Add a few useful lookup functions.

4 files changed, 104 insertions, 11 deletions

diff --git a/src/xml/repr-css.cpp b/src/xml/repr-css.cpp
index 5db698406..d035b9a4b 100644
--- a/src/xml/repr-css.cpp
+++ b/src/xml/repr-css.cpp
@@ -61,7 +61,7 @@ protected:
     SimpleNode *_duplicate(Document* doc) const override { return new SPCSSAttrImpl(*this, doc); }
 };
 
-static void sp_repr_css_add_components(SPCSSAttr *css, Node *repr, gchar const *attr);
+static void sp_repr_css_add_components(SPCSSAttr *css, Node const *repr, gchar const *attr);
 
 /**
  * Creates an empty SPCSSAttr (a class for manipulating CSS style properties).
@@ -90,7 +90,7 @@ void sp_repr_css_attr_unref(SPCSSAttr *css)
  * string is parsed by libcroco which returns a CRDeclaration list (a typical C linked list) of
  * properties and values. This list is then used to fill the attributes of the new SPCSSAttr.
  */
-SPCSSAttr *sp_repr_css_attr(Node *repr, gchar const *attr)
+SPCSSAttr *sp_repr_css_attr(Node const *repr, gchar const *attr)
 {
     g_assert(repr != nullptr);
     g_assert(attr != nullptr);
@@ -174,9 +174,9 @@ SPCSSAttr *sp_repr_css_attr_parse_color_to_fill(const Glib::ustring &text)
 /**
  * Adds an attribute to an existing SPCSAttr with the cascaded value including all parents.
  */ 
-static void sp_repr_css_attr_inherited_recursive(SPCSSAttr *css, Node *repr, gchar const *attr)
+static void sp_repr_css_attr_inherited_recursive(SPCSSAttr *css, Node const *repr, gchar const *attr)
 {
-    Node *parent = repr->parent();
+    const Node *parent = repr->parent();
 
     // read the ancestors from root down, using head recursion, so that children override parents
     if (parent) {
@@ -188,7 +188,7 @@ static void sp_repr_css_attr_inherited_recursive(SPCSSAttr *css, Node *repr, gch
 /**
  * Creates a new SPCSSAttr with one attribute whose value is determined by cascading.
  */
-SPCSSAttr *sp_repr_css_attr_inherited(Node *repr, gchar const *attr)
+SPCSSAttr *sp_repr_css_attr_inherited(Node const *repr, gchar const *attr)
 {
     g_assert(repr != nullptr);
     g_assert(attr != nullptr);
@@ -205,7 +205,7 @@ SPCSSAttr *sp_repr_css_attr_inherited(Node *repr, gchar const *attr)
  * (nominally a style attribute).
  * 
  */
-static void sp_repr_css_add_components(SPCSSAttr *css, Node *repr, gchar const *attr)
+static void sp_repr_css_add_components(SPCSSAttr *css, Node const *repr, gchar const *attr)
 {
     g_assert(css != nullptr);
     g_assert(repr != nullptr);
@@ -231,6 +231,23 @@ char const *sp_repr_css_property(SPCSSAttr *css, gchar const *name, gchar const
 }
 
 /**
+ * Returns a character string of the value of a given style property or a default value if the
+ * attribute is not found.
+ */
+Glib::ustring sp_repr_css_property(SPCSSAttr *css, Glib::ustring const &name, Glib::ustring const &defval)
+{
+    g_assert(css != nullptr);
+
+    Glib::ustring retval = defval;
+    char const *attr = ((Node *)css)->attribute(name.c_str());
+    if (attr) {
+        retval = attr;
+    }
+
+    return retval;
+}
+
+/**
  * Returns true if a style property is present and its value is unset.
  */
 bool sp_repr_css_property_is_unset(SPCSSAttr *css, gchar const *name)
diff --git a/src/xml/repr-io.cpp b/src/xml/repr-io.cpp
index b1bf26118..c0ebfa12c 100644
--- a/src/xml/repr-io.cpp
+++ b/src/xml/repr-io.cpp
@@ -981,10 +981,9 @@ void sp_repr_write_stream_element( Node * repr, Writer & out,
     }
     out.printf( "<%s", element_name );
 
-    // if this is a <text> element, suppress formatting whitespace
+    // If this is a <text> element, suppress formatting whitespace
     // for its content and children:
-    gchar const *xml_space_attr = repr->attribute("xml:space");
-    if (xml_space_attr != nullptr && !strcmp(xml_space_attr, "preserve")) {
+    if (strcmp(repr->name(),"svg:text") == 0) {
         add_whitespace = false;
     }
 
@@ -1014,6 +1013,7 @@ void sp_repr_write_stream_element( Node * repr, Writer & out,
             break;
         }
     }
+
     if (repr->firstChild()) {
         out.writeChar('>');
         if (loose && add_whitespace) {
diff --git a/src/xml/repr-util.cpp b/src/xml/repr-util.cpp
index a5dea02a2..a02997105 100644
--- a/src/xml/repr-util.cpp
+++ b/src/xml/repr-util.cpp
@@ -21,6 +21,8 @@
 
 
 #include <glib.h>
+#include <glibmm.h>
+
 #include <2geom/point.h>
 #include "svg/stringstream.h"
 #include "svg/css-ostringstream.h"
@@ -334,6 +336,36 @@ Inkscape::XML::Node *sp_repr_lookup_child(Inkscape::XML::Node *repr,
     return nullptr;
 }
 
+/**
+ * Recursive version of sp_repr_lookup_child().
+ */
+Inkscape::XML::Node const *sp_repr_lookup_descendant(Inkscape::XML::Node const *repr,
+                                                     gchar const *key,
+                                                     gchar const *value)
+{
+    Inkscape::XML::Node const *found = nullptr;
+    g_return_val_if_fail(repr != nullptr, NULL);
+    gchar const *repr_value = repr->attribute(key);
+    if ( (repr_value == value) ||
+         (repr_value && value && strcmp(repr_value, value) == 0) ) {
+        found = repr;
+    } else {
+        for (Inkscape::XML::Node const *child = repr->firstChild() ; child && !found; child = child->next() ) {
+            found = sp_repr_lookup_descendant( child, key, value );
+        }
+    }
+    return found;
+}
+
+
+Inkscape::XML::Node *sp_repr_lookup_descendant(Inkscape::XML::Node *repr,
+                                              gchar const *key,
+                                              gchar const *value)
+{
+    Inkscape::XML::Node const *found = sp_repr_lookup_descendant( const_cast<Inkscape::XML::Node const *>(repr), key, value );
+    return const_cast<Inkscape::XML::Node *>(found);
+}
+
 Inkscape::XML::Node const *sp_repr_lookup_name( Inkscape::XML::Node const *repr, gchar const *name, gint maxdepth )
 {
     Inkscape::XML::Node const *found = nullptr;
@@ -391,6 +423,34 @@ std::vector<Inkscape::XML::Node const *> sp_repr_lookup_name_many( Inkscape::XML
     return nodes;
 }
 
+std::vector<Inkscape::XML::Node *>
+sp_repr_lookup_property_many( Inkscape::XML::Node *repr, Glib::ustring const& property,
+                              Glib::ustring const &value, int maxdepth )
+{
+    std::vector<Inkscape::XML::Node *> nodes;
+    std::vector<Inkscape::XML::Node *> found;
+    g_return_val_if_fail(repr     != nullptr, nodes);
+
+    SPCSSAttr* css = sp_repr_css_attr (repr, "style");
+    if (value == sp_repr_css_property (css, property, "")) {
+        nodes.push_back(repr);
+    }
+
+    if ( maxdepth != 0 ) {
+        // maxdepth == -1 means unlimited
+        if ( maxdepth == -1 ) {
+            maxdepth = 0;
+        }
+
+        for (Inkscape::XML::Node *child = repr->firstChild() ; child; child = child->next() ) {
+            found = sp_repr_lookup_property_many( child, property, value, maxdepth - 1);
+            nodes.insert(nodes.end(), found.begin(), found.end());
+        }
+    }
+
+    return nodes;
+}
+
 /**
  * Determine if the node is a 'title', 'desc' or 'metadata' element.
  */
diff --git a/src/xml/repr.h b/src/xml/repr.h
index 1c3bf1193..e9f01c5d4 100644
--- a/src/xml/repr.h
+++ b/src/xml/repr.h
@@ -78,12 +78,13 @@ bool sp_repr_save_rebased_file(Inkscape::XML::Document *doc, char const *filenam
 
 SPCSSAttr *sp_repr_css_attr_new();
 void sp_repr_css_attr_unref(SPCSSAttr *css);
-SPCSSAttr *sp_repr_css_attr(Inkscape::XML::Node *repr, char const *attr);
+SPCSSAttr *sp_repr_css_attr(Inkscape::XML::Node const *repr, char const *attr);
 SPCSSAttr *sp_repr_css_attr_parse_color_to_fill(const Glib::ustring &text);
-SPCSSAttr *sp_repr_css_attr_inherited(Inkscape::XML::Node *repr, char const *attr);
+SPCSSAttr *sp_repr_css_attr_inherited(Inkscape::XML::Node const *repr, char const *attr);
 SPCSSAttr *sp_repr_css_attr_unset_all(SPCSSAttr *css);
 
 char const *sp_repr_css_property(SPCSSAttr *css, char const *name, char const *defval);
+Glib::ustring sp_repr_css_property(SPCSSAttr *css, Glib::ustring const &name, Glib::ustring const &defval);
 void sp_repr_css_set_property(SPCSSAttr *css, char const *name, char const *value);
 void sp_repr_css_unset_property(SPCSSAttr *css, char const *name);
 bool sp_repr_css_property_is_unset(SPCSSAttr *css, char const *name);
@@ -151,10 +152,25 @@ std::vector<Inkscape::XML::Node const *> sp_repr_lookup_name_many(Inkscape::XML:
                                                                   char const *name,
                                                                   int maxdepth = -1);
 
+// Find an element node using an unique attribute.
 Inkscape::XML::Node *sp_repr_lookup_child(Inkscape::XML::Node *repr,
                                           char const *key,
                                           char const *value);
 
+// Find an element node using an unique attribute recursively.
+Inkscape::XML::Node *sp_repr_lookup_descendant(Inkscape::XML::Node *repr,
+                                               char const *key,
+                                               char const *value);
+
+Inkscape::XML::Node const *sp_repr_lookup_descendant(Inkscape::XML::Node const *repr,
+                                                     char const *key,
+                                                     char const *value);
+
+// Find element nodes using a property value.
+std::vector<Inkscape::XML::Node *> sp_repr_lookup_property_many(Inkscape::XML::Node *repr,
+                                                                Glib::ustring const &property,
+                                                                Glib::ustring const &value,
+                                                                int maxdepth = -1);
 
 inline Inkscape::XML::Node *sp_repr_document_first_child(Inkscape::XML::Document const *doc) {
     return const_cast<Inkscape::XML::Node *>(doc->firstChild());