SystemPalette

Remarks

A mutable object rather than a value, and that is the whole point of it. A sheet that writes color: CanvasText is asking a question whose answer changes while the application runs — the user switches to dark, turns high contrast on, picks a different accent — and StyleEngine.SetMedia deliberately does not reload sheets when that happens. So the substitution cannot be baked into the parsed value at load time; the parsed value has to be able to come out different tomorrow from the same interned text.

⚠ Revision is how a cache knows, and it is a counter rather than an event for a reason. StyleValueParser caches a parse per interned value id and is created in eight places in this repository; wiring a change notification to each would have meant eight subscriptions to unsubscribe. A counter compared on the way into the cache costs one integer compare per parse and cannot leak.

⚠ Values are linear, like every other StyleValue colour, and the factories below therefore write sRGB bytes and convert. Handing this class an sRGB Color4 produces a palette that is visibly too bright and nothing will say so — see ToLinear.

Fields and properties (6)

• public const string PlatformAccentClass

  The class a document wears while a platform accent is filling AccentColor.

• public int Revision

  How many times any entry has changed.

• public Color4 this[SystemColor colour]

  Reads one role.

• public static ReadOnlySpan<uint> Light

  The light defaults, as sRGB bytes.

• public static ReadOnlySpan<uint> Dark

  The dark defaults, as sRGB bytes.

• public static ReadOnlySpan<uint> HighContrast

  The forced-colours defaults, as sRGB bytes.

Methods (9)

• public SystemPalette()

  Creates a palette holding the light defaults.

• public static bool TryParse(ReadOnlySpan<char> name, out SystemColor colour)

  Looks a CSS system colour keyword up.

• public static string NameOf(SystemColor colour)

  The keyword a role is spelt with.

• public bool Set(SystemColor colour, Color4 value)

  Sets one role, until the next Reset.

• public bool SetPlatform(SystemColor colour, Color4 value)

  Fills one role from what the operating system says it is.

• public bool ClearPlatform(SystemColor colour)

  Gives one role back to the default tables.

• public bool ClearPlatform()

  Gives every role back to the default tables.

• public bool IsFromPlatform(SystemColor colour)

  Whether one role is being filled by the platform rather than by a default table.

• public bool Reset(ReadOnlySpan<uint> srgb)

  Replaces every role at once, from a table of sRGB bytes.

Used by (8)

• DrawListBuilderVixen.Ui
• ForcedColorsTestsVixen.Ui.Tests
• PlatformInputVixen.Platform.Ui
• StyleSheetLoaderVixen.Ui.Styling
• StyleValueParserVixen.Ui.Styling
• SystemPaletteWiringTestsVixen.Platform.Ui.Tests
• ThemeAccentTokenTestsVixen.Ui.Controls.Tests
• UiDocumentVixen.Ui