Friday, August 23, 2013

Share bitmap between Activities

This exercise demonstrate how to using static Bitmap in a common class in application, to share between activities. Such that, no need to pass between activities.




CommonBitmap.java, it simple hold a static Bitmap. It can be accessed by all activities in application, using CommonBitmap.bitmap.
package com.example.androidcommonbitmap;

import android.graphics.Bitmap;

public class CommonBitmap {
 public static Bitmap bitmap = null;
}


MainActivity.java
package com.example.androidcommonbitmap;

import java.io.FileNotFoundException;

import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.app.Activity;
import android.content.Intent;
import android.graphics.BitmapFactory;

public class MainActivity extends Activity {
 
 Button btnLoadImage1;
 TextView textSource1;
 Button btnStartActivity;
 ImageView imageResult;
 
 final int RQS_LOADIMAGE = 1;
 final int RQS_ACTIVITY2 = 2;
 
 Uri source1;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  btnLoadImage1 = (Button)findViewById(R.id.loadimage1);
  textSource1 = (TextView)findViewById(R.id.sourceuri1);
  btnStartActivity = (Button)findViewById(R.id.startactivity);
  imageResult = (ImageView)findViewById(R.id.result);
  
  btnLoadImage1.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View arg0) {
    Intent intent = new Intent(Intent.ACTION_PICK,
      android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
    startActivityForResult(intent, RQS_LOADIMAGE);
   }});
  
  btnStartActivity.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View arg0) {
    Intent intent = new Intent(MainActivity.this, Activity2.class);
       startActivityForResult(intent, RQS_ACTIVITY2);
   }});
 }
 
 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);
  if(resultCode == RESULT_OK){
   switch (requestCode){
   case RQS_LOADIMAGE:
    source1 = data.getData();
    textSource1.setText(source1.toString());
    
    try {
     //save common static bitmap
     CommonBitmap.bitmap = BitmapFactory.decodeStream(
       getContentResolver().openInputStream(source1));
    } catch (FileNotFoundException e) {
     // TODO Auto-generated catch block
     e.printStackTrace();
    }
    break;
   case RQS_ACTIVITY2:
    imageResult.setImageBitmap(CommonBitmap.bitmap);
    break;
   }
  }
 }

}


activity_main.xml
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold"
        android:layout_gravity="center_horizontal"
        android:autoLink="web" />

    <Button
        android:id="@+id/loadimage1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Load Image 1" />
    <TextView
        android:id="@+id/sourceuri1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <Button
        android:id="@+id/startactivity"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Start Another Activity" />
    <ImageView
        android:id="@+id/result"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    
</LinearLayout>


Activity2.java, code of the second activity.
package com.example.androidcommonbitmap;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;

public class Activity2 extends Activity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity2_layout);
  
  ImageView image2 = (ImageView)findViewById(R.id.image2);
  image2.setImageBitmap(CommonBitmap.bitmap);
  
  Button btnFinish = (Button)findViewById(R.id.finish);
  btnFinish.setOnClickListener(new OnClickListener(){

   @Override
   public void onClick(View arg0) {
    setResult(RESULT_OK);
    finish();
   }});
 }

}


activity2_layout.xml
<LinearLayout 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"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="http://android-er.blogspot.com/"
        android:textStyle="bold"
        android:layout_gravity="center_horizontal"
        android:autoLink="web" />
    <Button
        android:id="@+id/finish"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Finish" />
    <ImageView
        android:id="@+id/image2"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
    
</LinearLayout>


Finally, add the second activity Activity2.java to AndroidManifest.xml.
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.androidcommonbitmap"
    android:versionCode="1"
    android:versionName="1.0" >

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

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.androidcommonbitmap.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>
        <activity
            android:name="com.example.androidcommonbitmap.Activity2"
            android:label="@string/app_name" >
        </activity>
    </application>

</manifest>


download filesDownload the files.



more: Something about processing images in Android

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