]> gitweb.michael.orlitzky.com - libsvgtiny.git/blobdiff - src/svgtiny.c
src/svgtiny.c: eliminate pointless NULL check
[libsvgtiny.git] / src / svgtiny.c
index 3b886fe770502d384e17cf7ffb8e5b4e075a693b..a77e3b46d9f7c0ca382190075f6971af475c4da9 100644 (file)
 #define degToRad(angleInDegrees) ((angleInDegrees) * M_PI / 180.0)
 #define radToDeg(angleInRadians) ((angleInRadians) * 180.0 / M_PI)
 
+static svgtiny_code svgtiny_parse_style_element(dom_element *style,
+               struct svgtiny_parse_state state);
+static css_stylesheet *svgtiny_parse_style_inline(const uint8_t *data,
+               size_t len);
+static svgtiny_code svgtiny_preparse_styles(dom_element *svg,
+               struct svgtiny_parse_state state);
 static svgtiny_code svgtiny_parse_svg(dom_element *svg,
                struct svgtiny_parse_state state);
 static svgtiny_code svgtiny_parse_path(dom_element *path,
@@ -691,22 +697,21 @@ svgtiny_code svgtiny_parse(struct svgtiny_diagram *diagram,
        lwc_string_unref(svg_name_lwc);
        dom_string_unref(svg_name);
 
-       /* get graphic dimensions */
+       /* initialize the state struct with zeros */
        memset(&state, 0, sizeof(state));
+
+       /* get graphic dimensions */
        state.diagram = diagram;
        state.document = document;
        state.viewport_width = viewport_width;
        state.viewport_height = viewport_height;
 
-
        /* Initialize CSS context */
-       if (state.select_ctx == NULL) {
-               css_code = css_select_ctx_create(&state.select_ctx);
-               if (css_code != CSS_OK) {
-                       dom_node_unref(svg);
-                       dom_node_unref(document);
-                       return svgtiny_LIBCSS_ERROR;
-               }
+       css_code = css_select_ctx_create(&state.select_ctx);
+       if (css_code != CSS_OK) {
+               dom_node_unref(svg);
+               dom_node_unref(document);
+               return svgtiny_LIBCSS_ERROR;
        }
 
 #define SVGTINY_STRING_ACTION2(s,n)                                    \
@@ -719,6 +724,19 @@ svgtiny_code svgtiny_parse(struct svgtiny_diagram *diagram,
 #include "svgtiny_strings.h"
 #undef SVGTINY_STRING_ACTION2
 
+       /* Intern SVG's xmlns separately because it's an lwc_string
+        * and not a dom_string. We initialize its pointer to NULL
+        * because the "cleanup:" test to see if it needs to be free'd
+        * looks for NULL. Returning a LIBDOM_ERROR on failure is not
+        * perfect but it's the closest of the available options. */
+       state.interned_svg_xmlns = NULL;
+       if (lwc_intern_string("http://www.w3.org/2000/svg",
+                             26,
+                             &state.interned_svg_xmlns) != lwc_error_ok) {
+               code = svgtiny_LIBDOM_ERROR;
+               goto cleanup;
+       }
+
        svgtiny_parse_position_attributes(svg, state, &x, &y, &width, &height);
        diagram->width = width;
        diagram->height = height;
@@ -737,7 +755,10 @@ svgtiny_code svgtiny_parse(struct svgtiny_diagram *diagram,
        state.stroke_width = 1;
 
        /* parse tree */
-       code = svgtiny_parse_svg(svg, state);
+       code = svgtiny_preparse_styles(svg, state);
+       if (code == svgtiny_OK) {
+               code = svgtiny_parse_svg(svg, state);
+       }
 
        dom_node_unref(svg);
        dom_node_unref(document);
@@ -753,10 +774,181 @@ cleanup:
                dom_string_unref(state.interned_##s);
 #include "svgtiny_strings.h"
 #undef SVGTINY_STRING_ACTION2
+
+       if (state.interned_svg_xmlns != NULL) {
+               lwc_string_unref(state.interned_svg_xmlns);
+       }
+
        return code;
 }
 
 
+/**
+ * Parse a single <style> element, appending the result to the CSS
+ * select context within the given parser state.
+ */
+svgtiny_code svgtiny_parse_style_element(dom_element *style,
+               struct svgtiny_parse_state state)
+{
+       css_stylesheet *sheet;
+       css_error code;
+       dom_exception exc;
+
+       code = svgtiny_create_stylesheet(&sheet, false);
+       if (code != CSS_OK) {
+               return svgtiny_LIBCSS_ERROR;
+       }
+
+       /* Parse the style element's "media" attribute if it has
+          one. We don't do anything with it right now. */
+       dom_string *media_attr;
+       exc = dom_element_get_attribute(style, state.interned_media,
+                                       &media_attr);
+       if (exc != DOM_NO_ERR) {
+               css_stylesheet_destroy(sheet);
+               return svgtiny_LIBDOM_ERROR;
+       }
+
+       if (media_attr) {
+               /* Here's where we'd actually change the media type if
+                  we were going to use it */
+               dom_string_unref(media_attr);
+       }
+
+       dom_string *data;
+       dom_node_get_text_content(style, &data);
+       if (data == NULL) {
+               /* Empty stylesheet? That's fine. */
+               css_stylesheet_destroy(sheet);
+               return svgtiny_OK;
+       }
+
+       code = css_stylesheet_append_data(sheet,
+                                         (uint8_t *)dom_string_data(data),
+                                         dom_string_byte_length(data));
+       if (code != CSS_OK && code != CSS_NEEDDATA) {
+               dom_string_unref(data);
+               css_stylesheet_destroy(sheet);
+               return svgtiny_LIBCSS_ERROR;
+       }
+
+       code = css_stylesheet_data_done(sheet);
+       if (code != CSS_OK) {
+               dom_string_unref(data);
+               css_stylesheet_destroy(sheet);
+               return svgtiny_LIBCSS_ERROR;
+       }
+
+       code = css_select_ctx_append_sheet(state.select_ctx,
+               sheet,
+               CSS_ORIGIN_AUTHOR,
+               NULL);
+       if (code != CSS_OK) {
+               dom_string_unref(data);
+               return svgtiny_LIBCSS_ERROR;
+       }
+
+       dom_string_unref(data);
+       return svgtiny_OK;
+}
+
+
+/**
+ * Parse the contents of an inline style and return (a pointer to) the
+ * corresponding stylesheet for use with css_select_style(). Returns
+ * NULL if anything goes wrong.
+ */
+css_stylesheet *svgtiny_parse_style_inline(const uint8_t *data,
+               size_t len)
+{
+       css_stylesheet *sheet;
+       css_error code;
+
+       code = svgtiny_create_stylesheet(&sheet, true);
+       if (code != CSS_OK) {
+               return NULL;
+       }
+
+       code = css_stylesheet_append_data(sheet, data, len);
+       if (code != CSS_OK && code != CSS_NEEDDATA) {
+               css_stylesheet_destroy(sheet);
+               return NULL;
+       }
+
+       code = css_stylesheet_data_done(sheet);
+       if (code != CSS_OK) {
+               css_stylesheet_destroy(sheet);
+               return NULL;
+       }
+
+       return sheet;
+}
+
+/**
+ * Parse all <style> elements within a root <svg> element. This
+ * should be called before svgtiny_parse_svg() because that function
+ * makes a single pass through the document and we'd like all style
+ * information to be available during that pass. Specifically, we'd
+ * like a <style> sheet at the end of the document to affect the
+ * rendering of elements at its beginning.
+ *
+ * The element-parsing inner loop here is essentially the same as
+ * that within svgtiny_parse_svg().
+ */
+svgtiny_code svgtiny_preparse_styles(dom_element *svg,
+               struct svgtiny_parse_state state)
+{
+       dom_element *child;
+       dom_exception exc;
+
+       exc = dom_node_get_first_child(svg, (dom_node **) (void *) &child);
+       if (exc != DOM_NO_ERR) {
+               return svgtiny_LIBDOM_ERROR;
+       }
+       while (child != NULL) {
+               dom_element *next;
+               dom_node_type nodetype;
+               svgtiny_code code = svgtiny_OK;
+
+               exc = dom_node_get_node_type(child, &nodetype);
+               if (exc != DOM_NO_ERR) {
+                       dom_node_unref(child);
+                       return svgtiny_LIBDOM_ERROR;
+               }
+               if (nodetype == DOM_ELEMENT_NODE) {
+                       dom_string *nodename;
+                       exc = dom_node_get_node_name(child, &nodename);
+                       if (exc != DOM_NO_ERR) {
+                               dom_node_unref(child);
+                               return svgtiny_LIBDOM_ERROR;
+                       }
+
+                       if (dom_string_caseless_isequal(state.interned_style,
+                                                       nodename)) {
+                               /* We have a <style> element, parse it */
+                               code = svgtiny_parse_style_element(child,
+                                                               state);
+                       }
+
+
+                       dom_string_unref(nodename);
+               }
+               if (code != svgtiny_OK) {
+                       dom_node_unref(child);
+                       return code;
+               }
+               exc = dom_node_get_next_sibling(child,
+                                               (dom_node **) (void *) &next);
+               dom_node_unref(child);
+               if (exc != DOM_NO_ERR) {
+                       return svgtiny_LIBDOM_ERROR;
+               }
+               child = next;
+       }
+
+       return svgtiny_OK;
+}
+
 /**
  * Parse a <svg> or <g> element node.
  */
@@ -1880,6 +2072,13 @@ void svgtiny_parse_paint_attributes(dom_element *node,
        dom_string *attr;
        dom_exception exc;
 
+       /* We store the result of svgtiny_parse_style_inline() in
+        * inline_sheet, and that function returns NULL on error; in
+        * particular you do not need to css_stylesheet_destroy() the
+        * result if it is NULL. We initialize inline_sheet to NULL to
+        * retain the same semantics. */
+       css_stylesheet *inline_sheet = NULL;
+
        exc = dom_element_get_attribute(node, state->interned_fill, &attr);
        if (exc == DOM_NO_ERR && attr != NULL) {
                svgtiny_parse_color(attr, &state->fill, &state->fill_grad, state);
@@ -1901,6 +2100,14 @@ void svgtiny_parse_paint_attributes(dom_element *node,
 
        exc = dom_element_get_attribute(node, state->interned_style, &attr);
        if (exc == DOM_NO_ERR && attr != NULL) {
+               /* First parse the style attribute into a libcss stylesheet
+                  in case any of its properties are known to libcss. */
+               inline_sheet = svgtiny_parse_style_inline(
+                                       (uint8_t *)dom_string_data(attr),
+                                       dom_string_byte_length(attr));
+
+               /* Parse any other properties "by hand" until they can
+                  be supported in libcss. */
                char *style = strndup(dom_string_data(attr),
                                      dom_string_byte_length(attr));
                const char *s;
@@ -1933,6 +2140,10 @@ void svgtiny_parse_paint_attributes(dom_element *node,
                free(style);
                dom_string_unref(attr);
        }
+
+       if (inline_sheet != NULL) {
+               css_stylesheet_destroy(inline_sheet);
+       }
 }