Best-Selling Android Development eBooks of All Time – BookAuthority

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Best-Selling Android Development Books of All Time – BookAuthority

The most important part of a modern day app is how real time they are. With this book, you will create a smooth back-end for your app, ensure dynamic and real time communication between different app layers. You will implement effective testing techniques to make your app reliable and robust and finally you will learn to deploy it efficiently.

You will create a complex enterprise grade app in this book. You will get a quick refresher of the latest android SDK and how to configure your development environment. Then you will move onto creating app layouts, component and module building, creating smart and efficient UIs. The most important part of a modern day app is how real time they are. Mobile app yang dibuat menggunakan mobile hybrid apps Android dan IOS , bebas menggunakan framework apapun.

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Expert android programming prajyot mainkar pdf free

Who This Book Prajypt For This book is for http://replace.me/4473.txt developers having some expertise in building android apps and who wish to now take a leap into building complex app such as Zomato, using latest Android N power of Google. If you want to create smart android applications which are expert android programming prajyot mainkar pdf free, lightweight and also adobe pro apply redaction free download efficient then this is the book that will solve all your problems.

You will create a complex enterprise grade app in this book. You will get a quick refresher of the latest android SDK and how to configure your development environment. Then you will move onto creating app layouts, component and module building, creating smart and efficient UIs. The most important part of a modern day app is how real time they http://replace.me/2441.txt. With this book, you will create a smooth back-end for your app, ensure dynamic and real time communication between different app layers.

You will implement effective testing techniques to make your app reliable and robust and finally you will learn to deploy it efficiently.

The multiple stages of android expert android programming prajyot mainkar pdf free will also be simplified by giving you an industry standard set of best practices.

The examples in each chapter will be modular and will prograjming help you to create a complete fully fueatured android app by the end of the book.

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Expert android programming prajyot mainkar pdf free

The color images will help you better understand the changes in the output. If you find a mistake in one of our books-maybe a mistake in the text or the codewe would be grateful if you could report this to us.

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Questions If you have a problem with any aspect of this book, you can contact us at [email protected] , and we will do our best to address the problem. They wanted to ensure that it becomes easier for developers to reuse code and also help them create build variants with ease. In this chapter, we will discuss: Setting up Gradle in Android Studio Dependent libraries to be used in Android Studio, including Identifiers If you have been using Eclipse, it’s likely that some of you won’t know of any alternative to the default APK generation technique within the IDE.

But, as such as alternative, you can do this using the command line. The Android build system compiles app resources and source code, and packages them into APKs that you can test, deploy, sign, and distribute. Gradle was designed keeping in mind the support for multi-project builds which grow to be quite a large size, and it supports incremental builds.

Gradle does this by understanding which parts of the build tree are up to date. Understanding the Gradle System This ensures that tasks dependent on those parts will not be re-executed.

Gradle can automate the building, testing, publishing, deployment, and more of software packages or other types of projects. Using the combination of the power and flexibility of ANT and the dependency management and conventions of Maven, Gradle helps to build in a more effective manner. First, let’s get familiarized with the Gradle environment inside Android Studio.

To do that we should first create a new Android Project. I assume you have Android Studio installed by now. Just click Finish when done: [ 11 ] Understanding the Gradle System When the project load is complete, just change the view structure to Project. You may leave it at Project Files by default: [ 12 ] Understanding the Gradle System Once this is done open the build.

Here you will see the libraries that are compiled in the project: We have completed the launch of a blank project and we now should understand the basic setup of the same. In the next section, we will talk about adding Gradle to this app. Adding Gradle to your app You can Gradle build script dependency to your app in the following way: Open the file from your app module. Here are a few pointers to make note of: com. We will be using several libraries in our App. In the next section, we will see how to add new Gradle Libraries.

Adding a new Gradle library Making Android Development more awesome, Gradle allows us to incorporate libraries in to Android Studio in different ways. Using these, developers can easily include their libraries using Gradle dependencies.

In this section we will discuss the following techniques: Adding a Gradle identifier Adding as a module Adding a Gradle identifier To add a new Gradle library, find the Gradle identifier for the third party library, and add it to the dependencies list.

To sync your project files, click Sync Now as seen in the following figure in the notification bar this appears when you make a change , or click Sync Project from the menu bar. If Android Studio notices any errors with your configuration–for example, if your code uses API features that are only available in an API level higher than your compileSdkVersion– the Messages window appears to describe the issue: Next, we will discuss how libraries can be added using a module.

To add the module: 1. First, place the library code in any folder of your choice 2. Then, you need to Import the library as a module in your app. The figure below shows the steps to add the library as a Module: This will open a new window where you need to select the library that you have saved to the directory.

When you have selected the directory, click on Done. This will import the external library into your project. As an example, I have added the module crop image to my project, which appears in my project folder. To do this, right click on the module that has been added and click on the Open Module Settings option: It will open a new window with your app module and library module in the list.

Choose you app module, and then select the dependency list. Select it and click OK: This will build the Gradle and add the module to the build. Alternatively, you can also define the dependencies of a project in the root build. In this case, we won’t be focusing on these points. Summary We started the chapter by looking at what Gradle is and how it is important in project development.

We briefly looked at the Android Studio setup and how it can help in building the system along with Gradle. After the introduction, we talked about how developers can set up Gradle in Android Studio. We also created a new project in Android and discussed how Gradle libraries can be added to the project. To make these trade-offs, it’s important to know what the consumer wants. Now that we know how to use Gradle, in this chapter we will discuss some of the tools that provide help in building apps and also help in debugging and performance tooling.

Gradle, by default, builds a single APK, no matter what libraries you include. This compiled and packaged file includes all of the application’s code. Exploring Android Studio Developer Tools The library, within itself, comprises multiple copies of the same native code, optimized for the different architecture. A developer can easily run the command unzip. APK to understand the content of an APK: When your app, and the libraries it references, reaches a specific threshold, you encounter build errors that point to the app’s limit of the Android App Build Architecture.

The most recent Android build system displays an error, trouble writing output: Too many field references: ; max is You may try using –multi-dex option. Looking closely at the log, the number has a significant reason for appearing. This number represents the total number of references that can be invoked by the code within a single Dalvik Executable dex bytecode file.

Both these error conditions display a common number: This number is significant in that it represents the total number of references that can be invoked by the code within a single dex bytecode file. If you have built an Android app and received this error, then congratulations, you have a lot of code! Memory space on the phone is a competitive area and to make it worse, if users spot the large APK size they may well decide not to bother.

Ensure that your app utilizes memory in a way appropriate for making users download and retain the app. The smaller you make your APK, the more likely it is for the user to at least download the app in the first instance. Hence, the actions that need to be performed should be followed skillfully using some tools like APK Analyser, before the build is shipped. This tool helps to understand the contents and the sizes of the different components in your APK. With the help of this tool, you can reduce the size of your APK, by identifying the raw file size and estimated download size of each component that combine, to make up your APK.

Follow this step by selecting the APK you want to take a closer look at. The tool will then output in the main Android Studio window, so that you can explore the various components that make up the APK.

Using this information, you can nail down the areas where you think there’s a loss of some excess bytes. You need to understand the contents and sizes of different components in your APK, avoid 64K referenced method limit issues with your dex files, diagnose ProGuard configuration issues, view the merged AndroidManifest.

This feature can help you reduce your APK size you’ll see both the raw file size as well as the download size of the various components.

Understanding basic battery drain Earlier editions of Android OS used to run on Dalvik Runtime, which means apps used to compile at execution time. Post-Lollipop edition, Android has switched to Android runtime ART , which means the apps are compiled beforehand, ensuring they are launched faster. ART, as the runtime, executes the Dalvik Executable format and dex bytecode specification. Apart from the launch, the entire consumer experience using the app is essential for app retention.

One important feature is the battery – a dear feature of the phone. An app which is greedy for power often finds itself in the position of either being uninstalled or lower rated when reviewed on the Google Play Store listing. Take a look at some of the most popular apps on the Store, including Facebook, which has had consistently bad reviews that quote battery drain as one of the top sources of user dissatisfaction.

If your app has the reputation of being a battery hog, that might incur a loss of potential users that could otherwise be using the app. Android developers usually neglect the way that their app could impact the battery life of the smartphone.

Not that it needs deeper insights in embedded systems, but a few tips can help you to appreciate the impact of an app on battery life. If your app is one of the top drainers of the battery in the device, what’s the best way to figure it out? The battery setting menu has an information resource to diagnose battery drain issues caused by mobile apps. Simply heading to Settings Battery will provide the user with the necessary information in a graphical format, comparing consumption against time.

The records are maintained since the last full charge status. There is also an interesting statistical overview of the applications that have contributed to battery drain: Clicking on the graphs opens an extended section that shows how much time your device has spent in various cellular states. The different color patterns such as green, yellow, and orange indicate the signal strength. This might be the result of a Wakelock or alarm that uses the device resources when the user might not be actively using the device.

If this is frequently seen, it calls for some optimization. We will be talking about the Wakelocks and their impacts during the performance section of this book. Batterystats and Battery Historian The Android Settings menu options provide high level measurements of battery drain. However, to gain more insight into battery consuming apps, there are some tools that can be useful. Tools such as Batterystats and Battery Historian come in handy. Batterystats collects battery data from your device, and Battery Historian converts that data into a HTML visualization that helps you understand power consumption graphically.

Batterystats, was introduced in KitKat, but Lollipop brought a large dataset for the users which included data about every Wakelock action on the device. Please reset the data and enable full Wakelock reporting to receive comprehensive information including how the device utilizes the battery, along with details about all the running processes.

Here are some of the commands you can run after connecting your device: adb shell dumpsys batterystats –reset Resets all of the data in the Battery Settings menu before generating the new dataset adb shell dumpsys batterystats –enable full-wake-history Enables full Wakelock reporting adb shell dumpsys batterystats –charged Enables you to receive the data since the phone was last fully charged [ 24 ] Exploring Android Studio Developer Tools If you wish to know what a Batterystats System Dump looks like, you can run the command using the command line interface in Android Studio.

Take a look at the sample as follows: We will be talking more about what each of these components mean during performance in Chapter 15, Understanding App Store Analytics for Optimization later in the book, where we will cover in detail how each of these elements help users to optimize the Android App for better performance.

This was launched with new reports completely rewritten in GO. This tool provides extensive information that helps you drill down into battery data for your specific application. To run the latest edition of Battery Historian, you will need Android Devices with versions later than Android 5. Please follow the installation guide given on the link above to complete the setup.

You can either save the file or check the output right from the terminal window. Exploring each component, the following are the important keywords of the stats: Battery History: This shows the time series of various power-relevant events, such as the screen being on, radio signals and app launch. You can also get details of each one of these using the Battery Historian graph, which we will discuss in the next section. Some of the statistics include, but are not limited to: phone signal levels, screen brightness, signal scanning time, time on battery, time on battery screen off, Wi-Fi signal levels, Wi-Fi idle time, and Wi-Fi Power drain in mAh.

Estimated power use mAh by UID and peripheral: This is an extremely rough estimate and its use should avoid consideration as an experiment data. Per-app mobile ms per packet: Shows the Radio-awake-time divided by packets sent – which means, since an efficient app transfers all its traffic in batches, the lower the value, the better it is for the app’s performance.

All partial wake locks: All app-held Wakelocks, by aggregate duration and count. Batterystats collects battery data from your device. Using these Batterystats, the battery usage could be discovered using a Battery Historian, which would create a HTML file for viewing the Batterystats results in a browser for user viewing.

A graphical representation from Battery Historian of the live Zomato App is shown in the following screenshot: [ 26 ] Exploring Android Studio Developer Tools Using the Battery Historian, important statistics can be drawn upon: It shows you the processes from the device that consume your battery. Here, you could compare the battery usage for each process. It also shows you the tasks from an app that consume more of the battery, so that you can take necessary action on them.

The preceding graph representation shows the readings, based on various categories of the Historian. A few of the major categories to look out for, and to analyze regarding the battery consumption for a device, are listed as follows: Battery level: This shows the battery level of the device when it was recorded.

It helps you determine how fast the device battery drains out. Screen: Shows whether the screen was ON. Top: It shows the application that consumes the most battery usage. Currently the Zomato App is at the top, as the records have been taken, resetting the battery usage and using only the Zomato App.

The usual process of the App is to wake up, do a small amount of work, and then go back to sleep. Waking up the app is very expensive to the battery. So if there are lot of bars showing up, it might be a problem. Running: This shows if the CPU is awake. Here, it should be awake at the times when you are doing some processing, and in sleep mode when not. If it shows as running even if you are not performing any actions, it means there are background processes that are making your CPU do a lot of processing, and hence consuming the battery.

Unzip the file to extract the Battery Historian folder. Find the historian. Connect your mobile device to your computer. On your computer, open a terminal window. Change the directory path to the path where you have saved historian. Shut down your running adb server : adb kill-server 7. This will show the list of devices. If you don’t see any devices, make sure your phone is connected and USB Debugging is turned on, and then kill and restart adb.

Resetting erases old battery collection data; otherwise, the output will be huge. Disconnect your device from your computer so that you are only drawing current from the device’s battery. Use the app for a while, until it gathers a sufficient amount of data for your use. Reconnect your phone. Dump all battery data. Open the batterystats. The Battery Historian tool makes it simpler to dig into the data for one single process. As a developer, you can easily spot battery drain functions using this tool and work on its resolution.

In the next section, we will discuss the memory monitor tools. Managing the RAM is the most critical section in the Android app development process, as the physical memory is often constrained.

The fundamental principle of memory management is to avoid a memory leak from your app. In Android Studio there is a tool we can use to check the memory usage in the App. To check this you could follow these steps: 1. Run your app on an Android device connected to an emulator. Open the Android Monitor tab in Android Studio situated at the bottom window. Open the Monitor section within it, and you are there. Here you’ll be able to continuously check the memory usage of the app as and when the app is being used.

The following image shows the memory usage for an app: [ 29 ] Exploring Android Studio Developer Tools The preceding memory graph shows the memory used by a device against time. This graph shows the memory usage in the app when any process is performed by the app, be it loading data over the network, displaying an image, rendering a view on the screen, or running a background task.

There are two graphs being plotted at the same time here, one with the allocated memory that could be used by the device. OutOfMemoryException error is the most common cause of unconventional crashing of an app due to memory leaks, and the Memory Monitor tool can help you to debug the same. Wondering what the various causes of memory increase are? In any app, the memory is bound to increase at various points of time as and when you use it.

Do not panic if the memory keeps on increasing when you do some stuff in the app, like loading data over the network, displaying an image, rendering a view on the screen or running a background task. It means that for whatever task you do in the app, for example displaying an image onto the screen, the app needs to allocate some amount of space in the RAM.

Now, this allocation is for one particular process. Similar allocations will also happen for other processes. These will increase the memory and, if not handled, may cause a memory leak in your App. For most of the Apps, Android has a Dalvik garbage collector, which takes care of the memory allocations and releases the memory when done.

This will help prevent memory leaks. By carefully understanding how your Android application handles memory operations, you can ensure that the app is running efficiently on memory contained devices.

Eventually, this will also lead to a reduction in out-of-memory crashes. Logcat displays messages in real time and also keeps a history so you can view older messages. Log Log Level Description Log. Error Tag and message are the string data-type.

You can search for messages in the logcat by; Typing a character sequence in the search field Optionally selecting Regex if you want to use a regular expression search pattern The logcat will reflect the changes accordingly. Apps without optimization can severely impact the battery life of a device. We’ve walked though in-depth analysis of battery drain in Android Apps. We also looked at Batterystats and the Historian tool to analyse battery usage patterns. Additionally, we explored memory optimization to ensure the app runs smoothly and stays off the memory leaking track.

These include smartphones, tablets, Smart Wears, smart TV’s, and even cars. From just a mobile computing platform, Google has used the powers of Android to a great and deeper extent. Looking at the Android distribution, Android 4. Comparing smartphone OS global market shares from Q to Q, Android has grown massively from 1. At this pace, we can expect M users by In this chapter, we will look at the Android Support Library features and how they assist us in the project.

The Android Support Library Supporting multiple devices can pose issues, particularly when users expect apps to function seamlessly on every device, in the same way. This expectation rises even when users know very well that there is a significant difference in the software and hardware of the phone.

While Google releases, latest updates to Android, it is not necessarily true that all OEMs follow up on this update on their smartphone. This leads to the fact that most of the users tend to use releases which are approximately 15 months old or older.

Leap into the Android Support Library If that is held true, developers would have to compromise a lot in order to support most of their users, running several versions of Android. Fortunately, the Android team is aware of this and endeavors to provide consistent help for the developer in this regard.

This is a tricky issue, especially considering the consistency of the app feature that shouldn’t affect the architectural structure.

The Android Support Library is a collection of libraries, which are available on several API levels, that help developers to focus on the unique parts of their app, supporting new functionality and compatibility issues that might arise due to different versions running on different devices. Setting up Android Support Libraries in your development environment depends entirely on what features you want to use and what range of Android platform versions you are targeting with your application.

Please follow the steps given as follows to set up the Support Library files: 1. If you have opened the standalone SDK Manager, this option would be in the Extras section, as shown in the following image: 2.

Here is the list of supported libraries: Support Library Description Gradle Dependency v4 compat library Provides compatibility wrappers for a com.

We will be using these primarily in our app. Here is the list of supported libraries: Support Library Description Gradle Dependency v7 appcompat library This will be one library that com.

This library supports the Action Bar Design pattern. Moreover, it also includes support for material design user interface implementations. This library depends on the v4 Support Library.

This allows us to show up information in the form of cards, which can be supported on any device. Using this library adds support for the GridLayout class, which allows you to arrange UI elements using a grid styling. In short, it supports streaming and routing of media channels from one device to external devices. This is mainly used in music applications. This library provides support for building apps that support multiple dex files. Apps that have references to more than methods would be required to use multidex configuration.

The gradle dependency identifier for this library is as follows: com. It has v8 renderscript library – which adds support for the RenderScript computation framework. It supports the FragmentCompat class and additional fragment support classes. We followed this by discussing several libraries that can help developers to use libraries which can offer backward-compatible versions of new features.

With automatic platform updates distributed as an APK on the Google Play Store, developers can easily receive the updates and more easily integrate Google features. This interface also allows you to obtain authorization from users to gain access to these services using the users’ credentials. These services include Google Drive, Play Games and more.

Since the library derives updates from Google Play, it does contain APIs that help you resolve any issues at runtime. Sometimes you may have come across apps that prompt you to update Google Play Services before proceeding.

The service performs the desired action on your behalf. Also, to include a specific dependency for your app, proceed to add specific services in your app’s build Gradle. The various services provided by Google Play Services could be included in an Android app using a Gradle path in the app’s build. The default password for the debug keystore is android. Post this, you will able to see the fingerprint displayed onto the terminal.

To make this possible, you need to register your Android app with the Google Cloud Console by providing your app’s package name and the SHA1 fingerprint of the keystore, using which you will sign the release APK.

To register your Android app with Google Cloud Console, follow these simple steps: 1. Click on Create project and enter the project name. Click Create. This will create a new project in your Google Developer Console. Since we have created the project, we will now enable the APIs that are required for the project.

To enable the APIs, click on the library tab. Here you will see the list of all APIs that can be added to the app.

First go to the library tab in the Google developer console. Next go to the Credentials. Here we will be creating an OAuth credential for the app so that the user can log in from the Android app.

Before we create a new credential, we have to fill in OAuth details of the app: [ 46 ] Google Play Services 4. After all of these details have been filled, go to the Credentials tab and click on Create credential: [ 47 ] Google Play Services 5. In our case, it is an Android app, so we would select Android: 6. Then you will see an option to add the app’s package name and signingcertificate fingerprint. Here you will see an option to select an app and enter the package name. Fill in the details and click on Choose and configure services: [ 49 ] Google Play Services 9.

At this screen, enable Google Sign In and enter the signing-certificate fingerprint. Then click on Generate configuration file: [ 50 ] Google Play Services You can now download the google-services. Now, add the dependency to your project-level build. Also, add this plugin in your app-level build.

Finally, add the dependency into your app-level Gradle: Compile com. We have now completed the setup for Google Play Services for this app. In the next section we will discuss the Android Architecture we would follow, along with discussion on the UI patterns for this app. After saving the API key, use the key in your app. Now in your app, add the dependency in your app’s build. Save the file. After adding, save the AndroidManifest. Next, we discussed Google Sign up, followed by Google Maps.

Google has set design principles as guidelines to help developers work with material design for their apps. This principle sets up visual cues, motion, and interaction design across platforms and devices, making it a unified design belief. In this section, we will cover how to incorporate material design into your app. Wireframing and tools to gather feedback Wireframing is a technique to plan out the high-level screen hierarchy for your application and display the forms that would be present in your app by providing some mode of navigation, to allow users to effectively traverse your app flow.

Some apps have wireframes expressed in a tree structure, a graph, or a flowchart. The methods of wireframing could vary based on the type and magnitude of the app, but the standard patterns of wireframing remain the same.

Also, there are varieties of tools that could be used across different types of apps and different kinds of information that represent the types of things users interact with in your app.

Software engineers and data architects often use entity-relationship diagrams ERDs to describe an application’s information model. We will understand and learn the various techniques of wireframing in detail in this chapter. Material Design Understanding the wireframing process tangible and digital Before understanding the actual wireframing process, it will be nice to gather some initial information about things that would help draw some effective wireframes. Once you understand what your app will do, the first step is to list the screens present on the app step by step.

Doing this will give you a clear idea about the basic outline of the wireframing screens required. Wireframing is the step in a design process where screens are laid out creatively, by arranging the UI elements to allow users to navigate through your app.

These wireframing screens need not be same as the final UI for the app. They could be somewhat rough wireframes, which would give you an idea of what elements would be present on a screen. The easiest and fastest way to get started is to sketch out your screens by hand using paper and pencils.

Once you begin sketching, you may uncover practicality issues in your original screen map or the patterns you use. In some cases, patterns may apply well to a given design problem in theory, but in practice they may break down and cause visual clutter or interactional issues for example, if there are two rows of tabs on the screen. If that happens, explore other navigational patterns, or variations on chosen patterns, to arrive at a more optimal set of sketches.

After you’re satisfied with the initial sketches, it’s a good idea to move on to digital wireframing, using software such as Adobe Illustrator, Adobe Fireworks, OmniGraffle, or any other vector illustration tools. When choosing a tool to use, consider the following features: Material UI for Android developers Material design for Android includes implementation of visual, motion, and interactive designs for your app on different devices.

Android now includes support for material design apps. To use material design in your Android apps, follow the guidelines defined in the material design specification and use the new components and functionality available in Android 5. The Android library provides many components for giving a material experience to the user.

We will explain some of the components provided in the Android library in this section. They are distinguished by a circled icon floating above the UI and have special motion behaviors related to morphing, launching, and the transferring anchor point. Floating action buttons come in two sizes: the default and mini. The size can be controlled with the FABSize attribute.

As this class descends from ImageView, you can control the icon that is displayed via setImageDrawable Drawable. The background color of this view defaults to your theme’s colorAccent. The FAB could be used to carry out different kinds of transitions on click. The following are a few images that show the different places where the FAB could be used: [ 58 ] Material Design Figure 1.

Consider the restaurant details screen where we have a FAB button present, as follows; the button can be used at various different places: Figure 1. Clicking on the button opens up the bottom menu and shows us the various options. Here, the transition from the FAB button to the bottom menu forms the major chunk of its material aspect.

The following is the complete transition showing how the FAB gets converted to the bottom menu: Figure 1. Firstly, make sure that you have added the gradle dependency in your app’s build. The next step is to import and initialize it in your Java class: import android.

FloatingActionButton; If you are using Android Studio, the import will be handled automatically, and you don’t have to worry about it.

The code for the on click of the FAB is mentioned below. Refer to PlaceDetailActivity. Also, we need to close the bottom menu when clicking anywhere outside. Clicking on the search icon will produce a ripple effect, which helps a user to get a better experience: Figure 1.

When this screen opens up, there is a smooth transition that takes place as each of the components appears on the screen. The search icon first opens up smoothly to form the toolbar: Figure 1. The in-between transition when the search icon opens up smoothly [ 70 ] Material Design The search icon’s in-between transition shows that the ripple wave grows gradually until it completely covers the toolbar: Figure 1.

The search icon completely opens up to form the toolbar [ 71 ] Material Design Once the search icon translates to form the toolbar, the EditText translates down from the top to the bottom and the quick search options simultaneously translate up, creating a smooth transition effect: Figure 1. The Search icon completely opens up to form the toolbar [ 72 ] Material Design The XML layout of the search view is shown in the following code: [ 73 ] Material Design [ 74 ] Material Design The major components on this screen are the EditText, for typing the text for searching.

Another important component is the RecyclerView, which displays the list of all the details. Here, we are concerned more about the way the UX for the search gives a smooth experience to a user. The view being passed to the method as a parameter is the searchViewLayout, which means that it makes the search view visible. Then it adds the animation to that particular search view layout. Then, the animation is started using the start method. The following is the explanation of the showBottom method inside the enterViews method: private void showBottom View view, Animator.

This animation will have a listener, which will let you know when the animation starts and when it ends. The exitViews method will be called when the search view has to be closed. Android library provides many ways and built-in libraries for building a good UX. Besides these, you need to build your own UX patterns depending on the flow of your app. To build a good UX, you need to use animations in the right places.

Understanding UX principles and how it’s different from UI The user experience is very important for keeping a user engaged with the app by making them understand what is happening on the screen. Download Example Code. Build feature-rich, reliable Android Pie apps with the help of more than proven industry standard ….

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Unclog your development highway by utilising the industry standard best practices techniques. In Android Studio there is a tool we can use to check the memory usage in the App. To check this you could follow these steps:. Run your app on an Android device connected to an emulator. Open the Android Monitor tab in Android Studio situated at the bottom window. Open the Monitor section within it, and you are there. Here you’ll be able to continuously check the memory usage of the app as and when the app is being used.

The following image shows the memory usage for an app:. The preceding memory graph shows the memory used by a device against time. This graph shows the memory usage in the app when any process is performed by the app, be it loading data over the network, displaying an image, rendering a view on the screen, or running a background task.

There are two graphs being plotted at the same time here, one with the allocated memory that could be used by the device. Wondering what the various causes of memory increase are? In any app, the memory is bound to increase at various points of time as and when you use it. Do not panic if the memory keeps on increasing when you do some stuff in the app, like loading data over the network, displaying an image, rendering a view on the screen or running a background task.

It means that for whatever task you do in the app, for example displaying an image onto the screen, the app needs to allocate some amount of space in the RAM. Now, this allocation is for one particular process. Similar allocations will also happen for other processes. These will increase the memory and, if not handled, may cause a memory leak in your App.

For most of the Apps, Android has a Dalvik garbage collector, which takes care of the memory allocations and releases the memory when done. This will help prevent memory leaks. By carefully understanding how your Android application handles memory operations, you can ensure that the app is running efficiently on memory contained devices.

Eventually, this will also lead to a reduction in out-of-memory crashes. Logcat Android Studio has a logcat tab inside Android Monitor that prints system events, such as when a garbage collection occurs, as well as messages your app prints with the Log class, to assist with debugging. Logcat displays messages in real time and also keeps a history so you can view older messages.

Log Log Level Description Log. Typing a character sequence in the search field Optionally selecting Regex if you want to use a regular expression search pattern.

Summary Battery life is an excellent indicator of how your App performs. Apps without optimization can severely impact the battery life of a device. We’ve walked though in-depth analysis of battery drain in Android Apps. We also looked at Batterystats and the Historian tool to analyse battery usage patterns.

Additionally, we explored memory optimization to ensure the app runs smoothly and stays off the memory leaking track. These include smartphones, tablets, Smart Wears, smart TV’s, and even cars.

From just a mobile computing platform, Google has used the powers of Android to a great and deeper extent. Looking at the Android distribution, Android 4. Comparing smartphone OS global market shares from Q to Q, Android has grown massively from 1.

At this pace, we can expect M users by In this chapter, we will look at the Android Support Library features and how they assist us in the project. The Android Support Library Supporting multiple devices can pose issues, particularly when users expect apps to function seamlessly on every device, in the same way.

This expectation rises even when users know very well that there is a significant difference in the software and hardware of the phone. While Google releases, latest updates to Android, it is not necessarily true that all OEMs follow up on this update on their smartphone. This leads to the fact that most of the users tend to use releases which are approximately 15 months old or older. Leap into the Android Support Library.

If that is held true, developers would have to compromise a lot in order to support most of their users, running several versions of Android. Fortunately, the Android team is aware of this and endeavors to provide consistent help for the developer in this regard. This is a tricky issue, especially considering the consistency of the app feature that shouldn’t affect the architectural structure.

Setting up Android Support Libraries in your development environment depends entirely on what features you want to use and what range of Android platform versions you are targeting with your application. If you have opened the standalone SDK Manager, this option would be in the Extras section, as shown in the following image:.

After downloading, the tool installs the Support library files to your existing Android SDK directory. Here is the list of supported libraries:.

We will be using these primarily in our app. This library supports the Action Bar Design pattern. Moreover, it also includes support for material design user interface implementations. This library depends on the v4 Support Library. This allows us to show up information in the form of cards, which can be supported on any device.

Using this library adds support for the GridLayout class, which allows you to arrange UI elements using a grid styling. In short, it supports streaming and routing of media channels from one device to external devices. This is mainly used in music applications. Google recommends including the v4 support and v7 appcompat libraries, because they support a wide range of Android versions and provide APIs for recommended design patterns.

This library provides support for building apps that support multiple dex files. Apps that have references to more than methods would be required to use multidex configuration. The gradle dependency identifier for this library is as follows: com.

It has v8 renderscript library – which adds support for the RenderScript computation framework. It supports the FragmentCompat class and additional fragment support classes. Annotations Support Library This library provides support to add annotation metadata to your Apps. We followed this by discussing several libraries that can help developers to use libraries which can offer backward-compatible versions of new features.

With automatic platform updates distributed as an APK on the Google Play Store, developers can easily receive the updates and more easily integrate Google features. First, let’s see what the architecture of Google Play Services looks like:. This interface also allows you to obtain authorization from users to gain access to these services using the users’ credentials. These services include Google Drive, Play Games and more.

The service performs the desired action on your behalf. Google Play Services. Google com. Google Cloud com. Google Places com.

Android com. Also, to include a specific dependency for your app, proceed to add specific services in your app’s build Gradle. The various services provided by Google Play Services could be included in an Android app using a Gradle path in the app’s build.

Make sure these changes are saved and you click Sync Project with Gradle Files in the toolbar. The key tool utility should now prompt you to enter a password for the keystore.

The default password for the debug keystore is android. Post this, you will able to see the fingerprint displayed onto the terminal. To make this possible, you need to register your Android app with the Google Cloud Console by providing your app’s package name and the SHA1 fingerprint of the keystore, using which you will sign the release APK. Click on Create project and enter the project name. In our case, we have named it Zomato Project:.

Since we have created the project, we will now enable the APIs that are required for the project. To enable the APIs, click on the library tab. Here you will see the list of all APIs that can be added to the app. First go to the library tab in the Google developer console. Next go to the Credentials. Here we will be creating an OAuth credential for the app so that the user can log in from the Android app.

Before we create a new credential, we have to fill in OAuth details of the app:. After all of these details have been filled, go to the Credentials tab and click on Create credential:.

In our case, it is an Android app, so we would select Android:. Then you will see an option to add the app’s package name and signing- certificate fingerprint. Here you will see an option to select an app and enter the package name. Fill in the details and click on Choose and configure services:.

At this screen, enable Google Sign In and enter the signing-certificate fingerprint. Then click on Generate configuration file:. You can now download the google-services.

Now, add the dependency to your project-level build. Also, add this plugin in your app-level build. Finally, add the dependency into your app-level Gradle: Compile com. We have now completed the setup for Google Play Services for this app.

In the next section we will discuss the Android Architecture we would follow, along with discussion on the UI patterns for this app. Google Maps Google Maps is used in the app for finding the location of a place, or to navigate you to that place. Integrating Google Maps in the app is simple; check out the steps below:. Next, enable the API so that it can be used in our application. Here, select Android app and enter your app’s package name and Sha-1 certificate. After saving the API key, use the key in your app.

Save the file. Next, we discussed Google Sign up, followed by Google Maps. Google has set design principles as guidelines to help developers work with material design for their apps. This principle sets up visual cues, motion, and interaction design across platforms and devices, making it a unified design belief. In this section, we will cover how to incorporate material design into your app.

Wireframing and tools to gather feedback Wireframing is a technique to plan out the high-level screen hierarchy for your application and display the forms that would be present in your app by providing some mode of navigation, to allow users to effectively traverse your app flow.

Also, there are varieties of tools that could be used across different types of apps and different kinds of information that represent the types of things users interact with in your app. Software engineers and data architects often use entity-relationship diagrams ERDs to describe an application’s information model. We will understand and learn the various techniques of wireframing in detail in this chapter.

Material Design. Understanding the wireframing process tangible and digital Before understanding the actual wireframing process, it will be nice to gather some initial information about things that would help draw some effective wireframes. Once you understand what your app will do, the first step is to list the screens present on the app step by step.

They could be somewhat rough wireframes, which would give you an idea of what elements would be present on a screen. The easiest and fastest way to get started is to sketch out your screens by hand using paper and pencils. Once you begin sketching, you may uncover practicality issues in your original screen map or the patterns you use. In some cases, patterns may apply well to a given design problem in theory, but in practice they may break down and cause visual clutter or interactional issues for example, if there are two rows of tabs on the screen.

If that happens, explore other navigational patterns, or variations on chosen patterns, to arrive at a more optimal set of sketches. After you’re satisfied with the initial sketches, it’s a good idea to move on to digital wireframing, using software such as Adobe Illustrator, Adobe Fireworks, OmniGraffle, or any other vector illustration tools. When choosing a tool to use, consider the following features:. Material UI for Android developers Material design for Android includes implementation of visual, motion, and interactive designs for your app on different devices.

Android now includes support for material design apps. To use material design in your Android apps, follow the guidelines defined in the material design specification and use the new components and functionality available in Android 5. Building meaningful motions In the following section, we will cover how to provide motions in our app to improve a user’s app experience.

The Android library provides many components for giving a material experience to the user. We will explain some of the components provided in the Android library in this section. They are distinguished by a circled icon floating above the UI and have special motion behaviors related to morphing, launching, and the transferring anchor point. Floating action buttons come in two sizes: the default and mini. The size can be controlled with the FABSize attribute. As this class descends from ImageView, you can control the icon that is displayed via setImageDrawable Drawable.

The background color of this view defaults to your theme’s colorAccent. The FAB could be used to carry out different kinds of transitions on click. The following are a few images that show the different places where the FAB could be used:. Let’s take a look at how to use the FAB in our Zomato code. Consider the restaurant details screen where we have a FAB button present, as follows; the button can be used at various different places:.

The FAB animation has a button. Clicking on the button opens up the bottom menu and shows us the various options. Here, the transition from the FAB button to the bottom menu forms the major chunk of its material aspect. The following is the complete transition showing how the FAB gets converted to the bottom menu:.

Let’s now look at how to implement FAB in our code. Firstly, make sure that you have added the gradle dependency in your app’s build. The next step is to import and initialize it in your Java class: import android. If you are using Android Studio, the import will be handled automatically, and you don’t have to worry about it. Once it is initialized, you need to handle what will happen when you click on the FAB button: mFab. Now, the menu will appear when you click on the FAB button.

The code for the on click of the FAB is mentioned below. Refer to PlaceDetailActivity. Once this is done, the animation of opening the menu will be executed smoothly. Also, we need to close the bottom menu when clicking anywhere outside. Implementing Search in Zomato The search screen in Zomato opens up when you click on the search icon on the Toolbar on the home page.

Clicking on the search icon will produce a ripple effect, which helps a user to get a better experience:. Figure 1. When you click on the search icon, it opens up a new screen of search. When this screen opens up, there is a smooth transition that takes place as each of the components appears on the screen. The search icon first opens up smoothly to form the toolbar:.

The in-between transition when the search icon opens up smoothly. The search icon’s in-between transition shows that the ripple wave grows gradually until it completely covers the toolbar:. The search icon completely opens up to form the toolbar. Once the search icon translates to form the toolbar, the EditText translates down from the top to the bottom and the quick search options simultaneously translate up, creating a smooth transition effect:.

The Search icon completely opens up to form the toolbar. The major components on this screen are the EditText, for typing the text for searching. Another important component is the RecyclerView, which displays the list of all the details. Here, we are concerned more about the way the UX for the search gives a smooth experience to a user. The showTop method makes the view visible. The view being passed to the method as a parameter is the searchViewLayout, which means that it makes the search view visible.

Then it adds the animation to that particular search view layout. Then, the animation is started using the start method. The following is the explanation of the showBottom method inside the enterViews method: private void showBottom View view, Animator. The showBottom method, similar to the showTop method, will do the same translation animation for the mightLike layout.

This animation will have a listener, which will let you know when the animation starts and when it ends. The exitViews method will be called when the search view has to be closed. In the hideTop method, the searchViewLay will be made to animate along the Y-axis in the opposite direction with respect to the preceding translation: private void hideBottom final View view, Animator.

Building the UX Design With the increased expectation of users who are becoming more accustomed to high quality apps, and as UX plays a very important part in making a user’s app experience better, it is necessary to build a proper UX pattern.

Android library provides many ways and built-in libraries for building a good UX. Besides these, you need to build your own UX patterns depending on the flow of your app.

To build a good UX, you need to use animations in the right places. Understanding UX principles and how it’s different from UI The user experience is very important for keeping a user engaged with the app by making them understand what is happening on the screen. Here is another simple material aspect of UX, where a user gets a very good experience when they click on view on the screen; the UX shows a ripple effect when the user clicks on the view:.

The ripple effect starts from the point of contact with the screen. The ripple is high at the point of contact and gradually decreases its force.

Firstly, a user should know when they click on a button and should not have a doubt whether they have clicked or not. Having this effect gives a user a very good experience when they click on a button. Let’s see how to integrate the ripple effect on the button click of any views. We will use the CardView as the outermost clickable view. The following is the code to do that:.

An inset is used when you need a background that is of smaller bounds than the actual view’s bounds. We need to set a drawable for the inset. This drawable is a selector, which checks three states.

It gives a color to the view, which is set is the colors. The ffffff color set is a white color, and 96 is the alpha value set to give transparency to the white color. Here, the ripple is a built-in class, which defines the ripple effect. It needs to set a drawable and a color.

The ripple color is the same one defined earlier. Summary Material design plays an important part in how a user is able to use an app easily, and hence it makes sure that they use the app more often. In this chapter, we covered material design and followed with the material design animation. We then processed this animation to build animation in the app.

In the next section, we will cover building the core features of the foodspotting app. The idea behind this principle is to design a class that has one responsibility or various methods with unique functionality. According to this principle, a method should not do more than one task at a time. Each function must be designated a unique task. The preceding code is the onBindViewHolder of the adapter of a recyclerView.

It does not satisfy the single responsibility principle, as we are formatting the values as we are setting the text to the views. The onBindViewHolder of the recyclerView adapter is mainly responsible for binding the view with the values of its object class. In the preceding code, the onBindViewHolder is doing more tasks than it should. If we have kept the same format in more than one place and there comes a need to make changes to the format, then we will have to make the changes everywhere and this may result in software logic duplication issues.

If we don’t update the code in some places, it may cause an error. If the code was a logical change that had been replicated, the entire flow of the app would change.

To prevent this, we have to write the code in a way that we don’t have to make many changes if the features are changed. Now, as can be seen, the code checking and formatting are not done in the onBindViewHolder function but they are being done elsewhere.

Due to this, the change of the functionality or format can be done in the common function instead of each instance of the code. Software entities classes, modules, functions, etc should be open for extension, but closed for modification. This principle basically states that we have to design our modules, classes, and functions in a way that when a new functionality is needed, we should not modify our existing code but rather write new code that will be used by existing code. Let us assume we are trying to calculate the area of some shapes.

So let’s take the example of a rectangle and a circle. As can be seen from the preceding function, as new shapes are introduced, the calculateArea function will grow bigger and lots of handling and changes will be required.

Both the rectangle and circle can implement this interface by which the method to calculate the area will remain inside the object class instead of the AreaManager. Now, as the methods for calculating the areas are present inside the objects, the AreaManager will look something like this:. Now we can calculate the total area without ever needing to change the calculateArea method.

The same shape interface can be now used in new classes to calculate the area without changing the AreaManager.

According to this principle, a subclass should override the parent class’s methods in a way that does not break functionality from a client’s point of view. According to this principle, if a class is extending another class, the functionality of the child class should not conflict with that of its parent.

Here we have a rectangle. As we know, a square is also a type of rectangle, so it can extend the Rectangle class. As can be seen from the preceding definition, we can get a rectangle also from the square implementation. Now if we try to get the area, we will get instead of 50, as a square has both the same length and height, which is not the case with a rectangle, and this violates the Liskov Substitution Principle. An ArrayList implements a List but it does not change the basic functionality of the List.

According to this principle, if an interface has too many methods, then we need to divide the interface into smaller interfaces with fewer methods. A simple example of this principle is shown next. Now, while implementing this listener, we only want the onItemClickListener or the onItemLongClickListener; the others are not required but we still have to use them in the code. This violates the Interface Segregation Principle.

Now we will only initialize the ClickListener and use its methods instead of the old interface where we had to utilize four methods. Here we have segregated them into two different interfaces. High-level modules should not depend on low-level modules. Both should depend on abstractions. The best way to explain this principle is by giving an example. Let’s assume we have a worker class that is a low level class and a Manager class that is a high level class.

The Manager class contains many complex functionalities which it implements along with the Worker class, so the classes will look something like this:. Here the Manager class has been implemented and is directly associated with the Worker class due to which changes in the Worker class directly affect the Manager class. If we have to add another class which would be a parent of the Worker class, and the Worker class does similar work to that of the Manager class, it will require lots of changes.

Now the both the worker and SuperWorker class implement the IWorker, while the Manager class directly uses the IWorker to complete its functionality by which changes to the Worker and SuperWorker do not affect the Manager class. They are at times tough to put into practice when it comes to the usage of each individual principle, but making a habit of following these principles will keep your code readable, reusable, and easy to maintain.

It is a style of coding by which we can manage various components of the system we are making. The MVC consists of three main components:. Model: The model represents the object in the application. This has the logic of where the data is to be fetched from.

This can also have the logic by which the controller can update the view. In Android, the model is mostly represented by object classes. View: The view consists of the components that can interact with the user and is responsible for how the model is displayed in the application. In Android, the view is mostly represented by the XML where the layouts can be designed. Controller: The controller acts as a mediator between the model and the view. It controls the data flow into the model object and updates the view whenever data changes.

In Android, the controller is mostly represented by the activities and fragments. All of these components interact with each other and perform specific tasks, as shown in the following figure:. Therefore, to solve this problem, we can use different design patterns or can implement MVC carefully by taking care of conventions and following proper programming guidelines. To explain the MVC pattern components shown in the preceding code; the model here is LocationItem, which holds the name and address of the location.

The view is an XML file, which contains a TextView, through which the name of the location can be displayed. The activity, which is the controller, contains a LocationItem. It gets the name of the LocationItem at a specific position in the list and sets it up in the view, which displays it. It separates the view and model by using the presenter. The presenter decides what should be displayed on the view.

Model: The model represents the objects in the application. View: The view renders information to users and contains a UI Component. It does not have any other logic implemented. Presenter: The presenter layer performs the task of the controller and acts as the mediator between the view and model. But unlike the controller, it is not dependent on the view. The view interacts with the presenter for the data to be displayed, and the presenter then takes the data from the model and returns it to the view in a presentable format.

The presenter does not contain any UI components; it just manipulates data from the model and displays it on the view. The interaction between the various components of the MVP are shown in the following figure:.

In the MVP design, the presenter communicates with the view through interfaces. The interfaces are defined in the presenter class, to which it passes the required data. The connection between the presenter and the view is one to one. In this example, we will show how the MVP design can be used to display a list into a recyclerview:.

This is the LocationInteractorImpl class which is the model. This class interacts with the presenter to provide the list of locations. The loadLocations function is used by the presenter to interact with the model and fetch the list of locations.

The model LocationInteractorImpl then uses the listener. The LocationPresenter class is used by the view to communicate with the presenter. Depending on the functions called by the view, the presenter will communicate with the model and get the responses: public class LocationPresenterImpl implements LocationPresenter, LocationInteractor.

The LocationPresenterImpl class is the presenter class which communicates between the view and the model. This class implements LocationPresenter with which the view communicates with the presenter and the LocationInteractor.

OnLoadFinishedListener from which the model communicates with the presenter. When the view calls the loadLocations function of the presenter, the presenter interacts with the model and calls the loadLocations method of the model, indicating that the model is to return the list of locations to be displayed. The onSuccess and onFailed functions are then called by the model after the list has been fetched successfully or has failed. Then the presenter communicates with the view through the locationLoaded function.

The LocationListActivity is the view where all the interaction with the user will happen. The view implements the LocationInterface, by which it gets the responses from the presenter. It then calls the presenter. It is similar to the MVC model, the only difference being it has two-way data binding with the view and view-model. The changes in the view are being propagated via the view-model, which uses an observer pattern to communicate between the view-model and the model.

The view in this case is completely isolated from the model. The major advantage of using MVVM is it enables automatic changes in the view via the view-model:.

View-model: The view-model helps in maintaining the state of the view and does changes to the model based on the inputs gained from the view. Many views can be linked to one view-model, which creates a many-to-one relation between the view and a view-model. Also, a view has information about the view-model but the view-model does not have any information about the view. The view is not responsible for the state of information; rather, that is being managed by the view-model and the view and the model are only reflected via the changes made to the view-model.

In developer’s terminology, one can say that the view-model is the interface between a designer and a coder.

Clean Architecture Pattern The Clean Architecture Pattern, in its simplest terms, means to write a clean code, by separating it into layers, with the outer layer being your implementations and the inner layer being the business logic.

An interface connects these two layers, controlling how the outer layers use the inner layers. This kind of code architecture pattern is also known as Onion Architecture because of its different layers, as seen in the following figure:. The inner layers have no idea about the outer layers. The outer layer uses the components from the inner layers based upon its needs, meaning the outer layers are dependent on the business logic implementations of the inner layers.

Hence, the dependency points inwards. Understanding the layers of Clean Architecture Understanding the various layers present in this architecture helps to achieve a code implementation that is clean and independent. I will outline the layers in the figure, but focus more on the Clean Architecture core conceptual rules: The Dependency Rule, Abstraction Principle, and communication between the layers:.

Entities: Entities form the core of your app, which means they define what exactly your app is doing. Entities are basically objects created to make a data model to hold the business logic and the functionality that would be carried out on it. Some of the entities for an app could be a user entity, a restaurant entity, a place entity, and so on. Use cases: Use cases are in the layer that forms objects using the core entities. The use cases may contain one or more entities based upon their use.

The use cases are a direct object used for forming a business logic. A simple use case could be order, which books a restaurant for a user. Hence, this use case may contain entities such as user and restaurant. Presenter: This layer is the one that presents a use case for its use. This means that it may have a business logic which would be using the entities to give an output data to the UI for rendering. UI: This is basically the output that you see and is formed by the components such as activities, fragments, views, adapters, and so on.

All of these components form the core of the architecture. This could be forming the way the structure should look like when things are being coded.