#include <color_math.h>

Classes
struct	ContrastRatios
struct	TextOnFill

Static Public Member Functions
static double	relativeLuminance (const QColor &color)
static qreal	contrastRatio (const QColor &color1, const QColor &color2)
static QColor	ensureContrast (const QColor &c, const QColor &bg, qreal minRatio)
static bool	isDark (const QColor &color)
static constexpr ContrastRatios	ratiosFor (ThemeContrast level)
static const ContrastRatios &	activeRatios ()
static void	setActiveContrast (ThemeContrast level)
static TextOnFill	readableOnFill (const QColor &text, const QColor &fill, qreal minRatio)
static QColor	readableFill (const QColor &fill, const ContrastRatios &ratios=activeRatios())
static TextOnFill	selectionHover (const QColor &base, const QColor &selection, const QColor &text, const ContrastRatios &ratios=activeRatios())
static QColor	selectionHoverFill (const QColor &base, const QColor &selection, const ContrastRatios &ratios=activeRatios())
static QColor	readableText (const QColor &text, const QColor &surface, const ContrastRatios &ratios=activeRatios())
static bool	isReadable (const QColor &text, const QColor &surface, const ContrastRatios &ratios=activeRatios())
static QColor	mix (const QColor &a, const QColor &b, qreal ratio=0.5)
static ThemeColorPair	mix (const ThemeColorPair &a, const ThemeColorPair &b, qreal ratio=0.5)
static QColor	darken (const QColor &c, int percent)
static ThemeColorPair	darken (const ThemeColorPair &p, int percent)
static QColor	lighten (const QColor &c, int percent)
static ThemeColorPair	lighten (const ThemeColorPair &p, int percent)
static QColor	withAlpha (const QColor &c, int alpha)
static ThemeColorPair	withAlpha (const ThemeColorPair &p, int alpha)
static QColor	withAlphaF (const QColor &c, qreal alpha)
static ThemeColorPair	withAlphaF (const ThemeColorPair &p, qreal alpha)
static QColor	contrastingText (const QColor &surface)
static ThemeColorPair	contrastingText (const ThemeColorPair &pair)
static QColor	compositeOver (const QColor &surface, const QColor &backdrop)
static QColor	contrastingTextOver (const QColor &surface, const QColor &backdrop)
static QColor	disabled (const QColor &c, const QColor &background)
static ThemeColorPair	disabled (const ThemeColorPair &p, const QColor &background)
static QColor	hoverBg (const QColor &c, const QColor &background)
static ThemeColorPair	hoverBg (const ThemeColorPair &p, const QColor &background)
static QColor	hoverEmphasis (const QColor &c)

Detailed Description

Pure color-math helpers, with two deliberate couplings to the running theme:

contrastingText(QColor), when the surface has alpha, asks ThemeManager for the current app mode to pick a fallback backdrop. The caller wants "the right foreground for this translucent surface as rendered right now", which is a theme-runtime question.
The active contrast ratio set. setActiveContrast() changes it (process-global, GUI thread; ThemeManager sets it before each apply), and activeRatios() and every default ratios argument read it, so runtime consumers follow the applied level. Code that may derive for another level (ThemeTokenHandler::deriveAll(), ThemePaletteBuilder::build(), theme previews) passes a set explicitly.

Every other method is static and side-effect-free.

Member Function Documentation

◆ activeRatios()

const ColorMath::ContrastRatios & ColorMath::activeRatios ( )

static

The ratio set of the applied contrast level (Standard until setActiveContrast() is called). GUI thread only.

◆ compositeOver()

QColor ColorMath::compositeOver	(	const QColor &	surface,
		const QColor &	backdrop )

static

surface composited over the opaque backdrop with the "over" operator; an opaque surface is returned unchanged.

◆ contrastingText()

QColor ColorMath::contrastingText ( const QColor & surface )

static

Returns Qt::black or Qt::white — whichever reads better on the given surface color. If the surface is translucent, picks the app's current dark/light mode as the backdrop.

◆ contrastingTextOver()

QColor ColorMath::contrastingTextOver	(	const QColor &	surface,
		const QColor &	backdrop )

static

Same as contrastingText(), but with the caller supplying the backdrop explicitly — useful when rendering onto a known surface (e.g. the welcome header bar) rather than the app palette.

◆ contrastRatio()

qreal ColorMath::contrastRatio	(	const QColor &	color1,
		const QColor &	color2 )

static

WCAG contrast ratio between two opaque colors. Higher values are more contrasty; 4.5 is the AA threshold for body text.

◆ darken()

QColor ColorMath::darken	(	const QColor &	c,
		int	percent )

static

Mix the given color with black at percent %. Hover typically 8-12 %, pressed 16-20 %, bar backdrop 50-65 %.

◆ disabled()

QColor ColorMath::disabled	(	const QColor &	c,
		const QColor &	background )

static

Standard "disabled" fade: mix(color, background, 0.4).

◆ ensureContrast()

QColor ColorMath::ensureContrast	(	const QColor &	c,
		const QColor &	bg,
		qreal	minRatio )

static

Mix c toward contrastingText(bg) until contrastRatio(result, bg) >= minRatio. Binary-searches the mix ratio (24 iterations → < 0.001 precision). Used to enforce WCAG contrast on derived tokens (section headers against the base, the welcome header against its title text) without forcing every theme author to hand-pick the values. When c already meets the target it is returned unchanged. If the math can't reach the target (rare; only when c is already on the same luminance side as contrastingText(bg) and saturated), returns contrastingText(bg) directly — favoring readability over hue.

◆ hoverBg()

QColor ColorMath::hoverBg	(	const QColor &	c,
		const QColor &	background )

static

Subtle hover tint: mix(color, background, 0.1).

◆ hoverEmphasis()

QColor ColorMath::hoverEmphasis ( const QColor & c )

static

Hover colour of an icon glyph whose icon names no explicit hover colour: c.lighter(HoverEmphasisFactor), a slight brightening with the hue kept. Shared by the theme icon engines so every glyph lights up alike.

◆ isDark()

bool ColorMath::isDark ( const QColor & color )

static

Returns true if the given color's relative luminance is below the WCAG equal-contrast threshold (≈0.179). Purely a color- math helper; independent of the running app's theme.

◆ isReadable()

bool ColorMath::isReadable	(	const QColor &	text,
		const QColor &	surface,
		const ContrastRatios &	ratios = activeRatios() )

static

True when text already reaches the set's readableText ratio against surface, i.e. readableText() would return it unchanged.

◆ lighten()

QColor ColorMath::lighten	(	const QColor &	c,
		int	percent )

static

Mix the given color with white at percent %. Used for text on dark surfaces (30-70 %).

◆ mix()

QColor ColorMath::mix	(	const QColor &	a,
		const QColor &	b,
		qreal	ratio = 0.5 )

static

Linear blend of two colors at ratio r. r=0 returns a, r=1 returns b. Alpha-aware.

◆ ratiosFor()

constexpr ContrastRatios ColorMath::ratiosFor ( ThemeContrast level )

inlinestaticconstexpr

The ratio set for a contrast level.

◆ readableFill()

QColor ColorMath::readableFill	(	const QColor &	fill,
		const ContrastRatios &	ratios = activeRatios() )

static

fill unchanged when its contrastingText() reads on it at the set's readableText ratio, else moved away from that text until it does.

◆ readableOnFill()

ColorMath::TextOnFill ColorMath::readableOnFill	(	const QColor &	text,
		const QColor &	fill,
		qreal	minRatio )

static

text lifted to minRatio against fill; when it cannot get there, fill moves away from the lifted text until the pair reads at minRatio.

◆ readableText()

QColor ColorMath::readableText	(	const QColor &	text,
		const QColor &	surface,
		const ContrastRatios &	ratios = activeRatios() )

static

text lifted to the set's readableText ratio against surface; returned unchanged when it already reads.

◆ relativeLuminance()

double ColorMath::relativeLuminance ( const QColor & color )

static

WCAG relative luminance in the [0, 1] range.

◆ selectionHover()

ColorMath::TextOnFill ColorMath::selectionHover	(	const QColor &	base,
		const QColor &	selection,
		const QColor &	text,
		const ContrastRatios &	ratios = activeRatios() )

static

Hover fill and text for an item view: the fill is selectionHoverFill(), the text text made readable on it. In High the fill moves toward readability of text as long as it stays distinct from selection.

◆ selectionHoverFill()

QColor ColorMath::selectionHoverFill	(	const QColor &	base,
		const QColor &	selection,
		const ContrastRatios &	ratios = activeRatios() )

static

Hover fill for an item view, derived from that view's own selection color so the view uses one highlight hue. A 55 % tint of selection over base, pushed away from selection until the two are the set's distinctSurface ratio apart, so a hovered row never reads as a second selection. Dark selections sit too close to the base for any in-between tint to be distinct from both, so in dark schemes the fill ends up lighter than the selection.

◆ setActiveContrast()

void ColorMath::setActiveContrast ( ThemeContrast level )

static

Make the ratio set of level the active one. Called by ThemeManager before it derives the palette and tokens.

◆ withAlpha()

QColor ColorMath::withAlpha	(	const QColor &	c,
		int	alpha )

static

Set the alpha channel to an integer 0-255.

◆ withAlphaF()

QColor ColorMath::withAlphaF	(	const QColor &	c,
		qreal	alpha )

static

Set the alpha channel to a float 0.0-1.0.

The documentation for this class was generated from the following files:

/builds/wireshark/wireshark/ui/qt/utils/themes/color_math.h
/builds/wireshark/wireshark/ui/qt/utils/themes/color_math.cpp

Classes

Static Public Member Functions

Detailed Description

Member Function Documentation

◆ activeRatios()

◆ compositeOver()

◆ contrastingText()

◆ contrastingTextOver()

◆ contrastRatio()

◆ darken()

◆ disabled()

◆ ensureContrast()

◆ hoverBg()

◆ hoverEmphasis()

◆ isDark()

◆ isReadable()

◆ lighten()

◆ mix()

◆ ratiosFor()

◆ readableFill()

◆ readableOnFill()

◆ readableText()

◆ relativeLuminance()

◆ selectionHover()

◆ selectionHoverFill()

◆ setActiveContrast()

◆ withAlpha()

◆ withAlphaF()