Monday, August 24, 2009

Google Chrome in the clouds

Recently, you may have heard a lot about Google Chrome OS, an open source, lightweight operating system that will initially be targeted at netbooks that will provide a platform to run Google Chrome browser.
This will be available for consumers in the second half of 2010 and some time earlier for developers.
Well, if you impatience triggers and you can't wait so long, here is something that may help you cope with it.


This video demonstrates a cult thin client google chrome edition software booting straight to a Google Chrome browser.





IMPORTANT: This is not Google Chrome OS and is not related in any way with Google.



The main idea behind cult google chrome edition is to move everything to the cloud, even the operating system and configuration. This started as a cult stress test, which is a platform to further develop and customize thin clients Operating Systems.
cult google chrome edition it's initially targeted at thin clients, however it can be used by other classes of hardware and virtual machines as well. Using network boot, provides a platform to run Google Chrome browser too, but avoiding OS installation.
To achieve this goal cult google chrome edition is kept as small and fast as possible.

An early preview, as showed in the video, containing the most fundamental features but there's still a lot to be done.
A LiveCD/LiveDVD ISO image (only 35MB) is available for download. This same image can also be used to network boot thin clients, PCs or virtual machines as explained in the documentation.
Download it from http://sourceforge.net/projects/cult-thinclient/files/cult-classic-custom/cult-google-chrome-edition/cult-3.1-classic-custom-tiny-google-chrome.iso/download, enjoy it and send you comments and suggestions to improve future versions.

More in depth information can be found at http://cult.codtech.com, specifically here.

Tuesday, August 18, 2009

AutoAndroid: Pizza order sample









This document can be read in Google Docs (http://docs.google.com/View?id=ddwc44gs_203g7xcxfr9), cut and paste link if you have problems accessing it.






We analyzed the basic concepts behind autandroid in a previous post, now let's introduce a slightly more interesting example.


pizza order example












This sample includes autoandroid.jar and can be downloaded from http://codtech.com/downloads/android/index.html#source as an Eclipse project (AutoAndroidSamples.zip).





This introductory example provides some automatic behavior of UI components.

Our objective is to obtain, writing as less code as possible, the following functionality.



A standard Activity displays some Buttons to launch different samples. Right now we have only two Buttons corresponding to our samples.













Clicking the Pizza order samples Button launches the Dialog.











Some automatic behavior has been defined in the XML file and thus it's automatically available in the Dialog.

This behavior includes:



  • If quantity is 0, then OK is disabled


  • Quantity value is automatically updated depending on the seek bar position



  • All values are exported so they can be retrieved from the parent Activity


  • Cancel and OK buttons have the corresponding default behavior




Once some values are entered, pressing the OK Button the Dialog is dismissed and the values are passed back to the invoking Activity.











pizza_order_sample.xml


This is the layout of our sample dialog.

We can do it as we normally do using ADT's Layout Editor.













However, to provide the extra behavior we have to add some properties in the XML view of the editor.










<?xml version="1.0" encoding="utf-8"?>

<LinearLayout

    xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:auto="http://schemas.android.com/apk/res/com.codtech.android.samples.autoandroid"

    android:orientation="vertical" android:layout_height="fill_parent"

    android:layout_width="300dip"  

    android:id="@+id/LinearLayoutPizzaOrder">



    <com.codtech.android.auto.widget.AutoRadioGroup

        android:id="@+id/RadioGroupPizza"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        auto:export="true"

        auto:name="pizza">

        <RadioButton android:id="@+id/RadioButton01"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_marginLeft="6dip" android:text="Margherita"

            android:layout_marginTop="-6dip" android:checked="true">

        </RadioButton>

        <RadioButton android:id="@+id/RadioButton02"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_marginLeft="6dip" android:text="Prosciutto">

        </RadioButton>

        <RadioButton android:id="@+id/RadioButton03"

            android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_marginLeft="6dip"

            android:text="Quattro Stagioni">

        </RadioButton>

    </com.codtech.android.auto.widget.AutoRadioGroup>

    

    <TextView android:id="@+id/TextView02"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" android:text="Additionals"

        android:textStyle="bold" android:layout_marginLeft="3dip"

        android:layout_marginTop="3dip"></TextView>

        

    <com.codtech.android.auto.view.AutoCheckBox 

        android:id="@+id/CheckBoxExtraMozzarella"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginLeft="6dip"

        android:text="Extra mozzarella"

        auto:export="true">

    </com.codtech.android.auto.view.AutoCheckBox>

        

    <com.codtech.android.auto.view.AutoCheckBox

        android:id="@+id/CheckBoxPepperoni"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginLeft="6dip"

        android:text="Pepperoni"

        auto:export="true">

    </com.codtech.android.auto.view.AutoCheckBox>

        

    <TextView android:id="@+id/TextView03"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content" android:text="Quantity"

        android:textStyle="bold" android:layout_marginLeft="3dip"

        android:layout_marginTop="3dip"></TextView>



    <LinearLayout android:id="@+id/LinearLayout02"

        android:layout_height="wrap_content"

        android:layout_width="fill_parent"

        android:orientation="horizontal">

        <com.codtech.android.auto.view.AutoSeekBar 

            android:layout_height="wrap_content"

            android:layout_margin="6dip"

            android:layout_width="wrap_content"

            android:layout_weight="1" android:id="@+id/SeekBarQuantity"

            auto:update="@+id/TextViewQuantity"

            android:max="10"

            auto:export="true"

            auto:name="quantity"

            auto:sensitize="@+id/ButtonPizzaOrderDialogOk">

        </com.codtech.android.auto.view.AutoSeekBar>

        <TextView android:layout_width="wrap_content"

            android:layout_weight="0" android:layout_margin="6dip"

            android:layout_height="fill_parent"

            android:layout_gravity="center"

            android:gravity="center_vertical|right"

            android:textStyle="bold" android:id="@id/TextViewQuantity"

            android:maxLength="3" android:text="0"

            android:background="#555555"

            ></TextView>

    </LinearLayout>

    

    <RelativeLayout android:id="@+id/LinearLayout01"

        android:layout_height="wrap_content"

        android:layout_width="fill_parent"

        android:layout_margin="3dip"

        android:background="@color/dialog_action_background">

        <Button android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_alignParentLeft="true"

            android:text="Cancel" android:width="100dip"

            android:id="@+id/ButtonPizzaOrderDialogCancel"

            auto:dialog_action="cancel"

            android:layout_margin="3dip"></Button>

        <Button android:layout_width="wrap_content"

            android:layout_height="wrap_content"

            android:layout_alignParentRight="true"

            android:text="OK" android:width="100dip"

            android:id="@id/ButtonPizzaOrderDialogOk"

            auto:dialog_action="positive"

            android:clickable="false"

            android:enabled="false"

            android:layout_margin="3dip"

            ></Button>

    </RelativeLayout>



</LinearLayout>







Let's explain the changes:




  1. Define the namespace auto. The name that appears after http://schemas.android.com/apk/res is usually the package name of your application and will be used in an attribute definition (attrs.xml).


  2. The root layout must have an ID as it's used by some methods in the library and should be identifiable. The name here is LinearLayoutPizzaOrder but it could be whatever you like.


  3. Then, a com.codtech.android.auto.widget.AutoRadioGroup which is a class that extends RadioGroup and provides some automatic behavior.


  4. Mark the AutoRadioGroup as exported so we can obtain its value later. This is achieved using auto:export="true".



  5. As it is exported we give it a name, text in this case, to obtain the value later. auto:name="pizza" does the trick.



  6. Two AutoCheckBoxes,also exported hold additional options.


  7. An AutoSeekBar, exported under the name "quantity" provides also two other options, automatically update a text field depending on the seek bar value using auto:update="@+id/TextViewQuantity". It also automatically sensitize the OK Button using auto:sensitize="@+id/ButtonPizzaOrderDialogOk".


  8. Finally, mark the buttons using auto:dialog_action="positive" and auto:dialog_action="cancel".



Styleable attributes


The way we are adding these attributes is by defining styleable attributes in a file usually attrs.xml.










<?xml version="1.0" encoding="utf-8"?>



<resources>

<declare-styleable name="com.codtech.android.samples.autoandroid">

    <attr name="name" format="string" />

    <attr name="init" format="string" />

    <attr name="sensitize" format="reference" />

    <attr name="show" format="reference" />

    <attr name="update" format="reference" />

    <attr name="export" format="boolean" />

    <attr name="dialog_ok" format="boolean" />

    <attr name="dialog_action" format="string" />

</declare-styleable>

</resources>




AutoAndroidSamples.java


This is our sample Activity.










/*

 * Copyright © 2009 COD Technologies Ltd.  www.codtech.com


 *


 * $Id: AutoAndroidSamples.java 131 2009-08-15 00:28:47Z diego $


 *


 *


 */




package com.codtech.android.samples.autoandroid;




import android.app.Activity;


import android.app.Dialog;


import android.content.DialogInterface;


import android.content.DialogInterface.OnDismissListener;


import android.os.Bundle;


import android.view.View;


import android.view.View.OnClickListener;


import android.widget.Button;


import android.widget.Toast;




import com.codtech.android.auto.app.AutoDialog;






public class AutoAndroidSamples extends Activity implements OnClickListener, OnDismissListener {


    private static final int DIALOG_SAMPLE_ID = R.id.Button01;


    private static final int DIALOG_PIZZA_ORDER_SAMPLE_ID = R.id.Button02;


    


    private AutoDialog ad01;


    private AutoDialog ad02;




    /** Called when the activity is first created. */


    @Override


    public void onCreate(Bundle savedInstanceState) {


        super.onCreate(savedInstanceState);


        setContentView(R.layout.samples);


        


        ((Button) findViewById(R.id.Button01)).setOnClickListener(this);


        ((Button) findViewById(R.id.Button02)).setOnClickListener(this);


    }




    /* (non-Javadoc)


     * @see android.view.View.OnClickListener#onClick(android.view.View)


     */


    @Override


    public void onClick(View v) {


        showDialog(v.getId());        


    }




    


    /* (non-Javadoc)


     * @see android.app.Activity#onCreateDialog(int)


     */


    @Override


    protected Dialog onCreateDialog(int id) {


        switch (id) {


        case DIALOG_SAMPLE_ID:


            ad01 = new AutoDialog(this, R.layout.dialog_sample,


                R.string.dialog_sample_title);


            ad01.setOnDismissListener(this);


            return ad01;




        case DIALOG_PIZZA_ORDER_SAMPLE_ID:


            
ad02 = new AutoDialog(this, R.layout.pizza_order_sample,

               
R.string.dialog_pizza_order_sample_title);

            
ad02.setOnDismissListener(this);

            
return ad02;

            


        default:


            break;


        }


        


        return super.onCreateDialog(id);


    }




    /* (non-Javadoc)


     * @see android.app.Activity#onPrepareDialog(int, android.app.Dialog)


     */


    @Override


    protected void onPrepareDialog(int id, Dialog dialog) {


        // TODO Auto-generated method stub


        super.onPrepareDialog(id, dialog);


    }




    /* (non-Javadoc)


     * @see android.content.DialogInterface.OnDismissListener#
onDismiss(android.content.DialogInterface)


     */


    @Override


    public void onDismiss(DialogInterface dialog) {


        if ( dialog instanceof AutoDialog ) {


            AutoDialog ad = (AutoDialog)dialog;


            


            if ( ad.isCanceled() ) {


                return;


            }


            


            
Bundle bundle = ad.getAutoBundle();

            


            if ( ad.equals(ad01) ) {


                Toast.makeText(this, "Entered value: " + bundle.getString("text"),


                    Toast.LENGTH_SHORT).show();


            }


            else if ( ad.equals(ad02)) {


                
Toast.makeText(this, composePizzaOrderMessage(bundle),

                   
Toast.LENGTH_SHORT).show();

            }


        }


    }




    /**


     * @param bundle


     * @return


     */


    private String composePizzaOrderMessage(Bundle bundle) {


        final int quantity = bundle.getInt("quantity");


        if ( quantity > 0 ) {


            final StringBuilder msg = new StringBuilder(String.format("Make %d %s pizza%s",


               quantity, bundle.get("pizza"), (quantity > 1) ? "s" : ""));


            final boolean extraMozzarella = bundle.getBoolean("extra mozzarella");


            final boolean pepperoni = bundle.getBoolean("pepperoni");


            if ( extraMozzarella ) {


                msg.append(" with extra mozzarella");


                if ( pepperoni ) {


                    msg.append(" and pepperoni");


                }


            }


            else if ( pepperoni ) {


                msg.append(" with pepperoni");


            }


            


            return msg.toString();


        }




        return "No pizzas ordered";


    }




}



Creating the AutoDialog specifying the layout and the title in the constructor is all we need to have our Dialog working.

When the Dialog is dismissed we can obtain all of the exported values in a Bundle using the getAutoBundle() method.




Conclusion


This is a more practical example of AutoAndroid. With almost no code we have managed common behavior that frequently appears in Android applications. Some other samples will follow demonstrating other features. Stay tuned.



If you have comments, ideas, critiques or whatever just drop me a line or leave a comment in the blog.




Copyright © 2009 Diego Torres Milano. All rights reserved.


















































Thursday, August 13, 2009

Save the date: Android Tutorial at 1st Linux Symposium Japan

Mark your calendars. On October 23, 2009, 13:30 I will be presenting Introduction to Android Development a tutorial where we will be analyzing the components from the Linux kernel to the middleware and key applications that make up the Android software stack.
We will be also introducing the keys to start developing Android applications on Linux presenting some sample application featuring the most relevant features of the platform from UI design to Location Based Services.

Japan Linux Symposium takes place at Akihabara Convention Hall - Tokyo, Japan from October 21 till October 23, 2009.
Hope to see you there.

Wednesday, August 12, 2009

Android: Is AutoAndroid possible ?









This document can be read in Google Docs (http://docs.google.com/View?id=ddwc44gs_195pgbkpfwn), cut and paste link if you have problems accessing it.






Some time ago, while working on some Linux projects requiring GUIs for some commands I've started autoglade, an Open Source project aiming to fill some gap between scripts and command line utilities and GUIs.

As a proof of concept, I'm wondering if a similar approach would be possible in Android, so let's find out what can be done.

Your comments and suggestions are greatly appreciated.


autoglade


autoglade's main objective is to automate as much as possible the design and implementation of Gnome/GTK based, cross platform applications whose GUI is designed with Glade.

A clear idea of what autoglade is about can be obtained taking a glimpse at autoglade tutorial: first steps (problems with SF's wiki ? access this Google cached version) .

More in-depth treatment of autoglade features and a very interesting cross-platform example, autoeditor, can be found at autoglade features.


autoandroid


Would it be at all possible to take a similar approach to streamline android UI design and implementation, factoring the repetitive tasks you have to write again and again for many applications ?

autoandroid library is distributed as a jar file that you can add to your android project java build path.




introductory example


This introductory example provides some automatic behavior of UI components.

Our objective is to obtain, writing as less code as possible, the following functionality.











This sample including autoandroid-0.2.jar can be downloaded from http://codtech.com/downloads/android/index.html#source as an Eclipse project (AutoAndroidSamples.zip).







A standard Activity displays our custom Dialog once the Button is clicked








The custom Dialog displayed has an EditText and a Button. The EditText starts empty and the Button disabled.








Once some text is entered the Button is activated. If the text is deleted the Button returns to its disabled state.








When the Button is pressed the text entered in the EditText is displayed by the main Activity using a Toast, that is we are easily getting the exported values from the Dialog.












dialog_sample.xml


This is the layout of our sample dialog.

We can do it as we normally do using ADT's Layout Editor.








However, to provide the extra behavior we have to add some properties in the XML view of the editor.










<?xml version="1.0" encoding="utf-8"?>



<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"


    
xmlns:auto="http://schemas.android.com/apk/res/com.codtech.android.samples.autoandroid"

    android:layout_height="wrap_content" android:layout_width="fill_parent"


    android:orientation="vertical"


    
android:id="@+id/Root">

    <
com.codtech.android.auto.view.AutoEditText android:id="@+id/EditText01"

        android:layout_height="wrap_content"


        android:layout_width="fill_parent" android:layout_margin="6dip"


        
auto:export="true"

        
auto:name="text"

        
auto:sensitize="@+id/Button01"

        android:hint="@string/edittext_hint" />


    <Button android:id="@id/Button01"


        android:layout_width="wrap_content"


        android:layout_height="wrap_content" android:text="OK" android:width="150dip"


        android:layout_gravity="right"


        android:enabled="false"


        android:clickable="false"


        
auto:dialog_action="positive" />

</LinearLayout>




Let's explain the changes:




  1. Define the namespace auto. The name that appears after http://schemas.android.com/apk/res is usually the package name of your application and will be used in an attribute definition (attrs.xml). More on this later.


  2. The root layout must have an ID as it's used by some methods in the library and should be identifiable. The name here is Root but it could be whatever you like, though Root seems to be a good option.


  3. Instead of EditText we use com.codtech.android.auto.view.AutoEditText which is a class that extends EditText and provides some automatic behavior. As you can see, this usually doesn't affect how the layout is displayed in the editor.


  4. Mark the AutoEditText as exported so we can obtain its value later. This is achieved using auto:export="true".



  5. As it is exported we give it a name, text in this case, to obtain the value later. auto:name="text" does the trick.



  6. We automatically sensitize Button01 depending on the content of this EditText. Note that here we are assigning the ID to the Button using @+id because it has not yet been defined and we want to create the ID.


  7. Mark Button01 as the positive action of the Dialog using auto:dialog_action="positive"




Styleable attributes


The way we are adding these attributes is by defining styleable attributes in a file usually attrs.xml.










<?xml version="1.0" encoding="utf-8"?>



<resources>


<declare-styleable name="com.codtech.android.samples.autoandroid">


    <attr name="name" format="string" />


    <attr name="init" format="string" />


    <attr name="sensitize" format="reference" />


    <attr name="show" format="reference" />


    <attr name="update" format="reference" />


    <attr name="export" format="boolean" />


    <attr name="dialog_ok" format="boolean" />


    <attr name="dialog_action" format="string" />


</declare-styleable>


</resources>




AutoAndroidSamples.java


This is our sample Activity.










package com.codtech.android.samples.autoandroid;



import android.app.Activity;


import android.content.DialogInterface;


import android.content.DialogInterface.OnDismissListener;


import android.os.Bundle;


import android.view.View;


import android.view.View.OnClickListener;


import android.widget.Button;


import android.widget.Toast;




import com.codtech.android.auto.app.AutoDialog;




public class AutoAndroidSamples extends Activity implements OnClickListener, OnDismissListener {


    private AutoDialog ad;




    /** Called when the activity is first created. */


    @Override


    public void onCreate(Bundle savedInstanceState) {


        super.onCreate(savedInstanceState);


        setContentView(R.layout.samples);


        


        ((Button) findViewById(R.id.Button01)).setOnClickListener(this);


    }




    @Override


    public void onClick(View v) {


        ad =
new AutoDialog(this, R.layout.dialog_sample,

            R.string.dialog_sample_title);

        ad.setOnDismissListener(this);


        ad.show();


    }




    @Override


    public void onDismiss(DialogInterface arg0) {


        if ( ! ad.isCanceled() ) {


            Bundle bundle =
ad.getAutoBundle();

            Toast.makeText(this, "Entered value: " +


                bundle.getString("text"), Toast.LENGTH_SHORT)


                .show();


        }


    }


}





  1. Set the layout to samples, a simple layout containing the button to display the Dialog when clicked


  2. Set the OnClickListener on this Button


  3. On the onClick handler create the AutoDialog using dialog_sample layout shown previously and a title we defined in strings.xml


  4. Set the OnDismissListener of the AutoDialog


  5. On the onDismiss handler check if the AutoDialog was canceled, a value that is automaticaly set, and if not get the Bundle containing the exported values, extract the String for "text" and display it as a Toast.




Conclusion


We have just scratched the ice.
There are some limitations imposed by the SDK, for example there's no a way to specify a list of resource ids in a styleable attribute, so if we want to update or sensitize a list of Views depending on the state of other View we need to find another way of doing it.

Anyway, this is an extremely simple example of AutoAndroid and its common use. Some other samples will follow demonstrating other features like Pizza Shop which is also an autoglade sample.





If you have comments, ideas, critiques or whatever just drop me a line or leave a comment in the blog.




Copyright © 2009 Diego Torres Milano. All rights reserved.