path: root/src/attribute-rel-util.cpp

// SPDX-License-Identifier: GPL-2.0-or-later
/** @file
 * TODO: insert short description here
 *//*
 * Authors: see git history
 *
 * Copyright (C) 2018 Authors
 * Released under GNU GPL v2+, read the file 'COPYING' for more information.
 */
/*
 * attribute-rel-util.h
 *
 *  Created on: Sep 8, 2011
 *      Author: tavmjong
 */

/**
 * Utility functions for cleaning SVG tree of unneeded attributes and style properties.
 */

#include <fstream>
#include <sstream>
#include <iostream>

#include "preferences.h"

#include "xml/attribute-record.h"

#include "attribute-rel-css.h"
#include "attribute-rel-svg.h"

#include "attribute-rel-util.h"

using Inkscape::XML::Node;

/**
 * Get preferences
 */
unsigned int sp_attribute_clean_get_prefs() {

    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    unsigned int flags = 0;
    if( prefs->getBool("/options/svgoutput/incorrect_attributes_warn") )          flags += SP_ATTRCLEAN_ATTR_WARN;
    if( prefs->getBool("/options/svgoutput/incorrect_attributes_remove") &&
       !prefs->getBool("/options/svgoutput/disable_optimizations" ) )             flags += SP_ATTRCLEAN_ATTR_REMOVE;
    if( prefs->getBool("/options/svgoutput/incorrect_style_properties_warn") )    flags += SP_ATTRCLEAN_STYLE_WARN;
    if( prefs->getBool("/options/svgoutput/incorrect_style_properties_remove" ) &&
       !prefs->getBool("/options/svgoutput/disable_optimizations" ) )             flags += SP_ATTRCLEAN_STYLE_REMOVE;
    if( prefs->getBool("/options/svgoutput/style_defaults_warn") )                flags += SP_ATTRCLEAN_DEFAULT_WARN;
    if( prefs->getBool("/options/svgoutput/style_defaults_remove") &&
       !prefs->getBool("/options/svgoutput/disable_optimizations" ) )             flags += SP_ATTRCLEAN_DEFAULT_REMOVE;

    return flags;
}

/**
 * Remove or warn about inappropriate attributes and useless stype properties.
 * repr: the root node in a document or any other node.
 */
void sp_attribute_clean_tree(Node *repr) {

  g_return_if_fail (repr != nullptr);

  unsigned int flags = sp_attribute_clean_get_prefs();
 
  if( flags ) {
      sp_attribute_clean_recursive( repr, flags );
  }
}

/**
 * Clean recursively over all elements.
 */
void sp_attribute_clean_recursive(Node *repr, unsigned int flags) {

  g_return_if_fail (repr != nullptr);

  if( repr->type() == Inkscape::XML::NodeType::ELEMENT_NODE ) {
    Glib::ustring element = repr->name();

    // Only clean elements in svg namespace
    if( element.substr(0,4) == "svg:" ) {
      sp_attribute_clean_element(repr, flags );
    }
  }
  
  for(Node *child=repr->firstChild() ; child ; child = child->next()) {

    // Don't remove default css values if element is in <defs> or is a <symbol>
    Glib::ustring element = child->name();
    unsigned int flags_temp = flags;
    if( element.compare( "svg:defs" ) == 0 || element.compare( "svg:symbol" ) == 0 ) {
      flags_temp &= ~(SP_ATTRCLEAN_DEFAULT_WARN|SP_ATTRCLEAN_DEFAULT_REMOVE);
    }
    sp_attribute_clean_recursive( child, flags_temp );
  }
}

/**
 * Clean attributes on an element
 */
void sp_attribute_clean_element(Node *repr, unsigned int flags) {

  g_return_if_fail (repr != nullptr);
  g_return_if_fail (repr->type() == Inkscape::XML::NodeType::ELEMENT_NODE);

  Glib::ustring element = repr->name();
  Glib::ustring id = (repr->attribute( "id" )==nullptr ? "" : repr->attribute( "id" ));

  // Clean style: this attribute is unique in that normally we want to change it and not simply
  // delete it.
  sp_attribute_clean_style(repr, flags );

  // Clean attributes
  std::set<Glib::ustring> attributesToDelete;
  for ( const auto & iter : repr->attributeList()) {

    Glib::ustring attribute = g_quark_to_string(iter.key);
    //Glib::ustring value = (const char*)iter->value;

    bool is_useful = sp_attribute_check_attribute( element, id, attribute, flags & SP_ATTRCLEAN_ATTR_WARN );
    if( !is_useful && (flags & SP_ATTRCLEAN_ATTR_REMOVE) ) {
      attributesToDelete.insert( attribute );
    }
  }

  // Do actual deleting (done after so as not to perturb List iterator).
  for(const auto & iter_d : attributesToDelete) {
      repr->removeAttribute(iter_d);
  }
}


/**
 * Clean CSS style on an element.
 */
void sp_attribute_clean_style(Node *repr, unsigned int flags) {

  g_return_if_fail (repr != nullptr);
  g_return_if_fail (repr->type() == Inkscape::XML::NodeType::ELEMENT_NODE);

  // Find element's style
  SPCSSAttr *css = sp_repr_css_attr( repr, "style" );
  sp_attribute_clean_style(repr, css, flags);

  // Convert css node's properties data to string and set repr node's attribute "style" to that string.
  // sp_repr_css_set( repr, css, "style"); // Don't use as it will cause loop.
  Glib::ustring value;
  sp_repr_css_write_string(css, value);
  repr->setAttributeOrRemoveIfEmpty("style", value);

  sp_repr_css_attr_unref( css );
}


/**
 * Clean CSS style on an element.
 */
Glib::ustring sp_attribute_clean_style(Node *repr, gchar const *string, unsigned int flags) {

  g_return_val_if_fail (repr != nullptr, "");
  g_return_val_if_fail (repr->type() == Inkscape::XML::NodeType::ELEMENT_NODE, "");

  SPCSSAttr *css = sp_repr_css_attr_new();
  sp_repr_css_attr_add_from_string( css, string );
  sp_attribute_clean_style(repr, css, flags);
  Glib::ustring string_cleaned;
  sp_repr_css_write_string (css, string_cleaned);

  sp_repr_css_attr_unref( css );

  return string_cleaned;
}


/**
 * Clean CSS style on an element.
 *
 * 1. Is a style property appropriate on the given element?
 *    e.g, font-size is useless on <svg:rect>
 * 2. Is the value of the style property useful?
 *    Is it the same as the parent and it inherits?
 *    Is it the default value (and the property on the parent is not set or does not inherit)?
 */
void sp_attribute_clean_style(Node* repr, SPCSSAttr *css, unsigned int flags) {

  g_return_if_fail (repr != nullptr);
  g_return_if_fail (css != nullptr);

  Glib::ustring element = repr->name();
  Glib::ustring id = (repr->attribute( "id" )==nullptr ? "" : repr->attribute( "id" ));

  // Find parent's style, including properties that are inherited.
  // Note, a node may not have a parent if it has not yet been added to tree.
  SPCSSAttr *css_parent = nullptr;
  if( repr->parent() ) css_parent = sp_repr_css_attr_inherited( repr->parent(), "style" );

  // Loop over all properties in "style" node, keeping track of which to delete.
  std::set<Glib::ustring> toDelete;
  for ( const auto & iter : css->attributeList()) {

    gchar const * property = g_quark_to_string(iter.key);
    gchar const * value = iter.value;

    // Check if a property is applicable to an element (i.e. is font-family useful for a <rect>?).
    if( !SPAttributeRelCSS::findIfValid( property, element ) ) {
        if( flags & SP_ATTRCLEAN_STYLE_WARN ) {
            g_warning( "<%s id=\"%s\">: CSS Style property: \"%s\" is inappropriate.",
                       element.c_str(), id.c_str(), property );
        }
        if( flags & SP_ATTRCLEAN_STYLE_REMOVE ) {
            toDelete.insert(property);
        }
        continue;
    }

    // Find parent value for same property (property)
    gchar const * value_p = nullptr;
    if( css_parent != nullptr ) {
        for ( const auto & iter_p : css_parent->attributeList()) {

            gchar const * property_p = g_quark_to_string(iter_p.key);

            if( !g_strcmp0( property, property_p ) ) {
                value_p = iter_p.value;
                break;
            }
        }
    }

    // If parent has same property value and property is inherited, mark for deletion.
    if ( !g_strcmp0( value, value_p ) && SPAttributeRelCSS::findIfInherit( property ) ) {

        if ( flags & SP_ATTRCLEAN_DEFAULT_WARN ) {
            g_warning( "<%s id=\"%s\">: CSS Style property: \"%s\" has same value as parent (%s).",
                       element.c_str(), id.c_str(), property, value );
        }
        if ( flags & SP_ATTRCLEAN_DEFAULT_REMOVE ) {
            toDelete.insert( property );
        }
        continue;
    }

    // If property value is same as default and the parent value not set or property is not inherited,
    // mark for deletion.
    if ( SPAttributeRelCSS::findIfDefault( property, value ) &&
         ((value_p == nullptr) || !SPAttributeRelCSS::findIfInherit( property ) ) ) {

        if ( flags & SP_ATTRCLEAN_DEFAULT_WARN ) {
            g_warning( "<%s id=\"%s\">: CSS Style property: \"%s\" with default value (%s) not needed.",
                       element.c_str(), id.c_str(), property, value );
        }
        if ( flags & SP_ATTRCLEAN_DEFAULT_REMOVE ) {
            toDelete.insert( property );
        }
        continue;
    }

  } // End loop over style properties

  // Delete unneeded style properties. Do this at the end so as to not perturb List iterator.
  for(const auto & iter_d : toDelete) {
    sp_repr_css_set_property( css, iter_d.c_str(), nullptr );
  }

}

/**
 * Remove CSS style properties with default values.
 */
void sp_attribute_purge_default_style(SPCSSAttr *css, unsigned int flags) {

  g_return_if_fail (css != nullptr);

  // Loop over all properties in "style" node, keeping track of which to delete.
  std::set<Glib::ustring> toDelete;
  for ( const auto & iter : css->attributeList()) {

    gchar const * property = g_quark_to_string(iter.key);
    gchar const * value = iter.value;

    // If property value is same as default mark for deletion.
    if ( SPAttributeRelCSS::findIfDefault( property, value ) ) {

        if ( flags & SP_ATTRCLEAN_DEFAULT_WARN ) {
            g_warning( "Preferences CSS Style property: \"%s\" with default value (%s) not needed.",
                       property, value );
        }
        if ( flags & SP_ATTRCLEAN_DEFAULT_REMOVE ) {
            toDelete.insert( property );
        }
        continue;
    }

  } // End loop over style properties

  // Delete unneeded style properties. Do this at the end so as to not perturb List iterator.
  for(const auto & iter_d : toDelete) {
    sp_repr_css_set_property( css, iter_d.c_str(), nullptr );
  }

}

/**
 * Check one attribute on an element
 */
bool sp_attribute_check_attribute(Glib::ustring element, Glib::ustring id, Glib::ustring attribute, bool warn) {

    bool is_useful = true;

    if( SPAttributeRelCSS::findIfProperty( attribute ) ) {

        // First check if it is a presentation attribute. Presentation attributes can be applied to
        // any element.  At the moment, we are only going to check if it is a possibly useful
        // attribute. Note, we don't explicitly check against the list of elements where presentation
        // attributes are allowed (See SVG1.1 spec, Appendix M.2).
        if( !SPAttributeRelCSS::findIfValid( attribute, element ) ) {

            // Non-useful presentation attribute on SVG <element>
            if( warn ) {
                g_warning( "<%s id=\"%s\">: Non-useful presentation attribute: \"%s\" found.",
                           element.c_str(),
                           id.c_str(),
                           attribute.c_str() );
            }
            is_useful = false;
        }

    } else {

        // Second check if it is a valid attribute
        if (  !SPAttributeRelSVG::findIfValid( attribute, element ) ) {

            // Invalid attribute on SVG <element>
            if( warn ) {
                g_warning( "<%s id=\"%s\">: Invalid attribute: \"%s\" found.",
                           element.c_str(),
                           id.c_str(),
                           attribute.c_str() );
            }
            is_useful = false;
        }
    }

    return is_useful;
}

/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
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