Extended color

[Regina Henschel]

Hi all,

There is ongoing development on theme colors and on multi-color 
gradients. These require additions to the API and additions to ODF. The 
current solutions are not sufficient (I think) or do not exist. 
Therefore I suggest a concept of "extended color". Such "extended color" 
has information about the type of the color, a color value and 
transformations of the color.

Currently in API, the gradient2 misses theme colors and XThemeColor 
misses color transformations. rng additions for theme color misses that 
color transformations in OOXML can be combined with any kind of color 
type, not only with theme colors, and thus ODF should be extended 
accordingly.

More concrete descriptions of my idea are below.

Kind regards,
Regina

For the API in css::awt or in css::util or mixed, here written for awt
struct ExtColor
     css::awt::ColorType Type
     string              Value
     sequence<css::awt::ColorTransform> Transform

enum ColorType {RGBHex, Theme, RGBZeroToOne}

The ColorType determines how the string in Value has to be interpreted.
Examples:
Type="RGBHex" Value="#ffcc00". Value is a color in #rrggbb notation.
Type="Theme" Value="7". Value is an index into ThemeUnoRepresentation[2] 
(="ColorScheme") or css::util::XScheme::ColorSet, respectively.
Type="RGBZeroToOne" Value="1.0 0.8 0"

struct ColorTransform
     css::awt::ColorTransformType Type
     short                        Value

enum ColorTransformType {LumMod, LumOff, Alpha}

The ColorTransformType determines how the number in Value has to be 
interpreted.
Examples: Type="LumMod" Value="6000" means to modify the luminance of 
the color with 60% as specified in OOXML.

struct ColorStop
     double               StopOffset
     css::awt::ExtColor   StopColor


These can be straightforward transported to ODF.
Examples:
<rng:define name="draw-gradient">
     <rng:element name="draw:gradient">
       <rng:ref name="common-draw-gradient-attlist"/>
       <rng:ref name="draw-gradient-attlist"/>
       <rng:optional>
         <rng:ref name="style-gradient-stop" />
       </rng:optional>
</rng:element

<rng:define name="style-gradient-stop"
     <rng:element name="style:gradient-stop>
         <rng:attribute name="style:color-offset>
             <rng:ref name="zeroToOneDecimal" />
         </rng:attribute>
         <rng:element name="style:color-stop">
             <rng:ref name="style-extended-color"/>
         </rng:element>
     </rng:element>
</rng:define>

<rng:define name="style-extended-color">
     <rng:element name="style:extended-color>
         <rng:attribute name="style:color-type">
             <rng:choice>
                 <value>RGBHex</value>
                 <Value>Theme</value>
                 <value>RGBZeroToOne</value>
             </rng:choice>
         </rng:attribute>
         <rng:attribute name="style:value">
             <rng:ref name="string" />
         </rng:attribute>
         <rng:zeroOrMore>
             <rng:ref name="style-color-transform">
         </rng:zeroOrMore>
     </rng:element>
</rng:define>

<rng:define name="style-color-transform">
     <rng:element name="style:color-transform">
         <rng:attribute name="style:color-transform-type">
             <rng:choice>
                 <rng:value>LumMod</rng:value>
                 <rng:value>LumOff</rng:value>
                 <rng:value>Alpha</rng:value>
             </rng:choice>
         </rng:attribute>
         <rng:attribute name="style:value">
             <rng:ref name="integer" />
         </rng:attribute>
         <rng:empty/>
     </rng:element>
</rng:define>

<rng:define name="style-graphic-fill-properties-attlist">
...
     <rng:optional>
         <rng:attribute name="draw:fill-extended-color">
             <rng:ref name="style-extended-color"/>
         </rng:attribute>
     <rng:optional>
     <rng:optional>
         <rng:attribute name="draw:stroke-extended-color">
             <rng:ref name="style-extended-color"/>
         </rng:attribute>
     </rng:optional>
...
</rng:define>

<rng:define name="style-text-properties-attlist">
...
     <rng:optional>
         <rng:attribute name="style:text-extended-color>
             <rng:ref name="style-extended-color"/>
         </rng:attribute>
     </rng:optional>
...
</rng:define>


If we want to be more flexible in ODF for color-type or 
color-transform-type, we could use a namespaced string as datatype and 
make it implementation-dependent (to allow all of enum class 
TransformationType, for example).