Chapter 1

If you compare this with the Solo Ships design described in Chapter 9, you'll notice that
� instead of the document owning the controller, and the app UI owning the view, the
app UI owns the controller, and the controller owns the view,
� the engine and view classes perform the same function as in Solo Ships,
� there are actually five views in this application: each player's fleet view and their view
of the opponent's fleet plus a hider view.
There are two interesting aspects to this program:
� It does some interesting Uikon tricks: it has five app views, and it manipulates its menu
options. It's useful to know this kind of trick, so we'll have a closer look at the code.
� It doesn't use communications to get information about the other player's fleet :
instead, it uses object-oriented plumbing. We'll have a look at the code involved, and
we'll explain why changing the ten or so lines of plumbing to support communications is
going to take several hard chapters to explain a suitable replacement for them. Or, put
another way, we'll understand why I wanted to take the tp-ships shortcut before
doing all that communications work.
Let's look at these two things in turn.
16.2.1 View and Menu Tricks
As we saw in Chapter 9, a GUI application can have more than a single view. Many of the
built-in Symbian OS applications have more than one view:
� Agenda can have day, week, month, year, to-do, and anniversary views
� Contacts has card and list views
� Messaging supports various types of message types and has appropriate views for
each of them.
In a Symbian OS GUI application, it's very easy to change views without changing the app
UI, because the view is quite a distinct entity from the app UI.
The app UI has seven members, five of which are views:
CGameController* iController; //Controller for both players
COppFleetView* iP1OppFleetView; //Fleet views for P1 fleet and
target fleet
CMyFleetView* iP1MyFleetView;
COppFleetView* iP2OppFleetView; //Fleet views for P2 fleet and
target fleet
CMyFleetView* iP2MyFleetView;
CHiderView* iHiderView; //Hider view
CFleetView* iActiveView;
There are also three associated flags that control whether the views are visible. The Hide
menu option calls CmdHideL() which is coded as:
void CGameAppUi::CmdHideL()
{
ActivateViewL(TVwsViewId(KUidTpShips,KHiderViewUID));
iActiveView = NULL;
// toggle player turn