Fixes CJK wide character display

By jumping two columns when wide character prints,
and draw wide background under wide character.

diff --git a/clients/terminal.c b/clients/terminal.c
index 6701fb6..4df0abb 100644 (file)
--- a/clients/terminal.c
+++ b/clients/terminal.c
@@ -20,6 +20,8 @@
  * OF THIS SOFTWARE.
  */
 
+#define _XOPEN_SOURCE 700 /* for strnlen, snprintf and wcwidth */
+
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -33,6 +35,8 @@
 #include <ctype.h>
 #include <cairo.h>
 #include <sys/epoll.h>
+#include <wchar.h>
+#include <locale.h>
 
 #include <wayland-client.h>
 
@@ -218,6 +222,13 @@ get_unicode(union utf8_char utf8)
        return machine.unicode;
 }
 
+static bool
+is_wide(union utf8_char utf8)
+{
+       uint32_t unichar = get_unicode(utf8);
+       return wcwidth(unichar) > 1;
+}
+
 struct char_sub {
        union utf8_char match;
        union utf8_char replace;
@@ -876,6 +887,8 @@ terminal_send_selection(struct terminal *terminal, int fd)
        for (row = 0; row < terminal->height; row++) {
                p_row = terminal_get_row(terminal, row);
                for (col = 0; col < terminal->width; col++) {
+                       if (p_row[col].ch == 0x200B) /* space glyph */
+                               continue;
                        /* get the attributes for this character cell */
                        terminal_decode_attr(terminal, row, col, &attr);
                        if (!attr.attr.s)
@@ -972,6 +985,7 @@ redraw_handler(struct widget *widget, void *data)
        struct glyph_run run;
        cairo_font_extents_t extents;
        double average_width;
+       double unichar_width;
 
        surface = window_get_surface(terminal->window);
        widget_get_allocation(terminal->widget, &allocation);
@@ -997,6 +1011,7 @@ redraw_handler(struct widget *widget, void *data)
                        allocation.y + top_margin);
        /* paint the background */
        for (row = 0; row < terminal->height; row++) {
+               p_row = terminal_get_row(terminal, row);
                for (col = 0; col < terminal->width; col++) {
                        /* get the attributes for this character cell */
                        terminal_decode_attr(terminal, row, col, &attr);
@@ -1004,12 +1019,17 @@ redraw_handler(struct widget *widget, void *data)
                        if (attr.attr.bg == terminal->color_scheme->border)
                                continue;
 
+                       if (is_wide(p_row[col]))
+                               unichar_width = 2 * average_width;
+                       else
+                               unichar_width = average_width;
+
                        terminal_set_color(terminal, cr, attr.attr.bg);
                        cairo_move_to(cr, col * average_width,
                                      row * extents.height);
-                       cairo_rel_line_to(cr, average_width, 0);
+                       cairo_rel_line_to(cr, unichar_width, 0);
                        cairo_rel_line_to(cr, 0, extents.height);
-                       cairo_rel_line_to(cr, -average_width, 0);
+                       cairo_rel_line_to(cr, -unichar_width, 0);
                        cairo_close_path(cr);
                        cairo_fill(cr);
                }
@@ -1901,6 +1921,10 @@ handle_char(struct terminal *terminal, union utf8_char utf8)
        row[terminal->column] = utf8;
        attr_row[terminal->column++] = terminal->curr_attr;
 
+       /* cursor jump for wide character. */
+       if (is_wide(utf8))
+               row[terminal->column++].ch = 0x200B; /* space glyph */
+
        if (utf8.ch != terminal->last_char.ch)
                terminal->last_char = utf8;
 }
@@ -2737,6 +2761,10 @@ int main(int argc, char *argv[])
        struct terminal *terminal;
        int config_fd;
 
+       /* as wcwidth is locale-dependent,
+          wcwidth needs setlocale call to function properly. */
+       setlocale(LC_ALL, "");
+
        option_shell = getenv("SHELL");
        if (!option_shell)
                option_shell = "/bin/bash";