decoration: stack: stacks multiple decorations on top of each other

CMakeLists.txt

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

config.c

@@ -9,6 +9,7 @@
 
 #include "decoration.h"
 #include "decorations/background.h"
+#include "decorations/stack.h"
 #include "decorations/underline.h"
 
 #include "particle.h"
@@ -115,6 +116,29 @@ deco_underline_from_config(const struct yml_node *node)
         yml_value_as_int(size), color_from_hexstr(yml_value_as_string(color)));
 }
 
+static struct deco *deco_from_config(const struct yml_node *node);
+
+static struct deco *
+deco_stack_from_config(const struct yml_node *node)
+{
+    assert(yml_is_list(node));
+
+    size_t count = yml_list_length(node);
+    assert(count > 0);
+
+    struct deco *decos[count];
+    size_t idx = 0;
+
+    for (struct yml_list_iter it = yml_list_iter(node);
+         it.node != NULL;
+         yml_list_next(&it), idx++)
+    {
+        decos[idx] = deco_from_config(it.node);
+    }
+
+    return deco_stack(decos, count);
+}
+
 static struct deco *
 deco_from_config(const struct yml_node *node)
 {
@@ -126,7 +150,6 @@ deco_from_config(const struct yml_node *node)
     const struct yml_node *deco_data = it.value;
 
     assert(yml_is_scalar(deco_type));
-    assert(yml_is_dict(deco_data));
 
     const char *type = yml_value_as_string(deco_type);
 
@@ -134,6 +157,8 @@ deco_from_config(const struct yml_node *node)
         return deco_background_from_config(deco_data);
     else if (strcmp(type, "underline") == 0)
         return deco_underline_from_config(deco_data);
+    else if (strcmp(type, "stack") == 0)
+        return deco_stack_from_config(deco_data);
     else
         assert(false);
 }

decorations/stack.c

@@ -0,0 +1,45 @@
+#include "underline.h"
+
+#include <stdlib.h>
+
+struct private {
+    struct deco **decos;
+    size_t count;
+};
+
+static void
+destroy(struct deco *deco)
+{
+    struct private *d = deco->private;
+    for (size_t i = 0; i < d->count; i++)
+        d->decos[i]->destroy(d->decos[i]);
+    free(d->decos);
+    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;
+    for (size_t i = 0; i < d->count; i++)
+        d->decos[i]->expose(d->decos[i], cr, x, y, width, height);
+}
+
+struct deco *
+deco_stack(struct deco *decos[], size_t count)
+{
+    struct private *priv = malloc(sizeof(*priv));
+    priv->decos = malloc(count * sizeof(priv->decos[0]));
+    priv->count = count;
+
+    for (size_t i = 0; i < count; i++)
+        priv->decos[i] = decos[i];
+
+    struct deco *deco = malloc(sizeof(*deco));
+    deco->private = priv;
+    deco->expose = &expose;
+    deco->destroy = &destroy;
+
+    return deco;
+}

decorations/stack.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include "../color.h"
+#include "../decoration.h"
+
+struct deco *deco_stack(struct deco *decos[], size_t count);