Learn Python


Click to Learn Python3

Friday, September 23, 2011

Image and content is populated from Sqlite in Android

In this below application we had populated the listview's data and image from the sqlite



Here we are using a java class for creating the table


PlaceDataSQL.java
package com.data.pack;

package com.data.pack;

import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

/** Helper to the database, manages versions and creation */
public class PlaceDataSQL extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "sample.db";
private static final int DATABASE_VERSION = 1;

private Context context;

public PlaceDataSQL(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE gallery (id varchar(20), image BLOB,caption varchar(160),description varchar(200))");
}

private void versionUpdation(SQLiteDatabase db) {

}

/**
* Check if the database already exist to avoid re-copying the file each
* time you open the application.
*
* @return true if it exists, false if it doesn't
*/
public boolean checkDataBase(String db) {

SQLiteDatabase checkDB = null;

try {
String myPath = "data/data/com.data.pack/databases/" + db;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);

} catch (SQLiteException e) {

// database does't exist yet.

} catch (Exception e) {

}

if (checkDB != null) {

checkDB.close();

}

return checkDB != null ? true : false;
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (oldVersion >= newVersion)
return;

if (oldVersion == 1) {
Log.d("New Version", "Datas can be upgraded");
}

Log.d("Sample Data", "onUpgrade : " + newVersion);
}

}



Here in the onCreate function the table is created, here for image we are using blog, so that we can insert the image inside the table itself and the onUpgrade function is used to upgrade the table on the next release, for example you had create an application and published it in market and a guy is using your application, now suddenly you like to add another field on your table means you need to change the " DATABASE_VERSION " to 2 and in the onUpgrade funtion you need to write the alter query there. Likewise i had using a funtion checkDataBase(), this is to check whether the database is exist or not.

Then in the main activity we are calling delete to delete the table content, likewise we will be using a function insertData, inside this function we will be inserting data to the table, like that we will be using getDataAndPopulate(), here we will be retrieving data from the table and displaying in the list.

The main thing is we inserting the image to database for this we are using HttpClient and on the retriving time it is very easy to assign the data, so while calling on the next time we can assign and there is no need of url call for showing image.


SqliteDBActivity.java
package com.data.pack;


package com.data.pack;


import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;

import android.app.ListActivity;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

public class SqliteDBActivity extends ListActivity {
private static PlaceDataSQL placeData;
private ArrayList id = new ArrayList();
private ArrayList image = new ArrayList();
private ArrayList caption = new ArrayList();
private ArrayList description = new ArrayList();
private Button populate;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
populate = (Button) findViewById(R.id.populate);
placeData = new PlaceDataSQL(this);

SQLiteDatabase db = placeData.getWritableDatabase();

Cursor cursors = getRawEvents("select * from gallery");

if (cursors.moveToNext()) {
populate.setVisibility(View.GONE);
getDataAndPopulate();
} else {
populate.setVisibility(View.VISIBLE);
}


db.delete("gallery", "id=?", new String[] {
"12" });
populate.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
try {
callInsertion("1","https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXQTlp6hJ5voBMw9WxJFAFUGW_kUzEeBdoHuRFMkEn8j-mYxrDDmoBizU3Seo1P0BxPre5g2i2JUZi1UpaISGq00rp-h1apLEUxMzVl8WHWQWiZUzhiFRyA63wsvq2tMsN2Ze5LbmhaPk/s1600/twitter_follow.gif","First","This is the first item");
callInsertion("2","https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6KGi-xGVQybCuzpxCAGMXIKz91RSKaLSCEhUF_yDtzNolI6jAfls0nh_xLEB9wJw0kExxZs0FgRHjxFU2Vm4EDzoFWebBinKNFvi8lc_xhpToMInmiOG71ER8jTSEFySuQ_u1lHgbW6I/s320/seek.JPG","Second","This is the second item");
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

getDataAndPopulate();
}
});

}

private void callInsertion(String id, String url, String caption, String description) throws ClientProtocolException, IOException {
DefaultHttpClient mHttpClient = new DefaultHttpClient();
HttpGet mHttpGet = new HttpGet(url);
HttpResponse mHttpResponse = mHttpClient.execute(mHttpGet);
if (mHttpResponse.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
HttpEntity entity = mHttpResponse.getEntity();
if ( entity != null) {
// insert to database
insertData(id,EntityUtils.toByteArray(entity),caption,description);
}
}
}

private void insertData(String id, byte[] image, String caption, String description) {
SQLiteDatabase db = placeData.getWritableDatabase();
ContentValues values;
values = new ContentValues();
values.put("id", id);
values.put("image", image);
values.put("caption", caption);
values.put("description", description);

db.insert("gallery", null, values);
}

private void getDataAndPopulate() {
id = new ArrayList();
image = new ArrayList();
caption = new ArrayList();
description = new ArrayList();
Cursor cursor = getEvents("gallery");
while (cursor.moveToNext()) {
String temp_id = cursor.getString(0);
byte[] temp_image = cursor.getBlob(1);
String temp_caption = cursor.getString(2);
String temp_description = cursor.getString(3);
id.add(temp_id);
image.add(temp_image);
caption.add(temp_caption);
description.add(temp_description);
}
String[] captionArray = (String[]) caption.toArray(
new String[caption.size()]);

ItemsAdapter itemsAdapter = new ItemsAdapter(
SqliteDBActivity.this, R.layout.item,
captionArray);
setListAdapter(itemsAdapter);
populate.setVisibility(View.GONE);
}


private class ItemsAdapter extends BaseAdapter {
String[] items;

public ItemsAdapter(Context context, int textViewResourceId,
String[] items) {
this.items = items;
}

@Override
public View getView(final int POSITION, View convertView,
ViewGroup parent) {
TextView desc;
TextView cap;
View view = convertView;
ImageView img;
if (view == null) {
LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = vi.inflate(R.layout.item, null);

}
img = (ImageView) view.findViewById(R.id.image);
cap = (TextView) view.findViewById(R.id.caption);

desc = (TextView) view.findViewById(R.id.description);

cap.setText(caption.get(POSITION));
desc.setText(description.get(POSITION));
img.setImageBitmap(BitmapFactory.decodeByteArray(image.get(POSITION), 0, image.get(POSITION).length));


return view;
}

public int getCount() {
return items.length;
}

public Object getItem(int position) {
return position;
}

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

private Cursor getRawEvents(String sql) {
SQLiteDatabase db = (placeData).getReadableDatabase();
Cursor cursor = db.rawQuery(sql, null);

startManagingCursor(cursor);
return cursor;
}

private Cursor getEvents(String table) {
SQLiteDatabase db = (placeData).getReadableDatabase();
Cursor cursor = db.query(table, null, null, null, null, null, null);

startManagingCursor(cursor);
return cursor;
}
}


In this example i had wrote two types of retrieving methods from the table, by writing the query and specifying the table name itself.

You can download the full source code


Download source


Have a good day.

Monday, September 19, 2011

Customize the tab in Android

I had attached two tab examples






First we are going to see about First example


CustomTabActivity.java

package com.customs.tabs;

import com.customs.tabs.R;
import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ImageView;
import android.widget.TabHost;
import android.widget.TextView;

public class CustomTabActivity extends TabActivity{
private TabHost tabHost;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
setTabs();
}

private void setTabs() {
tabHost = getTabHost();

addTab(R.string.tab_1, R.drawable.info);
addTab(R.string.tab_2, R.drawable.info);
addTab(R.string.tab_3, R.drawable.info);
}

private void addTab(int labelId, int drawableId) {
Intent intent = new Intent(this, TabAct.class);
TabHost.TabSpec spec = tabHost.newTabSpec("tab" + labelId);

View tabIndicator = LayoutInflater.from(this).inflate(R.layout.indicator, getTabWidget(), false);

TextView title = (TextView) tabIndicator.findViewById(R.id.title);
title.setText(labelId);
ImageView icon = (ImageView) tabIndicator.findViewById(R.id.icon);
icon.setImageResource(drawableId);

spec.setIndicator(tabIndicator);
spec.setContent(intent);
tabHost.addTab(spec);

}
}


The class extends TabActivity and the header of the tab is provided in seperate activity which is called on the addTab method. The selection / unselection / active colors are mentioned in the indicator xml file in the layout



indicator.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="0dip"
android:layout_height="64dip"
android:layout_weight="1"
android:orientation="vertical"
android:background="@drawable/indicator"
android:padding="5dp">

<ImageView android:id="@+id/icon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
/>

<TextView android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:layout_centerHorizontal="true"
style="?android:attr/tabWidgetStyle"
/>
</RelativeLayout>


Now we can see the Second example of Tab

Here we are not going to extend the tabactivity, instead of that we can set the tab headers through setting background images or colors using xml and without using xml


CustomTabs.java

package com.customized.tabs;

import com.customized.tabs.R;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.TabHost;
import android.widget.TextView;
import android.widget.TabHost.TabContentFactory;
import android.widget.TabHost.TabSpec;

public class CustomTabs extends Activity {

private TabHost mTabHost;
private TextView mTabLayout;

private void setupTabHost() {
mTabHost = (TabHost) findViewById(android.R.id.tabhost);
mTabHost.setup();
mTabLayout = (TextView) findViewById(R.id.taber);
mTabHost.setOnTabChangedListener(new TabHost.OnTabChangeListener() {

@Override
public void onTabChanged(String tabId) {
mTabHost.getTabWidget().getChildAt(0)
.setBackgroundResource(R.drawable.m2);
if ("Tab 1".equals(tabId)) {
mTabHost.getTabWidget().getChildAt(0)
.setBackgroundResource(R.drawable.m1);
mTabLayout.setText("This is Tab 1");
} else if("Tab 2".equals(tabId)) {
mTabLayout.setText("This is Tab 2");
} else {
mTabLayout.setText("This is Tab 3");
}
}
});
}

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// construct the tabhost
setContentView(R.layout.main);

setupTabHost();

//mTabHost.getTabWidget().setDividerDrawable(R.drawable.divider);

setupTab(new TextView(this), "Tab 1");
setupTab(new TextView(this), "Tab 2");
setupTab(new TextView(this), "Tab 3");
}

private void setupTab(final View view, final String tag) {
View tabview = createTabView(mTabHost.getContext(), tag);

TabSpec setContent = mTabHost.newTabSpec(tag).setIndicator(tabview).setContent(new TabContentFactory() {
public View createTabContent(String tag) {return view;}
});
mTabHost.addTab(setContent);
if ("Tab 1".equals(tag))
mTabHost.getTabWidget().getChildAt(0).setBackgroundResource(
R.drawable.m1);


}

private static View createTabView(final Context context, final String text) {
View view = LayoutInflater.from(context).inflate(R.layout.bg, null);
TextView tv = (TextView) view.findViewById(R.id.tabsText);
tv.setText(text);
return view;
}
}


In the above code i had commented the divider between each header, if you need means you can uncomment and i had set a different image for the Tab 1 alone, if you need you can set different images for each tab like that. Then in the bg_selector.xml i had commented the xml files for background color and i had set images for that

You can download the full source code


Download source


Have a good day.

Using Sqlite to populate a ListView in Android

In this below application we had populated the listview using the data from the sqlite



Here we are using a java class for creating the table


PlaceDataSQL.java
package com.data.pack;

import android.content.Context;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteException;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

/** Helper to the database, manages versions and creation */
public class PlaceDataSQL extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "sample.db";
private static final int DATABASE_VERSION = 1;

private Context context;

public PlaceDataSQL(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
this.context = context;
}

@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE gallery (id varchar(20), image varchar(2000),caption varchar(160),description varchar(200))");
}

private void versionUpdation(SQLiteDatabase db) {

}

/**
* Check if the database already exist to avoid re-copying the file each
* time you open the application.
*
* @return true if it exists, false if it doesn't
*/
public boolean checkDataBase(String db) {

SQLiteDatabase checkDB = null;

try {
String myPath = "data/data/com.data.pack/databases/" + db;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READONLY);

} catch (SQLiteException e) {

// database does't exist yet.

} catch (Exception e) {

}

if (checkDB != null) {

checkDB.close();

}

return checkDB != null ? true : false;
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (oldVersion >= newVersion)
return;

if (oldVersion == 1) {
Log.d("New Version", "Datas can be upgraded");
}

Log.d("Sample Data", "onUpgrade : " + newVersion);
}

}


Here in the onCreate function the table is created and the onUpgrade function is used to upgrade the table on the next release, for example you had create an application and published it in market and a guy is using your application, now suddenly you like to add another field on your table means you need to change the " DATABASE_VERSION " to 2 and in the onUpgrade funtion you need to write the alter query there. Likewise i had using a funtion checkDataBase(), this is to check whether the database is exist or not.

Then in the main activity we are calling delete to delete the table content, likewise we will be using a function insertData, inside this function we will be inserting data to the table, like that we will be using getDataAndPopulate(), here we will be retrieving data from the table and displaying in the list.



SqliteDBActivity.java
package com.data.pack;


import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;

import android.app.ListActivity;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

public class SqliteDBActivity extends ListActivity {
private static PlaceDataSQL placeData;
private ArrayList id = new ArrayList();
private ArrayList image = new ArrayList();
private ArrayList caption = new ArrayList();
private ArrayList description = new ArrayList();
private Button populate;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
populate = (Button) findViewById(R.id.populate);
placeData = new PlaceDataSQL(this);

SQLiteDatabase db = placeData.getWritableDatabase();

Cursor cursors = getRawEvents("select * from gallery");

if (cursors.moveToNext()) {
populate.setVisibility(View.GONE);
getDataAndPopulate();
} else {
populate.setVisibility(View.VISIBLE);
}


db.delete("gallery", "id=?", new String[] {
"12" });
populate.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
insertData("1","https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjXQTlp6hJ5voBMw9WxJFAFUGW_kUzEeBdoHuRFMkEn8j-mYxrDDmoBizU3Seo1P0BxPre5g2i2JUZi1UpaISGq00rp-h1apLEUxMzVl8WHWQWiZUzhiFRyA63wsvq2tMsN2Ze5LbmhaPk/s1600/twitter_follow.gif","First","This is the first item");
insertData("2","https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi6KGi-xGVQybCuzpxCAGMXIKz91RSKaLSCEhUF_yDtzNolI6jAfls0nh_xLEB9wJw0kExxZs0FgRHjxFU2Vm4EDzoFWebBinKNFvi8lc_xhpToMInmiOG71ER8jTSEFySuQ_u1lHgbW6I/s320/seek.JPG","Second","This is the second item");
getDataAndPopulate();
}
});

}

private void insertData(String id, String image, String caption, String description) {
SQLiteDatabase db = placeData.getWritableDatabase();
ContentValues values;
values = new ContentValues();
values.put("id", id);
values.put("image", image);
values.put("caption", caption);
values.put("description", description);

db.insert("gallery", null, values);
}

private void getDataAndPopulate() {
id = new ArrayList();
image = new ArrayList();
caption = new ArrayList();
description = new ArrayList();
Cursor cursor = getEvents("gallery");
while (cursor.moveToNext()) {
String temp_id = cursor.getString(0);
String temp_image = cursor.getString(1);
String temp_caption = cursor.getString(2);
String temp_description = cursor.getString(3);
id.add(temp_id);
image.add(temp_image);
caption.add(temp_caption);
description.add(temp_description);
}
String[] captionArray = (String[]) caption.toArray(
new String[caption.size()]);

ItemsAdapter itemsAdapter = new ItemsAdapter(
SqliteDBActivity.this, R.layout.item,
captionArray);
setListAdapter(itemsAdapter);
populate.setVisibility(View.GONE);
}


private class ItemsAdapter extends BaseAdapter {
String[] items;

public ItemsAdapter(Context context, int textViewResourceId,
String[] items) {
this.items = items;
}

@Override
public View getView(final int POSITION, View convertView,
ViewGroup parent) {
TextView desc;
TextView cap;
View view = convertView;
ImageView img;
if (view == null) {
LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = vi.inflate(R.layout.item, null);

}
img = (ImageView) view.findViewById(R.id.image);
cap = (TextView) view.findViewById(R.id.caption);

desc = (TextView) view.findViewById(R.id.description);

cap.setText(caption.get(POSITION));
desc.setText(description.get(POSITION));
try {
URL url = new URL(image.get(POSITION));
HttpURLConnection connection = (HttpURLConnection) url
.openConnection();
connection.setDoInput(true);
connection.connect();
InputStream input = connection.getInputStream();
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[16 * 1024];
Bitmap bmp = null;
bmp = BitmapFactory.decodeStream(input, null,
bfOptions);
img.setImageBitmap(bmp);
connection.disconnect();
input.close();

} catch (MalformedURLException e) {
} catch (IOException e) {
} catch (IllegalAccessError e) {
} catch (NullPointerException e) {
}

return view;
}

public int getCount() {
return items.length;
}

public Object getItem(int position) {
return position;
}

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

private Cursor getRawEvents(String sql) {
SQLiteDatabase db = (placeData).getReadableDatabase();
Cursor cursor = db.rawQuery(sql, null);

startManagingCursor(cursor);
return cursor;
}

private Cursor getEvents(String table) {
SQLiteDatabase db = (placeData).getReadableDatabase();
Cursor cursor = db.query(table, null, null, null, null, null, null);

startManagingCursor(cursor);
return cursor;
}
}


In this example i had wrote two types of retrieving methods from the table, by writing the query and specifying the table name itself.

You can download the full source code


Download source


Have a good day.