src/svgtiny_css.c: add svgtiny_select_style() wrapper

[libsvgtiny.git] / src / svgtiny_css.c

diff --git a/src/svgtiny_css.c b/src/svgtiny_css.c
index 76b01d196abdd6c0fe4a72dc9987555e5922fdc4..b80d0578b7bd219d8397a2532b23f1b4491e608d 100644 (file)
--- a/src/svgtiny_css.c
+++ b/src/svgtiny_css.c
@@ -73,6 +73,47 @@ static css_error get_libcss_node_data(void *pw, void *node,
 static struct css_select_handler svgtiny_select_handler;
 
 
+/**
+ * Convenient wrapper around css_select_style()
+ *
+ * \param state         The current state of the libsvgtiny parser
+ * \param node          The node that we're getting styles for
+ * \param inline_sheet  The inline stylesheet for the given node
+ * \param result        Address at which to store the results array
+ */
+css_error svgtiny_select_style(struct svgtiny_parse_state *state,
+                               dom_element *node,
+                               const css_stylesheet *inline_sheet,
+                               css_select_results **result)
+{
+       const css_media media_all = {
+               .type = CSS_MEDIA_ALL,
+       };
+
+       /* These magic numbers below were taken from the libcss
+        * example program without much thought, because at the moment
+        * we don't support any properties with units. */
+       const css_unit_ctx unitctx = {
+               .viewport_width    = FLTTOFIX(state->viewport_width),
+               .viewport_height   = FLTTOFIX(state->viewport_height),
+               .font_size_default = FLTTOFIX(16.0),
+               .font_size_minimum = FLTTOFIX(6.0),
+               .device_dpi        = FLTTOFIX(96.0),
+               .root_style        = NULL,
+               .pw                = NULL,
+               .measure           = NULL,
+       };
+
+       return css_select_style(state->select_ctx,
+                       node,
+                       &unitctx,
+                       &media_all,
+                       inline_sheet,
+                       &svgtiny_select_handler,
+                       state,
+                       result);
+}
+
 /**
  * Resolve a relative URL to an absolute one by doing nothing. This is
  * the simplest possible implementation of a URL resolver, needed for
@@ -1860,6 +1901,57 @@ css_error ua_default_for_property(void *pw, uint32_t property,
 }
 
 
+/**
+ * A "user handler" function that we pass to dom_node_set_user_data()
+ * in set_libcss_node_data(). The set_libcss_node_data() documentation
+ * says that if the node (on which data is set) is is deleted or
+ * cloned, or if its ancestors are modified, then we must call
+ * css_libcss_node_data_handler() on the user data. This function
+ * basically just checks to see which DOM event has happened and
+ * calls css_libcss_node_data_handler() when any of those criteria
+ * are met.
+ */
+static void svgtiny_dom_user_data_handler(dom_node_operation operation,
+       dom_string *key, void *data, struct dom_node *src,
+       struct dom_node *dst)
+{
+       /* We only care about the userdata that is identified by our
+        * userdata key. Unfortunately I see no obvious way to obtain
+        * the copy of the userdata key that is already interned in
+        * svgtiny_strings.h; so we duplicate it here (ugh). */
+       dom_string *str;
+       dom_string_create((const uint8_t *)"_libcss_user_data", 17, &str);
+       if (dom_string_isequal(str,key) == false || data == NULL) {
+               /* Wrong key, or no data */
+               return;
+       }
+
+       /* Check the DOM operation, and make the corresponding call to
+        * css_libcss_node_data_handler(). No error handling is done.
+        */
+       switch (operation) {
+               case DOM_NODE_CLONED:
+                       css_libcss_node_data_handler(&svgtiny_select_handler,
+                                               CSS_NODE_CLONED,
+                                               NULL, src, dst, data);
+                       break;
+               case DOM_NODE_RENAMED:
+                       css_libcss_node_data_handler(&svgtiny_select_handler,
+                                               CSS_NODE_MODIFIED,
+                                               NULL, src, NULL, data);
+                       break;
+               case DOM_NODE_IMPORTED:
+               case DOM_NODE_ADOPTED:
+               case DOM_NODE_DELETED:
+                       css_libcss_node_data_handler(&svgtiny_select_handler,
+                                               CSS_NODE_DELETED,
+                                               NULL, src, NULL, data);
+               default:
+                       /* Our list of cases should have been exhaustive */
+                       assert(false);
+       }
+}
+
 /**
  * Store libcss data on a node
  *
@@ -1880,15 +1972,12 @@ css_error set_libcss_node_data(void *pw, void *node,
        void *old_data;
 
        /* A unique "userdata key" (a string) is used to identify this
-        * data. The fourth parameter (NULL) is a "user handler
-        * function." We will eventually have one, but for now we set
-        * it to NULL to avoid a circular reference mess that would
-        * break the build temporarily. */
+        * data. */
        state = (struct svgtiny_parse_state *)pw;
        dom_node_set_user_data((dom_node *)node,
                                state->interned_userdata_key,
                                libcss_node_data,
-                               NULL,
+                               svgtiny_dom_user_data_handler,
                                &old_data);
 
        /* dom_node_set_user_data() always returns DOM_NO_ERR */
@@ -1969,3 +2058,5 @@ static css_select_handler svgtiny_select_handler = {
        set_libcss_node_data,
        get_libcss_node_data,
 };
+
+