android: Galleries

Steps to write the Galleries

go to File->New->Android Application Project

Give the Application Name: (you can give any name) Ex:

click on Next button, then the we will get following:

copy the jpg or gif files (photos) and paste into "drawable-hdpi of res folder

Once you pasted into the drawable-hdpi folder, automatically, jpg (or picture) integer varaibles will be created into the R.java file, its reference also will be created in the form of hexa decimal format.
Go to "res" folder of left side, and choose "layout " , double click on "activity_mail.xml" file

Go to Layouts, select LinearLayout(Horizontal) (since i want to scroll my images Horizontally), and drag into the box:

Automatically generates the xml tags, Now you can see the xml tags by double clicking "activity_main.xml" file

Now we need to create the Gallery tags, to do that one, click on GraphicalLayout, click on Images & Media option from the list

now we can see the code, by double clicking activity_main.xml

Now we need to access the images so to do this one we need to create the derived class of BaseAdapter class,
Now im creating a child class of BaseAdapter class

extend the BaseAdapter class, and import that package
Now create the Integer class array in MyAdapter.java, and store the images in that array;

package com.example.gallerydemos;

import android.widget.BaseAdapter;

public class MyAdapter public class MyAdapter extends BaseAdapter

{

Integer myimages[]={R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e,R.drawable.f};

}

Now create Context class reference

package com.example.gallerydemos;

import android.widget.BaseAdapter;

import android.content.Context;

public class MyAdapter extends BaseAdapter

{

Integer myimages[]={R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e,R.drawable.f};

Context con;

}

Now we will get error derived class, so we need to right click the mouse at that class, choose "add unimplemented methods"

Now we will get the followng window

create parameterized constructor:

package com.example.gallerydemos;

import android.content.Context;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

public class MyAdapter extends BaseAdapter{

Integer myimages[]={R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e,R.drawable.f};

Context con;

//Now create a parameterized constructor

public MyAdapter(Context con)

{

super();//call the super class constructor (BaseAdapter)

this.con=con;

}

@Override

public int getCount() {

// TODO Auto-generated method stub

return 0;

}

@Override

public Object getItem(int arg0) {

// TODO Auto-generated method stub

return null;

}

@Override

public long getItemId(int arg0) {

// TODO Auto-generated method stub

return 0;

}

@Override

public View getView(int arg0, View arg1, ViewGroup arg2) {

// TODO Auto-generated method stub

return null;

}

Rewrite the methods like below:

package com.example.gallerydemos;

import android.content.Context;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.ImageView;

public class MyAdapter extends BaseAdapter{

Integer myimages[]={R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d,R.drawable.e,R.drawable.f};

Context con;

//Now create a parameterized constructor

public MyAdapter(Context con)

{

super();//super class constructor

this.con=con;

}

@Override

public int getCount() {

// TODO Auto-generated method stub

return myimages.length;//total images

}

@Override

public Object getItem(int arg0) {

// TODO Auto-generated method stub

return myimages;

}

@Override

public long getItemId(int arg0) {

// TODO Auto-generated method stub

return arg0;

}

@Override

public View getView(int arg0, View arg1, ViewGroup arg2) {

// TODO Auto-generated method stub

//create ImageView object

ImageView iv=new ImageView(con);

//to display images

iv.setImageResource(myimages[arg0]);

//to give the space between the images

iv.setPadding(52, 0, 52, 0);

//return the imageview object iv

return iv;

}

screen shot is like below:

Now we need to create the Gallery class object in MainActivity.java

Now create the MyAdapter class object (derived class of BaseAdapter) and pass the current class (MainActivity) to MyAdapter class: code looks like the below:

package com.example.gallerydemos;

import android.os.Bundle;

import android.app.Activity;

import android.view.Menu;

import android.widget.Gallery;

public class MainActivity extends Activity {

//creating the reference variable for Gallery

Gallery gal;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);