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Teach the line editor to scroll + prompt

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Přemysl Eric Janouch 2017-06-26 03:10:02 +02:00
parent 6b2def7531
commit 4261c81468
Signed by: p
GPG Key ID: B715679E3A361BE6
1 changed files with 37 additions and 18 deletions
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nncmpp.c
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@ -639,6 +639,7 @@ static struct app_context
int *editor_w; ///< Codepoint widths, 0-terminated
size_t editor_len; ///< Editor length
size_t editor_alloc; ///< Editor allocated
char editor_prompt; ///< Prompt character
void (*on_editor_changed) (void); ///< Callback on text change
void (*on_editor_end) (bool); ///< Callback on abort
@ -1362,21 +1363,33 @@ row_buffer_append_c (struct row_buffer *self, ucs4_t c, chtype attrs)
static int
app_write_editor (struct row_buffer *row)
{
// TODO: there should be a one-character prefix to distinguish operations
// (also known as the prompt)
// TODO: some scrolling mechanism
// - left = point - COLS/2 worth of cells
// - while there's space on the right, move the left further
// This seems to work in all cases.
int offset = 0;
for (size_t i = 0; i < g.editor_len; i++)
int limit = COLS;
if (g.editor_prompt)
{
if (g.editor_point > (int) i)
offset += g.editor_w[i];
row_buffer_append_c (row, g.editor_line[i], APP_ATTR (HIGHLIGHT));
hard_assert (g.editor_prompt < 127);
row_buffer_append_c (row, g.editor_prompt, APP_ATTR (HIGHLIGHT));
limit--;
}
return MIN (offset, COLS - 1);
int following = 0;
for (size_t i = g.editor_point; i < g.editor_len; i++)
following += g.editor_w[i];
int preceding = 0;
size_t start = g.editor_point;
while (start && preceding < limit / 2)
preceding += g.editor_w[--start];
// There can be one extra space at the end of the line but this way we
// don't need to care about non-spacing marks following full-width chars
while (start && limit - preceding - following > 2 /* widest char */)
preceding += g.editor_w[--start];
// XXX: we should also show < > indicators for overflow but it'd probably
// considerably complicate this algorithm
for (; start < g.editor_len; start++)
row_buffer_append_c (row, g.editor_line[start], APP_ATTR (HIGHLIGHT));
return !!g.editor_prompt + preceding;
}
static void
@ -1612,22 +1625,25 @@ app_editor_abort (bool status)
g.on_editor_end = NULL;
free (g.editor_line);
free (g.editor_w);
g.editor_line = NULL;
free (g.editor_w);
g.editor_w = NULL;
g.editor_alloc = 0;
g.editor_len = 0;
g.editor_point = 0;
g.editor_prompt = 0;
}
/// Start the line editor; remember to fill in "change" and "abort" callbacks
static void
app_editor_start (void)
app_editor_start (char prompt)
{
g.editor_alloc = 16;
g.editor_line = xcalloc (sizeof *g.editor_line, g.editor_alloc);
g.editor_w = xcalloc (sizeof *g.editor_w, g.editor_alloc);
g.editor_len = 0;
g.editor_point = 0;
g.editor_prompt = prompt;
app_invalidate ();
}
@ -1751,7 +1767,7 @@ app_editor_process_action (enum action action)
static void
app_editor_insert (ucs4_t codepoint)
{
while (g.editor_alloc - g.editor_len < 2)
while (g.editor_alloc - g.editor_len < 2 /* inserted + sentinel */)
{
g.editor_alloc <<= 1;
g.editor_line = xreallocarray
@ -1759,11 +1775,14 @@ app_editor_insert (ucs4_t codepoint)
g.editor_w = xreallocarray
(g.editor_w, sizeof *g.editor_w, g.editor_alloc);
}
app_editor_move (g.editor_point + 1, g.editor_point,
g.editor_len - g.editor_point);
g.editor_line[g.editor_point] = codepoint;
// FIXME: this should care about app_is_character_in_locale() as well
g.editor_w[g.editor_point] = uc_width (codepoint, locale_charset ());
g.editor_w[g.editor_point] = app_is_character_in_locale (codepoint)
? uc_width (codepoint, locale_charset ())
: 1 /* the replacement question mark */;
g.editor_point++;
g.editor_len++;
app_editor_changed ();