* (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)
* 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
-#include <stdint.h> /* for uint16_t, uint32_t */
+#include <stdint.h> /* for uint8_t, uint16_t, uint32_t */
#include <ncurses.h> /* for the WINDOW typedef */
#include "yx_uint16.h" /* for yx_uint16 coordinates */
-/* Individual windows consist of potential (real if window is visible) ncurses
- * WINDOWs wrapped inside Frame structs (that keep a window's designated size
- * even when it is invisible) wrapped inside metadata-rich Win structs. Win
- * structs are chained into a linked list of all the windows visible on the
- * virtual screen and also contain pointers to what content is to be drawn
- * inside the window, and by use of what method.
+
+/* Individual windows consist of potential (real only if window is visible
+ * inside the virtual screen) ncurses WINDOWs wrapped inside Frame structs (that
+ * keep a window's designated size even when it is invisible) wrapped inside
+ * metadata-rich Win structs. Win structs are chained into a linked list of all
+ * the windows visible on the virtual screen and also contain pointers to what
+ * content is to be drawn inside the window, and by use of what method.
*/
-struct Frame
-{
- WINDOW * curses_win;
- struct yx_uint16 size; /* the size curses_win fits into; for the virtual */
-}; /* screen padframe: the terminal screen size */
+struct Frame /* If Frame is Win's "frame", "size" is the */
+{ /* designated size of curses_win's ncurses WINDOW. */
+ WINDOW * curses_win; /* If Frame is WinMeta's "padframe", curses_win is */
+ struct yx_uint16 size; /* the ncurses pad representing the virtual screen */
+}; /* and "size" desribes the terminal screen size. */
struct Win
{
- struct Win * prev; /* prev=next=0 if Win is outside the chain */
- struct Win * next;
- struct yx_uint16 start; /* upper left corner (of WINDOW or border?) */
+ /* members supposed to be used ONLY INTERNALLY */
+ struct Win * _prev; /* chain pointers; if 0, they mark the start or end */
+ struct Win * _next; /* of the chain; if both are 0, Win is outside chain */
+ struct yx_uint16 _start; /* upper left corner of "frame" WINDOW */
+ char * _title; /* title to be used in window title bar */
+ void (* _draw) (struct Win *); /* how to draw window content ("data") */
+
+ /* members to be available EXTERNALLY */
struct Frame frame;
- char * title; /* title to be shown on window border top */
- void (* draw) (struct Win *); /* function to draw window content ("data") */
- void * data; /* content to be drawn; draw() knows how */
+ void * data; /* window content to be drawn by _draw() */
};
-/* The window manager's parent struct WinMeta provides the virtual screen and a
- * representation of the terminal screen. It also anchors start and end of the
- * windows chain.
+/* The window manager's parent struct WinMeta contains the virtual screen,
+ * relates it to the terminal screen and anchors the chain of visible windows.
*/
struct WinMeta
{
- WINDOW * screen; /* 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; /* first Win, whose .prev shall point to 0 */
- struct Win * chain_end; /* last Win, whose .next shall point to 0 */
- struct Win * active; /* window highlighted/selected for manipulation */
+ /* members supposed to be used ONLY INTERNALLY */
+ WINDOW * _screen; /* ncurses' pointer to the terminal screen */
+ struct Win * _chain_start; /* first Win in chain; its _prev == 0 */
+ struct Win * _chain_end; /* last Win in chain; its _next == 0 */
+
+ /* members to be available EXTERNALLY */
+ 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 */
};
-/* Create on the terminal "screen" an empty WinMeta. Note that 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.
+/* Initialize empty WinMeta "wmeta" on the terminal "screen". (Note that
+ * emptiness is marked by WinMeta.chain_start=0.) Other struct members are also
+ * initialized 0, except for the virtual screen (height = that of the terminal
+ * screen; width = 1) amd its frame sized to the size of the terminal screen.
*/
-extern struct WinMeta init_win_meta(WINDOW * screen);
+extern uint8_t init_win_meta(WINDOW * screen, struct WinMeta * wmeta);
-/* Create a window below inside "wmeta" titled "title" and appointing "func"()
- * to interpret and draw the content stored at "data" if the window is visible.
+/* Create a window as child of "wmeta" titled "title" of "height" and "width"
+ * and appointing "func"() to interpret and draw the content stored at "data"
+ * if the window is visible.
*
- * The start size for the Frame will be a width of 20 cells and a height one
- * less than the height of the virtual screen (so as to fit the title bar on top
- * of the window). Other values will be initialized to 0. The window will stay
- * invisible until appended to the chain of visible windows via append_win().
+ * A value for "width" <1 will trigger a fallback to width=1. A "height" < 1 or
+ * larger than the maximum window height possible within the virtual screen will
+ * trigger a fallback to the maximum height possible (i.e. pass a "height" of 0
+ * to initialize the window to its largest possible height).
*
- * TODO: Why a default start width instead of passing a start width?
+ * Other members of the Win struct are initialized to 0. The window will stay
+ * invisible until appended to the chain of visible windows via append_win().
*/
extern struct Win init_win(struct WinMeta * wmeta, char * title,
+ uint16_t height, uint16_t width,
void * data, void * func);
-/* Append/suspend window "w" to/from chain of visible windows in "wmeta".
+/* Append/suspend window "w" to/from chain of visible windows below "wmeta".
* 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.
*/
-extern void append_win(struct WinMeta * wmeta, struct Win * w);
-extern void suspend_win(struct WinMeta * wmeta, struct Win * w);
+extern uint8_t append_win(struct WinMeta * wmeta, struct Win * w);
+extern uint8_t suspend_win(struct WinMeta * wmeta, struct Win * w);
/* 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).
+ * the screen's vertical height (to provide space for the title bar). Does
+ * nothing if no window is active.
*/
-extern void resize_active_win(struct WinMeta * wmeta, struct yx_uint16 size);
+extern uint8_t resize_active_win(struct WinMeta * wmeta, struct yx_uint16 size);
-/* Cycle active window selection forwards (set dir="n") or backwards. Wrap
- * around in the windows chain if start / end of it is met.
+/* Cycle active window selection forwards ("dir" == "f") or backwards (any
+ * other "dir"). Wrap around in the windows chain if start / end of it is met.
+ * Does nothing if no window is active.
*/
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.
+/* Move active window forwards ("dir" == "f") or backwards ("dir" == "b").
+ * Wrap around in the window chain if start / end of it is met. Does nothing if
+ * no window is active.
*/
-extern void shift_active_win(struct WinMeta * wmeta, char dir);
+extern uint8_t shift_active_win(struct WinMeta * wmeta, char dir);
-/* Draw virtual screen including all windows. Also add scroll hints (a line
- * stating that there is more to see on scrolling further into a certain
- * direction) for where the edges of the terminal screen hit non-edges of and
- * inside the virtual screen. Then update the terminal screen.
+/* 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.
*/
-extern void draw_all_wins(struct WinMeta * wmeta);
+extern uint8_t draw_all_wins(struct WinMeta * wmeta);
* 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.
*/
-extern void draw_scroll_hint(struct Frame * frame, uint16_t pos, uint32_t dist,
- char dir);
+extern uint8_t draw_scroll_hint(struct Frame * frame, uint16_t pos,
+ uint32_t dist, char dir);
projects / plomrogue / blobdiff