Add dashed and dotted lineslines

Extend the PangoUnderline and PangoOverline enumerations to
cover dashed and dotted variants of the various lines, add
api to PangoRenderer to render such lines, and implement it
in the cairo renderer.

1 files changed, 128 insertions, 0 deletions

diff --git a/pango/pango-renderer.c b/pango/pango-renderer.c
index 2d676782..52d44061 100644
--- a/pango/pango-renderer.c
+++ b/pango/pango-renderer.c
@@ -87,6 +87,13 @@ static void pango_renderer_default_draw_error_underline (PangoRenderer    *rende
                                                          int               y,
                                                          int               width,
                                                          int               height);
+static void pango_renderer_default_draw_line            (PangoRenderer    *renderer,
+                                                         PangoRenderPart   part,
+                                                         PangoRenderLineStyle style,
+                                                         int               x,
+                                                         int               y,
+                                                         int               width,
+                                                         int               height);
 static void pango_renderer_default_prepare_run          (PangoRenderer    *renderer,
                                                          PangoLayoutRun   *run);
 
@@ -123,6 +130,7 @@ pango_renderer_class_init (PangoRendererClass *klass)
   klass->draw_glyph_item = pango_renderer_default_draw_glyph_item;
   klass->draw_rectangle = pango_renderer_default_draw_rectangle;
   klass->draw_error_underline = pango_renderer_default_draw_error_underline;
+  klass->draw_line = pango_renderer_default_draw_line;
   klass->prepare_run = pango_renderer_default_prepare_run;
 
   gobject_class->finalize = pango_renderer_finalize;
@@ -239,6 +247,48 @@ draw_underline (PangoRenderer *renderer,
                                      rect->width,
                                      rect->height);
       break;
+    case PANGO_UNDERLINE_DOUBLE_DASHED:
+    case PANGO_UNDERLINE_DOUBLE_LINE_DASHED:
+      pango_renderer_draw_line (renderer,
+                                PANGO_RENDER_PART_UNDERLINE,
+                                PANGO_RENDER_LINE_DASHED,
+                                rect->x,
+                                rect->y + 2 * rect->height,
+                                rect->width,
+                                rect->height);
+      G_GNUC_FALLTHROUGH;
+    case PANGO_UNDERLINE_SINGLE_DASHED:
+    case PANGO_UNDERLINE_LOW_DASHED:
+    case PANGO_UNDERLINE_SINGLE_LINE_DASHED:
+      pango_renderer_draw_line (renderer,
+                                PANGO_RENDER_PART_UNDERLINE,
+                                PANGO_RENDER_LINE_DASHED,
+                                rect->x,
+                                rect->y,
+                                rect->width,
+                                rect->height);
+      break;
+    case PANGO_UNDERLINE_DOUBLE_DOTTED:
+    case PANGO_UNDERLINE_DOUBLE_LINE_DOTTED:
+      pango_renderer_draw_line (renderer,
+                                PANGO_RENDER_PART_UNDERLINE,
+                                PANGO_RENDER_LINE_DOTTED,
+                                rect->x,
+                                rect->y + 2 * rect->height,
+                                rect->width,
+                                rect->height);
+      G_GNUC_FALLTHROUGH;
+    case PANGO_UNDERLINE_SINGLE_DOTTED:
+    case PANGO_UNDERLINE_LOW_DOTTED:
+    case PANGO_UNDERLINE_SINGLE_LINE_DOTTED:
+      pango_renderer_draw_line (renderer,
+                                PANGO_RENDER_PART_UNDERLINE,
+                                PANGO_RENDER_LINE_DOTTED,
+                                rect->x,
+                                rect->y,
+                                rect->width,
+                                rect->height);
+      break;
     case PANGO_UNDERLINE_ERROR:
     case PANGO_UNDERLINE_ERROR_LINE:
       pango_renderer_draw_error_underline (renderer,
@@ -271,6 +321,24 @@ draw_overline (PangoRenderer *renderer,
                                      rect->width,
                                      rect->height);
       break;
+    case PANGO_OVERLINE_SINGLE_DASHED:
+      pango_renderer_draw_line (renderer,
+                                PANGO_RENDER_PART_OVERLINE,
+                                PANGO_RENDER_LINE_DASHED,
+                                rect->x,
+                                rect->y,
+                                rect->width,
+                                rect->height);
+      break;
+    case PANGO_OVERLINE_SINGLE_DOTTED:
+      pango_renderer_draw_line (renderer,
+                                PANGO_RENDER_PART_OVERLINE,
+                                PANGO_RENDER_LINE_DOTTED,
+                                rect->x,
+                                rect->y,
+                                rect->width,
+                                rect->height);
+      break;
     }
 }
 
@@ -364,15 +432,25 @@ add_underline (PangoRenderer    *renderer,
       g_assert_not_reached ();
       break;
     case PANGO_UNDERLINE_SINGLE:
+    case PANGO_UNDERLINE_SINGLE_DASHED:
+    case PANGO_UNDERLINE_SINGLE_DOTTED:
     case PANGO_UNDERLINE_DOUBLE:
+    case PANGO_UNDERLINE_DOUBLE_DASHED:
+    case PANGO_UNDERLINE_DOUBLE_DOTTED:
     case PANGO_UNDERLINE_ERROR:
       new_rect.y -= underline_position;
       break;
     case PANGO_UNDERLINE_LOW:
+    case PANGO_UNDERLINE_LOW_DASHED:
+    case PANGO_UNDERLINE_LOW_DOTTED:
       new_rect.y += ink_rect->y + ink_rect->height + underline_thickness;
       break;
     case PANGO_UNDERLINE_SINGLE_LINE:
+    case PANGO_UNDERLINE_SINGLE_LINE_DASHED:
+    case PANGO_UNDERLINE_SINGLE_LINE_DOTTED:
     case PANGO_UNDERLINE_DOUBLE_LINE:
+    case PANGO_UNDERLINE_DOUBLE_LINE_DASHED:
+    case PANGO_UNDERLINE_DOUBLE_LINE_DOTTED:
     case PANGO_UNDERLINE_ERROR_LINE:
       new_rect.y -= underline_position;
       if (state->underline == renderer->underline)
@@ -425,6 +503,8 @@ add_overline (PangoRenderer    *renderer,
       g_assert_not_reached ();
       break;
     case PANGO_OVERLINE_SINGLE:
+    case PANGO_OVERLINE_SINGLE_DASHED:
+    case PANGO_OVERLINE_SINGLE_DOTTED:
       new_rect.y -= ascent;
       if (state->overline == renderer->priv->overline)
         {
@@ -889,6 +969,42 @@ pango_renderer_draw_rectangle (PangoRenderer   *renderer,
   PANGO_RENDERER_GET_CLASS (renderer)->draw_rectangle (renderer, part, x, y, width, height);
 }
 
+/**
+ * pango_renderer_draw_line:
+ * @renderer: a `PangoRenderer`
+ * @part: type of object this rectangle is part of
+ * @style: the style of line to draw
+ * @x: X position of upper left corner, in user space coordinates
+ *   in Pango units
+ * @y: Y position of upper left corner, in user space coordinates
+ *   in Pango units
+ * @width: width of line in Pango units
+ * @height: height of line in Pango units
+ *
+ * Draws a line with the given style into an axis-aligned rectangle
+ * in user space coordinates with the specified `PangoRenderer`.
+ *
+ * This should be called while @renderer is already active.
+ * Use [method@Pango.Renderer.activate] to activate a renderer.
+ *
+ * Since: 1.50
+ */
+void
+pango_renderer_draw_line (PangoRenderer        *renderer,
+                          PangoRenderPart       part,
+                          PangoRenderLineStyle  style,
+                          int                   x,
+                          int                   y,
+                          int                   width,
+                          int                   height)
+{
+  g_return_if_fail (PANGO_IS_RENDERER_FAST (renderer));
+  g_return_if_fail (IS_VALID_PART (part));
+  g_return_if_fail (renderer->active_count > 0);
+
+  PANGO_RENDERER_GET_CLASS (renderer)->draw_line (renderer, part, style, x, y, width, height);
+}
+
 static int
 compare_points (const void *a,
                 const void *b)
@@ -996,6 +1112,18 @@ pango_renderer_default_draw_rectangle (PangoRenderer  *renderer,
   draw_rectangle (renderer, renderer->matrix, part, x, y, width, height);
 }
 
+static void
+pango_renderer_default_draw_line (PangoRenderer        *renderer,
+                                  PangoRenderPart       part,
+                                  PangoRenderLineStyle  style,
+                                  int                   x,
+                                  int                   y,
+                                  int                   width,
+                                  int                   height)
+{
+  draw_rectangle (renderer, renderer->matrix, part, x, y, width, height);
+}
+
 /**
  * pango_renderer_draw_error_underline:
  * @renderer: a `PangoRenderer`