File indexing completed on 2024-05-12 16:33:59

 /* This file is part of the KDE project
    Copyright (C) 2006 Martin Pfeiffer <hubipete@gmx.net> 
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.
 
    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.
 
    You should have received a copy of the GNU Library General Public License
    along with this library; see the file COPYING.LIB.  If not, write to
    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
    Boston, MA 02110-1301, USA.
 */
 
 #ifndef ATTRIBUTEMANAGER_H
 #define ATTRIBUTEMANAGER_H
 
 #include <QFont>
 #include "koformula_export.h"
 
 class KoViewConverter;
 class BasicElement;
 
 /** Enum encoding all possibilities to align */
 enum Align {
     Left /**< Align to the left*/,
     Center /**< Align to the center*/,
     Right /**< Align to the right*/,
     Top /**< Align to the top*/,
     Bottom /**< Align to the bottom*/,
     BaseLine /**< Align to the baseline*/,
     Axis /**< Align to the axis*/,
     InvalidAlign
 };
 
 class Length {
   public:
     enum Unit {
         Em, /**< ems (font-relative unit traditionally used for horizontal lengths) */
         Ex,     /**< exs (font-relative unit traditionally used for vertical lengths) */
         Px,     /**< pixels, or pixel size of a "typical computer display" */
         In,     /**< inches (1 inch = 2.54 centimeters) */
         Cm,     /**< centimeters */
         Mm,     /**< millimeters */
         Pt,     /**< points (1 point = 1/72 inch) */
         Pc,     /**< picas (1 pica = 12 points) */
         Percentage, /**< percentage of default value */
         None    /**< For when no unit has been specified */
     };
 
     enum UnitType {
         NoType,
         Relative,
         Absolute,
         Pixel
     };
 
     Length() : value(0), unit(None), type(NoType) {};
     qreal value;
     Unit unit;
     UnitType type;
 };
 
 /**
  * @short manages all the attributes, used by the elements to obtain attribute values
  *
  * The AttributeManager is the central point dealing with the MathML attributes and
  * their values. It is in fact something like a StyleManager. As the normal elements
  * only have a general hash list of the elements they hold, there is the need for a
  * class that manages conversion and heritage of the attributes during the painting
  * phase. These are the two main tasks of AttributeManager.
  * The AttributeManager is always called when an element needs a value to work with.
  * The AttributeManager looks for that value first in the asking element's own
  * attribute list. If nothing is found the AttributeManager looks for a parent element
  * that might inherit the right value. If AttributeManager has no success again it
  * returns the default value for that attribute.
  *
  * @author Martin Pfeiffer <hubipete@gmx.net>
  */
 class KOFORMULA_EXPORT AttributeManager {
 public:
     /// The constructor
     AttributeManager();
 
     /// The destructor
     ~AttributeManager();
 
     /**
      * Obtain the @p attribute's value as color
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The value that was looked up
      */
     QColor colorOf( const QString& attribute, const BasicElement* element  ) const;
 
     /**
      * Obtain the @p attribute's value as boolean
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The value that was looked up
      */
     bool boolOf( const QString& attribute, const BasicElement* element ) const;
 
     /**
      * Obtain the @p attribute's value as qreal
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The value that was looked up
      */
     qreal doubleOf( const QString& attribute, const BasicElement* element ) const;
 
     /**
      * Obtain the @p attribute's value as list of qreals
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The value that was looked up
      */
     QList<qreal> doubleListOf( const QString& attribute,
                                 const BasicElement* element ) const;
 
     /**
      * Obtain the @p attribute's value as string
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The value that was looked up
      */
     QString stringOf( const QString& attribute, const BasicElement* element ) const;
 
     /**
      * Obtain the @p attribute's value as align
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The value that was looked up
      */
     Align alignOf( const QString& attribute, const BasicElement* element ) const;
 
     /**
      * Obtain the @p attribute's value as list of aligns
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The value that was looked up
      */
     QList<Align> alignListOf( const QString& attribute, const BasicElement* element ) const;
 
     /**
      * Obtain the @p attribute's value as Qt::PenStyle
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The value that was looked up
      */
     Qt::PenStyle penStyleOf( const QString& attribute, const BasicElement* element ) const;
 
     /**
      * Obtain the @p attribute's value as list of Qt::PenStyles
      * @param attribute A string with the attribute to look up
      * @param element The element the value is looked up for
      * @return The valuefont  that was looked up
      */
     QList<Qt::PenStyle> penStyleListOf( const QString& attribute,
                                         const BasicElement* element ) const;
 
     /**
      * Obtain the scaling level for @p parent 's child element at index @p index
      * Usually the first child is treated different.  For example in 
      * @verbatim
      * <msup><mi>b</mi><mn>2</mn></msup>
      * @endverbatim
      * to represent  b^2,  the 2 is smaller
      * than the b.
      * @param parent The parent of the element for which scaling is determined
      * @param index The index of the child element for which scaling is determined
      * @return The scaling level for the font size
      */
     int scriptLevel( const BasicElement* parent, int index ) const;
     
     /// @return Line thickness for mfrac, mroot etc lines
     qreal lineThickness( const BasicElement* element ) const;
 
     /// @return A value used for spacing tasks during layouting
     qreal layoutSpacing( const BasicElement* element ) const;
 
     /**
      * Determine the maximal height of an given element's child elements
      * @param element The element whose children are used
      * @return The maximal height
      */
     qreal maxHeightOfChildren( const BasicElement* element ) const;
 
     /**
      * Determine the maximal height of an given element's child elements
      * @param element The element whose children are used
      * @return The maximal height
      */
     qreal maxWidthOfChildren( const BasicElement* element ) const;
 
     /// @return The Align value that was passed as QString @p value
     Align parseAlign( const QString& value ) const;
 
     /// @return The font that is set for @p element 
     QFont font( const BasicElement* element ) const;
 
     /// Set the KoViewConverter to use
     void setViewConverter( KoViewConverter* converter );
 
     /// @return The parsed the @p value into a Qt::PenStyle
     Qt::PenStyle parsePenStyle( const QString& value ) const;
 
     /// @return The parsed @p value which is given with a unit
     Length parseUnit( const QString& value, const BasicElement* element ) const;
 
     //// @return The given Length converted to units of pixels
     qreal lengthToPixels( Length length, const BasicElement* element, const QString &attribute) const;
 
     /// Find a value for @p attribute that applies to @p element
     QString findValue( const QString& attribute, const BasicElement* element ) const;
 
     /// Convert a math space string, such as "thinmathspace", to a size in pixels
     qreal parseMathSpace( const QString& value, const BasicElement *element ) const;
 
     /// The KoViewConverter used to determine the point values of pixels
     KoViewConverter* m_viewConverter;
 };
 
 #endif // ATTRIBUTEMANAGER_H