What is special about the O'Reilly Cookbook Series?

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Every wiki site seems to accept a slightly different subset of the Wiki language originated in 1995 by Ward Cunningham, and later adopted by Wikipedia and others. Here's how this site works in this regard.

Android apps are written in the Java(tm) programming language before they are converted into Android's own class file format, DEX. If you don't know how to program in Java you will find it hard to write Android apps.

You want to create a new Android project without using the Eclipse ADT plug-in.

You want to use Eclipse to develop your Android application.

Android apps do not have a "main" method; you need to learn how they get started and how they stop or get stopped.

App stores are a huge element of the attraction of modern smartphones. The Android Market is the official one, but you may want to use app stores other than Google's Android App store.

You need to reference an external library in your Android source project

The SDK must be kept updated to allow App developers to work with the latest APIs on the evolving Android platform.

You need a standard way of getting screenshots for use in the Android Cookbook or any other documentation.

A tip calculator is quite a simple application. When you go with friends to a restaurant and wish to divide the check and tip, you simply add the tip percentage to the total and divide by the number of diners. Tipster is an implementation of this in Android, to show a complete application.

You keep hearing about Gingerbread, Ice Cream Sandwiches, and Jelly Beans, and need to know what it all means.

Java has a well-defined exception handling mechanism, but it takes some time to learn to use it effectively without frustrating either users or tech support people.

When the user rotates the device, Android will normally destroy and re-create the current Activity. You want to keep some data across this destroy-re-create cycle, but all the fields in your activity are lost during it.

Your long-running application needs a means of detecting the battery level for notifying the user when the battery level goes below a certain threshold.

Most applications require an introductory opening screen.

Often developers want to track their application in terms of features used by users. How can one find which feature is most used by the App's users?

I have developed an application for my smart phone. Is there a way to run it gracefully on a tablet without any significant changes to my code?

I want to display the date and time in different standard formats. What is the the easiest approach to achieve this?

If a user performs a factory reset or converts to a new Android-powered device, the application loses stored data or application settings.

Most applications will require some introduction for non-technical users. The "onboarding" process, that of introducing the user and your app to each other, is your chance to inform, to inspire, and to get the user excited about using your app. This is a standard aspect of "user experience" (UX) design, but is often overlooked when technical people design an app.

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Successful Apps must run on a wide range of Android devices and versions.

You need to create and use a new Test Project to test your Android application.

Many a times even though the Java code compiles without error, running the application crashes giving a 'Force Close' (or similar) error message.

Users reported something about your App that you don't think should happen, but now that the 'release mode' App is on the market, you have no way to find out whats going on in the users environment and bug reports end up in a 'cannot reproduce' scenario.

Making sure your app's GUI is as snappy as possible isn't easy. But with the help of Android's StrictMode it doesn't seem all that bad.

You have made an app which needs to place or listen for calls or send or receive text messages and you want to test this.

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Often the application generates data, which can be processed and analyzed by another application. What is the safest way to achieve this, without giving direct access to our application's database?

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When your device's configuration changes (most frequently due to an orientation change), your Activity is destroyed and recreated, making state information difficult to maintain.

You need to do something when the user presses a Button.

You want to offer the user a set of choices that is more limited than a list.

You need to create your own custom button style for all your application buttons.

You want to listen for long press / long click events and react to them, without having manually to check for multiple events.

There is a need to limit the range and type of values being input.

Searching for items/entries, that can occur in more that a single category. Perform autocompletion and simultaneously make the difference in categories immediately apparent using icons. For example, the term Pain (in bold) occurs in both Symptoms category as well as Reactions category, but also text in the Notes category. Categories:

Symptoms: Pain, Depression, Weakness Reactions: Pain, Inflammation, Itchiness Notes: I had a pain in my buttocks.

You need to designate an EditText as a password field, so that characters the user types will not be visible to "shoulder surfers".

Intercepting the keys pressed by the user and performing actions corresponding to them.

You want a View component to shake for a few seconds to catch the user's attention.

You want to move from an activity within a tab view to another activity within the same tab.

You need to format numbers, because the default formatting of Double.toString() and friends do not give you enough control over how the results are displayed.

New App developers need a simple example on how to open another screen, thus understanding how Android handles UI creation.

The proper layout of SlidingDrawer isn't covered to well in the SDK documentation. Here's how to use the control to overlay other components in a layout. As well as how to position elements in the underlying layout to avoid the drawer handle.

You want the SlidingDrawer to overlap other UI components eg. ListView

You want to traverse through different screens using simple gestures like flip/scroll the page.

You want to add Fragments to the UI in Android 2.0+ versions, though they were originally only available in 3.0+. Fragments, as the name suggests, are nothing but the small chunks of UI which constitutes a single activity. It can be treated as individual portlets of a portal page. It is very similar to activity in terms of its looks, lifecycle, etc but it is also different than Activity in the sense that 'A fragment should always reside in an Activity'; fragments cannot exist independently as Activities.

Widgets are simple graphical user interfaces that allow users to easily interact with an existing application (activity and/or service). It's rather simple to create one. Just try it!

A Spinner is not like a TextView, the textSize attribute will not work (a Spinner is a ViewGroup).

You want to know how to arrange your GUI components within your view.

This is a placeholder recipe for some ideas on layout management aka ViewGroup

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You want to create a basic OpenGL ES application.

You want to allow the user to draw smooth curves, such as freehand bezier curves, legal signatures, etc.

You want to have more control on the various stages involved when taking a picture.

Depicting data graphically in an Android application.

A good icon for an App is important. It helps set an App apart from others and is a must for an App to appear professional.

Need to visualize data in a chart and ability to interaction with the plot/chart via Javascript.

You need to add interest to a screen with custom buttons.

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Creating UI for browse through multiple images.

Face detection is a cool and fun hidden api feature of Android, and has been around since Android 1.5. In essence face detection is part of a machine learning technique of recognizing objects using a set of features.

You want to play an audio file with no interaction.

You want your application to pronounce words of text so the user can perceive them without watching the screens (e.g., when driving).

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You need to access data stored in a file in /res/raw directory.

You want to find out the amount of total and available space on the SD card

Android provides a very easy way to setup default preferences by defining a PreferenceActivity and providing it a resource file. What is not clear is how to perform checks on preferences given by the user

Data persistence in the application.

Loading items from an existing SQLite database.

Many websites provide data in JSON. Many applications require to parse JSON and provide that data in the application.

You have data in XML, and you want to transform it into something useful in your application.

You want to persist data locally and have it backed to a persistence store in the cloud.

You need to extract details, such as a phone number or email address, from the Contacts database.

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You want to block certain calls, or alter the phone number about to be called.

A simple way to send either a single part or a multipart (handing the message concatenation UDH) from a single entry point

For testing SMS based applications sending SMS to the emulator.

Some Android applications require the Android device's IMEI number, the phone number or the phone type (GSM/CDMA).

You need to access a RESTful Web Service.

You want to parse RSS/Atom feeds.

How to access services over HTTP fcrom a handset application

You need to make webpage URLs into hyper-links in a TextView of your Android app

You need to customize the WebView opened by your application.

Integrate an Android application with Facebook

Instead of diving into the API you can simply add Social networking support.

You want to know where you are.

You need to demonstrate your application, but are scared it might choke trying to triangulate your GPS coordinates. Or you'd like to simulate being in a place you're not.

You want to get set up to use the current (V2) Google Maps API.

Sometimes the steps needed to add a Google Map and show the User's location to Android Apps is not clear as water on the Internet and Documentation.

You want to see where you are in a map using the built-in GPS in Android devices

You have a geo location and you want to display it on a Google MapView view object

You have several GeoPoints which you want to display on a Google MapView.

Showing an appropriate view of a MapView based on the context in the application.

You want to place a MapView object within TabView.

Target application outline

• Draw two empty tabs
• Show map on the first tab

You want to use OpenStreetMap (OSM) map data in your application in place of the standard Google Maps.

You need to show a map scale on your OSM to indicate the level of zoom on the MapView

You need to react to the changes in the device's location and move the map focus to changed location

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Sometimes it makes sense to evaluate not only on-screen input, but also gestures like tilting or shaking the telephone. But how can you use the accelerometer to detect whether the phone has been shaken?

Being able to detect which side of the android device is higher up compared to the rest (Top/Bottom/Right/Left side)

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You need to connect to other bluetooth enabled device and want to communicate with it.

You want to display a list of Bluetooth devices in the vicinity.

Sometimes it can be convenient to start one of the Linux commands that are available on the phone such as rm, sync, top, uptime...

You want to write your application in one of several popular scripting languages, or, you want to program interactively on your phone.

You need to create an alert box or pop-up dialog using Python in the Scripting Layer for Android (SL4A)

You need to get the details of your Google documents after logging in with your Google ID and password.

You need to distribute your ASE scripts using QR (Quick Response) Codes

Creating an Android-application using Flex 4.5. The application uses a company stock symbol as query, and an HTTP service to Google's Finance API, retrieving stock data.

You want an application to run on different platforms like iOS, Android, BlackBerry, Bada, Symbian, Windows etc.

You need to access your methods from Activity.java in JavaScript

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You need to find all the strings in your application, internationalize them, and begin the process of translating them.

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You want to sign your application prior to uploading it to the Android Market.

You want to monetize your free app by showing ads within it.

Your developed App is running on a device; you want a link to your other Apps on the Android Market to encourage users to try them.

If you have two different application say one is application and one is service layer then how to send them in one apk?

You need to provide an alternate home screen for your phone.

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Your App needs the user to select an item from several options.

You want to write a ListView that shows an image next to a string.

You want to display categorized items e.g., by time/day, by product category or sales price.

Lists are ubiquitous throughout mobile applications. Android provides a simple and powerful interface to make exactly the list you need. This recipe explains the steps for customizing the content of a ListView.

Accomplish view changes on device orientation changes. For example, data values to be plotted are contained in a Portrait ListView, and upon device orientation a graphical display of the data values in a chart/plot is displayed.

Game design

To determine if a user generated message, like a key press/release, has occoured within a certain time interval. Useful in game input handling.

You want to find information about phones network connectivity

You need to put the Android device to silent, vibrate or normal mode

Some Android phones are equipped with LEDs. An application can flash different color lights using the LED.

You need to run a shell command from your application (for instance pwd, ls etc).

For some strange reason, you want the user's Android device to reboot.

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You want to send an Email containing text or images from a View. The data to be emailed is passed as a parameter using an Intent.

You need to pass some parameters into an activity while launching it.

You want part of your application to continue running in the background while the user switches to interact with other apps.

You need to get different applications deployed on a device to communicate. For instance, the running application wishes to notify another application (which is in the background) of a certain event.

How to create a responsive application.

If you run a thread to execute some source code, you can't use or change any graphical widget from this thread and you don't know when the thread has finished.

You need to pass information or data from a Service or other background task, to an Activity. Since Activities run on the UI thread it is not safe to call them from a background thread.

You want to push array data from Java to JavaScript and/or from JavaScript to Java

Within the Activity, showing a menu on pressing the Menu button of the Android device.

Display options to the user in an floating window.

Sometimes we need to ask the user to enter the time for processing some element in the application. Accepting time in Text boxes is not graceful as well as requires validation.

Categorizing information display in an custom Dialog.

Using a custom dialog in the application. The dialog is provided with text, images, buttons and also providing tabs in the dialog.

You want to customize the look of Toast notifications.

The ActionBar component, introduced in Honeycomb and upgraded in ICS, is a combination of a titlebar, menu items that get promoted to buttons, and a Menu Button to replace the hardware button that is absent in almost all 3.0+ devices. This is good functionality, and it would be nice to be able to use it on pre-4.x devices.