view.h

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