1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
static size_t input_offset_top(void) {
return 0;
}
static size_t input_offset_bottom(struct zsvsheet_input_dimensions *input_dims,
size_t buffer_row_count // number of rows in the buffer, w/o regard to header
) {
return input_dims->row_count - buffer_row_count;
}
static size_t input_offset_centered(struct zsvsheet_input_dimensions *input_dims,
size_t buffer_row_count, // number of rows in the buffer, w/o regard to header
size_t target_raw_ix // raw row index starting at zero, w/o regard to header
) {
if (input_dims->row_count <= buffer_row_count) // entire input fits in buffer
return input_offset_top();
size_t buffer_half_row_count = buffer_row_count / 2;
if (target_raw_ix <= buffer_half_row_count) // target is at the top of the file
return input_offset_top();
if (target_raw_ix + buffer_half_row_count > input_dims->row_count) // target is at the end of the file
return input_offset_bottom(input_dims, buffer_row_count);
return target_raw_ix - buffer_half_row_count;
}
// zsvsheet_goto_input_raw_row
// return non-zero if buffer must be reloaded
/*
------- INPUT
0 | header | => BUFFER[BHEADSPAN]
1 | ... | => BUFFER[BHEADSPAN]
2 | data
------- BUFFER[BHEADSPAN:]
ioff->3 |
4 |
------- DISPLAY DATA
5 | boff-> | displayed data 1
6 | | displayed data 2
...
N+4| | displayed data M = max_y - BHEADSPAN - 1
-------
*/
static void set_window_to_cursor(struct zsvsheet_rowcol *buff_offset, size_t target_raw_row,
struct zsvsheet_rowcol *input_offset, size_t input_header_span,
struct zsvsheet_display_dimensions *ddims, size_t cursor_row) {
// assume that input_offset->row is fixed; set buff_offset->row
if (target_raw_row + ddims->header_span >= input_offset->row + cursor_row + input_header_span)
buff_offset->row = target_raw_row - input_offset->row - cursor_row + ddims->header_span - input_header_span;
else
buff_offset->row = 0;
}
static int zsvsheet_goto_input_raw_row(struct zsvsheet_ui_buffer *uib, size_t input_raw_num, size_t input_header_span,
struct zsvsheet_display_dimensions *ddims, size_t final_cursor_position) {
zsvsheet_screen_buffer_t buffer = uib->buffer;
struct zsvsheet_rowcol *input_offset = &uib->input_offset;
struct zsvsheet_rowcol *buff_offset = &uib->buff_offset;
struct zsvsheet_input_dimensions *input_dims = &uib->dimensions;
size_t *cursor_rowp = &uib->cursor_row;
size_t buffer_rows = zsvsheet_screen_buffer_rows(buffer);
int update_buffer = 0;
if (input_raw_num < input_offset->row + input_header_span // move the buffer up
|| input_raw_num + input_header_span + 1 > input_offset->row + buffer_rows // move the buffer down
) {
input_offset->row = input_offset_centered(input_dims, buffer_rows, input_raw_num);
update_buffer = 1;
} else if (!(input_raw_num >= input_offset->row + buff_offset->row &&
input_raw_num <=
input_offset->row + buff_offset->row + (ddims->rows + ddims->header_span + ddims->footer_span))) {
// buffer already has the data but display window needs to move
} else {
if (final_cursor_position == (size_t)-1) {
// just move the cursor however much we needed to shift
size_t current = zsvsheet_get_input_raw_row(input_offset, buff_offset, *cursor_rowp);
final_cursor_position = *cursor_rowp + input_raw_num - current;
}
}
if (final_cursor_position == (size_t)-1)
final_cursor_position = ddims->header_span;
if (final_cursor_position < ddims->header_span)
final_cursor_position = ddims->header_span;
if (final_cursor_position > ddims->rows - ddims->footer_span - 1)
final_cursor_position = ddims->rows - ddims->footer_span - 1;
*cursor_rowp = final_cursor_position;
// we may still need to update the buffer if the row we are jumping to will be
// in the middle of the screen and therefore we still want to display additional
// rows, and those additional rows are not loaded into the buffer
if (!update_buffer && final_cursor_position < ddims->rows - 1) {
size_t last_raw_row_to_display = input_raw_num + (ddims->rows - 1 - final_cursor_position);
if (last_raw_row_to_display > input_dims->row_count)
last_raw_row_to_display = input_dims->row_count;
if (last_raw_row_to_display < input_offset->row + input_header_span // move the buffer up
|| last_raw_row_to_display + input_header_span + 1 > input_offset->row + buffer_rows // move the buffer down
) {
input_offset->row = input_offset_centered(input_dims, buffer_rows, input_raw_num);
update_buffer = 1;
}
}
set_window_to_cursor(buff_offset, input_raw_num, input_offset, input_header_span, ddims, *cursor_rowp);
return update_buffer;
}
static int cursor_right(int max_x, unsigned display_width, size_t max_col_count, size_t *cursor_colp,
size_t *start_colp) {
size_t cursor_col = *cursor_colp;
size_t start_col = *start_colp;
int rc = 1;
if (cursor_col + 1 < max_x / display_width && start_col + cursor_col + 1 < max_col_count) {
cursor_col++;
} else if ((start_col + max_x / display_width) < max_col_count) {
start_col++;
} else
rc = 0;
*cursor_colp = cursor_col;
*start_colp = start_col;
return rc;
}
|
