Tag: Android app development

There are numerous camera apps in the market which displays shopping items (i.e. image view). In these camera apps we need to arrange each photo items in a list view, basically a ‘Grid View’.

In such cases, ‘table layout’ would be easier to use; but it is difficult to arrange large number of items in

side scroll view. As ‘table view’ is just a layout manager, it doesn’t allow direct interaction with each item to the users.

In order to tackle such development issues, it would be smart to implement ‘Grid View’ Layout.

What is “Grid View” Layout?

Grid View (android.widget.Grid View) is a layout that is implemented to show two-dimensional view with scrollable structure.

With the help of ‘List’ adapter, we can add images dynamically to a ‘Grid View’ layout by customizing the number of columns.

Let me tell you the process to show your Android Smartphone captured images dynamically in “Grid View” layout with some example.

Example of Layout xml

[sourcecode]<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"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >

<RelativeLayout
android:id="@+id/RelativeGridLayout"
android:layout_width="wrap_content"
android:layout_height="fill_parent" >

<GridView
android:id="@+id/gridviewimg"
android:layout_width="wrap_content"
android:layout_height="fill_parent"
android:gravity="center"
android:numColumns="2"
android:scrollbarStyle="outsideInset"
android:smoothScrollbar="true"
android:verticalSpacing="10dp"
android:paddingBottom="50dp"
android:paddingTop="10dp"
/>
</RelativeLayout>

<RelativeLayout
android:id="@+id/RelativeLayout01"
android:layout_width="fill_parent"
android:layout_height="40dp"
android:layout_alignBottom="@+id/RelativeGridLayout"
>

<Button
android:id="@+id/capture_btn1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true"
android:text="Camera" />
</RelativeLayout>

</RelativeLayout>[/sourcecode]

Example of Main form Activity class

1.MainActivity.java

[sourcecode]package com.example.gridviewimagesdemo;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;

import android.net.Uri;
import android.os.Bundle;
import android.os.Environment;
import android.provider.MediaStore;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener {

Button captureBtn = null;
final int CAMERA_CAPTURE = 1;
private Uri picUri;
private DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
private GridView grid;
private  List<String> listOfImagesPath;

public static final String GridViewDemo_ImagePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/GridViewDemo/";

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

captureBtn = (Button)findViewById(R.id.capture_btn1);
captureBtn.setOnClickListener(this);
grid = ( GridView) findViewById(R.id.gridviewimg);

listOfImagesPath = null;
listOfImagesPath = RetriveCapturedImagePath();
if(listOfImagesPath!=null){
grid.setAdapter(new ImageListAdapter(this,listOfImagesPath));
}
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if (arg0.getId() == R.id.capture_btn1) {

try {
//use standard intent to capture an image
Intent captureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
//we will handle the returned data in onActivityResult
startActivityForResult(captureIntent, CAMERA_CAPTURE);
} catch(ActivityNotFoundException anfe){
//display an error message
String errorMessage = "Whoops – your device doesn’t support capturing images!";
Toast toast = Toast.makeText(this, errorMessage, Toast.LENGTH_SHORT);
toast.show();
}
}

}

protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
//user is returning from capturing an image using the camera
if(requestCode == CAMERA_CAPTURE){
Bundle extras = data.getExtras();
Bitmap thePic = extras.getParcelable("data");
String imgcurTime = dateFormat.format(new Date());
File imageDirectory = new File(GridViewDemo_ImagePath);
imageDirectory.mkdirs();
String _path = GridViewDemo_ImagePath + imgcurTime+".jpg";
try {
FileOutputStream out = new FileOutputStream(_path);
thePic.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.close();
} catch (FileNotFoundException e) {
e.getMessage();
} catch (IOException e) {
e.printStackTrace();
}
listOfImagesPath = null;
listOfImagesPath = RetriveCapturedImagePath();
if(listOfImagesPath!=null){
grid.setAdapter(new ImageListAdapter(this,listOfImagesPath));
}
}
}
}

private List<String> RetriveCapturedImagePath() {
List<String> tFileList = new ArrayList<String>();
File f = new File(GridViewDemo_ImagePath);
if (f.exists()) {
File[] files=f.listFiles();
Arrays.sort(files);

for(int i=0; i<files.length; i++){
File file = files[i];
if(file.isDirectory())
continue;
tFileList.add(file.getPath());
}
}
return tFileList;
}

public class ImageListAdapter extends BaseAdapter
{
private Context context;
private List<String> imgPic;
public ImageListAdapter(Context c, List<String> thePic)
{
context = c;
imgPic = thePic;
}
public int getCount() {
if(imgPic != null)
return imgPic.size();
else
return 0;
}

//—returns the ID of an item—
public Object getItem(int position) {
return position;
}

public long getItemId(int position) {
return position;
}

//—returns an ImageView view—
public View getView(int position, View convertView, ViewGroup parent)
{
ImageView imageView;
BitmapFactory.Options bfOptions=new BitmapFactory.Options();
bfOptions.inDither=false;                     //Disable Dithering mode
bfOptions.inPurgeable=true;                   //Tell to gc that whether it needs free memory, the Bitmap can be cleared
bfOptions.inInputShareable=true;              //Which kind of reference will be used to recover the Bitmap data after being clear, when it will be used in the future
bfOptions.inTempStorage=new byte[32 * 1024];
if (convertView == null) {
imageView = new ImageView(context);
imageView.setLayoutParams(new GridView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
imageView.setPadding(0, 0, 0, 0);
} else {
imageView = (ImageView) convertView;
}
FileInputStream fs = null;
Bitmap bm;
try {
fs = new FileInputStream(new File(imgPic.get(position).toString()));

if(fs!=null) {
bm=BitmapFactory.decodeFileDescriptor(fs.getFD(), null, bfOptions);
imageView.setImageBitmap(bm);
imageView.setId(position);
imageView.setLayoutParams(new GridView.LayoutParams(200, 160));
}
} catch (IOException e) {
e.printStackTrace();
} finally{
if(fs!=null) {
try {
fs.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return imageView;
}
}
}[/sourcecode]

Example of Manifest.xml file content:

Example of AndroidManifest.xml

[sourcecode]<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.gridviewimagesdemo"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.gridviewimagesdemo.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>[/sourcecode]

Conclusion:

So, a ‘Grid view’ implementation would result in following features and benefits:

• In ‘GridView’ layout items would be listed in a static grid, defined in layout xml file.

• ‘Gridview’ extends android.widget.Adapter, so it could be used where large amount of data is managed in a single page frame.

• Enhanced data source binding capabilities (Direct interaction with SQLite Data Source)

• Built-in support for sorting and paging mechanism

• Additional Column types (ImageField)

I would like to recommend you to go through my previous article on where I have clearly narrate the process to display your iPhone captured images in Grid View layout.

I hope you find this useful. If you want to develop android or iPhone mobile app for you or for your organization, then you can hire single or group of developers from the pool of skilled and accomplished android specialists. Drop me a line below with your thoughts, thanks.