decoration/underline: draws a line at the bottom of the particle

CMakeLists.txt

@@ -36,6 +36,7 @@ add_executable(f00bar
   yml.c yml.h
 
   decorations/background.c decorations/background.h
+  decorations/underline.c decorations/underline.h
 
   particles/list.c particles/list.h
   particles/map.c particles/map.h

config.c

@@ -9,6 +9,7 @@
 
 #include "decoration.h"
 #include "decorations/background.h"
+#include "decorations/underline.h"
 
 #include "particle.h"
 #include "particles/list.h"
@@ -100,6 +101,20 @@ deco_background_from_config(const struct yml_node *node)
     return deco_background(color_from_hexstr(yml_value_as_string(color)));
 }
 
+static struct deco *
+deco_underline_from_config(const struct yml_node *node)
+{
+    assert(yml_is_dict(node));
+
+    const struct yml_node *size = yml_get_value(node, "size");
+    const struct yml_node *color = yml_get_value(node, "color");
+    assert(yml_is_scalar(size));
+    assert(yml_is_scalar(color));
+
+    return deco_underline(
+        yml_value_as_int(size), color_from_hexstr(yml_value_as_string(color)));
+}
+
 static struct deco *
 deco_from_config(const struct yml_node *node)
 {
@@ -117,6 +132,8 @@ deco_from_config(const struct yml_node *node)
 
     if (strcmp(type, "background") == 0)
         return deco_background_from_config(deco_data);
+    else if (strcmp(type, "underline") == 0)
+        return deco_underline_from_config(deco_data);
     else
         assert(false);
 }
@@ -268,11 +285,6 @@ particle_ramp_from_config(const struct yml_node *node, const struct font *parent
 static struct particle *
 particle_from_config(const struct yml_node *node, const struct font *parent_font)
 {
-#if 0
-    const struct yml_node *deco_node = yml_get_value(node, "deco");
-
-    assert(deco_node == NULL || yml_is_dict(deco_node));
-#endif
     assert(yml_is_dict(node));
     assert(yml_dict_length(node) == 1);
 

decorations/underline.c

@@ -0,0 +1,41 @@
+#include "underline.h"
+
+#include <stdlib.h>
+
+struct private {
+    int size;
+    struct rgba color;
+};
+
+static void
+destroy(struct deco *deco)
+{
+    struct private *d = deco->private;
+    free(d);
+    free(deco);
+}
+
+static void
+expose(const struct deco *deco, cairo_t *cr, int x, int y, int width, int height)
+{
+    const struct private *d = deco->private;
+    cairo_set_source_rgba(
+        cr, d->color.red, d->color.green, d->color.blue, d->color.alpha);
+    cairo_rectangle(cr, x, y + height - d->size, width, d->size);
+    cairo_fill(cr);
+}
+
+struct deco *
+deco_underline(int size, struct rgba color)
+{
+    struct private *priv = malloc(sizeof(*priv));
+    priv->size = size;
+    priv->color = color;
+
+    struct deco *deco = malloc(sizeof(*deco));
+    deco->private = priv;
+    deco->expose = &expose;
+    deco->destroy = &destroy;
+
+    return deco;
+}

decorations/underline.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include "../color.h"
+#include "../decoration.h"
+
+struct deco *deco_underline(int size, struct rgba color);