Chapter 1

BSP state, and panics the program if it finds otherwise. It is the responsibility of the event
source to precheck validity – for instance, the opponent's fleet view should not issue a hit
request unless the BSP state is my-turn: this particular condition is assured by dimming the
view unless the BSP state is my-turn.
Finally the app UI uses two dialogs, to initiate a game (and RGCP communications session),
and to start a new game (in the context of the same RGCP communications session).
You can find the code for Battleships on the website:
Source Files Purpose
engine.cpp, engine.h The engine, exactly as in Solo Ships
view.cpp, view.h The fleet view, exactly as in Solo Ships
appui.cpp, appui.h The application, document, and app UI classes,
along with the initiate and new game dialogs
controller.cpp, controller.h The controller
battleships.rss,battleships.hrh Resource file and shared constants
If you've read the walkthrough of Solo Ships and the description of BSP, then the
implementation of Battleships will contain few surprises.
I'll pause to look at a few representative functions, so you can get a flavor of how things
hang together in a real TOGS game.
16.5.1 The Status View
Before we get involved in the communications code, let's look at the status view. There's not
much to learn from its code, but there are a couple of reminders of the realities of graphic
design here.
My choice for the design of the status view was primarily determined by the capabilities of
the device it was designed for, in particular the portrait screen format used by UIQ based
devices. In the Battleships application the fleet view occupies the majority of the screen,
leaving very little space for a permanent status view. The simplest, but not necessarily the
best option is to use a dialog to display the game status available and make this available
from the menu options.
This has the advantage of leaving the maximum available area for playing the game and
also offers a more flexible approach to the presentation of the status information rather than
trying to squeeze the information into too small a space.
16.5.2 Handling Hit Requests
Remember that, in Solo Ships, the controller handled hit requests from the view using
void CGameController::ViewCmdHitFleet(TInt aX, TInt aY)
{
__ASSERT_ALWAYS(!(iEngine->iOppFleet.IsKnown(aX, aY)),
Panic(EHitFleetAlreadyKnown));
// hit fleet