From 6f5572ff6b29d1919711995008d317e19b4ff0ff Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Sat, 29 Dec 2018 20:54:41 +0100
Subject: [PATCH] particle/map: implement left/right margin

This is done by wrapping the selected particle/exposable in a
ramp-specific exposable. This way, we can add the margins before
delegating begin_expose() and expose() to the selected exposable.
---
 particles/map.c | 66 ++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 60 insertions(+), 6 deletions(-)

diff --git a/particles/map.c b/particles/map.c
index 5735e9f..34d65ea 100644
--- a/particles/map.c
+++ b/particles/map.c
@@ -11,6 +11,45 @@ struct private {
     size_t count;
 };
 
+struct eprivate {
+    struct exposable *exposable;
+};
+
+static void
+exposable_destroy(struct exposable *exposable)
+{
+    struct eprivate *e = exposable->private;
+    e->exposable->destroy(e->exposable);
+
+    free(e);
+    exposable_default_destroy(exposable);
+}
+
+static int
+begin_expose(struct exposable *exposable, cairo_t *cr)
+{
+    struct eprivate *e = exposable->private;
+
+    exposable->width = (
+        exposable->particle->left_margin +
+        e->exposable->begin_expose(e->exposable, cr) +
+        exposable->particle->right_margin);
+
+    return exposable->width;
+}
+
+static void
+expose(const struct exposable *exposable, cairo_t *cr, int x, int y, int height)
+{
+    const struct deco *deco = exposable->particle->deco;
+    if (deco != NULL)
+        deco->expose(deco, cr, x, y, exposable->width, height);
+
+    struct eprivate *e = exposable->private;
+    e->exposable->expose(
+        e->exposable, cr, x + exposable->particle->left_margin, y, height);
+}
+
 static struct exposable *
 instantiate(const struct particle *particle, const struct tag_set *tags)
 {
@@ -23,17 +62,35 @@ instantiate(const struct particle *particle, const struct tag_set *tags)
 
 
     const char *tag_value = tag->as_string(tag);
+    struct particle *pp = NULL;
+
     for (size_t i = 0; i < p->count; i++) {
         const struct particle_map *e = &p->map[i];
 
         if (strcmp(e->tag_value, tag_value) != 0)
             continue;
 
-        return e->particle->instantiate(e->particle, tags);
+        pp = e->particle;
+        break;
     }
 
-    assert(p->default_particle != NULL);
-    return p->default_particle->instantiate(p->default_particle, tags);
+    if (pp == NULL) {
+        assert(p->default_particle != NULL);
+        pp = p->default_particle;
+    }
+
+    struct eprivate *e = malloc(sizeof(*e));
+    e->exposable = pp->instantiate(pp, tags);
+
+    char *on_click = tags_expand_template(particle->on_click_template, tags);
+    struct exposable *exposable = exposable_common_new(particle, on_click);
+    exposable->private = e;
+    exposable->destroy = &exposable_destroy;
+    exposable->begin_expose = &begin_expose;
+    exposable->expose = &expose;
+
+    free(on_click);
+    return exposable;
 }
 
 static void
@@ -61,9 +118,6 @@ particle_map_new(const char *tag, const struct particle_map *particle_map,
                  size_t count, struct particle *default_particle,
                  int left_margin, int right_margin)
 {
-    assert(left_margin == 0 && right_margin == 0
-        && "map: margins not implemented");
-
     struct particle *particle = particle_common_new(
         left_margin, right_margin, NULL);
     particle->destroy = &particle_destroy;