[librsvg: 4/8] try_apply_by_selector(): move function from CssRules::lookup_apply()

[Federico Mena Quintero <federico src gnome org>]

commit c24679b91b2af2bdcb7554dfbd870b51f866dfaf
Author: Federico Mena Quintero <federico gnome org>
Date:   Fri May 3 13:23:10 2019 -0500

    try_apply_by_selector(): move function from CssRules::lookup_apply()
    
    CssRules should not have to deal with SpecifiedValues nor the stateful
    important_styles.

 rsvg_internals/src/css.rs  | 23 ++---------------------
 rsvg_internals/src/node.rs | 39 +++++++++++++++++++++++++++++++--------
 2 files changed, 33 insertions(+), 29 deletions(-)
---
diff --git a/rsvg_internals/src/css.rs b/rsvg_internals/src/css.rs
index a41e683a..2a12cb2d 100644
--- a/rsvg_internals/src/css.rs
+++ b/rsvg_internals/src/css.rs
@@ -1,6 +1,6 @@
 use cssparser::{Parser, ParserInput};
 use std::collections::hash_map::{Entry, Iter as HashMapIter};
-use std::collections::{HashMap, HashSet};
+use std::collections::HashMap;
 use std::ptr;
 use std::str::{self, FromStr};
 
@@ -15,7 +15,7 @@ use crate::attributes::Attribute;
 use crate::croco::*;
 use crate::error::LoadingError;
 use crate::io::{self, BinaryData};
-use crate::properties::{parse_attribute_value_into_parsed_property, Declaration, SpecifiedValues};
+use crate::properties::{parse_attribute_value_into_parsed_property, Declaration};
 use crate::util::utf8_cstr;
 
 pub struct DeclarationList {
@@ -154,25 +154,6 @@ impl CssRules {
     pub fn lookup(&self, selector: &str) -> Option<&DeclarationList> {
         self.selectors_to_declarations.get(selector)
     }
-
-    /// takes CSS rules which match the given `selector` name and applies them
-    /// to the `values`.
-    pub fn lookup_apply(
-        &self,
-        selector: &str,
-        values: &mut SpecifiedValues,
-        important_styles: &mut HashSet<Attribute>,
-    ) -> bool {
-        if let Some(decl_list) = self.lookup(selector) {
-            for declaration in decl_list.iter() {
-                values.set_property_from_declaration(declaration, important_styles);
-            }
-
-            true
-        } else {
-            false
-        }
-    }
 }
 
 struct DocHandlerData<'a> {
diff --git a/rsvg_internals/src/node.rs b/rsvg_internals/src/node.rs
index 34f9c948..b5feb698 100644
--- a/rsvg_internals/src/node.rs
+++ b/rsvg_internals/src/node.rs
@@ -461,10 +461,10 @@ impl Node {
         let mut important_styles = self.data.important_styles.borrow_mut();
 
         // *
-        css_rules.lookup_apply("*", &mut specified_values, &mut important_styles);
+        try_apply_by_selector(css_rules, "*", &mut specified_values, &mut important_styles);
 
         // tag
-        css_rules.lookup_apply(element_name, &mut specified_values, &mut important_styles);
+        try_apply_by_selector(css_rules, element_name, &mut specified_values, &mut important_styles);
 
         if let Some(klazz) = self.get_class() {
             for cls in klazz.split_whitespace() {
@@ -475,7 +475,8 @@ impl Node {
                     if let Some(id) = self.get_id() {
                         let target = format!("{}.{}#{}", element_name, cls, id);
                         found = found
-                            || css_rules.lookup_apply(
+                            || try_apply_by_selector(
+                                css_rules,
                                 &target,
                                 &mut specified_values,
                                 &mut important_styles,
@@ -486,7 +487,8 @@ impl Node {
                     if let Some(id) = self.get_id() {
                         let target = format!(".{}#{}", cls, id);
                         found = found
-                            || css_rules.lookup_apply(
+                            || try_apply_by_selector(
+                                css_rules,
                                 &target,
                                 &mut specified_values,
                                 &mut important_styles,
@@ -496,7 +498,8 @@ impl Node {
                     // tag.class
                     let target = format!("{}.{}", element_name, cls);
                     found = found
-                        || css_rules.lookup_apply(
+                        || try_apply_by_selector(
+                            css_rules,
                             &target,
                             &mut specified_values,
                             &mut important_styles,
@@ -505,7 +508,8 @@ impl Node {
                     if !found {
                         // didn't find anything more specific, just apply the class style
                         let target = format!(".{}", cls);
-                        css_rules.lookup_apply(
+                        try_apply_by_selector(
+                            css_rules,
                             &target,
                             &mut specified_values,
                             &mut important_styles,
@@ -518,11 +522,11 @@ impl Node {
         if let Some(id) = self.get_id() {
             // id
             let target = format!("#{}", id);
-            css_rules.lookup_apply(&target, &mut specified_values, &mut important_styles);
+            try_apply_by_selector(css_rules, &target, &mut specified_values, &mut important_styles);
 
             // tag#id
             let target = format!("{}#{}", element_name, id);
-            css_rules.lookup_apply(&target, &mut specified_values, &mut important_styles);
+            try_apply_by_selector(css_rules, &target, &mut specified_values, &mut important_styles);
         }
     }
 
@@ -677,3 +681,22 @@ pub fn node_new(
         node_impl,
     ))
 }
+
+/// takes CSS rules which match the given `selector` name and applies them
+/// to the `values`.
+pub fn try_apply_by_selector(
+    css_rules: &CssRules,
+    selector: &str,
+    values: &mut SpecifiedValues,
+    important_styles: &mut HashSet<Attribute>,
+) -> bool {
+    if let Some(decl_list) = css_rules.lookup(selector) {
+        for declaration in decl_list.iter() {
+            values.set_property_from_declaration(declaration, important_styles);
+        }
+
+        true
+    } else {
+        false
+    }
+}