Adding upstream version 1.2.2.upstream/1.2.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1278 insertions, 0 deletions

diff --git a/src/style-internal.h b/src/style-internal.h
new file mode 100644
index 0000000..41b246e
--- /dev/null
+++ b/src/style-internal.h
@@ -0,0 +1,1278 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_SP_STYLE_INTERNAL_H
+#define SEEN_SP_STYLE_INTERNAL_H
+
+/** \file
+ * SPStyle internal: classes that are internal to SPStyle
+ */
+/* Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com>
+ *   Jon A. Cruz <jon@joncruz.org>
+ *   Tavmjong Bah <tavmjong@free.fr>
+ *
+ * Copyright (C) 2014, 2018 Tavmjong Bah
+ * Copyright (C) 2010 Jon A. Cruz
+ * Copyright (C) 2001-2002 Lauris Kaplinski
+ * Copyright (C) 2001 Ximian, Inc.
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <utility>
+#include <vector>
+#include <map>
+
+#include "attributes.h"
+#include "style-enums.h"
+
+#include "color.h"
+
+#include "object/sp-marker-loc.h"
+#include "object/sp-filter.h"
+#include "object/sp-filter-reference.h"
+#include "object/sp-paint-server-reference.h"
+#include "object/sp-shape-reference.h"
+
+#include "object/uri.h"
+
+#include "svg/svg-icc-color.h"
+
+#include "xml/repr.h"
+
+namespace Inkscape {
+class ObjectSet;
+};
+
+static const unsigned SP_STYLE_FLAG_ALWAYS (1 << 2);
+static const unsigned SP_STYLE_FLAG_IFSET  (1 << 0);
+static const unsigned SP_STYLE_FLAG_IFDIFF (1 << 1);
+static const unsigned SP_STYLE_FLAG_IFSRC  (1 << 3); // If source matches
+
+enum class SPStyleSrc : unsigned char
+{
+    UNSET,
+    ATTRIBUTE,   // fill="red"
+    STYLE_PROP,  // style="fill:red"
+    STYLE_SHEET, // .red { fill:red; }
+};
+
+/* General comments:
+ *
+ * This code is derived from the original C style code in style.cpp.
+ *
+ * Overview:
+ *   Style can be obtained (in order of precedence) [CHECK]
+ *     1. "style" property in an element (style="fill:red").
+ *     2. Style sheet, internal or external (<style> rect {fill:red;}</style>). 
+ *     3. Attributes in an element (fill="red").
+ *     4. Parent's style.
+ *   A later property overrides an earlier property. This is implemented by
+ *   reading in the properties backwards. If a property is already set, it
+ *   prevents an earlier property from being read.
+ *
+ *   A declaration with an "!important" rule overrides any other declarations (except those that
+ *   also have an "!important" rule). Attributes can not use the "!important" rule and the rule
+ *   is not inherited.
+ *
+ *   In order for cascading to work, each element in the tree must be read in from top to bottom
+ *   (parent before child). At each step, if a style property is not explicitly set, the property
+ *   value is taken from the parent. Some properties have "computed" values that depend on:
+ *      the parent's value (e.g. "font-size:larger"),
+ *      another property value ("stroke-width":1em"), or
+ *      an external value ("stroke-width:5%").
+ *
+ * To summarize:
+ *
+ *   An explicitly set value (including 'inherit') has a 'true' "set" flag.
+ *   The "value" is either explicitly set or inherited.
+ *   The "computed" value (if present) is calculated from "value" and some other input. 
+ *
+ * Functions:
+ *   write():    Write a property and its value to a string.
+ *     Flags:
+ *       ALWAYS: Always write out property.
+ *       IFSET:  Write a property if 'set' flag is true, otherwise return empty string.
+ *       IFDIFF: Write a property if computed values are different, otherwise return empty string,
+ *               This is only used for text!!
+ *       IFSRC   Write a property if the source matches the requested source (style sheet, etc.).
+ *
+ *   read():     Set a property value from a string.
+ *   clear():    Set a property to its default value and set the 'set' flag to false.
+ *   cascade():  Cascade the parent's property values to the child if the child's property
+ *               is unset (and it allows inheriting) or the value is 'inherit'.
+ *               Calculate computed values that depend on parent.
+ *               This requires that the parent already be updated.
+ *   merge():    Merge the property values of a child and a parent that is being deleted,
+ *               attempting to preserve the style of the child.
+ *   operator=:  Assignment operator required due to use of templates (in original C code).
+ *   operator==: True if computed values are equal.  TO DO: DEFINE EXACTLY WHAT THIS MEANS
+ *   operator!=: Inverse of operator==.
+ *
+ *
+ * Outside dependencies:
+ *
+ *   The C structures that these classes are evolved from were designed to be embedded in to the
+ *   style structure (i.e they are "internal" and thus have an "I" in the SPI prefix). However,
+ *   they should be reasonably stand-alone and can provide some functionality outside of the style
+ *   structure (i.e. reading and writing style strings). Some properties do need access to other
+ *   properties from the same object (e.g. SPILength sometimes needs to know font size) to
+ *   calculate 'computed' values. Inheritance, of course, requires access to the parent object's
+ *   style class.
+ *
+ *   The only real outside dependency is SPObject... which is needed in the cases of SPIPaint and
+ *   SPIFilter for setting up the "href". (Currently, SPDocument is needed but this dependency
+ *   should be removed as an "href" only needs the SPDocument for attaching an external document to
+ *   the XML tree [see uri-references.cpp]. If SPDocument is really needed, it can be obtained from
+ *   SPObject.)
+ *
+ */
+
+/// Virtual base class for all SPStyle internal classes
+class SPIBase
+{
+
+public:
+    SPIBase(bool inherits_ = true)
+        : inherits(inherits_),
+          set(false),
+          inherit(false),
+          important(false),
+          style_src(SPStyleSrc::STYLE_PROP), // Default to property, see bug 1662285.
+          style(nullptr)
+    {}
+
+    virtual ~SPIBase()
+    = default;
+
+    virtual void read( gchar const *str ) = 0;
+    void readIfUnset(gchar const *str, SPStyleSrc source = SPStyleSrc::STYLE_PROP);
+
+protected:
+    char const *important_str() const { return important ? " !important" : ""; }
+
+public:
+    void readAttribute(Inkscape::XML::Node *repr)
+    {
+        readIfUnset(repr->attribute(name().c_str()), SPStyleSrc::ATTRIBUTE);
+    }
+
+    virtual const Glib::ustring get_value() const = 0;
+    bool shall_write( guint const flags = SP_STYLE_FLAG_IFSET,
+                      SPStyleSrc const &style_src_req = SPStyleSrc::STYLE_PROP,
+                      SPIBase const *const base = nullptr ) const;
+    virtual const Glib::ustring write( guint const flags = SP_STYLE_FLAG_IFSET,
+                                       SPStyleSrc const &style_src_req = SPStyleSrc::STYLE_PROP,
+                                       SPIBase const *const base = nullptr ) const;
+    virtual void clear() {
+        set = false, inherit = false, important = false;
+        // Attr::D is a special case where the best default for it is actually ATTRIBUTE
+        // and not STYLE_PROP, this exception allows us to not have to refactor more.
+        if (id() != SPAttr::D) {
+            style_src = SPStyleSrc::STYLE_PROP;
+        }
+    }
+
+    virtual void cascade( const SPIBase* const parent ) = 0;
+    virtual void merge(   const SPIBase* const parent ) = 0;
+
+    void setStylePointer(SPStyle *style_in) { style = style_in; }
+
+    // Explicit assignment operator required due to templates.
+    SPIBase& operator=(const SPIBase& rhs) = default;
+
+    // Check apples being compared to apples
+    virtual bool operator==(const SPIBase& rhs) const {
+        return id() == rhs.id();
+    }
+
+    bool operator!=(const SPIBase& rhs) const {
+        return !(*this == rhs);
+    }
+
+    virtual SPAttr id() const { return SPAttr::INVALID; }
+    Glib::ustring const &name() const;
+
+  // To do: make private
+public:
+    bool inherits : 1;    // Property inherits by default from parent.
+    bool set : 1;         // Property has been explicitly set (vs. inherited).
+    bool inherit : 1;     // Property value set to 'inherit'.
+    bool important : 1;   // Property rule 'important' has been explicitly set.
+    SPStyleSrc style_src; // Source (attribute, style attribute, style-sheet).
+
+protected:
+    SPStyle* style;       // Used by SPIPaint, SPIFilter... to find values of other properties
+};
+
+
+/**
+ * Decorator which overrides SPIBase::id()
+ */
+template <SPAttr Id, class Base>
+class TypedSPI : public Base {
+  public:
+    using Base::Base;
+
+    /**
+     * Get the attribute enum
+     */
+    SPAttr id() const override { return Id; }
+    static SPAttr static_id() { return Id; }
+
+    /**
+     * Upcast to the base class
+     */
+    Base *upcast() { return static_cast<Base *>(this); }
+    Base const *upcast() const { return static_cast<Base const *>(this); }
+};
+
+
+/// Float type internal to SPStyle. (Only 'stroke-miterlimit')
+class SPIFloat : public SPIBase
+{
+
+public:
+    SPIFloat(float value_default = 0.0 )
+        : value(value_default),
+          value_default(value_default)
+    {}
+
+    ~SPIFloat() override = default;
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        value = value_default;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIFloat& operator=(const SPIFloat& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private
+public:
+    float value = 0.0;
+
+private:
+    float value_default = 0.0;
+};
+
+/*
+ * One might think that the best value for SP_SCALE24_MAX would be ((1<<24)-1), which allows the
+ * greatest possible precision for fitting [0, 1] fractions into 24 bits.
+ *
+ * However, in practice, that gives a problem with 0.5, which falls half way between two fractions
+ * of ((1<<24)-1).  What's worse is that casting double(1<<23) / ((1<<24)-1) to float on x86
+ * produces wrong rounding behaviour, resulting in a fraction of ((1<<23)+2.0f) / (1<<24) rather
+ * than ((1<<23)+1.0f) / (1<<24) as one would expect, let alone ((1<<23)+0.0f) / (1<<24) as one
+ * would ideally like for this example.
+ *
+ * The value (1<<23) is thus best if one considers float conversions alone.
+ *
+ * The value 0xff0000 can exactly represent all 8-bit alpha channel values,
+ * and can exactly represent all multiples of 0.1.  I haven't yet tested whether
+ * rounding bugs still get in the way of conversions to & from float, but my instinct is that
+ * it's fairly safe because 0xff fits three times inside float's significand.
+ *
+ * We should probably use the value 0xffff00 once we support 16 bits per channel and/or LittleCMS,
+ * though that might need to be accompanied by greater use of double instead of float for
+ * colours and opacities, to be safe from rounding bugs.
+ */
+static const unsigned SP_SCALE24_MAX = 0xff0000;
+#define SP_SCALE24_TO_FLOAT(v) ((double) (v) / SP_SCALE24_MAX)
+#define SP_SCALE24_FROM_FLOAT(v) unsigned(((v) * SP_SCALE24_MAX) + .5)
+
+/** Returns a scale24 for the product of two scale24 values. */
+#define SP_SCALE24_MUL(_v1, _v2) unsigned((double)(_v1) * (_v2) / SP_SCALE24_MAX + .5)
+
+
+/// 24 bit data type internal to SPStyle.
+// Used only for opacity, fill-opacity, stroke-opacity.
+// Opacity does not inherit but stroke-opacity and fill-opacity do. 
+class SPIScale24 : public SPIBase
+{
+    static unsigned get_default() { return SP_SCALE24_MAX; }
+
+public:
+    SPIScale24(bool inherits = true )
+        : SPIBase(inherits),
+          value(get_default())
+    {}
+
+    ~SPIScale24() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        value = get_default();
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIScale24& operator=(const SPIScale24& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+
+  // To do: make private
+public:
+    unsigned value : 24;
+};
+
+
+enum SPCSSUnit {
+    SP_CSS_UNIT_NONE,
+    SP_CSS_UNIT_PX,
+    SP_CSS_UNIT_PT,
+    SP_CSS_UNIT_PC,
+    SP_CSS_UNIT_MM,
+    SP_CSS_UNIT_CM,
+    SP_CSS_UNIT_IN,
+    SP_CSS_UNIT_EM,
+    SP_CSS_UNIT_EX,
+    SP_CSS_UNIT_PERCENT
+};
+
+
+/// Length type internal to SPStyle.
+// Needs access to 'font-size' and 'font-family' for computed values.
+// Used for 'stroke-width' 'stroke-dash-offset' ('none' not handled), text-indent
+class SPILength : public SPIBase
+{
+
+public:
+    SPILength(float value = 0)
+        : unit(SP_CSS_UNIT_NONE),
+          value(value),
+          computed(value),
+          value_default(value)
+    {}
+
+    ~SPILength() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        unit = SP_CSS_UNIT_NONE, value = value_default;
+        computed = value_default;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPILength& operator=(const SPILength& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+    void setDouble(double v);
+    virtual const Glib::ustring toString(bool wname = false) const;
+
+    // To do: make private
+  public:
+    unsigned unit : 4;
+    float value = 0.f;
+    float computed = 0.f;
+
+private:
+    float value_default = 0.f;
+};
+
+
+/// Extended length type internal to SPStyle.
+// Used for: line-height, letter-spacing, word-spacing
+class SPILengthOrNormal : public SPILength
+{
+
+public:
+    SPILengthOrNormal(float value = 0)
+        : SPILength(value),
+          normal(true)
+    {}
+
+    ~SPILengthOrNormal() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPILength::clear();
+        normal = true;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPILengthOrNormal& operator=(const SPILengthOrNormal& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private
+public:
+    bool normal : 1;
+};
+
+
+/// Extended length type internal to SPStyle.
+// Used for: font-variation-settings
+class SPIFontVariationSettings : public SPIBase
+{
+
+public:
+    SPIFontVariationSettings()
+        : normal(true)
+    {}
+
+    ~SPIFontVariationSettings() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        axes.clear();
+        normal = true;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIFontVariationSettings& operator=(const SPIFontVariationSettings& rhs) {
+        SPIBase::operator=(rhs);
+        axes = rhs.axes;
+        normal = rhs.normal;
+        return *this;
+    }
+
+    bool operator==(const SPIBase& rhs) const override;
+
+    virtual const Glib::ustring toString() const;
+
+  // To do: make private
+public:
+    bool normal : 1;
+    std::map<Glib::ustring, float> axes;
+};
+
+
+/// Enum type internal to SPStyle.
+// Used for many properties. 'font-stretch' and 'font-weight' must be special cased.
+template <typename T>
+class SPIEnum : public SPIBase
+{
+
+public:
+    SPIEnum(T value = T(), bool inherits = true) :
+        SPIBase(inherits),
+        value(value),
+        value_default(value)
+    {
+        update_computed();
+    }
+
+    ~SPIEnum() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        value = value_default;
+        update_computed();
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIEnum& operator=(const SPIEnum& rhs) {
+        SPIBase::operator=(rhs);
+        value            = rhs.value;
+        computed         = rhs.computed;
+        value_default    = rhs.value_default;
+        return *this;
+    }
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private
+public:
+    T value{};
+    T computed{};
+
+private:
+    T value_default{};
+
+    //! Update computed from value
+    void update_computed();
+    //! Update computed from parent computed
+    void update_computed_cascade(T const &parent_computed) {}
+    //! Update value from parent
+    //! @pre computed is up to date
+    void update_value_merge(SPIEnum<T> const &) {}
+    void update_value_merge(SPIEnum<T> const &, T, T);
+};
+
+
+#if 0
+/// SPIEnum w/ bits, allows values with multiple key words.
+class SPIEnumBits : public SPIEnum
+{
+
+public:
+    SPIEnumBits( Glib::ustring const &name, SPStyleEnum const *enums, unsigned value = 0, bool inherits = true ) :
+        SPIEnum( name, enums, value, inherits )
+    {}
+
+    ~SPIEnumBits() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+};
+#endif
+
+
+/// SPIEnum w/ extra bits. The 'font-variants-ligatures' property is a complete mess that needs
+/// special handling. For OpenType fonts the values 'common-ligatures', 'contextual',
+/// 'no-discretionary-ligatures', and 'no-historical-ligatures' are not useful but we still must be
+/// able to parse them.
+using _SPCSSFontVariantLigatures_int = typename std::underlying_type<SPCSSFontVariantLigatures>::type;
+class SPILigatures : public SPIEnum<_SPCSSFontVariantLigatures_int>
+{
+
+public:
+    SPILigatures() :
+        SPIEnum<_SPCSSFontVariantLigatures_int>(SP_CSS_FONT_VARIANT_LIGATURES_NORMAL)
+    {}
+
+    ~SPILigatures() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+};
+
+
+/// SPIEnum w/ extra bits. The 'font-variants-numeric' property is a complete mess that needs
+/// special handling. Multiple key words can be specified, some exclusive of others.
+using _SPCSSFontVariantNumeric_int = typename std::underlying_type<SPCSSFontVariantNumeric>::type;
+class SPINumeric : public SPIEnum<_SPCSSFontVariantNumeric_int>
+{
+
+public:
+    SPINumeric() :
+        SPIEnum<_SPCSSFontVariantNumeric_int>(SP_CSS_FONT_VARIANT_NUMERIC_NORMAL)
+    {}
+
+    ~SPINumeric() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+};
+
+
+/// SPIEnum w/ extra bits. The 'font-variants-east-asian' property is a complete mess that needs
+/// special handling. Multiple key words can be specified, some exclusive of others.
+using _SPCSSFontVariantEastAsian_int = typename std::underlying_type<SPCSSFontVariantEastAsian>::type;
+class SPIEastAsian : public SPIEnum<_SPCSSFontVariantEastAsian_int>
+{
+
+public:
+    SPIEastAsian() :
+        SPIEnum<_SPCSSFontVariantEastAsian_int>(SP_CSS_FONT_VARIANT_EAST_ASIAN_NORMAL)
+    {}
+
+    ~SPIEastAsian() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+};
+
+
+/// String type internal to SPStyle.
+// Used for 'marker', ..., 'font', 'font-family', 'inkscape-font-specification'
+class SPIString : public SPIBase
+{
+
+public:
+    SPIString(bool inherits = true)
+        : SPIBase(inherits)
+    {}
+
+    SPIString(const SPIString &rhs) { *this = rhs; }
+
+    ~SPIString() override {
+        g_free(_value);
+    }
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override; // TODO check about value and value_default
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIString& operator=(const SPIString& rhs) {
+        if (this == &rhs) {
+            return *this;
+        }
+        SPIBase::operator=(rhs);
+        g_free(_value);
+        _value = g_strdup(rhs._value);
+        return *this;
+    }
+
+    bool operator==(const SPIBase& rhs) const override;
+
+    //! Get value if set, or inherited value, or default value (may be NULL)
+    char const *value() const;
+
+  private:
+    char const *get_default_value() const;
+
+    gchar *_value = nullptr;
+};
+
+/// Shapes type internal to SPStyle.
+// Used for 'shape-inside', shape-subtract'
+// Differs from SPIString by creating/deleting listeners on referenced shapes.
+class SPIShapes : public SPIString
+{
+    void hrefs_clear();
+
+public:
+    ~SPIShapes() override;
+    SPIShapes();
+    SPIShapes(const SPIShapes &) = delete; // Copying causes problems with hrefs.
+    void read( gchar const *str ) override;
+    void clear() override;
+
+public:
+    std::vector<SPShapeReference *> hrefs;
+    bool containsAnyShape(Inkscape::ObjectSet *set);
+};
+
+/// Color type internal to SPStyle, FIXME Add string value to store SVG named color.
+class SPIColor : public SPIBase
+{
+
+public:
+    SPIColor(bool inherits = true)
+        : SPIBase(inherits)
+        , currentcolor(false)
+    {
+        value.color.set(0);
+    }
+
+    ~SPIColor() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        value.color.set(0);
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIColor& operator=(const SPIColor& rhs) {
+        SPIBase::operator=(rhs);
+        currentcolor = rhs.currentcolor;
+        value.color  = rhs.value.color;
+        return *this;
+    }
+
+    bool operator==(const SPIBase& rhs) const override;
+
+    void setColor( float r, float g, float b ) {
+        value.color.set( r, g, b );
+    }
+
+    void setColor( guint32 val ) {
+        value.color.set( val );
+    }
+
+    void setColor( SPColor const& color ) {
+        value.color = color;
+    }
+
+public:
+    bool currentcolor : 1;
+    // FIXME: remove structure and derive SPIPaint from this class.
+    struct {
+         SPColor color;
+    } value;
+};
+
+
+
+#define SP_STYLE_FILL_SERVER(s) ((const_cast<SPStyle *> (s))->getFillPaintServer())
+#define SP_STYLE_STROKE_SERVER(s) ((const_cast<SPStyle *> (s))->getStrokePaintServer())
+
+// SVG 2
+enum SPPaintOrigin {
+    SP_CSS_PAINT_ORIGIN_NORMAL,
+    SP_CSS_PAINT_ORIGIN_CURRENT_COLOR,
+    SP_CSS_PAINT_ORIGIN_CONTEXT_FILL,
+    SP_CSS_PAINT_ORIGIN_CONTEXT_STROKE
+};
+
+
+/// Paint type internal to SPStyle.
+class SPIPaint : public SPIBase
+{
+
+public:
+    SPIPaint()
+        : paintOrigin(SP_CSS_PAINT_ORIGIN_NORMAL),
+          colorSet(false),
+          noneSet(false) {
+        value.href = nullptr;
+        tag = nullptr;
+        clear();
+    }
+
+    ~SPIPaint() override;  // Clear and delete href.
+    void read( gchar const *str ) override;
+    virtual void read( gchar const *str, SPStyle &style, SPDocument *document = nullptr);
+    const Glib::ustring get_value() const override;
+    void clear() override;
+    virtual void reset( bool init ); // Used internally when reading or cascading
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIPaint& operator=(const SPIPaint& rhs) {
+        SPIBase::operator=(rhs);
+        paintOrigin     = rhs.paintOrigin;
+        colorSet        = rhs.colorSet;
+        noneSet         = rhs.noneSet;
+        value.color     = rhs.value.color;
+        value.href      = rhs.value.href;
+        return *this;
+    }
+
+    bool operator==(const SPIBase& rhs) const override;
+
+    bool isSameType( SPIPaint const & other ) const {
+        return (isPaintserver() == other.isPaintserver()) && (colorSet == other.colorSet) && (paintOrigin == other.paintOrigin);
+    }
+
+    bool isNoneSet() const {
+        return noneSet;
+    }
+
+    bool isNone() const {
+        return !colorSet && !isPaintserver() && (paintOrigin == SP_CSS_PAINT_ORIGIN_NORMAL);
+    } // TODO refine
+
+    bool isColor() const {
+        return colorSet && !isPaintserver();
+    }
+
+    bool isPaintserver() const {
+        return value.href && value.href->getObject() != nullptr;
+    }
+
+    void setColor( float r, float g, float b ) {
+        value.color.set( r, g, b ); colorSet = true;
+    }
+
+    void setColor( guint32 val ) {
+        value.color.set( val ); colorSet = true;
+    }
+
+    void setColor( SPColor const& color ) {
+        value.color = color; colorSet = true;
+    }
+
+    void setNone() {noneSet = true; colorSet=false;}
+
+    void setTag(SPObject* tag) { this->tag = tag; }
+    SPObject* getTag() { return tag; }
+
+  // To do: make private
+public:
+    SPPaintOrigin paintOrigin : 2;
+    bool colorSet : 1;
+    bool noneSet : 1;
+    struct {
+         SPPaintServerReference *href;
+         SPColor color;
+    } value;
+    SPObject* tag;
+};
+
+
+// SVG 2
+enum SPPaintOrderLayer {
+    SP_CSS_PAINT_ORDER_NORMAL,
+    SP_CSS_PAINT_ORDER_FILL,
+    SP_CSS_PAINT_ORDER_STROKE,
+    SP_CSS_PAINT_ORDER_MARKER
+};
+
+// Normal maybe should be moved out as is done in other classes.
+// This could be replaced by a generic enum class where multiple keywords are allowed and
+// where order matters (in contrast to 'text-decoration-line' where order does not matter).
+
+// Each layer represents a layer of paint which can be a fill, a stroke, or markers.
+const size_t PAINT_ORDER_LAYERS = 3;
+
+/// Paint order type internal to SPStyle
+class SPIPaintOrder : public SPIBase
+{
+
+public:
+    SPIPaintOrder() {
+        this->clear();
+    }
+
+    SPIPaintOrder(const SPIPaintOrder &rhs) { *this = rhs; }
+
+    ~SPIPaintOrder() override {
+        g_free( value );
+    }
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        for( unsigned i = 0; i < PAINT_ORDER_LAYERS; ++i ) {
+            layer[i]     = SP_CSS_PAINT_ORDER_NORMAL;
+            layer_set[i] = false;
+        }
+        g_free(value);
+        value = nullptr;
+    }
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIPaintOrder& operator=(const SPIPaintOrder& rhs) {
+        if (this == &rhs) {
+            return *this;
+        }
+        SPIBase::operator=(rhs);
+        for( unsigned i = 0; i < PAINT_ORDER_LAYERS; ++i ) {
+            layer[i]     = rhs.layer[i];
+            layer_set[i] = rhs.layer_set[i];
+        }
+        g_free(value);
+        value            = g_strdup(rhs.value);
+        return *this;
+    }
+
+    bool operator==(const SPIBase& rhs) const override;
+
+
+  // To do: make private
+public:
+    SPPaintOrderLayer layer[PAINT_ORDER_LAYERS];
+    bool layer_set[PAINT_ORDER_LAYERS];
+    gchar *value = nullptr; // Raw string
+};
+
+
+/// Filter type internal to SPStyle
+class SPIDashArray : public SPIBase
+{
+
+public:
+    SPIDashArray() = default;
+
+    ~SPIDashArray() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        values.clear();
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIDashArray& operator=(const SPIDashArray& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private, change double to SVGLength
+public:
+  std::vector<SPILength> values;
+};
+
+/// Filter type internal to SPStyle
+class SPIFilter : public SPIBase
+{
+
+public:
+    SPIFilter()
+        : SPIBase(false)
+    {}
+
+    ~SPIFilter() override;
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override;
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIFilter& operator=(const SPIFilter& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private
+public:
+    SPFilterReference *href = nullptr;
+};
+
+
+
+enum {
+    SP_FONT_SIZE_LITERAL,
+    SP_FONT_SIZE_LENGTH,
+    SP_FONT_SIZE_PERCENTAGE
+};
+
+/// Fontsize type internal to SPStyle (also used by libnrtype/Layout-TNG-Input.cpp).
+class SPIFontSize : public SPIBase
+{
+
+public:
+    SPIFontSize() {
+        this->clear();
+    }
+
+    ~SPIFontSize() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        type = SP_FONT_SIZE_LITERAL, unit = SP_CSS_UNIT_NONE,
+            literal = SP_CSS_FONT_SIZE_MEDIUM, value = 12.0, computed = 12.0;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIFontSize& operator=(const SPIFontSize& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+public:
+    static float const font_size_default;
+
+  // To do: make private
+public:
+    unsigned type : 2;
+    unsigned unit : 4;
+    unsigned literal : 4;
+    float value;
+    float computed;
+
+private:
+    double relative_fraction() const;
+    static float const font_size_table[];
+};
+
+
+/// Font type internal to SPStyle ('font' shorthand)
+class SPIFont : public SPIBase
+{
+
+public:
+    SPIFont() = default;
+
+    ~SPIFont() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+    }
+
+    void cascade( const SPIBase* const /*parent*/ ) override
+    {} // Done in dependent properties
+
+    void merge(   const SPIBase* const /*parent*/ ) override
+    {}
+
+    SPIFont& operator=(const SPIFont& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+};
+
+
+enum {
+    SP_BASELINE_SHIFT_LITERAL,
+    SP_BASELINE_SHIFT_LENGTH,
+    SP_BASELINE_SHIFT_PERCENTAGE
+};
+
+/// Baseline shift type internal to SPStyle. (This is actually just like SPIFontSize)
+class SPIBaselineShift : public SPIBase
+{
+
+public:
+    SPIBaselineShift()
+        : SPIBase(false) {
+        this->clear();
+    }
+
+    ~SPIBaselineShift() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        type=SP_BASELINE_SHIFT_LITERAL, unit=SP_CSS_UNIT_NONE,
+            literal = SP_CSS_BASELINE_SHIFT_BASELINE, value = 0.0, computed = 0.0;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPIBaselineShift& operator=(const SPIBaselineShift& rhs) = default;
+
+    // This is not used but we have it for completeness, it has not been tested.
+    bool operator==(const SPIBase& rhs) const override;
+
+    bool isZero() const;
+
+  // To do: make private
+public:
+    unsigned type : 2;
+    unsigned unit : 4;
+    unsigned literal: 2;
+    float value; // Can be negative
+    float computed;
+};
+
+// CSS 2.  Changes in CSS 3, where description is for TextDecorationLine, NOT TextDecoration
+// See http://www.w3.org/TR/css-text-decor-3/
+
+// CSS3 2.2
+/// Text decoration line type internal to SPStyle.  THIS SHOULD BE A GENERIC CLASS
+class SPITextDecorationLine : public SPIBase
+{
+
+public:
+    SPITextDecorationLine() {
+        this->clear();
+    }
+
+    ~SPITextDecorationLine() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        underline = false, overline = false, line_through = false, blink = false;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPITextDecorationLine& operator=(const SPITextDecorationLine& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private
+public:
+    bool underline : 1;
+    bool overline : 1;
+    bool line_through : 1;
+    bool blink : 1;    // "Conforming user agents are not required to support this value." yay!
+};
+
+// CSS3 2.2
+/// Text decoration style type internal to SPStyle.  THIS SHOULD JUST BE SPIEnum!
+class SPITextDecorationStyle : public SPIBase
+{
+
+public:
+    SPITextDecorationStyle() {
+        this->clear();
+    }
+
+    ~SPITextDecorationStyle() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        solid = true, isdouble = false, dotted = false, dashed = false, wavy = false;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPITextDecorationStyle& operator=(const SPITextDecorationStyle& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private
+public:
+    bool solid : 1;
+    bool isdouble : 1;  // cannot use "double" as it is a reserved keyword
+    bool dotted : 1;
+    bool dashed : 1;
+    bool wavy : 1;
+};
+
+
+
+// This class reads in both CSS2 and CSS3 'text-decoration' property. It passes the line, style,
+// and color parts to the appropriate CSS3 long-hand classes for reading and storing values.  When
+// writing out data, we write all four properties, with 'text-decoration' being written out with
+// the CSS2 format. This allows CSS1/CSS2 renderers to at least render lines, even if they are not
+// the right style. (See http://www.w3.org/TR/css-text-decor-3/#text-decoration-property )
+
+/// Text decoration type internal to SPStyle.
+class SPITextDecoration : public SPIBase
+{
+
+public:
+    SPITextDecoration() = default;
+
+    ~SPITextDecoration() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    const Glib::ustring write( guint const flags = SP_STYLE_FLAG_IFSET,
+                                       SPStyleSrc const &style_src_req = SPStyleSrc::STYLE_PROP,
+                                       SPIBase const *const base = nullptr ) const override;
+    void clear() override {
+        SPIBase::clear();
+        style_td = nullptr;
+    }
+
+    void cascade( const SPIBase* const parent ) override;
+    void merge(   const SPIBase* const parent ) override;
+
+    SPITextDecoration& operator=(const SPITextDecoration& rhs) {
+        SPIBase::operator=(rhs);
+        return *this;
+    }
+
+    // Use CSS2 value
+    bool operator==(const SPIBase& rhs) const override;
+
+public:
+    SPStyle* style_td = nullptr;   // Style to be used for drawing CSS2 text decorations
+};
+
+
+// These are used to implement text_decoration. The values are not saved to or read from SVG file
+struct SPITextDecorationData {
+    float   phase_length;          // length along text line,used for phase for dot/dash/wavy
+    bool    tspan_line_start;      // is first  span on a line
+    bool    tspan_line_end;        // is last span on a line
+    float   tspan_width;           // from libnrtype, when it calculates spans
+    float   ascender;              // the rest from tspan's font
+    float   descender;
+    float   underline_thickness;
+    float   underline_position; 
+    float   line_through_thickness;
+    float   line_through_position;
+};
+
+/// Vector Effects.  THIS SHOULD BE A GENERIC CLASS
+class SPIVectorEffect : public SPIBase
+{
+
+public:
+    SPIVectorEffect()
+        : SPIBase(false)
+    {
+        this->clear();
+    }
+
+    ~SPIVectorEffect() override
+    = default;
+
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        stroke = false;
+        size   = false;
+        rotate = false;
+        fixed  = false;
+    }
+
+    // Does not inherit
+    void cascade( const SPIBase* const parent ) override {};
+    void merge(   const SPIBase* const parent ) override {};
+
+    SPIVectorEffect& operator=(const SPIVectorEffect& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private
+public:
+    bool stroke : 1;
+    bool size   : 1;
+    bool rotate : 1;
+    bool fixed  : 1;
+};
+
+/// Custom stroke properties. Only used for -inkscape-stroke: hairline.
+class SPIStrokeExtensions : public SPIBase
+{
+
+public:
+    SPIStrokeExtensions()
+        : hairline(false)
+    {}
+
+    ~SPIStrokeExtensions() override = default;
+    void read( gchar const *str ) override;
+    const Glib::ustring get_value() const override;
+    void clear() override {
+        SPIBase::clear();
+        hairline = false;
+    }
+
+    // Does not inherit
+    void cascade( const SPIBase* const parent ) override {};
+    void merge(   const SPIBase* const parent ) override {};
+
+    SPIStrokeExtensions& operator=(const SPIStrokeExtensions& rhs) = default;
+
+    bool operator==(const SPIBase& rhs) const override;
+
+  // To do: make private
+public:
+    bool hairline : 1;
+};
+
+#endif // SEEN_SP_STYLE_INTERNAL_H
+
+
+/*
+  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:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :