[ghex] gtkhex: de-jankify highlights

[Logan Rathbone <larathbone src gnome org>]

commit 6de1722d74c2d37ba45c65f2d426b40f6fcdd5dd
Author: Logan Rathbone <poprocks gmail com>
Date:   Wed Dec 8 19:54:53 2021 -0500

    gtkhex: de-jankify highlights
    
    There were some bugs left over from my prior rewrite of
    render_highlights, which only cropped up on optimized builds. This
    should address those issues.

 src/gtkhex.c | 178 +++++++++++++++++++++++++++++------------------------------
 1 file changed, 89 insertions(+), 89 deletions(-)
---
diff --git a/src/gtkhex.c b/src/gtkhex.c
index 54f3d3c..7ebd8fe 100644
--- a/src/gtkhex.c
+++ b/src/gtkhex.c
@@ -88,7 +88,6 @@ struct _GtkHex_Highlight
        int start, end;
        int start_line, end_line;
        GdkRGBA *bg_color; /* NULL to use the style color */
-       int min_select;
 
        GtkHex_Highlight *prev, *next;
        gboolean valid;
@@ -694,17 +693,15 @@ render_highlights (GtkHex *gh,
                int cursor_line,
                GtkHexViewType type)
 {
-       GtkHex_Highlight *curHighlight = &gh->selection;
-       GtkHex_AutoHighlight *nextList = gh->auto_highlight;
-       GtkStateFlags state;
-       GtkStyleContext *context;
+       /* Shorthand tracers to walk through highlight lists */
+       GtkHex_Highlight *highlight = &gh->selection;
+       GtkHex_AutoHighlight *auto_highlight = gh->auto_highlight;
        GtkWidget *widget;              /* shorthand for the hex or ascii drawing area */
        PangoLayout *layout;    /* shorthand for the hex or ascii pango layout */
+       GtkStyleContext *context;
        int hex_cpl;
        cairo_region_t *region;
        int y;
-       int range[2];
-       double x1, x2, y1, y2;
 
        if (type == VIEW_HEX)
        {
@@ -723,106 +720,112 @@ render_highlights (GtkHex *gh,
        context = gtk_widget_get_style_context (widget);
        gtk_style_context_save (context);
 
-       state = gtk_widget_get_state_flags (widget);
-       state |= GTK_STATE_FLAG_SELECTED;
-       gtk_style_context_set_state (context, state);
-
-       cairo_save (cr);
+       gtk_style_context_set_state (context,
+                       gtk_widget_get_state_flags (widget) | GTK_STATE_FLAG_SELECTED);
 
-       while (curHighlight)
+       while (highlight)
        {
-               if (ABS(curHighlight->start - curHighlight->end) >=
-                               curHighlight->min_select)
-               {
-                       int start, end;
-                       int start_line, end_line;
-                       int cursor_off = 0;
-                       int len;
+               int cursor_off = 0;
+               int len;
 
-                       gtk_hex_validate_highlight (gh, curHighlight);
+               int range[2];
+               double x1, x2, y1, y2;
 
-                       start = MIN(curHighlight->start, curHighlight->end);
-                       end = MAX(curHighlight->start, curHighlight->end);
-                       start_line = curHighlight->start_line;
-                       end_line = curHighlight->end_line;
+               /* Shorthands for readability of this loop */
+               int start, end, start_line, end_line;
 
-                       if (cursor_line == start_line)
-                       {
-                               if (type == VIEW_HEX)
-                               {
-                                       cursor_off = 2 * (start % gh->cpl) + (start % gh->cpl) / 
gh->group_type;
+               gtk_hex_validate_highlight (gh, highlight);
 
-                                       if (cursor_line == end_line)
-                                               len = 2*(end%gh->cpl + 1) + (end%gh->cpl)/gh->group_type;
-                                       else
-                                               len = hex_cpl;
+               start = MIN(highlight->start, highlight->end);
+               end = MAX(highlight->start, highlight->end);
+               start_line = highlight->start_line;
+               end_line = highlight->end_line;
 
-                                       len = len - cursor_off;
-                               }
-                               else
-                               {
-                                       cursor_off = start % gh->cpl;
+               if (start == end)
+                       goto end_of_loop;
 
-                                       if (cursor_line == end_line)
-                                               len = end - start + 1;
-                                       else
-                                               len = gh->cpl - cursor_off;
-                               }
+               if (cursor_line == start_line)
+               {
+                       if (type == VIEW_HEX) {
+                               cursor_off = 2 * (start % gh->cpl) +
+                                       (start % gh->cpl) / gh->group_type;
 
-                               range[0] = cursor_off;
-                               range[1] = cursor_off + len;
-                       }
-                       else if (cursor_line == end_line)
-                       {
-                               if (type == VIEW_HEX)
-                               {
-                                       cursor_off = 2 * (end % gh->cpl + 1) + 
+                               if (cursor_line == end_line)
+                                       len = 2 * (end % gh->cpl + 1) +
                                                (end % gh->cpl) / gh->group_type;
-                               }
                                else
-                               {
-                                       cursor_off = end % gh->cpl + 1;
-                               }
+                                       len = hex_cpl;
 
-                               range[0] = 0;
-                               range[1] = cursor_off;
+                               len = len - cursor_off;
                        }
-                       else if (cursor_line > start_line && cursor_line < end_line)
-                       {
-                               int cpl = (type == VIEW_HEX) ? hex_cpl : gh->cpl;
+                       else {  /* VIEW_ASCII */
+                               cursor_off = start % gh->cpl;
 
-                               range[0] = 0;
-                               range[1] = cpl;
+                               if (cursor_line == end_line)
+                                       len = end - start + 1;
+                               else
+                                       len = gh->cpl - cursor_off;
                        }
 
-                       region = gdk_pango_layout_get_clip_region (layout,
-                                       0,      /* x */
-                                       y,
-                                       range,
-                                       1);
-
-                       gdk_cairo_region (cr, region);
-                       cairo_save (cr);
-                       cairo_clip (cr);
-                       cairo_clip_extents (cr, &x1, &y1, &x2, &y2);
+                       range[0] = cursor_off;
+                       range[1] = cursor_off + len;
+               }
+               else if (cursor_line == end_line)
+               {
+                       if (type == VIEW_HEX) {
+                               cursor_off = 2 * (end % gh->cpl + 1) + 
+                                       (end % gh->cpl) / gh->group_type;
+                       }
+                       else {  /* VIEW_ASCII */
+                               cursor_off = end % gh->cpl + 1;
+                       }
 
-                       gtk_render_background (context, cr,
-                                       x1,
-                                       y1,
-                                       ABS(x2-x1),
-                                       ABS(y2-y1));
+                       range[0] = 0;
+                       range[1] = cursor_off;
+               }
+               else if (cursor_line > start_line && cursor_line < end_line)
+               {
+                       int cpl = (type == VIEW_HEX) ? hex_cpl : gh->cpl;
 
-                       cairo_restore (cr);
+                       range[0] = 0;
+                       range[1] = cpl;
                }
-               curHighlight = curHighlight->next;
-               while (curHighlight == NULL && nextList)
+               else
+                       goto end_of_loop;
+
+               cairo_save (cr);
+
+               region = gdk_pango_layout_get_clip_region (layout,
+                               0,      /* x */
+                               y,
+                               range,
+                               1);
+
+               gdk_cairo_region (cr, region);
+               cairo_clip (cr);
+               cairo_clip_extents (cr, &x1, &y1, &x2, &y2);
+
+               gtk_render_background (context, cr,
+                               x1,
+                               y1,
+                               ABS(x2-x1),
+                               ABS(y2-y1));
+
+               cairo_restore (cr);
+
+end_of_loop:
+               highlight = highlight->next;
+
+               /* if there are no selection highlights left, look for auto-highlights
+                */
+               while (highlight == NULL && auto_highlight)
                {
-                       curHighlight = nextList->highlights;
-                       nextList = nextList->next;
+                       highlight = auto_highlight->highlights;
+                       auto_highlight = auto_highlight->next;
                }
        }
-       cairo_restore (cr);
        gtk_style_context_restore (context);
+       gtk_widget_queue_draw (GTK_WIDGET(gh));
 }
 
 /* FIXME - Previously, this function was more sophisticated, and only
@@ -1839,15 +1842,13 @@ gtk_hex_insert_highlight (GtkHex *gh,
        g_return_val_if_fail (HEX_IS_DOCUMENT (gh->document), NULL);
 
        file_size = hex_document_get_file_size (gh->document);
-       GtkHex_Highlight *new = g_malloc0(sizeof(GtkHex_Highlight));
+       GtkHex_Highlight *new = g_new0 (GtkHex_Highlight, 1);
 
        new->start = CLAMP(MIN(start, end), 0, file_size);
        new->end = MIN(MAX(start, end), file_size);
 
        new->valid = FALSE;
 
-       new->min_select = 0;
-
        new->prev = NULL;
        new->next = ahl->highlights;
        if (new->next) new->next->prev = new;
@@ -2453,7 +2454,6 @@ gtk_hex_init (GtkHex *gh)
 
        gh->selection.start = gh->selection.end = 0;
        gh->selection.bg_color = NULL;
-       gh->selection.min_select = 1;
        gh->selection.next = gh->selection.prev = NULL;
        gh->selection.valid = FALSE;
 
@@ -3059,7 +3059,7 @@ gtk_hex_insert_autohighlight(GtkHex *gh,
                const char *search,
                int len)
 {
-       GtkHex_AutoHighlight *new = g_malloc0(sizeof(GtkHex_AutoHighlight));
+       GtkHex_AutoHighlight *new = g_new0 (GtkHex_AutoHighlight, 1);
 
        new->search_string = g_memdup2 (search, len);
        new->search_len = len;