[librsvg] css::parse_into_css_styles(): Take a &mut CssStyles instead of extracting it from the handle

[Federico Mena Quintero <federico src gnome org>]

commit 31029c68a73aa78e79035b566cdcab6468af143e
Author: Federico Mena Quintero <federico gnome org>
Date:   Tue Nov 27 08:00:55 2018 -0600

    css::parse_into_css_styles(): Take a &mut CssStyles instead of extracting it from the handle
    
    This is to decouple the handle from the CssStyles that is being
    parsed.  Currently the css module only uses the handle to be able to call
    handle::load_css(), i.e. essentially to go through the URL resolving
    mechanism.

 rsvg_internals/src/css.rs    | 30 +++++++++++++++++-------------
 rsvg_internals/src/handle.rs |  3 ++-
 rsvg_internals/src/xml.rs    |  4 +++-
 3 files changed, 22 insertions(+), 15 deletions(-)
---
diff --git a/rsvg_internals/src/css.rs b/rsvg_internals/src/css.rs
index 3f48ddf2..2e777063 100644
--- a/rsvg_internals/src/css.rs
+++ b/rsvg_internals/src/css.rs
@@ -80,12 +80,19 @@ impl CssStyles {
     }
 }
 
-struct DocHandlerData {
+struct DocHandlerData<'a> {
     handle: *mut RsvgHandle,
+    css_styles: &'a mut CssStyles,
     selector: *mut CRSelector,
 }
 
-pub fn parse_into_handle(handle: *mut RsvgHandle, buf: &str) {
+macro_rules! get_doc_handler_data {
+    ($doc_handler:expr) => {
+        &mut *((*$doc_handler).app_data as *mut DocHandlerData)
+    };
+}
+
+pub fn parse_into_css_styles(css_styles: &mut CssStyles, handle: *mut RsvgHandle, buf: &str) {
     if buf.len() == 0 {
         return; // libcroco doesn't like empty strings :(
     }
@@ -93,6 +100,7 @@ pub fn parse_into_handle(handle: *mut RsvgHandle, buf: &str) {
     unsafe {
         let mut handler_data = DocHandlerData {
             handle,
+            css_styles,
             selector: ptr::null_mut(),
         };
 
@@ -136,7 +144,7 @@ unsafe extern "C" fn css_import_style(
     _a_uri_default_ns: CRString,
     _a_location: CRParsingLocation,
 ) {
-    let handler_data = get_doc_handler_data(a_this);
+    let handler_data = get_doc_handler_data!(a_this);
 
     if a_uri.is_null() {
         return;
@@ -148,15 +156,11 @@ unsafe extern "C" fn css_import_style(
     handle::load_css(handler_data.handle, uri);
 }
 
-unsafe fn get_doc_handler_data<'a>(doc_handler: *mut CRDocHandler) -> &'a mut DocHandlerData {
-    &mut *((*doc_handler).app_data as *mut DocHandlerData)
-}
-
 unsafe extern "C" fn css_start_selector(
     a_this: *mut CRDocHandler,
     a_selector_list: *mut CRSelector,
 ) {
-    let handler_data = get_doc_handler_data(a_this);
+    let handler_data = get_doc_handler_data!(a_this);
 
     cr_selector_ref(a_selector_list);
     handler_data.selector = a_selector_list;
@@ -166,7 +170,7 @@ unsafe extern "C" fn css_end_selector(
     a_this: *mut CRDocHandler,
     _a_selector_list: *mut CRSelector,
 ) {
-    let handler_data = get_doc_handler_data(a_this);
+    let handler_data = get_doc_handler_data!(a_this);
 
     cr_selector_unref(handler_data.selector);
     handler_data.selector = ptr::null_mut();
@@ -178,7 +182,7 @@ unsafe extern "C" fn css_property(
     a_expression: CRTerm,
     a_is_important: gboolean,
 ) {
-    let handler_data = get_doc_handler_data(a_this);
+    let handler_data = get_doc_handler_data!(a_this);
 
     if a_name.is_null() || a_expression.is_null() || handler_data.selector.is_null() {
         return;
@@ -203,9 +207,9 @@ unsafe extern "C" fn css_property(
 
                 let important = from_glib(a_is_important);
 
-                let styles = handle::get_css_styles_mut(handler_data.handle);
-
-                styles.define(&selector_name, prop_name, &prop_value, important);
+                handler_data
+                    .css_styles
+                    .define(&selector_name, prop_name, &prop_value, important);
             }
         }
 
diff --git a/rsvg_internals/src/handle.rs b/rsvg_internals/src/handle.rs
index 6b74f9ea..1d4dc81e 100644
--- a/rsvg_internals/src/handle.rs
+++ b/rsvg_internals/src/handle.rs
@@ -208,7 +208,8 @@ pub fn load_css(handle: *mut RsvgHandle, href: &str) {
         }
 
         if let Ok(utf8) = String::from_utf8(bytes) {
-            css::parse_into_handle(handle, &utf8);
+            let css_styles = get_css_styles_mut(handle);
+            css::parse_into_css_styles(css_styles, handle, &utf8);
         } else {
             rsvg_log!(
                 "\"{}\" does not contain valid UTF-8 CSS data; ignoring",
diff --git a/rsvg_internals/src/xml.rs b/rsvg_internals/src/xml.rs
index 8ebbb499..5fe53900 100644
--- a/rsvg_internals/src/xml.rs
+++ b/rsvg_internals/src/xml.rs
@@ -266,7 +266,9 @@ impl XmlState {
         if node.get_type() == NodeType::Style {
             let css_data = node.with_impl(|style: &NodeStyle| style.get_css(&node));
 
-            css::parse_into_handle(handle, &css_data);
+            let css_styles = handle::get_css_styles_mut(handle);
+
+            css::parse_into_css_styles(css_styles, handle, &css_data);
         }
 
         self.current_node = node.get_parent();