"
        android:layout_toRightOf="@+id/editText2"
        android:background="@drawable/img"
         />

    <Button
        android:id="@+id/button3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/editText2"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="30dp"
        android:text="submit" />
 

</RelativeLayout>

In the activity class I have created a constant DATE_DIALOG_ID

static final int DATE_DIALOG_ID=0;

It is unique id for the DatePickerDialog. It can be any number.  Now we can discuss about showDatePickerDialog method

    mstart_date.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {

final Calendar c = Calendar.getInstance();
year=c.get(Calendar.YEAR);
month=c.get(Calendar.MONTH);
day=c.get(Calendar.DAY_OF_MONTH);
showDialog(START_DATE_DIALOG_ID);
   
}
});

First Iam getting current date status and storing to instance variables year,month,day. To display a dialog window we are using showDialog method and Iam also passing the unique id.
 
    This showDialog method is comes from android.app.Activity class.
                   
                      showDialog(START_DATE_DIALOG_ID);

       when the showDialog method is called,the onCreateDialog method will be automatically called.
     
               
              protected Dialog onCreateDialog(int id){
 switch(id){
 case START_DATE_DIALOG_ID:
 return new DatePickerDialog(this,dataSetListener,year, month, day);
 case END_DATE_DIALOG_ID:
 return new DatePickerDialog(this,endSetListener,year, month, day);  
 }
return null;  
 }

In the onCreateDialog method. creating the DatePickerDialog. Then return it to the calling location and dialog will be displayed automatically.

In the DatePickerDialog constructor passing the value for year,month,day and passing the reference of DatePickerDialog.OnDateSetListener.

  In OnDateSetListener  is automatically called onDateSet method when user click the on Set button of date picker dialog.

  onDateSet method assign the value for year,month,day and set the Text it.

private  DatePickerDialog.OnDateSetListener dataSetListener=new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear,
int dayOfMonth) {
// TODO Auto-generated method stub
year=year;
month=monthOfYear;
day=dayOfMonth;
mstart_edt1.setText(day+" - "+(month+1)+" - "+year);
}
};


Iam calling setText method of EditText by passing the selected year,month and day


Here the output is shown below
.
















   
      

Hi,