Added partial matching and introduced threads

1 files changed, 427 insertions, 0 deletions

diff --git a/examples/dte/screen-view.c b/examples/dte/screen-view.c
new file mode 100644
index 0000000..0f8d72c
--- /dev/null
+++ b/examples/dte/screen-view.c
@@ -0,0 +1,427 @@
+#include "screen.h"
+#include "indent.h"
+#include "selection.h"
+#include "syntax/highlight.h"
+#include "util/ascii.h"
+#include "util/debug.h"
+#include "util/str-util.h"
+#include "util/utf8.h"
+
+typedef struct {
+    const View *view;
+    size_t line_nr;
+    size_t offset;
+    ssize_t sel_so;
+    ssize_t sel_eo;
+
+    const unsigned char *line;
+    size_t size;
+    size_t pos;
+    size_t indent_size;
+    size_t trailing_ws_offset;
+    const TermColor **colors;
+} LineInfo;
+
+// Like mask_color() but can change bg color only if it has not been changed yet
+static void mask_color2(const ColorScheme *colors, TermColor *color, const TermColor *over)
+{
+    int32_t default_bg = colors->builtin[BC_DEFAULT].bg;
+    if (over->bg != COLOR_KEEP && (color->bg == default_bg || color->bg < 0)) {
+        color->bg = over->bg;
+    }
+
+    if (over->fg != COLOR_KEEP) {
+        color->fg = over->fg;
+    }
+
+    if (!(over->attr & ATTR_KEEP)) {
+        color->attr = over->attr;
+    }
+}
+
+static void mask_selection_and_current_line (
+    const ColorScheme *colors,
+    const LineInfo *info,
+    TermColor *color
+) {
+    if (info->offset >= info->sel_so && info->offset < info->sel_eo) {
+        mask_color(color, &colors->builtin[BC_SELECTION]);
+    } else if (info->line_nr == info->view->cy) {
+        mask_color2(colors, color, &colors->builtin[BC_CURRENTLINE]);
+    }
+}
+
+static bool is_non_text(CodePoint u, bool display_special)
+{
+    if (u == '\t') {
+        return display_special;
+    }
+    return u < 0x20 || u == 0x7F || u_is_unprintable(u);
+}
+
+static WhitespaceErrorFlags get_ws_error(const LocalOptions *opts)
+{
+    WhitespaceErrorFlags taberrs = WSE_TAB_INDENT | WSE_TAB_AFTER_INDENT;
+    WhitespaceErrorFlags extra = opts->expand_tab ? taberrs : WSE_SPACE_INDENT;
+    return opts->ws_error | ((opts->ws_error & WSE_AUTO_INDENT) ? extra : 0);
+}
+
+static bool whitespace_error(const LineInfo *info, CodePoint u, size_t i)
+{
+    const View *view = info->view;
+    WhitespaceErrorFlags flags = get_ws_error(&view->buffer->options);
+    WhitespaceErrorFlags trailing = flags & (WSE_TRAILING | WSE_ALL_TRAILING);
+    if (i >= info->trailing_ws_offset && trailing) {
+        // Trailing whitespace
+        if (
+            // Cursor is not on this line
+            info->line_nr != view->cy
+            // or is positioned before any trailing whitespace
+            || view->cx < info->trailing_ws_offset
+            // or user explicitly wants trailing space under cursor highlighted
+            || flags & WSE_ALL_TRAILING
+        ) {
+            return true;
+        }
+    }
+
+    bool in_indent = (i < info->indent_size);
+    if (u == '\t') {
+        WhitespaceErrorFlags mask = in_indent ? WSE_TAB_INDENT : WSE_TAB_AFTER_INDENT;
+        return (flags & mask) != 0;
+    }
+    if (!in_indent) {
+        // All checks below here only apply to indentation
+        return false;
+    }
+
+    const char *line = info->line;
+    size_t pos = i;
+    size_t count = 0;
+    while (pos > 0 && line[pos - 1] == ' ') {
+        pos--;
+    }
+    while (pos < info->size && line[pos] == ' ') {
+        pos++;
+        count++;
+    }
+
+    WhitespaceErrorFlags mask;
+    if (count >= view->buffer->options.tab_width) {
+        // Spaces used instead of tab
+        mask = WSE_SPACE_INDENT;
+    } else if (pos < info->size && line[pos] == '\t') {
+        // Space before tab
+        mask = WSE_SPACE_INDENT;
+    } else {
+        // Less than tab width spaces at end of indentation
+        mask = WSE_SPACE_ALIGN;
+    }
+    return (flags & mask) != 0;
+}
+
+static CodePoint screen_next_char(EditorState *e, LineInfo *info)
+{
+    size_t count, pos = info->pos;
+    CodePoint u = info->line[pos];
+    TermColor color;
+    bool ws_error = false;
+
+    if (likely(u < 0x80)) {
+        info->pos++;
+        count = 1;
+        if (u == '\t' || u == ' ') {
+            ws_error = whitespace_error(info, u, pos);
+        }
+    } else {
+        u = u_get_nonascii(info->line, info->size, &info->pos);
+        count = info->pos - pos;
+
+        if (
+            u_is_special_whitespace(u) // Highly annoying no-break space etc.
+            && (info->view->buffer->options.ws_error & WSE_SPECIAL)
+        ) {
+            ws_error = true;
+        }
+    }
+
+    if (info->colors && info->colors[pos]) {
+        color = *info->colors[pos];
+    } else {
+        color = e->colors.builtin[BC_DEFAULT];
+    }
+    if (is_non_text(u, e->options.display_special)) {
+        mask_color(&color, &e->colors.builtin[BC_NONTEXT]);
+    }
+    if (ws_error) {
+        mask_color(&color, &e->colors.builtin[BC_WSERROR]);
+    }
+    mask_selection_and_current_line(&e->colors, info, &color);
+    set_color(&e->terminal, &e->colors, &color);
+
+    info->offset += count;
+    return u;
+}
+
+static void screen_skip_char(TermOutputBuffer *obuf, LineInfo *info)
+{
+    CodePoint u = info->line[info->pos++];
+    info->offset++;
+    if (likely(u < 0x80)) {
+        if (likely(!ascii_iscntrl(u))) {
+            obuf->x++;
+        } else if (u == '\t' && obuf->tab_mode != TAB_CONTROL) {
+            obuf->x = next_indent_width(obuf->x, obuf->tab_width);
+        } else {
+            // Control
+            obuf->x += 2;
+        }
+    } else {
+        size_t pos = info->pos;
+        info->pos--;
+        u = u_get_nonascii(info->line, info->size, &info->pos);
+        obuf->x += u_char_width(u);
+        info->offset += info->pos - pos;
+    }
+}
+
+static bool is_notice(const char *word, size_t len)
+{
+    switch (len) {
+    case 3: return mem_equal(word, "XXX", 3);
+    case 4: return mem_equal(word, "TODO", 4);
+    case 5: return mem_equal(word, "FIXME", 5);
+    }
+    return false;
+}
+
+// Highlight certain words inside comments
+static void hl_words(Terminal *term, const ColorScheme *colors, const LineInfo *info)
+{
+    const TermColor *cc = find_color(colors, "comment");
+    const TermColor *nc = find_color(colors, "notice");
+
+    if (!info->colors || !cc || !nc) {
+        return;
+    }
+
+    size_t i = info->pos;
+    if (i >= info->size) {
+        return;
+    }
+
+    // Go to beginning of partially visible word inside comment
+    while (i > 0 && info->colors[i] == cc && is_word_byte(info->line[i])) {
+        i--;
+    }
+
+    // This should be more than enough. I'm too lazy to iterate characters
+    // instead of bytes and calculate text width.
+    const size_t max = info->pos + term->width * 4 + 8;
+
+    size_t si;
+    while (i < info->size) {
+        if (info->colors[i] != cc || !is_word_byte(info->line[i])) {
+            if (i > max) {
+                break;
+            }
+            i++;
+        } else {
+            // Beginning of a word inside comment
+            si = i++;
+            while (
+                i < info->size && info->colors[i] == cc
+                && is_word_byte(info->line[i])
+            ) {
+                i++;
+            }
+            if (is_notice(info->line + si, i - si)) {
+                for (size_t j = si; j < i; j++) {
+                    info->colors[j] = nc;
+                }
+            }
+        }
+    }
+}
+
+static void line_info_init (
+    LineInfo *info,
+    const View *view,
+    const BlockIter *bi,
+    size_t line_nr
+) {
+    *info = (LineInfo) {
+        .view = view,
+        .line_nr = line_nr,
+        .offset = block_iter_get_offset(bi),
+    };
+
+    if (!view->selection) {
+        info->sel_so = -1;
+        info->sel_eo = -1;
+    } else if (view->sel_eo != SEL_EO_RECALC) {
+        // Already calculated
+        info->sel_so = view->sel_so;
+        info->sel_eo = view->sel_eo;
+        BUG_ON(info->sel_so > info->sel_eo);
+    } else {
+        SelectionInfo sel;
+        init_selection(view, &sel);
+        info->sel_so = sel.so;
+        info->sel_eo = sel.eo;
+    }
+}
+
+static void line_info_set_line (
+    LineInfo *info,
+    const StringView *line,
+    const TermColor **colors
+) {
+    BUG_ON(line->length == 0);
+    BUG_ON(line->data[line->length - 1] != '\n');
+
+    info->line = line->data;
+    info->size = line->length - 1;
+    info->pos = 0;
+    info->colors = colors;
+
+    {
+        size_t i, n;
+        for (i = 0, n = info->size; i < n; i++) {
+            char ch = info->line[i];
+            if (ch != '\t' && ch != ' ') {
+                break;
+            }
+        }
+        info->indent_size = i;
+    }
+
+    static_assert_compatible_types(info->trailing_ws_offset, size_t);
+    info->trailing_ws_offset = SIZE_MAX;
+    for (ssize_t i = info->size - 1; i >= 0; i--) {
+        char ch = info->line[i];
+        if (ch != '\t' && ch != ' ') {
+            break;
+        }
+        info->trailing_ws_offset = i;
+    }
+}
+
+static void print_line(EditorState *e, LineInfo *info)
+{
+    // Screen might be scrolled horizontally. Skip most invisible
+    // characters using screen_skip_char(), which is much faster than
+    // buf_skip(screen_next_char(info)).
+    //
+    // There can be a wide character (tab, control code etc.) that is
+    // partially visible and can't be skipped using screen_skip_char().
+    Terminal *term = &e->terminal;
+    TermOutputBuffer *obuf = &term->obuf;
+    while (obuf->x + 8 < obuf->scroll_x && info->pos < info->size) {
+        screen_skip_char(obuf, info);
+    }
+
+    const ColorScheme *colors = &e->colors;
+    hl_words(term, colors, info);
+
+    while (info->pos < info->size) {
+        BUG_ON(obuf->x > obuf->scroll_x + obuf->width);
+        CodePoint u = screen_next_char(e, info);
+        if (!term_put_char(obuf, u)) {
+            // +1 for newline
+            info->offset += info->size - info->pos + 1;
+            return;
+        }
+    }
+
+    TermColor color;
+    if (e->options.display_special && obuf->x >= obuf->scroll_x) {
+        // Syntax highlighter highlights \n but use default color anyway
+        color = colors->builtin[BC_DEFAULT];
+        mask_color(&color, &colors->builtin[BC_NONTEXT]);
+        mask_selection_and_current_line(colors, info, &color);
+        set_color(term, colors, &color);
+        term_put_char(obuf, '$');
+    }
+
+    color = colors->builtin[BC_DEFAULT];
+    mask_selection_and_current_line(colors, info, &color);
+    set_color(term, colors, &color);
+    info->offset++;
+    term_clear_eol(term);
+}
+
+void update_range(EditorState *e, const View *view, long y1, long y2)
+{
+    const int edit_x = view->window->edit_x;
+    const int edit_y = view->window->edit_y;
+    const int edit_w = view->window->edit_w;
+    const int edit_h = view->window->edit_h;
+
+    Terminal *term = &e->terminal;
+    TermOutputBuffer *obuf = &term->obuf;
+    term_output_reset(term, edit_x, edit_w, view->vx);
+    obuf->tab_width = view->buffer->options.tab_width;
+    obuf->tab_mode = e->options.display_special ? TAB_SPECIAL : TAB_NORMAL;
+
+    BlockIter bi = view->cursor;
+    for (long i = 0, n = view->cy - y1; i < n; i++) {
+        block_iter_prev_line(&bi);
+    }
+    for (long i = 0, n = y1 - view->cy; i < n; i++) {
+        block_iter_eat_line(&bi);
+    }
+    block_iter_bol(&bi);
+
+    LineInfo info;
+    line_info_init(&info, view, &bi, y1);
+
+    y1 -= view->vy;
+    y2 -= view->vy;
+
+    bool got_line = !block_iter_is_eof(&bi);
+    hl_fill_start_states(view->buffer, &e->colors, info.line_nr);
+    long i;
+    for (i = y1; got_line && i < y2; i++) {
+        obuf->x = 0;
+        term_move_cursor(obuf, edit_x, edit_y + i);
+
+        StringView line;
+        fill_line_nl_ref(&bi, &line);
+        bool next_changed;
+        const TermColor **colors = hl_line(view->buffer, &e->colors, &line, info.line_nr, &next_changed);
+        line_info_set_line(&info, &line, colors);
+        print_line(e, &info);
+
+        got_line = !!block_iter_next_line(&bi);
+        info.line_nr++;
+
+        if (next_changed && i + 1 == y2 && y2 < edit_h) {
+            // More lines need to be updated not because their contents have
+            // changed but because their highlight state has
+            y2++;
+        }
+    }
+
+    if (i < y2 && info.line_nr == view->cy) {
+        // Dummy empty line is shown only if cursor is on it
+        TermColor color = e->colors.builtin[BC_DEFAULT];
+
+        obuf->x = 0;
+        mask_color2(&e->colors, &color, &e->colors.builtin[BC_CURRENTLINE]);
+        set_color(term, &e->colors, &color);
+
+        term_move_cursor(obuf, edit_x, edit_y + i++);
+        term_clear_eol(term);
+    }
+
+    if (i < y2) {
+        set_builtin_color(term, &e->colors, BC_NOLINE);
+    }
+    for (; i < y2; i++) {
+        obuf->x = 0;
+        term_move_cursor(obuf, edit_x, edit_y + i);
+        term_put_char(obuf, '~');
+        term_clear_eol(term);
+    }
+}