New infrastructure feature. Games are now permitted to be

_conditionally_ able to format the current puzzle as text to be sent
to the clipboard. For instance, if a game were to support playing on
a square grid and on other kinds of grid such as hexagonal, then it
might reasonably feel that only the former could be sensibly
rendered in ASCII art; so it can now arrange for the "Copy" menu
item to be greyed out depending on the game_params.

To do this I've introduced a new backend function
(can_format_as_text_now()), and renamed the existing static backend
field "can_format_as_text" to "can_format_as_text_ever". The latter
will cause compile errors for anyone maintaining a third-party front
end; if any such person is reading this, I apologise to them for the
inconvenience, but I did do it deliberately so that they'd know to
update their front end.

As yet, no checked-in game actually uses this feature; all current
games can still either copy always or copy never.

[originally from svn r8161]

4 files changed, 24 insertions, 4 deletions

diff --git a/unfinished/pearl.c b/unfinished/pearl.c
index af25415..41ab998 100644
--- a/unfinished/pearl.c
+++ b/unfinished/pearl.c
@@ -1236,6 +1236,11 @@ static char *solve_game(game_state *state, game_state *currstate,
     return NULL;
 }
 
+static int game_can_format_as_text_now(game_params *params)
+{
+    return TRUE;
+}
+
 static char *game_text_format(game_state *state)
 {
     return NULL;
@@ -1379,7 +1384,7 @@ const struct game thegame = {
     dup_game,
     free_game,
     FALSE, solve_game,
-    FALSE, game_text_format,
+    FALSE, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
     encode_ui,
diff --git a/unfinished/separate.c b/unfinished/separate.c
index d6542a1..2df4a5b 100644
--- a/unfinished/separate.c
+++ b/unfinished/separate.c
@@ -680,6 +680,11 @@ static char *solve_game(game_state *state, game_state *currstate,
     return NULL;
 }
 
+static int game_can_format_as_text_now(game_params *params)
+{
+    return TRUE;
+}
+
 static char *game_text_format(game_state *state)
 {
     return NULL;
@@ -823,7 +828,7 @@ const struct game thegame = {
     dup_game,
     free_game,
     FALSE, solve_game,
-    FALSE, game_text_format,
+    FALSE, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
     encode_ui,
diff --git a/unfinished/slide.c b/unfinished/slide.c
index d149657..af8f210 100644
--- a/unfinished/slide.c
+++ b/unfinished/slide.c
@@ -1166,6 +1166,11 @@ static char *solve_game(game_state *state, game_state *currstate,
     return ret;
 }
 
+static int game_can_format_as_text_now(game_params *params)
+{
+    return TRUE;
+}
+
 static char *game_text_format(game_state *state)
 {
     return board_text_format(state->w, state->h, state->board,
@@ -2317,7 +2322,7 @@ const struct game thegame = {
     dup_game,
     free_game,
     TRUE, solve_game,
-    TRUE, game_text_format,
+    TRUE, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
     encode_ui,
diff --git a/unfinished/sokoban.c b/unfinished/sokoban.c
index 2d76954..91f02a6 100644
--- a/unfinished/sokoban.c
+++ b/unfinished/sokoban.c
@@ -907,6 +907,11 @@ static char *solve_game(game_state *state, game_state *currstate,
     return NULL;
 }
 
+static int game_can_format_as_text_now(game_params *params)
+{
+    return TRUE;
+}
+
 static char *game_text_format(game_state *state)
 {
     return NULL;
@@ -1429,7 +1434,7 @@ const struct game thegame = {
     dup_game,
     free_game,
     FALSE, solve_game,
-    FALSE, game_text_format,
+    FALSE, game_can_format_as_text_now, game_text_format,
     new_ui,
     free_ui,
     encode_ui,