Improved windows library intro comment.

[plomrogue] / src / windows.h

diff --git a/src/windows.h b/src/windows.h
index 41211371bde6ad8d848256d94608cb90b0120e6f..9afc50fee82cce756eb5c7a95f129566a9b959f1 100644 (file)
--- a/src/windows.h
+++ b/src/windows.h
@@ -8,8 +8,8 @@
  * (in a bizarre fashion, see below) automatically.
  *
  * Windows can be almost any width (number has to fit into 16 bits); the virtual
- * screen grows with them as needed -- but only horizontally. Their height is
- * limited by the height of the terminal screen.
+ * screen grows with them as needed -- but only horizontally and only up to 2^16
+ * cells. Their height is limited by the height of the terminal screen.
  *
  * Positioning of windows can only indirectly be influenced: by resizing them,
  * and by shifting their relative position inside the (currently invisible)
@@ -19,11 +19,13 @@
  * that thrones over enough space to fit them in; failing that, they are placed
  * to the right of the window with the rightmost border.
  *
+ * Functions that return uint8_t return these error codes:
+ * 0 - success
+ * 1 - memory allocation error (of ncurses' pads/windows, or scroll hint texts)
+ * 2 - activity forces virtual screen to grow beyond width of 2^16 cells
+ *
  * TODO: Think up a more intuitive window positioning algorithm or at least make
  * the chain that windows are positioned by visible.
- *
- * TODO: Ensure there are only windows as many / as big as fit into the maximum
- * size of the virtual screen.
  */
 
 #ifndef WINDOWS_H
@@ -55,9 +57,9 @@ struct Win
     struct Win * _prev;            /* INTERNAL */ /* _prev == _next == 0 if   */
     struct Win * _next;            /* INTERNAL */ /* Win is outside the chain */
     struct yx_uint16 _start;       /* INTERNAL: upper left corner of WINDOW */
-    struct Frame frame;
     char * _title;                 /* INTERNAL: title for window title bar */
     void (* _draw) (struct Win *); /* INTERNAL: how to draw window content */
+    struct Frame frame;
     void * data;                   /* window content to be drawn by _draw() */
 };
 
@@ -70,10 +72,10 @@ struct Win
 struct WinMeta
 {
     WINDOW * _screen;          /* INTERNAL: terminal screen */
-    uint16_t pad_offset;       /* number of cells view is moved to the right */
-    struct Frame padframe;     /* virtual screen fitted into terminal screen */
     struct Win * _chain_start; /* INTERNAL: first Win, ._prev to point to 0 */
     struct Win * _chain_end;   /* INTERNAL: last Win, ._next to point to 0 */
+    uint16_t pad_offset;       /* number of cells view is moved to the right */
+    struct Frame padframe;     /* virtual screen fitted into terminal screen */
     struct Win * active;       /* Win highlighted/selected for manipulation */
 };
 
@@ -83,8 +85,6 @@ struct WinMeta
  * emptiness is marked by WinMeta.chain_start=0. Other struct values are also
  * initialized 0, except for the virtual screen (terminal screen height, width =
  * 1) and its terminal-sized frame.
- *
- * Returns 0 on success, 1 on (ncurses newpad() memory allocation) error.
  */
 extern uint8_t init_win_meta(WINDOW * screen, struct WinMeta * wmeta);
 
@@ -112,8 +112,6 @@ extern struct Win init_win(struct WinMeta * wmeta, char * title,
  * Appended windows will become active. Suspended active windows will move the
  * active window selection to their successor in the window chain or, failing
  * that, their predecessor; if no window remains, none will be active.
- *
- * Return 0 on success, and 1 on (ncurses window/pad memory allocation) error.
  */
 extern uint8_t append_win(struct WinMeta * wmeta, struct Win * w);
 extern uint8_t suspend_win(struct WinMeta * wmeta, struct Win * w);
@@ -133,8 +131,6 @@ extern void reset_pad_offset(struct WinMeta * wmeta, uint16_t new_offset);
 /* Apply new size "size" to the active window, but only if it provides for at
  * least one cell width/height and is in height at least one cell smaller than
  * the screen's vertical height (to provide space for the title bar).
- *
- * Returns 0 on success, 1 on (ncurses window/pad memory allocation) error.
  */
 extern uint8_t resize_active_win(struct WinMeta * wmeta, struct yx_uint16 size);
 
@@ -149,8 +145,6 @@ extern void cycle_active_win(struct WinMeta * wmeta, char dir);
 
 /* Move active window forwards (set dir="f") or backwards (set dir="b"). Wrap
  * around in the window chain if start / end of it is met.
- *
- * Returns 0 on success, 1 on (ncurses window/pad memory allocation) error.
  */
 extern uint8_t shift_active_win(struct WinMeta * wmeta, char dir);
 
@@ -159,8 +153,6 @@ extern uint8_t shift_active_win(struct WinMeta * wmeta, char dir);
 /* Draw virtual screen including all windows. Also add scroll hints (see comment
  * on draw_scroll_hint()) for where the edges of the terminal screen hit
  * non-edges of and inside the virtual screen. Then update the terminal screen.
- *
- * Returns 0 on success, 1 on error (of scroll hint text memory allocation).
  */
 extern uint8_t draw_all_wins(struct WinMeta * wmeta);
 
@@ -171,8 +163,6 @@ extern uint8_t draw_all_wins(struct WinMeta * wmeta);
  * a column or a row dependent on "dir" being *either* "<"/">" *or* something
  * else). It will consist of a line of "dir" symbols bracketing a descriptive
  * text stating the number of rows/columns further available beyond the hint.
- *
- * Return 0 on success, and 1 on error (of scroll hint text memory allocation).
  */
 extern uint8_t draw_scroll_hint(struct Frame * frame, uint16_t pos,
                                 uint32_t dist, char dir);