FACULTY OF MATHEMATICS AND INFORMATICS Final thesis: Android application for managing access to events Scientific Advisor Defender , Maria Mirou Serb… [614965]

2020

UNIVERSITY OF PITEȘTI

FACULTY OF MATHEMATICS AND INFORMATICS

Final thesis: Android application
for managing access to events

Scientific Advisor Defender ,
Maria Mirou Serb Mariana Denisa

Introduction
Through "EZ -Ticket", any event organizer user has an easy and convenient way to
analyze attendance figures and manage access to the event .
Its primary use is to have clerks use it as a scanner at the gates. Each barcode scanned off
of an event ticket is compared to those stored in the database. If it matches the event in question,
the application will signal that to the clerk and entrance may be allowed. The application takes into
account various cases when scanning a barcode. If a barcode does not belong to the database, the
clerk will be notified. As well, when the barcode has already been scanned or the internal scanner
does not recognize it as a barcode. Error messages according to each specific case will be displayed
to the user, in order to simplify the interaction with the participants and maintain fluidity at the
gates.
Its second use is for event organizers, who can see in realtime the attendace figures, with
the application fetching from the database, the number of tickets that have been scanned f or a
particular event. Also, for each ticket scanned, the venue capacity for that event (a known, given
number) is lowered by one. This feature was implemented to comply with safety regulations and
to help organizers avoid overcrowding.
In the world of An droid applications, the name, interface and logo are as important as
functionality itself. The name conveys the idea of convenience and simplicity. On the graphic side,
the logo is a blue ticket with the letters „EZ” incripted, on a white background. The c olor scheme
for this application is in fact a combination of white and blue. White was used mostly for
backgrounds and blue for action bars. Overall, the interface was kept simple and easy to use to
underline the convenience and simplicity aspects.
The company with the name “Android” started with the design and development of her
own operating system in the summer of 2005 when the google bought this. Android works with a
Linux -Kernel from Sun Microsystems (Oracle since 2010) and is based on the Java -Tech nology.
To develop new applications for desktop PCs many programmers prefer Java or C. To developing
new apps for smartphones in Java are easier for them . Apple released in 2007 their iPhone to
achieve the next goal in computing.

This new type of communica tion tool, called Smartphone, is generally refer to as a phone,
which is a poor labelling. Computers are continued to get smaller in size, using less power and
performing calculations that are more advanced. In 1992 was first used the term Smartphone,
Apple was the first company to release a Smartphone to a wider audience. This evolution is led by
computer manufacturers, software companies, and not handset manufacturers, which have
controlled the market thus far. The Android platform was spawned from the e fforts of an
organization known as the Open Handset Alliance (OHA), which had at the outset the mission
of collaborating to “build a better mobile phone.” Today, if you visit the Open Handset Alliance
website , you might think that their efforts were in vain, as the latest news item dates to 2011.
However, what was started with that group of carriers, hardware manufacturers, and
software vendors has grown into the world’s most popular platform. Is Google t he “man behind
the curtain” of the OHA? Maybe, but no matter. In the decade since its introduction, Android is
offered in the market by many large players across the globe and across numerous industries.
Samsung, also a member of the OHA, is the leading ma nufacturer of smartphone devices
worldwide, thanks to Android. Although a single device (the G1 device manufactured by HTC
and provisioned on the T -Mobile network) started it all, Android devices are now available in
virtually every market on the planet — not just for mobile phones.

Chapter 1 . Fundamentals of Android
What is Android?
Android is an operating system and programming platform developed by Google for
mobile phones and other mobile devices, such as tablets. It can run on many different devices
from many different manufacturers. Android includes a software development kit (SD K) that
helps you write original code and assemble software modules to create apps for Android
users. Android also provides a marketplace to distribute apps. Altogether , Android represents
an ecosystem for mobile apps.
In the market they are already severa l competing mobile phone software stacks, so why is
there such interest in Android?
In the development and sale of a new generation of mobile phone application software
android has the potential for removing the barriers to success. Just as the standardiz ed PC and
Macintosh platforms created markets for desktop and server software, Android, by providing a
standard mobile phone application environment, will create a market for mobile applications and
the opportunity for applications developers to profit fro m those applications. In the developers’
conference from May 2013, Google presented the new development environment for. The new
IDE is intended to replace Eclipse and is based on the "IntelliJ IDEA" Java -IDE by JetBrains. The
powerful Code -Editor with built -in functions such as "Smart Editing", which ensures bette r legible
code, or "Advanced Code Refactoring” is one of the core components of Android Studio. Android
Studio introduced another novel feature for the Gradle Build System . It replaces the Ant Build
System used until now. Gradle allows developers to creat e various configurations so that different
app versions can be produced using the same code. When you want to release a free and a paid
version this is really useful for an app. Gradle improves the reusability of the code and the
integration on a build ser ver. Similar to Eclipse, the layout of an app can be created either in the
text editor or in a graphical interface (design mode) in Android Studio. The Android Studio design
mode was improved whit the layout who shows the different resolutions, Android ver sions and
country -specific special features in the preview. In Android Studio were integrated a series of new
features and services. The developer console gives developers tips for optimizing an app and it
also allows uploading the “string files” (strings. xml) to be translated to a central server, and
to insert them again in the app after translating them. Android Studio was enhanced with an option

to add Google Cloud Messaging (CGM) to the project that allows sending messages to the app and
receiving the m essages from the app on the cloud server. It is not a new feature to connect an
Android app with a cloud server/ App Engine Server app. Novelty for Android app was the
integration in app project . Earlier, it was essential to create an App Engine Server ap p and an
Android app that is sup – posed to work with this server app separately from each other.

Google in collaboration with JetBrains has been developed Android Studio and is based on
the community version of IntelliJ. JetBrains Java IDE InelliJ sup – ports Android app development
since 2 years. IntelliJ Version 12 has new features that have been dev eloped in collaboration with
Google, but not yet integrated. These will be integrated in Version 13+. Like before, even the new
version will support a series of development environments such as Java, Android, Adobe Gaming
SDK, Groovy, Scala. Android Studio will be restricted to the development of An – droid apps.
Google has not specified an official release date for Android Studio. Android Studio is still being
developed and should not be used in the productive app development as yet. However, since a
major part of the IDE is already functional, users can still start befriending Android Studio. This
is recommended since they can rev up once the finished version is released.

About Android
Android is an operating system based on the Linux kernel and design ed primarily for
touchscreen mobile devices such as smart -phones and tablet computers. Android was created by
Andy Rubin as an operating system for mobile phones around the beginning of twenty -first
century. In 2005, Google acquired Android Inc., and jus t after made Andy Rubin the Director of
Mobile Platforms for Google. This was a great business decision for Google to purchase the talent
and intellectual property necessary to assert the company into this emerging space, which has been
become known as Int ernet 2.0.
Internet 2.0 was a great step in the history of computer science. It allows users of consumer
electronics to access content via varied data networks through a lot of portable consumer electronic
devices, such as touchscreen tablets, smartpho nes, e -books, iTVs and set -top boxes. This thing
has had a big impact by putting new media content such as 3D animation, digital audio, games,
HD imagery into our lives at every turn. Android has become a great tool that digital artists will
use to develp o media creations that users have never experienced before. Over the past years,
Android has evolved into an extremely reliable operating system platform, having gone from
version 1.0 to more stable versions at 3.0, 4.4, 5.0, 7.0. Today, Android has the po wer of a full –
blown computer operating system. It is based on the Linux open source platform and one of the
world’s most popular programming languages Oracle’s Java.

How do Android Apps Work?

There are different ways the programs run on various platforms. The lowest level software
can be written in machine code that runs directly on the microprocessor. This is shown in Figure
1.2. Since it is difficult to develop complex applications in machine code, operating systems are
used. Operating systems provide a communication and control layer between the application
software and the hardware as shown in Figure 1.3. If we want to develop a native application for
running on a specific hardware/operating system, we have to do this u sing a compiler and linker.
Compiler and linker takes the source code and creates the executable file that actually runs on the
operating system as shown in Figure 1.4. For example, if we want to develop an application in
C++ programming language, we have to utilize the compilation/linking process.

Figure 1.2. Machine code – hardware relation
The main advantage of native applications is their speed. However, the disadvantage is the
incompatibility across different platforms. For example, we cannot run a n ative Windows
application on Ubuntu and vice versa. Virtual machine concept is developed to overcome this
limitation. Virtual machine is software that runs on the operating system and provides an
abstraction to the developer as shown in Figure 1.5. The app lication software runs on top of the
virtual machine .

Figure 1.3. Operating system layer between the hardware and the app

Figure 1.4. Creating a native executable from the source code
Therefore, as long as a computer has the virtual machine running, the application software
can run on that computer independent of the hardware and the operating system. A good example
is the Java Virtual Machine (JVM). JVM runs on almost all operating sys tems and platforms.
Therefore, when we develop Java software, it will be run on the JVM independent of the operating
system/platform.
The obvious advantage of developing apps that run on virtual machines can then be stated
as: “develop once and run on all platforms”. However, applications running on virtual machines
are slower than native applications.
General development process of virtual machine applications is summarized in Figure 1.6.

Figure 1.5. Virtual machine between the app and the operating sy stem

Figure 1.6. Creating an intermediate code from the source code – intermediate code is interpreted
by the virtual machine
Similar to Java applications, Android applications also run on a JVM. There are two special
virtual machines used in Android: Dalvik Virtual Machine (DVM) and Android Runtime (ART).
These are specialized JVMs which can run on low system resources. The .apk files (executables
of Android apps) actually run on these virtual machines. DVM has been the default runtime
environ ment (~ virtual machine) until the Lollipop release (Android 5.0). ART is introduced by
Android 4.0 and has been the default VM as of Android 5.0. DVM and ART basically do the same
job: running Android apps independent of the platform. The main advantage o f ART over DVM
is the utilization of a concept called Ahead of Time (AOT) compilation instead of Just in Time
(JIT) approach. In AOT, apps are compiled during installation hence they load faster with lower
CPU usage. On the other hand, JIT compilation prov ides lower storage space consumption with
relatively longer loading times.

The evolution from the first to the latest version of android
In past mobile phones were used only to make calls but with the introduction of smartphone
the mobile phone has e volved to a low powered hand held processing system. This evolution was
caused by the operating system for the mobile phones making them smart that have processing and
storage of their own.
Now the mobile provides numerous functionalities from calling to texting, multimedia
sharing, emails, socializing applications, word processor, excel sheets to various multiplayer
games and much more. The operating system for these is Android by Google. Among the
competitors in smartphone operating system industry Andro id holds the largest market share in
terms of units shipped worldwide and number of users. Android is an open source operating system
based on Linux kernel on which applications run on an application framework that controls the
activities supported by the libraries and Dalvik virtual machine which compiles and converts all
java class files into a single file. There can be number of virtual machines running simultaneously
on a single device handling different applications or instances of an application. Andr oid operating
system provides memory management, process management to the applications and services
running. Each release of android improved user experience and brought enhanced features. This
paper presents a study of evolution that each release brought to the android operating system
Smart phones in today’s world have become so popular that they have captured a big
economical market along with a large number of users each using different types of smart phones
with varying features. The most prominent th ing that distinguish smartphones industry and their
user base is the operating system being used among which popular are Android, iOS and Windows
phone. With the statistical figures from International Data Corporation (IDC), the smartphone
industry grew by 1.1% last year and by third quarter of the year more than 350 million units were
shipped worldwide. Android has maintained its position on score board with market share of
86.8%.

This increase in the demand of android phones trade, customers concern is to select and
buy the phone that meets their requirement within affordable price. In the present era of
competition different vendors are trying to make profit by using the Android O S because of its
acceptance among the users. With each day the struggle and efforts been put to give an operating
system that is compatible with most hardware and provide all the necessary feature to the users in
an efficient way Android production is grow ing. Every corporation desires to give best quality in
their android phones and as well improving features to be its main objective. The immense usage
of android lead in the direction of advance method about usability, multitasking, accessibility,
protecti on of end user -private data and many more, in which each release is expected to cater the
mentioned issues provide something new to the user. The architecture of the android phones was
first developed by Android Inc. now owned by Google and launched Androi d Open Source Project
in 2007. That statement was taken by the foundation of the Open Handset Alliance.
The software used in it launched under the Apache license as an open source. The Open
Handset Alliance is a collection of many hardware, software and t elecom Firms may also include
Intel, Google, NVIDIA, Qualcomm, Motorola, HTC and T -Mobile, in which Android is the
adapted -able OS. Its core objective is to build up advance equipment according to its technology
that may considerably less the time and cost as well and also enhance the services and provides
best features to customer. At present android version in use are kit Kat, Marshmallow and ginger
bread. Table below shows the history of Android operating system from initial release to the day.
Operating system that acts as a bridge between user and the hardware, same is with Android OS.
We talk about android Operating system the latest version is Nougat this version upgraded up to
7.0-7.12 which is based on Linux 4.4.1 kernel that consist upon layers, th e architecture of which
is shown in figure 1. The application layer in an android operating system is the top layer that
include utilities like SMS, contacts, phone, browser, camera, media player, cleaner, etc.
All of which are develop in Java programming language. The utilities or applications
require application framework as a base to setup up and work. Application framework is large set
of analysis used for developing an apps with attractive GUI that may consist of check list,
navigation menus, text box, button, check box, and more likely an embedded and responsive web
browser. A Resource Manager provides access to resource as well but not access to source codelike
restricted String, GUI and design.

Table 1. Versions of Android Operating System

Notific ation Manager enable all apps to show routine alert on the screen. Activity Manager
Control the lifecycle process of apps also offer an ordinary routing back stack. Beneath library
layer consist a set of java library files applied by wide range of the Andr oid Operating system
processes and also offer maintenance to the Application framework. In Android Runtime layer
focus is on the set of core libraries and a Java Dalvik VM Dalvik virtual machine which can
redevelop and adapted via Google to become suitable source for Android OS. Linux kernel is
placed at the bottom layer of android OS to perform the task of fastest layer among the hardware
and software of Android. It may also provide major structure services of Operating System like
protection/security, mem ory management, processes functions, network system, driver modules
and functions such as management of threads of Dalvik virtual machine included in the Linux
kernel system.

Fig 1. Architecture of Android Operating System

Android operating system run i n the Linux kernel, its application are developed in Java
language so its task is to execute the applications on Java virtual machine called Dalvik VM.
Dalvik has been redeveloped and optimized by Google as for the hardware aspect of smart phone
devices. I n smart phone operating system a tool called .dx exist in the smart phone software
development kit which convert Java files compile in a standard Java compiler into the dex formats,
that join together all of the Java class files and remove unnecessary dat a in each Java class files.
Characteristics of Dalvik virtual machine is as follows; Smart phone application run in a instance
of a Dalvik virtual machine. There may exist various instances of Dalvik virtual machine instance
on single machine, each instanc e runs in the form of chunks or separate Linux process. Dalvik
virtual machine depend on the original OS Linux kernel for the execution, isolation memory
manage process and threads supporting. Dalvik virtual machine is register based process.

Each applica tion in android operating system is running separately of other and has
memory spaces reserved for them making each one data inaccessible to others.
For communication among applications message parsing is used. With the release of
Android cupcake in 2009 API level 3 was used and the operating system supported widgets, search
browsers, navigation applications that included free data of map to act as a navigation device.
Content can be updated and synchronized over the internet without the need of a computer system.
Android Donut Operating System released the same year of cupcake used API level 4 that provided
the features of phones screenshot capture and voice commands along with the features that were
available in cupcake. To enhance user experience Android Éclair release used API Level 5 that
enabled the operating system to support low density display screens from 320×240 to 854×480
high density screens. Instead of separate navigation centralized access was provided to user by
selecting a contact on which c all, message and email can be made with a tap.
Manage multiple email accounts with a universal account. Search and time based deletion
of SMS and MMS. Camera, browser features were improved and virtual keyboard was introduced
with intelligent auto correct feature. To accelerate the hardware graphics architecture was modified
for better performance. With the next release of froyo by Google it was claimed to have the fastest
browser than any other smartphone would have in 2010 that used API level 8 with an i mproved
performance rate of 2.5 times then all the previous versions released. To improve the security of
the devices alpha numeral and numeral options were added in password and remote access to reset
device data in case of theft or robbery to protect the privacy and integrity of the users. Before the
release of froyo android operating system only allowed installation of the applications to be done
on the device memory, whereas with froyo users can now install the applications on the external
media as well . Among improved camera features and remote access through android cloud APIs
for gesture detection for multi touch and OpenGL 2 for ETC1 text compression, YUV images was
also supported by the operating system.
As the android operating system was initially developed by Android Inc. which was based
on Linux kernels so google did not do the things from scratch and focused on providing better user
experience by continuing the work of Android Inc. Platform was initially developed by Android
Inc. So, with the re lease of Android gingerbread with API level 9 Linux kernel was upgraded to
2.6.35 due to which the operating system was now able to manage power more efficiently with

refined user interface. New devices were coming popular in market that have large display s, and
need for communication over internet. With android gingerbread near field communication (NFC)
was added that could have high frequency communication with in the radius of 10 cm. To meet
the market demand gingerbread supported SIP: Session Initiation Protocol for audio and video
calling if the device has a 3g or Wi -Fi connection of internet. The introduction of SIP broke the
traditional barriers of communication and the worry for billing for its users. Other features included
audio encoding, video pla yback, multi touch virtual keyboard and gyroscope sensor which in
extension to accelerometer that sense the alignment of phone calculates the rotation rate around x,
y and z axis which can also be termed as twists. Accelerometer measured the linear and gyr oscope
measured the angular movement of the device this addition paved way in support of virtual reality
With the second big release of honeycomb in 2011 google also introduced its first
smartphone Nexus S in liaison with Samsung. Honeycomb revolutionized the android operating
system by the support of multicore processor environment with symmetric multiprocessing due to
which multitasking was possible with all screens active at the moment. This update to the operating
system was a major advancement among ot her updates that include enhanced web browsing
experience, google talk, 3d effects in google map and multiple home screens to let the user
customize the interface as per their wish. The last release of 2011 was ice cream sandwich API
level 14; the ice -cream sandwich release was compatible with both low and high resolution
devices. Multitasking ability of operating system was further enhanced in which the opened
applications can be switched in between by seeing the list of running applications. Notifications
appearance was enhanced by removing the popups and showing them in the top of the screen where
a certain a notification will show its detail on tap. Ice cream sandwich operating system was
improved to open microphone voice command for which the system is always ready to receive
voice commands and process them instead of first starting the service before use. While the device
is lock previously all applications are stopped and cannot be accessed whereas in ice cream
sandwich operating system lets user answe r the incoming calls, move among the playing media,
and for authorization of user in addition to alpha numerals and numerals face lock feature is
introduced to verify the authenticity of the user. Pertaining to the users demand camera features
were refined that included increased snap shot speed, continuous focus, zero shutter, panorama for
image and at the same time recording videos of high definition. Ice cream sandwich release paved
the way for future in which innovative, interesting, customized applicat ions and features can be

provided to users. Example of which is Android Beem based on NFC that would allow the users
to share the content at a much higher speed which was not possible before. Jellybean release came
in 2012 with API level 16 that revamped a ll predecessors not in terms of speed and performance
but user experience in which all core features of Ice cream sandwich were intact with widgets
being intelligent to replace themselves based on the addition or deletion of any widget instead of
lying sti ll. For smooth user experience user interface design, had refresh rate of 60 frame per
second to make it more responsive. Other enhancements included support for five languages with
right to left languages support, digital rights management, security measu res, low energy Bluetooth
for audio, video calling and remote access. A drawback in the schema was operating system does
not prevent acquisition of device location even though Wi -Fi is turned off.
KitKat operating system was released in 2012 with API leve l 19 in which the along with
user interface focus was equally put on speed and performance as well that was achieved with
improved multiple sensors feedback, use of tri -core CPU, improved battery usage for long lasting
battery time, resolution up to four t housand and updated schema for user interface. With KitKat
operating system applications installed in devices can be exchanged with other device and all
previous versions of android were upgradeable to the KitKat. The edge to edge technology enabled
the us ers to not only remotely access their device but also to perform activities like cloud printing,
managing resources and many more. Android lollipop with API level 21 was released in 2015 to
enhance users’ experience with 3D views now elements can be viewed in real time with shadows
as the object moves. With shared visual elements transition of elements from one state to another
is done smoothly and seamlessly. With the new design threads are rendered for smooth execution
of animations even though there come s a delay in the user interface main thread. The lollipop
version does not compromise on the performance of system for which it runs on new Ahead of
time just in time and Android Run Time codes built from scratch to meet the needs that supports
64-bit MIPS and ARM architecture. This update fulfilled the need to efficiently reduce garbage
and keeping the applications responsive without affecting their performance. To strengthen the
claim of high performance android KitKat offers enhance audio, video synchron ization by the use
of pipelining for smooth output. For productivity, new sensors were introduced that included
sensor for heart rate, to detect interactions such as flick, swipe, pinch etc. interaction sensors and
for activity recognition tilt sensor. The new added APIs improved battery performance,
accessibility, web view, screen capture and camera features.Android marshmallow API

Level 23 was released same year of KitKat in which finger print detection was introduced with
which number tasks can be performed such as unlocking the device, answering incoming call and
holding up outgoing calls, browsing images in gallery, capturing and recording in camera and
many more but as per security authenticity and integrity of users’ device and data oper ating system
was able to provide an extra added layer by fingerprint sensor. Previously when an application was
installed it was mandatory to grant all the permissions asked at the time of installation and it cannot
be altered later on. With marshmallow, i t lets the user change the application permissions to
empower the user. For fast charging type C cable was introduced and doze mode enables operating
system to save more power and can almost double the battery time. Notifications and camera can
also be acc essed while the screen is lock. The most recent release of android operating system is
Android Nougat with API level 25 in 2016. In nougat operating system, the most prominent feature
is of multitasking of applications in split screen. With marshmallow per formance, look feel and
performance was delivered to the best and nougat focus was to improve the existing features
provided by marshmallow.

Table 2. Features of Android Operating System

Android v ersions history
The version of android is updating day by day since its relase.
Now, the question comes, why is a new version always needed? It is very simple, these updates to
the base operating system mainly focusing on fixing bugs as well as adding new features to provide
more comfortable environment.
This is the most recent released versions of android:

Let’s say something about each one and see every novelty they came up with.
Gingerbread
Launched in December of 2010, Android Gingerbread was the first major overhaul of the
OS, bringing cutting edge technologies like NFC (near -field communication), while improving
performance and app lication management. Additionally, the user interface was given a makeover
to facilitate user interaction and minimize resources.

Unlike previous versions of Android, Gingerbread received updates for a long period of
time. Mainly, this was due to the fact that version 3.0 Honeycomb was tablet -only, thus mobile
carriers continued selling phones that ran on Android 2.3, making it a key target for developers
for the next two years. This version refined the user interface, improved the soft keyboard and
copy/paste features, and added support for Near Field Communication.

Fig 1. Gingerbread android interface
Ice Cream Sandwich
Android 4.0 also upgraded the interface, while still adhering to the holographic standard set
the previous version. Monotone white and grey tones were removed from the menu and a new font
was introduced ,"Roboto", specially designed for smartphones with high resolution screens.
Although the icons used had a futuristic desi gn, they lacked the science -fiction style of Android
Honeycomb.
This version in particular, placed a great deal of focus on details. Among others, all the lines
and useless buttons were removed from the design and a few interface behaviours were
implemente d. For example, a flash of blue energy when scrolling to the end of a list, or a glowing
outline when icons would be rearranged. Into a "cohesive whole.

This version had new features added to the Smartphone’s Such as photo enhancements,
offline email sear ching, facial recognition unlock, network data, and usage monitoring
Furthermore, Ice Cream Sandwich brought common design elements to Google's own applications
, like the action bar and overflow menus. These design traits would evolve over time, but the most
important aspect of this version were the guidelines implemented by Google. Although it was
unprecedented, this was done in order to aesthetically blend applications in the "Holo" ecosystem.
There were also changes regarding functionality. Following t he trend set by tablets, smartphones
now had buttons on the touchscreen. A specially dedicated button to switch between recent
applications was added too, as more and more users used their phones for multi -tasking.

Fig 2. Ice Cream Sandwich interface

Jelly Bean
From a mechanical point of view, Android had come a long way from its first version on
the T -Mobile G1. Now, the second phase of development would focus on performance
improvement. More precisely, reducing the execution time and resources needed to carry out any
given task. The first steps in this direction were made once Android 4.1, informally known as Jelly
Bean, rolled around. The special attention this project got made version 4.1 the longest running
Android version of all t ime, receiving updates from summer of 2012 to autumn of 2013.For
developers, new accessibility APIs were added, expanded language support with bi -directional
text support and user -supplied keymaps, support for managing external input devices (video game
controllers), and low -level access to hardware and software audio/video codecs . In this version,
the home screen was presented with new features, like the ability of shortcuts and widgets to
rearrange themselves when moving or resizing an item, and the noti fication system was improved,
introducing the concept of "consumable" and "actionable" notifications .Now that Android was
regarded market leader in most countries around the world, aspect played a more important role.
Fluid transitions, improved scrollin g animations and an overall smoother visual experience were
pivotal to this project.
This was also the first version to introduce Google Now . By monitoring commonly input
keyboard data from conversations or internet searches, Google Now would proactively deliver
relevant results to the user, in the form of "cards". Specialized cards existed for birthdays, movies,
nearby events or locations, sports, restaurant reservations and weather, among others. At the time,
the feature was virtually praised , being named "Innovation of the year" for 2012, by Popular
Science magazine. The new focus on responsiveness with Project Butter, Jelly Bean brings multi –
user accounts, actionable notifications, lock screen widgets, quick -settings in the notification bar,
Photosphere to the "stock" Android camera and Google Now. Jelly Bean is hailed by many as the
turning point for Android, where all the great services and customization options finally meet great
design guidelines .

Fig 3. Jelly Bean interface
KitKat
The android version KitKat was launched on October 31st 2013, and although it did not
represent a total re -think of Android's visual style, it did bring some changes. Translucent status
bars and software keys opened up the large 5 -inch screens of the time, a nd lighter, brighter colors
throughout the UI made Android seem more approachable .
Moreover, the built -in application launcher was revised to incorporate Google Now to the
leftmost panel of the home screen, underscoring thus the importance of predictive search to
Google's vision of Android. Starting with the focus on visual improvement for Android 4.1, the
main goal of this version was overall performance improvement, particularly on low -end devices.
A special developing tool entitled "procstats" was en gineered to analyze the random accessed
memory for applications, especially those running background services . The collected data was
then used to optimize and decouple the inefficient applications and programs.
The KitKat android version brought a lighte r, flatter and far more colorful look to Android,
but many more changes were under the hood. These were the foundation for things like the Google
Now launcher, SMS integration with Hangouts, and easier and faster use all around.

Fig 4. KitKat interface

Oreo
It contains a number of major features, including notification grouping, picture -in
picture support for video, performance improvements and battery usage optimization, and support
for autofillers , Bluetooth 5 , system -level integration with VoIP apps, wide color gamut’s , and Wi-
Fi Aware . Android Oreo also introduc es two major platform features: Android Go – a software
distribution of the operating system for low -end devices – and support for implementing
a hardware abstraction layer .
The aspect of the OS was kept mostly unchanged from previous versions, with a few minor
changes. The "Settings" application features a new design, with a white theme and deeper
categorization of different settings, while the ringtone, alarm and notification settings now contain
an option for adding custom sounds to the list . The Android 8.1 update supports the display of
battery percentages for connected Blueto oth devices, made the notification shade slightly

translucent, and dimmed the on -screen navigation keys in order to reduce the possibility of screen
burn

Fig 5. Oreo interface
Lollipop
The android 5.0 Lollipop was released by the Google with the Nexus 6 and Nexus 9, and
it ushered in a new design language and support for 64 -bit devices. It's also the first time Google
has provided developer beta previews of the software.
This android ver sion was launched in October of 2014 and it came with a radical change
of style, having the "Holo" design pattern replaced with "Material Design" . This meant brighter
colors, thinner fonts and a meticulously thought out design, with many grid -based layout s that built
on the idea of folding layers of paper. Notifications could now be accessed from the lock screen
and displayed inside applications, as banners placed in the upper part of the screen. For the first
time ever, design guidelines and thousand of n ew APIs were released to developers beforehand,
through the "Android L" package

Still, Android Lollipop did not bring changes only on a design level. The new "Tap and
Go" setup process made it simpler to transition from one version of Android to another, " Guest"
mode and pinned applications were developed for situations when somebody else other than the
user would control the device and "Overview", the new multitasking view, made for a better way
to switch between applications . Moreover, Google made intern al changes, with Android Runtime
(ART) officially replacing Dalvik, thus improving performance .
A number of system characteristics focused on separating personal and professional data
were introduced as well, under the moniker "Android for Work" . Further more, with the "Smart
Lock" function, devices could be configured to remain unlocked while in a certain location or
connected to a specific Bluetooth device . Lollipop was also supposed to have built -in device
encryption on all capable smartphones. However , due to performance related issues, this feature
was postponed until the next version

Fig 6. Lollipop interface

Marshmallow
Android 6.0 gets better control over permissions, allowing you to control what parts of
your data apps can access, rather than approve it by simply installing the app in the first place.
That's just the beginning, and features like app linking and the new Assist API will allow
developers to build better and more powerful apps.
Perhaps the biggest improvement of this version was the redesigned permission -model.
This meant applications were no longer automatically granted all of their permissions at
installation time. Rather, an opt -in system was now used, in which users were prompted to grant
or deny individual permissions (s uch as the ability to use a device's camera) when they are needed
for the first time. The grants are remembered and can be revoked by the user at any time . However,
the new model can only be used by applications developed from Marshmallow onwards, with ol der
applications retaing their all -or-nothing approach

Fig 8. Marshmallow interface

Nougat
Nougat introduces notable changes to the operating system and its development platform,
including the ability to display multiple apps on -screen at once in a spl it-screen view, support for
inline replies to notifications, and an expanded "Doze" power -saving mode that restricts device
functionality once the screen has been off for a period of time. Additionally, the platform switched
to an OpenJDK -based Java environment and received support for the Vulkan graphics
rendering API, and "seamless" system updates on supported devices.
On the user interface side, Nougat redesigned the notification shade, which now feat ured a
smaller row of icons for settings, replacing notification cards with a new "sheet" design, and
allowing inline replies for notifications. Moreover, this version introduced the concept of bundled
notifications, and greater per -application control ove r them.

Fig 9. Nougat interface

Pie
Android 9 Pie brings Google's updated Material Design spec (don't call it "Material Design
2") to Android OS, and it begins a wave of UI updates that will spread across Google's entire
portfolio. In Android, that means revamped interfaces for the notification panel, Recent Apps,
settings, and various bits of system UI. For future smartphone designs (like, say, the Pixel 3),
Android 9 includes an experimental gesture navigation system and built -in notch support. The re's
also a new screenshot editor, lots of improvements for text selection, and changes to the way
rotation works.

Fig 10. Pie interface