Class GColor

Method Details

• getColorNames

  public static String[] getColorNames()

  Returns an array copy of all the color names sorted in alphabetical order. To avoid cloning, use the method getColorNamesList() instead.

  Returns:

  A cloned array of the color names.

• getColorNamesList

  public static List<String> getColorNamesList()

  Returns a list of all the color names sorted in alphabetical order.

  Returns:

  An immutable list of color names.

• getRGBColorFromCSS3Name

  public static int getRGBColorFromCSS3Name(String name)

  Gets a color RGB value from a CSS3 color name, WITHOUT the alpha component.

  The returned value is 0x00RRGGBB, in the range 0 to 0xFFFFFF, so the -1 returned for an unknown name cannot be mistaken for a color. The mask is applied even though the backing map holds no alpha today: it makes the contract true by construction rather than by coincidence, so a change to the map cannot silently turn this into an ARGB method.

  Use getARGBColorFromCSS3Name(String) when an opaque ARGB value is wanted. It cannot return an int for the reason this method can: opaque ARGB values occupy the whole 32-bit range, so -1 would be 0xFFFFFFFF, which is opaque white - a real color, and a common one. That is the same collision documented on equals(GColor) for INHERIT.

  Parameters:

  name - The color name, case-insensitive.

  Returns:

  The RGB color value 0 to 0xFFFFFF matching the name, or -1 for none.

  Throws:

  NullPointerException - if name is null.

• getARGBColorFromCSS3Name

  public static long getARGBColorFromCSS3Name(String name)

  Gets an opaque ARGB color value from a CSS3 color name.

  The returned value is 0xFFRRGGBB as a long, which is what every GColor constructor taking an RGB value produces. A long is used deliberately: as an int the natural error value -1 is 0xFFFFFFFF, i.e. opaque white, so no int-returning version of this method can report "not a color name" without also being unable to report white. As a long the color values occupy 0x00000000L to 0xFFFFFFFFL and -1L lies outside that range.

  Parameters:

  name - The color name, case-insensitive.

  Returns:

  The opaque ARGB color value 0xFF000000L to 0xFFFFFFFFL matching the name, or -1L for none.

  Throws:

  NullPointerException - if name is null.

• createGColor

  public static GColor createGColor(String string)

  Creates a GColor from a String. If the string is null or empty, GColor.NONE is returned, otherwise a new GColor as if new GColor(string) was called.

  Parameters:

  string - The string as 0xnnnnnnnn or decimal. It can be null or empty string for GColor.NONE, "inherit" for GColor.INHERIT, or "%" followed by a palette reference for a referenced color (ofRef(String)).

  Throws:

  IllegalArgumentException - for errors in the string specification, including an empty reference after "%".

  NumberFormatException - for invalid number formats.

• parseGColor

  public static GColor parseGColor(String string) throws ParseException

  Parses an HTML color String, such as "#nnn", "#123456", "rgb(r,g,b)", "rgba(r,g,b,a)" or a named color. Named colors are CSS3 names or IIZI palette references starting with "%", which keep their case: a reference is a property path and Brand/Primary is not brand/primary.

  Throws:

  ParseException - If parsing failed.

• ofRef

  public static GColor ofRef(String ref)

  Creates a referenced color: a color that names a palette color instead of holding a value.

  The reference is a property reference string, e.g. MyModule:/style/Brand/Primary, a module-relative /style/Brand/Primary, or a bare role name such as Accent that is resolved against the module's palette and then the platform roles (ColorRoles); see ColorResolver. It is kept exactly as given, case included. Persisted as %<reference> (getString()) and created back by createGColor(String).

  Parameters:

  ref - The reference, never null or blank, without the leading %.

  Returns:

  A new referenced color.

  Throws:

  IllegalArgumentException - If ref is null or blank.

• from

  public static GColor from(ReadTransaction trans)

  Creates a color from a transaction, the wire form appendColor(SendTransaction,GColor) writes: a tag byte, 0 literal, 1 inherit, 2 reference.

  For a reference the name is read and the fallback the sender computed is read and DISCARDED: the receiver holds the reference and resolves it against its own palette. A resolved value is never part of a referenced color.

  Parameters:

  trans - The transaction.

  Returns:

  The color.

  Throws:

  IllegalArgumentException - If the tag byte is not 0, 1 or 2.

• getName

  public String getName()

  Returns the color name.

  Returns:

  The color name is either a CSS3 color name matching the value or a predefined color name, or null if the color is not mapped to a named color. A referenced color has no CSS3 name (its reference is getRef()): the unresolved magenta it reports must not come back as "fuchsia".

• isReference

  public boolean isReference()

  Returns whether this color is a reference to a palette color.

  Returns:

  true for a referenced color (ofRef(String)), false for a literal or inherited color.

• getRef

  public String getRef()

  Gets the palette reference of a referenced color.

  Returns:

  The reference without the leading %, or null for a literal or inherited color.

• appendColor

  public void appendColor(SendTransaction trans)

  Appends the color to a transaction.

  The wire form is a tag byte: 0 literal, then the 32-bit ARGB value; 1 inherit, nothing follows; 2 reference, then the reference name, then the fallback color computed at send time as a literal-or-inherit (a boolean, then the ARGB value when not inherited). The tag replaced a boolean on 2026-09-26 (ruling R16): client and server are always the same build, so there is no version to negotiate, and a separate tag is what makes a third state impossible to confuse with a value.

  A referenced color appended through THIS method has no resolver, so its fallback is the UNRESOLVED magenta and a warning is logged; a holder that can resolve the reference against its tree calls appendColor(SendTransaction,GColor) instead (ColorProp, Color4Prop).

  Parameters:

  trans - The transaction.

• appendColor

  public void appendColor(SendTransaction trans, GColor fallback)

  Appends the color to a transaction, with the fallback a referenced color carries on the wire.

  For a literal or inherited color the fallback is ignored and the form is that of appendColor(SendTransaction). For a referenced color the tag 2 is written, then the reference name, then fallback as a boolean (inherited) and, when not inherited, its ARGB value: the color the client paints until something resolves the name.

  Parameters:

  trans - The transaction.

  fallback - The resolved color to carry as the fallback, a literal or INHERIT; UNRESOLVED when the reference did not resolve.

  Throws:

  IllegalArgumentException - If fallback is itself a referenced color.

  NullPointerException - If fallback is null and this color is a reference.

• equals

  public boolean equals(Object o)

  Checks if two color objects are equal.

  Overrides:

  equals in class Object

• equals

  public boolean equals(GColor color)

  Checks if two color objects are equal.

  The inherited color is equal only to itself: the flag is the discriminator, not the value. INHERIT carries the value -1, which is also the value of opaque white (0xFFFFFFFF), so a comparison that looked only at the value would call the two equal.

  A referenced color is equal only to a color with the same reference, and never to a literal, whatever it currently resolves to: resolution changes with the active scheme at run time and equality must not, or a color used as a map key becomes unfindable after a scheme switch (ruled 2026-09-12, Q12: compare the reference, never what it currently means).

  Parameters:

  color - another color object. If null, the colors are not equal.

  Returns:

  true if equal, false otherwise.

• hashCode

  public int hashCode()

  Hash code.

  The discriminator is mixed in for the same reason equals(GColor) tests it: two colors that are never equal must not hash equally, or they collide in every bucket. The class itself is no longer part of this - the class is final, so it is a constant. A referenced color hashes on its reference alone, as it compares.

  Overrides:

  hashCode in class Object

  Returns:

  Returns the hash code.

• isInherited

  public boolean isInherited()

  Returns whether the color is inherited or not.

  Returns:

  true for CSS "inherit" color, false otherwise.

• isTransparent

  public boolean isTransparent()

  Checks if this color is transparent, or no color is set.

  Returns:

  true if transparent, false otherwise (also false when inherited, and false for a referenced color, which reports its unresolved opaque magenta).

• isOpaque

  public boolean isOpaque()

  Checks if this color is (100%) opaque and not a color by name or not a system color, i.e. is a color of RGB type or ARGB with A=0x00.

  Returns:

  true if fully opaque, false otherwise (also false when inherited).

• getColor

  public int getColor()

  Gets the color value as ARGB.

  Returns:

  The color value, -1 if inherited, UNRESOLVED_ARGB for a referenced color.

• getString

  public String getString()

  Gets the color as a String in the form described below: 0xaarrggbb for a literal, inherit, or %<reference> for a referenced color - the persisted form, read back by createGColor(String).

  Returns:

  the String as described below.

• paramString

  protected String paramString()

  Returns the parameter string representing the state of this event. This string is useful for debugging. Subclasses adds extra information to the string by preceding it with a comma followed by the extra information.

  Returns:

  the parameter string of this event.

• toString

  public String toString()

  Returns a string representation of this class instance and its values.

  Overrides:

  toString in class Object

  Returns:

  a string representation of this class instance.

• getCSSValue

  public String getCSSValue()

  Gets the shortest CSS color string for this color.

  A referenced color returns the CSS of its unresolved magenta, #F0F: this class resolves nothing. The var(--izc-...) a referenced color becomes on the client is the delivery phase's (color.js), and a build-time consumer wants a resolved literal from ColorResolver.

  Returns:

  E.g. #123456 for opaque colors, rgba(r,g,b,a) for (semi-)transparency colors, or "inherit" if inherited.