Interface StyleDatabase

All Known Implementing Classes:
AbstractStyleDatabase

public interface StyleDatabase
CSS Style database.

To use CSS in practice, you need to have information about the target rendering device: available fonts, page sizes, etc. This information is supplied by an instance of the StyleDatabase interface.

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    Gives the number of bits allocated to colors (excluding the alpha channel) in the output device.
    default String
    Gets the real name of the default font.
    Gets the name of the default font used when a generic font family (serif, sans-serif, monospace, cursive, fantasy) is specified.
    float
    Gets the height of the device, expressed in its natural unit.
    float
    Gets the width of the device, expressed in its natural unit.
    default CSSValue
    getEnvValue(String envVarName)
    Get the value of the given env variable.
    default float
    getExSizeInPt(String familyName, float size)
    Gives the size of the 'ex' unit, expressed in 'pt' (typographic points) unit.
    default float
    getFontSizeFromIdentifier(String familyName, String fontSizeIdentifier)
    Gets the font size from the given size identifier (small, medium, etc.), expressed in typographic points.
    Gives the initial (default) value for the 'color' property on this device.
    default short
    Gets the identifier of the device's natural unit.
    default String
    Gives the style declaration adequate to provide the given system font.
    Gets the used font family name according to the given style.
    default float
    getWidthSize(String widthIdentifier, float fontSize)
    Gets the size corresponding to the given identifier (thin, thick, medium), in typographic points.
    boolean
    isFontFaceName(String requestedFamily)
    Is requestedFamily an available font family loaded by a font face rule?
    void
    Try to load the font family according to the given font face rule, and make it available to this object.
    void
    setInitialColor(String initialColor)
    Sets the initial (default) value for the 'color' property on this device.
    default boolean
    supports(String property, CSSValue value)
    Does this medium support the given property-value pair?
  • Method Details

    • getInitialColor

      CSSTypedValue getInitialColor()
      Gives the initial (default) value for the 'color' property on this device.
      Returns:
      the default color value.
    • setInitialColor

      void setInitialColor(String initialColor)
      Sets the initial (default) value for the 'color' property on this device.
      Parameters:
      initialColor - the String representing default color value.
    • getDefaultGenericFontFamily

      String getDefaultGenericFontFamily(String genericFamily)
      Gets the name of the default font used when a generic font family (serif, sans-serif, monospace, cursive, fantasy) is specified.
      Parameters:
      genericFamily - the name of the logical font.
      Returns:
      the name of the real font to which the generic name is mapped to, or null if none.
    • getDefaultGenericFontFamily

      default String getDefaultGenericFontFamily()
      Gets the real name of the default font.

      For example, if the default generic font name is 'serif', this method should return the same as getDefaultGenericFontFamily("serif").

      Returns:
      the name of the default real font.
    • getUsedFontFamily

      String getUsedFontFamily(CSSComputedProperties computedStyle)
      Gets the used font family name according to the given style.
      Parameters:
      computedStyle - the computed style.
      Returns:
      the name of the used font family.
    • getFontSizeFromIdentifier

      default float getFontSizeFromIdentifier(String familyName, String fontSizeIdentifier) throws DOMException
      Gets the font size from the given size identifier (small, medium, etc.), expressed in typographic points.
      Parameters:
      familyName - the font family name. Could be null.
      fontSizeIdentifier - the font size identifier.
      Returns:
      the font size.
      Throws:
      DOMException - if the identifier is unknown.
    • getSystemFontDeclaration

      default String getSystemFontDeclaration(String systemFontName)
      Gives the style declaration adequate to provide the given system font.
      Parameters:
      systemFontName - the system font name.
      Returns:
      the style declaration, or null if the system font name was not recognized.
    • isFontFaceName

      boolean isFontFaceName(String requestedFamily)
      Is requestedFamily an available font family loaded by a font face rule?
      Parameters:
      requestedFamily - the font family name in lower case.
      Returns:
      true if is an available font family, false otherwise.
    • loadFontFaceRule

      void loadFontFaceRule(CSSFontFaceRule rule)
      Try to load the font family according to the given font face rule, and make it available to this object.
      Parameters:
      rule - the font face rule.
    • getNaturalUnit

      default short getNaturalUnit()
      Gets the identifier of the device's natural unit.
      Returns:
      the unit identifier as in CSSUnit.
    • getExSizeInPt

      default float getExSizeInPt(String familyName, float size)
      Gives the size of the 'ex' unit, expressed in 'pt' (typographic points) unit.

      Although this type of information really belongs to CSSCanvas, having even an approximate value here is helpful.

      Parameters:
      familyName - the font family name.
      size - the font size in 'pt' units.
      Returns:
      the size of the 'ex' unit, in units of 'pt'.
    • getWidthSize

      default float getWidthSize(String widthIdentifier, float fontSize) throws DOMException
      Gets the size corresponding to the given identifier (thin, thick, medium), in typographic points.
      Parameters:
      widthIdentifier - the CSS width identifier.
      fontSize - the font size used by the box, in typographic points.
      Returns:
      the size.
      Throws:
      DOMException - if the identifier is unknown.
    • getColorDepth

      int getColorDepth()
      Gives the number of bits allocated to colors (excluding the alpha channel) in the output device.

      If the device is not a color device, the value is zero.

      From W3C's Screen interface.

      Returns:
      the number of bits allocated to colors, or zero if the output device does not support colors.
    • getDeviceHeight

      float getDeviceHeight()
      Gets the height of the device, expressed in its natural unit.
      Returns:
      the height of the rendering device.
    • getDeviceWidth

      float getDeviceWidth()
      Gets the width of the device, expressed in its natural unit.
      Returns:
      the width of the rendering device.
    • getEnvValue

      default CSSValue getEnvValue(String envVarName)
      Get the value of the given env variable.
      Parameters:
      envVarName - the env variable name.
      Returns:
      the value, or null if that name has no value set.
    • supports

      default boolean supports(String property, CSSValue value)
      Does this medium support the given property-value pair?
      Parameters:
      property - the property name.
      value - the optional property value to be tested against.
      Returns:
      true if the property (with the given value, if any) is supported, false otherwise.