3 * A tiled window manager for the terminal.
5 * It provides a virtual screen that can be scrolled horizontally and may
6 * contain any number of windows that can be appeared, disappeared, resized and
7 * (somewhat) moved around. They have borders and a title bar and are positioned
8 * (in a bizarre fashion, see below) automatically.
10 * Windows can be almost any width (number has to fit into 16 bits); the virtual
11 * screen grows with them as needed -- but only horizontally and only up to 2^16
12 * cells. Their height is limited by the height of the terminal screen, which
13 * must also fit into 2^16 cells.
15 * Positioning of windows can only indirectly be influenced: by resizing them,
16 * and by shifting their relative position inside the (currently invisible)
17 * chain that the window manager treats their plurality as. The first window
18 * goes into the upper left corner of the virtual screen. Further visible
19 * windows are fitted left-aligned below their (chain-wise) closest predecessor
20 * that thrones over enough space to fit them in; failing that, they are placed
21 * to the right of the window with the rightmost border.
23 * Functions that return uint8_t return these error codes:
25 * 1 - memory allocation error
26 * 2 - would force virtual screen to grow beyond width or height of 2^16 cells
28 * TODO: Think up a more intuitive window positioning algorithm or at least make
29 * the chain that windows are positioned by visible.
35 #include <stdint.h> /* for uint8_t, uint16_t, uint32_t */
36 #include <ncurses.h> /* for the WINDOW and chtype typedefs */
37 #include "yx_uint16.h" /* for yx_uint16 struct */
41 /* Individual windows are represented by "Win" structs. They describe frames
42 * located inside the virtual screen pad through which "winmaps" are visible,
43 * 2-dimensional maps of ncurses chtypes. Win structs are chained into a linked
44 * list of all the windows visible on the virtual screen and also contain
45 * pointers to what content is to be drawn inside the window, and by use of what
50 struct Win * prev; /* chain pointers; if 0, they mark the start or end */
51 struct Win * next; /* of the chain; if both are 0, Win is outside chain */
52 struct yx_uint16 framesize; /* window frame size to see winmap through */
53 struct yx_uint16 start; /* upper left corner of window in pad */
54 struct yx_uint16 center; /* window content center to focus window on */
55 char * title; /* title to be used in window title bar */
56 void (* draw) (struct Win *); /* how to draw window content ("data") */
57 chtype * winmap; /* sequence of cells, sorted into lines ... */
58 struct yx_uint16 winmapsize; /* ... with these geometry infos */
63 /* The window manager's parent struct WinMeta contains the virtual screen,
64 * relates it to the terminal screen and anchors the chain of visible windows.
68 WINDOW * screen; /* ncurses' pointer to the terminal screen */
69 WINDOW * pad; /* ncurses pad of virtual screen */
70 uint16_t pad_offset; /* number of cells view is moved to the right */
71 struct yx_uint16 padsize; /* virtual screen size */
72 struct Win * chain_start; /* first Win in chain; its _prev == 0 */
73 struct Win * chain_end; /* last Win in chain; its _next == 0 */
74 struct Win * active; /* Win highlighted/selected for manipulation */
79 /* Initialize empty WinMeta "wmeta" on the terminal "screen". (Note that
80 * emptiness is marked by WinMeta.chain_start=0.) Other struct members are also
81 * initialized 0, except for the virtual screen (height = that of the terminal
82 * screen; width = 1) sized to the size of the terminal screen.
84 extern uint8_t init_win_meta(WINDOW * screen, struct WinMeta ** wmeta);
88 /* Initialize a window child of "wmeta" to "title", "height" and "width" and
89 * appointing "func"() to interpret and draw the window when it's visible.
91 * Pass 0 for "width" to make the window as wide as the terminal screen. Pass
92 * negative values for "width" to make the width so many cells smaller than that
93 * of the terminal screen. Pass 0 for "height" to give the window the maximum
94 * allowed height: one cell smaller than that of the terminal screen. Pass
95 * negative values to make the window width so many cells smaller than that of
96 * the terminal screen. The maximum allowed height is also applied for positive
97 * values that exceed it or negative values that would reduce the window height
100 * Other members of the Win struct are initialized to 0.
102 extern uint8_t init_win(struct WinMeta * wmeta, struct Win ** w, char * title,
103 int16_t height, int16_t width, void * func);
107 /* Free allocated memory for an initialized Win / WinMeta structs. */
108 extern void free_winmeta(struct WinMeta * wmeta);
109 extern void free_win(struct Win * win);
113 /* Append/suspend window "w" to/from chain of visible windows below "wmeta".
114 * Appended windows will become active. Suspended active windows will move the
115 * active window selection to their successor in the window chain or, failing
116 * that, their predecessor; if no window remains, none will be active.
118 extern uint8_t append_win(struct WinMeta * wmeta, struct Win * w);
119 extern uint8_t suspend_win(struct WinMeta * wmeta, struct Win * w);
123 /* Apply scrolling offset "new_offset" to virtual screen if it is sane, i.e.
124 * it's equal/greater zero and does not push the view (further) beyond the
125 * virtual screen's border. If the view is already beyond the virtual screen's
126 * border due to it having shrunk after suspension of windows, only allow view
127 * movement leftwards.
129 extern void reset_pad_offset(struct WinMeta * wmeta, uint16_t new_offset);
133 /* Apply new size "size" to the active window, but only if it provides for at
134 * least one cell width/height and is in height at least one cell smaller than
135 * the screen's vertical height (to provide space for the title bar). Does
136 * nothing if no window is active.
138 extern uint8_t resize_active_win(struct WinMeta * wmeta, struct yx_uint16 size);
142 /* Cycle active window selection forwards ("dir" == "f") or backwards (any
143 * other "dir"). Wrap around in the windows chain if start / end of it is met.
144 * Does nothing if no window is active.
146 extern void cycle_active_win(struct WinMeta * wmeta, char dir);
150 /* Move active window forwards ("dir" == "f") or backwards (any other "dir").
151 * Wrap around in the window chain if start / end of it is met. Does nothing if
152 * no window is active.
154 extern uint8_t shift_active_win(struct WinMeta * wmeta, char dir);
158 /* Draw virtual screen including all windows. Also add scroll hints for where
159 * the edges of the terminal screen hit non-edges of and inside the virtual
160 * screen. Then update the terminal screen.
162 extern uint8_t draw_all_wins(struct WinMeta * wm);