Wiley.Developing.Software.for.Symbian.OS.2nd.Edition.Dec.2007 (779887), страница 69
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When a socket operation is performed that requiresdata to be sent on the network – for example, an RSocket::Connect()on a TCP socket, or SendTo() for UDP – the operating system establishes the connection for you, if it is not already established. This involveshandling the details of starting up a connection on the phone (i.e., anIAP), or finding one that is already connected, and then the socket willcommunicate using that connection.Alternatively, your program can connect to a specific IAP for the socketto use – this is known as an explicit connection.
You start up a particularconnection using the RConnection API (not covered in this book) andassociate that connection with a socket. Symbian OS also supports havingmultiple connections active at once, for example one socket could use aGPRS connection and another a Wi-Fi one at the same time.12GUI Application ProgrammingSmartphones are capable of running complex and powerful applications,but due to the smartphone’s small size, it can be challenging to make theseapplications intuitive and easy to use. Symbian OS addresses this wellby providing a full-featured graphical user interface (GUI) environmentespecially suited for the hardware characteristics of smartphone devices.To take full advantage of the GUI environment, your application’sinterface should be consistent with those of other applications, so thatsmartphone users do not get confused – yet it should also creativelyprovide good presentation and user control of the features unique toyour application.
UI style guides exist for both UIQ and S60 and areinvaluable sources of information about what can and what cannot bedone on each UI, so that your application has a consistent interfacesuited for that platform. The UI style guides for UIQ and S60 are available on the developer sites (http://www.developer.uiq.com for UIQ andhttp://www.forum.nokia.com for S60). Up-to-date links to these, andother links referenced in this book, will be kept in the Symbian DeveloperNetwork wiki (http://developer.symbian.com/wiki/ ).Your program’s GUI is its front to the world, and creating a goodone can greatly enhance, if not totally determine, the success of yoursmartphone application.This chapter covers Symbian OS GUI programming for the two majorUI platforms that use Symbian OS v9.
First, there is a discussion of the UIQ3 and S60 3rd Edition user interfaces. Then I describe the creation of GUIapplications – how to use the GUI framework to write your application,and how to use the various components of the GUI such as dialog boxes,menus, buttons, list boxes, etc. I also cover other GUI application aspects,including icons and internationalization – everything needed to create acomplete and ready-to-use application.36012.1GUI APPLICATION PROGRAMMINGSymbian OS User InterfacesFirst, let’s take a quick tour of the UIQ 3 and S60 3rd Edition userinterfaces from the user’s point of view.12.1.1UIQ 3 PhonesUIQ 3 is the UI platform adopted by Sony Ericsson and others, includingMotorola, for their Symbian OS smartphones.
Examples of UIQ 3 phonesinclude the Sony Ericsson W960i and P1i, and the Motorola MOTORIZRZ8. UIQ was originally designed for smartphones with quarter VGAresolution portrait screens, which had touchscreen input, but now withthe introduction of UIQ 3 it can run in numerous user and display modesincluding portrait and landscape, with and without touchscreens.The typical screen resolution is still QVGA portrait (240 × 320), orlandscape, but UIQ 3 also supports a smaller, 240 × 256 screen formatthat can also be in portrait and landscape.In addition to having the ability to display in portrait and landscape, inthe two different screen sizes, UIQ also supports two interaction styles:pen and softkey. The pen style is a way of presenting the user interface tothe user that is optimized for touchscreen devices, for example in the SonyEricsson P990. The softkey style provides a good one-handed user experience without needing a touchscreen by using hardware keys and optionaljog dial, and is found, for example, in the Motorola MOTORIZR Z8.Figures 12.1 and 12.2 show a sample screen of an application usingportrait pen style and softkey style, with smaller portrait screen, respectively.There is also a mode that combines the softkey style with a touchscreen.On the screen, this looks like the softkey style in Figure 12.2, except thatthere is a back key in the title bar, and the touchscreen can be used toselect the screen controls.A single device can support multiple display and interaction modes.For example, on the Sony Ericsson P990i, when you close the flip, thephone goes in the small portrait softkey mode and the touchscreen isdisabled.
When the flip is open, the phone goes to the larger portrait penmode. In fact, Figures 12.1 and 12.2 were taken on a P990i smartphonewith the flip open and closed, respectively.For the most part, you only need minor changes to your applicationto support these multiple display modes and the UIQ platform does therest. Section 12.4.3 discusses the changes needed for your application tosupport the various display modes.A UIQ 3 application screen is divided into the following areas:•Title barThe title bar shows the name of the application, with its icon.
Inpen mode, you select the application’s name via the touchscreen toSYMBIAN OS USER INTERFACESFigure 12.1 UIQ 3 Application, Pen StyleFigure 12.2 UIQ 3 Application, Softkey Style361362GUI APPLICATION PROGRAMMINGdisplay the pull-down menu. In non-touch, softkey mode, the title barcannot be selected in any way and is for informational purposes only.As mentioned previously, in softkey touch mode, a back button is alsodisplayed in the title bar. The title bar can also contain a view contextbar owned by an application view that can contain items like screentabs (not shown in the figures).•Application areaThe large central area below the title bar is the application area.
Thisis where the application-specific data and controls that make up anapplication view are displayed.•Button barIn pen mode, the application area has an optional button bar belowthe application area. The button bar is specific to the application andan application may or may not have one. The button bar often containsconvenient global controls that select specific views, or perform somesort of global operation specific to that application. A back buttonresides on this bar. Buttons can also contain graphics instead of text.
Insoftkey mode, there is no button bar but instead there is a softkey area.•Softkey areaIn softkey mode, as shown in Figure 12.2, the labels for softkeys aredisplayed at the bottom of the screen (these line up with device hardware keys). There are three softkeys. The rightmost softkey, labeled‘More’, contains the application menu. In some cases, the middlebutton can also be used to display multiple options.•Status paneUIQ devices display a one-line status pane that can be at the top orthe bottom of the screen depending on the display configuration (forexample, in Figure 12.1, pen style, it’s at the bottom).
The status panecontains items such as signal strength, battery status, and connectionstatus. In a touchscreen mode you can select the icons in this panefor more detailed information.User inputThere are multiple ways that a user can enter data on UIQ phones.If they have a touchscreen, you can use handwriting recognition ora virtual touchscreen-based keyboard.
You can also enter data on thedevice keyboard, with some models supplying a full QWERTY hardwarekeyboard.UIQ paper metaphorWhen you start an application, it remains running and persistent. Applications normally do not provide an exit option; you just switch awaySYMBIAN OS USER INTERFACES363from them when you want to use something else. Any data that youhave entered into the application remains intact and saved – when yougo back to your application, it looks as it did when you switched away.UIQ exposes none of the content of a file system to the user and does allstorage of data behind the scenes.UIQ dialogsAs with all of the Symbian user interface platforms, much of a GUIapplication’s functionality is performed in dialog boxes.
Dialogs displaya title bar, a set of controls, and a row of one or more buttons, which areused to save, cancel, or perform some other application-specific operation(or in the case of softkey style, softkeys are used instead of buttons). UIQsupports simple, single-page dialogs and multipage dialogs, in whicheach page can be selected via a row of tabs. Figure 12.3 shows anexample of a multipage dialog (this is the browser’s Preferences dialogwith the pen interaction style).Figure 12.3UIQ Dialog (Pen Style)12.1.2 S60 PhonesThe S60 user interface from Nokia was originally made for devices withsmaller screens (basic resolution 176 × 208) and no touchscreen. S60 3rd364GUI APPLICATION PROGRAMMINGEdition supports more varied phone display sizes and resolutions, rangingfrom basic resolution to QVGA, double (352 × 416), and even HVGA(240 × 640) in both portrait and landscape orientations.
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