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 * TODO: Think up a more intuitive window positioning algorithm or at least make
24 * the chain that windows are positioned by visible.
30 #include <stdint.h> /* for uint8_t, uint16_t, uint32_t */
31 #include <ncurses.h> /* for the WINDOW and chtype typedefs */
32 #include "yx_uint16.h" /* for yx_uint16 struct */
36 /* Individual windows are represented by "Win" structs. They describe frames
37 * located inside the virtual screen pad through which "winmaps" are visible,
38 * 2-dimensional maps of ncurses chtypes. Win structs are chained into a linked
39 * list of all the windows visible on the virtual screen and also contain
40 * pointers to what content is to be drawn inside the window, and by use of what
45 struct Win * prev; /* chain pointers; if 0, they mark the start or end */
46 struct Win * next; /* of the chain; if both are 0, Win is outside chain */
47 struct yx_uint16 framesize; /* window frame size to see winmap through */
48 struct yx_uint16 start; /* upper left corner of window in pad */
49 struct yx_uint16 center; /* window content center to focus window on */
50 char * title; /* title to be used in window title bar */
51 void (* draw) (struct Win *); /* how to draw window content ("data") */
52 chtype * winmap; /* sequence of cells, sorted into lines ... */
53 struct yx_uint16 winmapsize; /* ... with these geometry infos */
58 /* The window manager's parent struct WinMeta contains the virtual screen,
59 * relates it to the terminal screen and anchors the chain of visible windows.
63 WINDOW * screen; /* ncurses' pointer to the terminal screen */
64 WINDOW * pad; /* ncurses pad of virtual screen */
65 uint16_t pad_offset; /* number of cells view is moved to the right */
66 struct yx_uint16 padsize; /* virtual screen size */
67 struct Win * chain_start; /* first Win in chain; its _prev == 0 */
68 struct Win * chain_end; /* last Win in chain; its _next == 0 */
69 struct Win * active; /* Win highlighted/selected for manipulation */
74 /* Initialize empty WinMeta "wmeta" on the terminal "screen". (Note that
75 * emptiness is marked by WinMeta.chain_start=0.) Other struct members are also
76 * initialized 0, except for the virtual screen (height = that of the terminal
77 * screen; width = 1) sized to the size of the terminal screen.
79 extern void init_win_meta(WINDOW * screen);
83 /* Initialize a window child of "wmeta" to "title", "height" and "width" and
84 * appointing "func"() to interpret and draw the window when it's visible.
86 * Pass 0 for "width" to make the window as wide as the terminal screen. Pass
87 * negative values for "width" to make the width so many cells smaller than that
88 * of the terminal screen. Pass 0 for "height" to give the window the maximum
89 * allowed height: one cell smaller than that of the terminal screen. Pass
90 * negative values to make the window width so many cells smaller than that of
91 * the terminal screen. The maximum allowed height is also applied for positive
92 * values that exceed it or negative values that would reduce the window height
95 * Other members of the Win struct are initialized to 0.
97 extern void init_win(struct Win ** wp, char * title, int16_t height,
98 int16_t width, void * func);
100 /* Free allocated memory for an initialized Win / WinMeta structs. */
101 extern void free_winmeta();
102 extern void free_win(struct Win * win);
104 /* Append/suspend window "w" to/from chain of visible windows below "wmeta".
105 * Appended windows will become active. Suspended active windows will move the
106 * active window selection to their successor in the window chain or, failing
107 * that, their predecessor; if no window remains, none will be active.
109 extern void append_win(struct Win * w);
110 extern void suspend_win(struct Win * w);
112 /* Apply scrolling offset "new_offset" to virtual screen if it is sane, i.e.
113 * it's equal/greater zero and does not push the view (further) beyond the
114 * virtual screen's border. If the view is already beyond the virtual screen's
115 * border due to it having shrunk after suspension of windows, only allow view
116 * movement leftwards.
118 extern void reset_pad_offset(uint16_t new_offset);
120 /* Apply new size "size" to the active window, but only if it provides for at
121 * least one cell width/height and is in height at least one cell smaller than
122 * the screen's vertical height (to provide space for the title bar). Does
123 * nothing if no window is active.
125 extern void resize_active_win(struct yx_uint16 size);
127 /* Cycle active window selection forwards ("dir" == "f") or backwards (any
128 * other "dir"). Wrap around in the windows chain if start / end of it is met.
129 * Does nothing if no window is active.
131 extern void cycle_active_win(char dir);
133 /* Move active window forwards ("dir" == "f") or backwards (any other "dir").
134 * Wrap around in the window chain if start / end of it is met. Does nothing if
135 * no window is active.
137 extern void shift_active_win(char dir);
139 /* Draw virtual screen including all windows. Also add scroll hints for where
140 * the edges of the terminal screen hit non-edges of and inside the virtual
141 * screen. Then update the terminal screen.
143 extern void draw_all_wins();