saves it automatically into a default place, and if there’s a pending dialog it will be canceled. The user is not asked questions; all the operations needed to bring the application to the target state are done automatically.
After switching applications in this way, the Back function does not lead to the previous state. Instead, it functions as if the user had manually entered the second application and navigated to the target state: it leads to the previous state in the second application’s internal structure even though the user did not actually navigate through it.
Application A
State 1
back
State 2
back
State 3
switch
Application B
State 1
back
State 2
back
State 3
Figure 6-5: Switching between applications, interrupting application B. The Back function works inside application B, it does not lead back to application A.
Phone
Phone is the application for handling voice calls. It is a central application in the device. The idle state, described, earlier, can be thought of as a part of the Phone application: calls can be created by dialing from the idle state, and whenever there are one or more voice calls going on, the Phone application takes the place of idle; both can’t exist simultaneously.
In Application shell, the first application is Phone. If there are no calls when the user selects it, the device will go to idle state.
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