Development Of Mobile Applications GDF Mobilinfo

Transcription

1 Development Of Mobile Applications GDF Mobilinfo Sándor Kaczur, Miklós Kállai Dennis Gabor College, Budapest, Hungary Abstract - The article reviews the aspects of what we should consider during mobile application development. We pick out the suitable disciples/methods for mobile platforms from the basic approach of software development. We introduce a specific example that is capable of representing data related to course schedules, exams and consulting hours from the student-administration system of the institute for the students. The application came on Android and Windows Phone platforms, based on Windows WCF Service. We will introduce the application s functions and share the experiences of the publications. Keywords: higher education, mobile programming, mobile technology, mobile application INTRODUCTION The first commercially available mobile phone was introduces in Japan, in 1979 [1]. It is good to know that the devices are constantly developing with the wireless radio networks and their services. The mobile market has four market participants: network operator, service provider/service, device manufacturer, and user. The history of the mobile networks can be divided into generations, the short summary can be found on several links, f.e. [2]. Nowadays we live in the time of the third generation of mobile networks and devices, however 4G is spreading [3, 4]. The mobile devices can be divided into three categories; simple/common, smartphone, and PDA. Their services are continuously widening, the borders of the categories are changing [5]. MILESTONES Briefly review the development of the mobile market in terms of the manufacturers and platforms: In 1996 came out the Palm Pilot 1000 PDA device [6], which created an independent product category. In the same year, came out the Windows CE operating system [7] it also specified the characteristics of the devices (minimum hardware requirements) which could operate it. In 2000, Ericsson introduced R380, the first smartphone, which was built to run on Symbian operating system, and from 2001 Nokia created mobiles based on Symbian system [8]. In 2005, the Android mobile operating system [9] came out developed by OHA with numerous services [10]. In the beginning of 2007 Apple based on several successful devices and functions launched iphone smartphone. [11], again with many functions [12]. In 2010, Microsoft came out with Windows Phone smartphone [13]. Nowadays the penetration of the mobile phones is about 85% worldwide [14], within this smartphones are growing (Fig. 1). 25

2 sensors: accelerometer, gyroscope, ambient light, proximity. We can acquire the mobile apps through virtual marketplaces [18, 19, 20]. Fig. 1 The penetration of the mobile phones [15] PLATFORMS The mobile platform can be view as hardware (devices), operating system or virtual machine. It includes the architecture of the mobile devices, the operating system that operates the device and the programming language that enables the development, dynamic libraries and the user interface. The spread is constantly changing (Fig. 2). ANDROID Android is a Linux kernel based operating system, which is run by the Dalvik virtual machine. It supports directly the hardware of the mobile devices and the current multimedia formats. Originally the Open Handset Alliance was the developer, later it was Google. It is an open source project with Apach licence. There is a huge developer community behind it. In June 2012, there were 400 million Android devices worldwide and each day one million new Android devices get activated [21]. Java language can be used to develop applications, usually with Eclipse IDE supplemented with special class library (Andorid SDK). Activity can be regarded as a basic component. The GUI can be created declaratively. Currently the Android applications provide the 50% (half) of the downloads in Mobile Applications Market (Fig. 3) [22]. More about the platform and the development: [23]. Fig 3 Download of the Android applications worldwide (April 2012) Fig. 2 Operating systems of the smartphones [16] SMARTPHONES There is no industry standard for the functions and features of the smartphones. Smartphones have fully operational operating systems. These phones offer , internet access and include a complete keyboard. They can be viewed as mini computers. New applications can be installed, there are developer tools (SDK) with which we can develop our own mobile apps [17]. Some service/function that are supported by mobile operating systems are: touchscreen, camera, text message, MMS, internet, picture and voice recording, Bluetooth, WiFi, GPS, digital compass, The newest API version came out the same time (4.1, codename Jelly Bean) [9]. There are major design differences between the main API versions. The advantages of Android platform: more and more clear-out user interface, easier usage, mandatory Theme since ICS, and we can develop unique design. The disadvantage of Android platform is the fragmentation, the functionality has to be adjusted to the lowest version in use. 26

3 WINDOWS PHONE Windows Phone is the mobile platform and operating system of Microsoft Company. They developed the previously wide spread Windows Mobile platform, it is based on Windows CE kernel. IT has strict hardware requirements, however, has a narrower HCL. The modern, clean and elegant user interface called Metro, it can be regarded as a specific Silverlight surface. There are several device manufacturers; Samsung, HTC, LG, Nokia, however they cannot change the design. Currently, the latest version is the 8th. It supports multi-touch technology, further services [24]. Software updates can only happen under Microsoft s supervision. It is characterized by code reuse: WPF, Silverlight and WP7 can share the sources and the MVVM as robust architectural design pattern. We can develop to the platform in C # language, Windows Phone SDK, Visual Studio development tool. The GUI can be created declaratively in XAML markup language. LIMITATIONS Software development is still limited by the possibilities of the operating system and the hardware. Compared to desktop or web applications development, in case of the mobile platforms it is significantly smaller cross-sectional area. Weaker, more limited hardware: slower ARM RISC processors are available, there is less available memory, there is limited capacity power supply / battery and the devices grant smaller displays. In addition, the small number of graphical components, the SDK class library is not as diverse [17]. All these must be taken into consideration when we develop applications for mobile platforms. Take note on design regulations, recommendations, and therefore we cannot create applications with the same user interface on all platforms. The smaller display is an enormous challenge, attitude has to be changed to be able to provide a sufficiently user-friendly and easy to use interface. SPECIFICATION AND REQUIREMENTS GDF mobilinfo should be an easy to use mobile application that is capable of representing data related to course schedules, exams and consulting hours from the student-administration system of the institute (DGC) for the students. RESTful Windows Communication Foundation webservices that was developed for the learning system generates the data to be displayed in CSV format after the client request in a personalized and - to minimize the traffic - compressed manner. The mobile device should be able to initiate an update in an authenticated and encrypted way (NEPTUN code, Neptune password). The received compressed data is unpacked and stored on the client's local database, it can be processed and displayed in various ways. During the observed period, the statistics based on WiFi usage shows that the mobile devices connected to theinstitution's wireless network were 70% Android, 20% ios, 10% of the other platforms. Thus, the instruments used are as follows: On Android platform: Android SDK (minimum API level 7, Android 2.0/2.1), Eclipse IDE (Indigo, Juno), Android Developer Tools plugin for Eclipse (v15-20), test hardware: Samsung Nexus S (GTi9023) and Samsung Galaxy Nexus (GT-i9250), programming language: Java SE 1.6. On Windows Phone platform: Windows Phone SDK 7.1, Microsoft Visual Studio 2010 Express, Microsoft Blend for Windows Phone, test hardware: Samsung Omnia 7 (GTi8700), programming language: C#, Silverlight for Windows Phone. Windows WCF Service: Microsoft Visual Studio 2010 SP1, Microsoft SQL Server 2008, Entity Framework 4.0, programming language: C#. Participated in the development of the application: Tamás Endrődi (Database Programming), Miklós Kállai (WCF Service, Windows Phone and Android platforms). One direction for further development is the iphone platform, which will be created by Norbert Zsolt Zentai. DEVELOPMENT ON ANDROID PLATFORM Google has chosen for the development the Eclipse IDE development tool [25], and prepared the ADT (Android Developer Tools) plugin for it [26]. This allows to use the Android SDK, provides code completion, graphical UI editor, debugger, and pre-built templates. 27

4 Before the start of the development, it was necessary to determine the API version, which is considered a minimum. Those days the Android version 2.1 still had a share of over 10%, it could not be neglected. Due to the various Android versions, and the difference between the surfaces of the different manufacturers a custom graphical interface has been developed. Thus, the students are given a unified application. The basic principle was that the start screen promptly made available to the personal timetable, examination results, the office hours and time tables. Here is an excerpt from the GUI source code (Fig. 4). Fig. 5 Android source code snippet (event handling and application logic) When the application got in an adequate state some selected students received the last version and the reported errors have been corrected. Fig. 4 Android source code snippet (xml, GUI) This has been solved with a DashBoardLayout [27] interface that has four large buttons with icons and labels indicating the available features. From here we can navigate to the lists, which provides additional navigation to the list elements by a "click". In places where you have to navigate between the days of the week a ViewPager component [28] has been used, so the days can be swiped. On start, the application verify if there is a configured username and password. In their absence, the user is prompted to enter them, otherwise displays the start screen. If there is no database, it connects to the server and downloads the personalized csv, which is processed and stored in a SQLite database for offline use. Further updates can be automatic (personal preference), or manual. During the development process - although there is an emulator - a Google (Samsung) Nexus S device has been used as a developer device. It facilitated to troubleshoot the issues, update time could be tested on WiFi and cellular networks as well. Some source code excerpts (Fig. 5): Fig 6 GDF mobilinfo application in the Google Play Store The application was uploaded into Play Store after the testing with a beta marker [29] (Fig. 6). The publishing is relatively simple, which is preceded by a short registration (the developer registration will cost $ 25, a one-time fee). According to Play Store statistics there are about 180 active installs. Some screenshots of the application (Fig. 7): Fig. 7 Screenshots from GDF mobilinfo application (Android) 28

5 DEVELOPMENT ON WINDOWS PHONE PLATFORM For the Windows Phone development, we will need to have a Visual Studio 2010 (Express Edition or higher) and Windows Phone 7.1 SDK [30]. The Windows Phone uses a special version of Silverlight so what we have learned in Silverlight and Windows Presentation Foundation development, can immediately be used. The application's functionality is exactly the same with those of the Android version, but there is a difference in the user interface. Some screenshots of the application screen (Fig. 10): Fig. 10 Screenshots from GDF mobilinfo application (Windows Phone) Fig. 8 Windows Phone source code snippet (xaml, GUI) If we want to port a WPF or Silverlight application to WP7, it is a very simple thing; our code can be used nearly without modification. You can use the popular and robust architectural pattern Model-View-View-Model, in brief MVVM to [31]. The Windows Phone offers a completely new, clean user interface for us. Thus the application has been made in this notion. Panoramic view was implemented. Here, the panoramic view was used instead of DashBoardLayout, and Pivot in place of the ViewPager controller (functionally identical) [32] (Fig. 8). Some source code snippet (Figure 9): Fig. 9 Windows Phone source code snippet (event handling and application logic) EXPERIENCES AND FURTHER DEVELOPMENT OP- TIONS The development of two applications run parallel, this was an excellent opportunity to compare between the two platforms. The flexibility of Android development face emphasised the boundedness of the Windows Phone platform. The application quickly spread among the students. They welcomed the practical addition to the learning system that they can access the frequently updated data through their mobile phones, and they do not have to log on to Neptune. The feedback is clearly positive. The GUI is simple, the application is easy to install. The teachers/colleagues used with satisfaction. Lots of typical, everyday question is not asked via or in person, this ease the Study Office s Information Centre. Some reasonable idea for further development has been received. The development on iphone is going on. ACKNOWLEDGMENT The authors thank Erzsi Tiszai for the English translation of this article. REFERENCES [1] Mobile phone: e#history [2] Mobile Phone Generations: nerations.htm 29

6 [3] Elindult a 4G Magyarországon: yarorszagon [4] 4G/LTE: /4G [5] Types of Mobile Phones: es-mobile-phones.html [6] Pilot 1000 Retrospective: 3/pilot-1000-retrospective [7] The History of Microsoft Windows CE: wsce/wce1.asp [8] Symbian: [9] Android (operating system): rating_system) [10] Android (operating system): rating_system)#features [11] Apple Press Info Apple Reinvents the Phone with iphone: 09Apple-Reinvents-the-Phone-withiPhone.html [12] Apple iphone 4S See all the amazing new things iphone can do: [13] Windows Phone Update History: /en-us/howto/wp7/basics/updatehistory.aspx [14] Mobile phone penetration now at 85% worldwide: [15] Global Smartphone Penetration: al-smartphone-penetration-below-10 [16] Windows Phone to beat Android: mmons/thumb/a/ae/world-wide- Smartphone-Market-Share.png/800px- World-Wide-Smartphone-Market- Share.png [17] Forstner, B., Ekler, P., Kelényi, I.: Bevezetés a mobilprogramozásba Gyors prototípusfejlesztés Python és Java nyelven, SZAK Kiadó Kft., Bicske, 2008, ISBN [18] Google Play Store: play.google.com/store [19] Marketplace: wwww.windowsphone.com/marketplace [20] App Store: [21] Android activates 1 million devices per day, 400 million exist: activates-1-million-devices-per-day-400- million-exist-4x-as-many-as-a-year-ago [22] Android alkalmazások letöltése világszerte (2012. április): ge/scale/800/600/ png [23] Android 4.1 APIs Android Developers: ns/android-4.1.html [24] Windows Phone: one#features [25] Eclipse Downloads: [26] ADT Plugin Android Developers: ipse-adt.html [27] Android UI Patterns: Implementating Dashboard and Action Bar: 1/implementing-dashboard-and-actionbar.html [28] ViewPager Android Developers: droid/support/v4/view/viewpager.html [29] GDF mobilinfo alkalmazás a Google Play Store-ban: result#?t=w251bgwsmswxldesimluzm8 ua2fsbgfpbs5nzgzpbmzvil0. [30] Download WP SDK 7.1: [31] THE MODEL-VIEW-VIEWMODEL (MVVM) DESIGN PATTERN FOR WPF: 30

7 [32] Windows Phone 7 Part #5: Panorama and Pivot controls: dows-phone-7-part-5-panorama-and- Pivot-controls.aspx 31