ColorMath Class Reference

#include <color_math.h>

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 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	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)

Detailed Description

Pure color-math helpers, independent of the running app's theme or palette.

Every method is static and side-effect-free except contrastingText(QColor) which — when the surface has alpha — asks ThemeManager for the current app mode to pick a fallback backdrop. That coupling is deliberate: the caller wants "the right foreground for this translucent surface as rendered right now", which is a theme-runtime question.

Member Function Documentation

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 blue header gradient) 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 %, gradient 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, header-gradient end against the 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).

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.

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.

relativeLuminance()

double ColorMath::relativeLuminance ( const QColor & color )

static

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

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.

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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