view.h

   1 #ifndef VIEW_H
   2 #define VIEW_H
   3
   4 #include <stddef.h>
   5 #include <stdbool.h>
   6 #include <lua.h>
   7 #include "register.h"
   8 #include "text.h"
   9 #include "ui.h"
  10 #include "syntax.h"
  11
  12 typedef struct View View;
  13 typedef struct Cursor Cursor;
  14 typedef struct Selection Selection;
  15
  16 typedef struct {
  17         void *data;
  18         void (*selection)(void *data, Filerange*);
  19 } ViewEvent;
  20
  21 typedef struct {
  22         int width;          /* display width i.e. number of columns ocupied by this character */
  23         size_t len;         /* number of bytes the character displayed in this cell uses, for
  24                                character which use more than 1 column to display, their lenght
  25                                is stored in the leftmost cell wheras all following cells
  26                                occupied by the same character have a length of 0. */
  27         char data[8];       /* utf8 encoded character displayed in this cell might not be the
  28                                the same as in the underlying text, for example tabs get expanded */
  29         unsigned int attr;
  30         bool istab;
  31         bool selected;      /* whether this cell is part of a selected region */
  32         bool cursor;        /* whether a cursor is currently locaated on the cell */
  33 } Cell;
  34
  35 typedef struct Line Line;
  36 struct Line {               /* a line on the screen, *not* in the file */
  37         Line *prev, *next;  /* pointer to neighbouring screen lines */
  38         size_t len;         /* line length in terms of bytes */
  39         size_t lineno;      /* line number from start of file */
  40         int width;          /* zero based position of last used column cell */
  41         Cell cells[];       /* win->width cells storing information about the displayed characters */
  42 };
  43
  44 typedef struct {
  45         size_t line;
  46         size_t col;
  47 } CursorPos;
  48
  49 View *view_new(Text*, lua_State*, ViewEvent*);
  50 void view_ui(View*, UiWin*);
  51 /* change associated text displayed in this window */
  52 void view_reload(View*, Text*);
  53 void view_free(View*);
  54
  55 bool view_resize(View*, int width, int height);
  56 int view_height_get(View*);
  57 int view_width_get(View*);
  58 void view_draw(View*);
  59 void view_update(View*);
  60 /* changes how many spaces are used for one tab (must be >0), redraws the window */
  61 void view_tabwidth_set(View*, int tabwidth);
  62
  63 /* cursor movements which also update selection if one is active.
  64  * they return new cursor postion */
  65 size_t view_line_down(Cursor*);
  66 size_t view_line_up(Cursor*);
  67 size_t view_screenline_down(Cursor*);
  68 size_t view_screenline_up(Cursor*);
  69 size_t view_screenline_begin(Cursor*);
  70 size_t view_screenline_middle(Cursor*);
  71 size_t view_screenline_end(Cursor*);
  72 /* move window content up/down, but keep cursor position unchanged unless it is
  73  * on a now invisible line in which case we try to preserve the column position */
  74 size_t view_slide_up(View*, int lines);
  75 size_t view_slide_down(View*, int lines);
  76 /* scroll window contents up/down by lines, place the cursor on the newly
  77  * visible line, try to preserve the column position */
  78 size_t view_scroll_up(View*, int lines);
  79 size_t view_scroll_down(View*, int lines);
  80 /* place the cursor at the start ot the n-th window line, counting from 1 */
  81 size_t view_screenline_goto(View*, int n);
  82
  83 const Line *view_lines_get(View*);
  84 /* redraw current cursor line at top/center/bottom of window */
  85 void view_redraw_top(View*);
  86 void view_redraw_center(View*);
  87 void view_redraw_bottom(View*);
  88 /* get the currently displayed area in bytes from the start of the file */
  89 Filerange view_viewport_get(View*);
  90 /* move visible viewport n-lines up/down, redraws the view but does not change
  91  * cursor position which becomes invalid and should be corrected by calling
  92  * view_cursor_to. the return value indicates wether the visible area changed.
  93  */
  94 bool view_viewport_up(View *view, int n);
  95 bool view_viewport_down(View *view, int n);
  96 /* associate a set of syntax highlighting rules to this window. */
  97 bool view_syntax_set(View*, const char *name);
  98 const char *view_syntax_get(View*);
  99
 100 void view_options_set(View*, enum UiOption options);
 101 enum UiOption view_options_get(View*);
 102 void view_colorcolumn_set(View*, int col);
 103 int view_colorcolumn_get(View*);
 104
 105 /* A view can manage multiple cursors, one of which (the main cursor) is always
 106  * placed within the visible viewport. All functions named view_cursor_* operate
 107  * on this cursor. Additional cursor can be created and manipulated using the
 108  * functions named view_cursors_* */
 109
 110 /* get main cursor position in terms of screen coordinates */
 111 CursorPos view_cursor_getpos(View*);
 112 /* get main cursor position in bytes from start of the file */
 113 size_t view_cursor_get(View*);
 114 /* moves window viewport in direction until pos is visible. should only be
 115  * used for short distances between current cursor position and destination */
 116 void view_scroll_to(View*, size_t pos);
 117 /* move cursor to a given position. changes the viewport to make sure that
 118  * position is visible. if the position is in the middle of a line, try to
 119  * adjust the viewport in such a way that the whole line is displayed */
 120 void view_cursor_to(View*, size_t pos);
 121 /* create a new cursor */
 122 Cursor *view_cursors_new(View*);
 123 /* get number of active cursors */
 124 int view_cursors_count(View*);
 125 /* dispose an existing cursor with its associated selection (if any),
 126  * not applicaple for the last existing cursor */
 127 void view_cursors_dispose(Cursor*);
 128 /* only keep the main cursor, release all others together with their
 129  * selections (if any) */
 130 void view_cursors_clear(View*);
 131 /* get the main cursor which is always in the visible viewport */
 132 Cursor *view_cursor(View*);
 133 /* get the first cursor */
 134 Cursor *view_cursors(View*);
 135 Cursor *view_cursors_prev(Cursor*);
 136 Cursor *view_cursors_next(Cursor*);
 137 /* get current position of cursor in bytes from the start of the file */
 138 size_t view_cursors_pos(Cursor*);
 139 /* place cursor at `pos' which should be in the interval [0, text-size] */
 140 void view_cursors_to(Cursor*, size_t pos);
 141 void view_cursors_scroll_to(Cursor*, size_t pos);
 142 /* get register associated with this register */
 143 Register *view_cursors_register(Cursor*);
 144 /* start selected area at current cursor position. further cursor movements
 145  * will affect the selected region. */
 146 void view_cursors_selection_start(Cursor*);
 147 /* detach cursor from selection, further cursor movements will not affect
 148  * the selected region. */
 149 void view_cursors_selection_stop(Cursor*);
 150 /* clear selection associated with this cursor (if any) */
 151 void view_cursors_selection_clear(Cursor*);
 152 /* move cursor position from one end of the selection to the other */
 153 void view_cursors_selection_swap(Cursor*);
 154 /* move cursor to the end/boundary of the associated selection */
 155 void view_cursors_selection_sync(Cursor*);
 156 /* restore previous used selection of this cursor */
 157 void view_cursors_selection_restore(Cursor*);
 158 /* get/set the selected region associated with this cursor */
 159 Filerange view_cursors_selection_get(Cursor*);
 160 void view_cursors_selection_set(Cursor*, Filerange*);
 161
 162 Selection *view_selections_new(View*);
 163 void view_selections_free(Selection*);
 164 void view_selections_clear(View*);
 165 void view_selections_swap(Selection*);
 166 Selection *view_selections(View*);
 167 Selection *view_selections_prev(Selection*);
 168 Selection *view_selections_next(Selection*);
 169 Filerange view_selections_get(Selection*);
 170 void view_selections_set(Selection*, Filerange*);
 171
 172 #endif