ColorHelper Class Reference

Helper to manipulate colors. More...

#include <colorhelper.h>

Inheritance diagram for ColorHelper:

Public Types
enum	ShadeRole {   LightShade , MidlightShade , MidShade , DarkShade ,   ShadowShade }
enum	BackgroundRole {   NormalBackground = 0 , AlternateBackground = 1 , ActiveBackground = 2 , LinkBackground = 3 ,   VisitedBackground = 4 , NegativeBackground = 5 , NeutralBackground = 6 , PositiveBackground = 7 }
enum	ForegroundRole {   NormalText = 0 , InactiveText = 1 , ActiveText = 2 , LinkText = 3 ,   VisitedText = 4 , NegativeText = 5 , NeutralText = 6 , PositiveText = 7 }

Public Member Functions
	ColorHelper (QObject *parent=nullptr)
	~ColorHelper () override
Q_INVOKABLE QColor	shade (const QColor &color, ShadeRole role)
Q_INVOKABLE QColor	shade (const QColor &color, ShadeRole role, qreal contrast)
Q_INVOKABLE QColor	multiplyAlpha (const QColor &color, qreal alpha)
Q_INVOKABLE QColor	background (bool active, BackgroundRole role=NormalBackground) const
Q_INVOKABLE QColor	foreground (bool active, ForegroundRole role=NormalText) const
qreal	contrast () const

Properties
qreal	contrast

Detailed Description

Helper to manipulate colors.

Exports a few functions from KColorScheme.

Definition at line 16 of file colorhelper.h.

Member Enumeration Documentation

BackgroundRole

enum ColorHelper::BackgroundRole

This enumeration describes the background color being selected from the given set.

Background colors are suitable for drawing under text, and should never be used to draw text. In combination with one of the overloads of KColorScheme::shade, they may be used to generate colors for drawing frames, bevels, and similar decorations.

Enumerator
NormalBackground	Normal background.
AlternateBackground	Alternate background; for example, for use in lists. This color may be the same as BackgroundNormal, especially in sets other than View and Window.
ActiveBackground	Third color; for example, items which are new, active, requesting attention, etc. Alerting the user that a certain field must be filled out would be a good usage (although NegativeBackground could be used to the same effect, depending on what you are trying to achieve). Unlike ActiveText, this should not be used for mouseover effects.
LinkBackground	Fourth color; corresponds to (unvisited) links. Exactly what this might be used for is somewhat harder to qualify; it might be used for bookmarks, as a 'you can click here' indicator, or to highlight recent content (i.e. in a most-recently-accessed list).
VisitedBackground	Fifth color; corresponds to visited links. This can also be used to indicate "not recent" content, especially when a color is needed to denote content which is "old" or "archival".
NegativeBackground	Sixth color; for example, errors, untrusted content, etc.
NeutralBackground	Seventh color; for example, warnings, secure/encrypted content.
PositiveBackground	Eigth color; for example, success messages, trusted content.

Definition at line 68 of file colorhelper.h.

ForegroundRole

enum ColorHelper::ForegroundRole

This enumeration describes the foreground color being selected from the given set.

Foreground colors are suitable for drawing text or glyphs (such as the symbols on window decoration buttons, assuming a suitable background brush is used), and should never be used to draw backgrounds.

For window decorations, the following is suggested, but not set in stone:

• Maximize - PositiveText
• Minimize - NeutralText
• Close - NegativeText
• WhatsThis - LinkText
• Sticky - ActiveText

Enumerator
NormalText	Normal foreground.
InactiveText	Second color; for example, comments, items which are old, inactive or disabled. Generally used for things that are meant to be "less important". InactiveText is not the same role as NormalText in the inactive state.
ActiveText	Third color; for example items which are new, active, requesting attention, etc. May be used as a hover color for clickable items.
LinkText	Fourth color; use for (unvisited) links. May also be used for other clickable items or content that indicates relationships, items that indicate somewhere the user can visit, etc.
VisitedText	Fifth color; used for (visited) links. As with LinkText, may be used for items that have already been "visited" or accessed. May also be used to indicate "historical" (i.e. "old") items or information, especially if InactiveText is being used in the same context to express something different.
NegativeText	Sixth color; for example, errors, untrusted content, deletions, etc.
NeutralText	Seventh color; for example, warnings, secure/encrypted content.
PositiveText	Eigth color; for example, additions, success messages, trusted content.

Definition at line 138 of file colorhelper.h.

ShadeRole

enum ColorHelper::ShadeRole

This enumeration describes the color shade being selected from the given set.

Color shades are used to draw "3d" elements, such as frames and bevels. They are neither foreground nor background colors. Text should not be painted over a shade, and shades should not be used to draw text.

Enumerator
LightShade	The light color is lighter than dark() or shadow() and contrasts with the base color.
MidlightShade	The midlight color is in between base() and light().
MidShade	The mid color is in between base() and dark().
DarkShade	The dark color is in between mid() and shadow().
ShadowShade	The shadow color is darker than light() or midlight() and contrasts the base color.

Definition at line 34 of file colorhelper.h.

Constructor & Destructor Documentation

ColorHelper()

ColorHelper::ColorHelper ( QObject * parent = nullptr )

explicit

Definition at line 10 of file colorhelper.cpp.

~ColorHelper()

ColorHelper::~ColorHelper ( )

override

Definition at line 15 of file colorhelper.cpp.

Member Function Documentation

background()

QColor ColorHelper::background	(	bool	active,
		ColorHelper::BackgroundRole	role = NormalBackground ) const

Retrieve the requested background brush's color for the active button.

Parameters

active

Whether the active or inactive palette should be used.

Definition at line 41 of file colorhelper.cpp.

contrast()

qreal ColorHelper::contrast

(

)

const

Definition at line 29 of file colorhelper.cpp.

foreground()

QColor ColorHelper::foreground	(	bool	active,
		ColorHelper::ForegroundRole	role = NormalText ) const

Retrieve the requested foreground brush's color for the active button.

Parameters

active

Whether the active or inactive palette should be used.

Definition at line 47 of file colorhelper.cpp.

multiplyAlpha()

QColor ColorHelper::multiplyAlpha	(	const QColor &	color,
		qreal	alpha )

Retrieve the requested shade color, using the specified color as the base color and the specified contrast.

Parameters

contrast

Amount roughly specifying the contrast by which to adjust the base color, between -1.0 and 1.0 (values between 0.0 and 1.0 correspond to the value from KGlobalSettings::contrastF)

Note

Shades are chosen such that all shades would contrast with the base color. This means that if base is very dark, the 'dark' shades will be lighter than the base color, with midlight() == shadow(). Conversely, if the base color is very light, the 'light' shades will be darker than the base color, with light() == mid().

See also

KColorUtils::shade

Definition at line 34 of file colorhelper.cpp.

shade() [1/2]

QColor ColorHelper::shade	(	const QColor &	color,
		ColorHelper::ShadeRole	role )

Retrieve the requested shade color, using the specified color as the base color and the system contrast setting.

Note

Shades are chosen such that all shades would contrast with the base color. This means that if base is very dark, the 'dark' shades will be lighter than the base color, with midlight() == shadow(). Conversely, if the base color is very light, the 'light' shades will be darker than the base color, with light() == mid().

Definition at line 19 of file colorhelper.cpp.

shade() [2/2]

QColor ColorHelper::shade	(	const QColor &	color,
		ColorHelper::ShadeRole	role,
		qreal	contrast )

Definition at line 24 of file colorhelper.cpp.

Property Documentation

contrast

qreal ColorHelper::contrast

read

Same as KGlobalSettings::contrastF.

Definition at line 22 of file colorhelper.h.

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

• src/plugins/kdecorations/aurorae/src/colorhelper.h
• src/plugins/kdecorations/aurorae/src/colorhelper.cpp