QPalette Class
The QPalette class contains color groups for each widget state. More...
| Header: | #include <QPalette> |
| qmake: | QT += gui |
Public Types
| enum | ColorGroup { Disabled, Active, Inactive, Normal } |
| enum | ColorRole { Window, Background, WindowText, Foreground, Base, …, NoRole } |
Public Functions
| QPalette(QPalette &&other) | |
| QPalette(const QPalette &p) | |
| QPalette(const QBrush &windowText, const QBrush &button, const QBrush &light, const QBrush &dark, const QBrush &mid, const QBrush &text, const QBrush &bright_text, const QBrush &base, const QBrush &window) | |
| QPalette(const QColor &button, const QColor &window) | |
| QPalette(Qt::GlobalColor button) | |
| QPalette(const QColor &button) | |
| QPalette() | |
| QPalette & | operator=(QPalette &&other) |
| QPalette & | operator=(const QPalette &p) |
| ~QPalette() | |
| const QBrush & | alternateBase() const |
| const QBrush & | base() const |
| const QBrush & | brightText() const |
| const QBrush & | brush(ColorGroup group, ColorRole role) const |
| const QBrush & | brush(ColorRole role) const |
| const QBrush & | button() const |
| const QBrush & | buttonText() const |
| qint64 | cacheKey() const |
| const QColor & | color(ColorGroup group, ColorRole role) const |
| const QColor & | color(ColorRole role) const |
| ColorGroup | currentColorGroup() const |
| const QBrush & | dark() const |
| const QBrush & | highlight() const |
| const QBrush & | highlightedText() const |
| bool | isBrushSet(ColorGroup cg, ColorRole cr) const |
| bool | isCopyOf(const QPalette &p) const |
| bool | isEqual(ColorGroup cg1, ColorGroup cg2) const |
| const QBrush & | light() const |
| const QBrush & | link() const |
| const QBrush & | linkVisited() const |
| const QBrush & | mid() const |
| const QBrush & | midlight() const |
| const QBrush & | placeholderText() const |
| QPalette | resolve(const QPalette &other) const |
| void | setBrush(ColorRole role, const QBrush &brush) |
| void | setBrush(ColorGroup group, ColorRole role, const QBrush &brush) |
| void | setColor(ColorGroup group, ColorRole role, const QColor &color) |
| void | setColor(ColorRole role, const QColor &color) |
| void | setColorGroup(ColorGroup cg, const QBrush &windowText, const QBrush &button, const QBrush &light, const QBrush &dark, const QBrush &mid, const QBrush &text, const QBrush &bright_text, const QBrush &base, const QBrush &window) |
| void | setCurrentColorGroup(ColorGroup cg) |
| const QBrush & | shadow() const |
| void | swap(QPalette &other) |
| const QBrush & | text() const |
| const QBrush & | toolTipBase() const |
| const QBrush & | toolTipText() const |
| const QBrush & | window() const |
| const QBrush & | windowText() const |
| QVariant | operator QVariant() const |
| bool | operator!=(const QPalette &p) const |
| bool | operator==(const QPalette &p) const |
Related Non-Members
| QDataStream & | operator<<(QDataStream &s, const QPalette &p) |
| QDataStream & | operator>>(QDataStream &s, QPalette &p) |
Detailed Description
A palette consists of three color groups: Active, Disabled, and Inactive. All widgets in Qt contain a palette and use their palette to draw themselves. This makes the user interface easily configurable and easier to keep consistent.
If you create a new widget we strongly recommend that you use the colors in the palette rather than hard-coding specific colors.
The color groups:
- The Active group is used for the window that has keyboard focus.
- The Inactive group is used for other windows.
- The Disabled group is used for widgets (not windows) that are disabled for some reason.
Both active and inactive windows can contain disabled widgets. (Disabled widgets are often called inaccessible or grayed out.)
In most styles, Active and Inactive look the same.
Colors and brushes can be set for particular roles in any of a palette's color groups with setColor() and setBrush(). A color group contains a group of colors used by widgets for drawing themselves. We recommend that widgets use color group roles from the palette such as "foreground" and "base" rather than literal colors like "red" or "turquoise". The color roles are enumerated and defined in the ColorRole documentation.
We strongly recommend that you use the default palette of the current style (returned by QGuiApplication::palette()) and modify that as necessary. This is done by Qt's widgets when they are drawn.
To modify a color group you call the functions setColor() and setBrush(), depending on whether you want a pure color or a pixmap pattern.
There are also corresponding color() and brush() getters, and a commonly used convenience function to get the ColorRole for the current ColorGroup: window(), windowText(), base(), etc.
You can copy a palette using the copy constructor and test to see if two palettes are identical using isCopyOf().
QPalette is optimized by the use of implicit sharing, so it is very efficient to pass QPalette objects as arguments.
Warning: Some styles do not use the palette for all drawing, for instance, if they make use of native theme engines. This is the case for both the Windows Vista and the macOS styles.
See also QApplication::setPalette(), QWidget::setPalette(), and QColor.
Member Type Documentation
enum QPalette::ColorGroup
| Constant | Value | Description |
|---|---|---|
QPalette::Disabled | 1 | |
QPalette::Active | 0 | |
QPalette::Inactive | 2 | |
QPalette::Normal | Active | synonym for Active |
enum QPalette::ColorRole
The ColorRole enum defines the different symbolic color roles used in current GUIs.
The central roles are:
| Constant | Value | Description |
|---|---|---|
QPalette::Window | 10 | A general background color. |
QPalette::Background | Window | This value is obsolete. Use Window instead. |
QPalette::WindowText | 0 | A general foreground color. |
QPalette::Foreground | WindowText | This value is obsolete. Use WindowText instead. |
QPalette::Base | 9 | Used mostly as the background color for text entry widgets, but can also be used for other painting - such as the background of combobox drop down lists and toolbar handles. It is usually white or another light color. |
QPalette::AlternateBase | 16 | Used as the alternate background color in views with alternating row colors (see QAbstractItemView::setAlternatingRowColors()). |
QPalette::ToolTipBase | 18 | Used as the background color for QToolTip and QWhatsThis. Tool tips use the Inactive color group of QPalette, because tool tips are not active windows. |
QPalette::ToolTipText | 19 | Used as the foreground color for QToolTip and QWhatsThis. Tool tips use the Inactive color group of QPalette, because tool tips are not active windows. |
QPalette::PlaceholderText | 20 | Used as the placeholder color for various text input widgets. This enum value has been introduced in Qt 5.12 |
QPalette::Text | 6 | The foreground color used with Base. This is usually the same as the WindowText, in which case it must provide good contrast with Window and Base. |
QPalette::Button | 1 | The general button background color. This background can be different from Window as some styles require a different background color for buttons. |
QPalette::ButtonText | 8 | A foreground color used with the Button color. |
QPalette::BrightText | 7 | A text color that is very different from WindowText, and contrasts well with e.g. Dark. Typically used for text that needs to be drawn where Text or WindowText would give poor contrast, such as on pressed push buttons. Note that text colors can be used for things other than just words; text colors are usually used for text, but it's quite common to use the text color roles for lines, icons, etc. |
There are some color roles used mostly for 3D bevel and shadow effects. All of these are normally derived from Window, and used in ways that depend on that relationship. For example, buttons depend on it to make the bevels look attractive, and Motif scroll bars depend on Mid to be slightly different from Window.
| Constant | Value | Description |
|---|---|---|
QPalette::Light | 2 | Lighter than Button color. |
QPalette::Midlight | 3 | Between Button and Light. |
QPalette::Dark | 4 | Darker than Button. |
QPalette::Mid | 5 | Between Button and Dark. |
QPalette::Shadow | 11 | A very dark color. By default, the shadow color is Qt::black. |
Selected (marked) items have two roles:
| Constant | Value | Description |
|---|---|---|
QPalette::Highlight | 12 | A color to indicate a selected item or the current item. By default, the highlight color is Qt::darkBlue. |
QPalette::HighlightedText | 13 | A text color that contrasts with Highlight. By default, the highlighted text color is Qt::white. |
There are two color roles related to hyperlinks:
| Constant | Value | Description |
|---|---|---|
QPalette::Link | 14 | A text color used for unvisited hyperlinks. By default, the link color is Qt::blue. |
QPalette::LinkVisited | 15 | A text color used for already visited hyperlinks. By default, the linkvisited color is Qt::magenta. |
Note that we do not use the Link and LinkVisited roles when rendering rich text in Qt, and that we recommend that you use CSS and the QTextDocument::setDefaultStyleSheet() function to alter the appearance of links. For example:
QTextBrowser browser;
QColor linkColor(Qt::red);
QString sheet = QString::fromLatin1("a { text-decoration: underline; color: %1 }").arg(linkColor.name());
browser.document()->setDefaultStyleSheet(sheet);
| Constant | Value | Description |
|---|---|---|
QPalette::NoRole | 17 | No role; this special role is often used to indicate that a role has not been assigned. |
Member Function Documentation
QPalette::QPalette(QPalette &&other)
Move-constructs a QPalette instance, making it point at the same object that other was pointing to.
After being moved from, you can only assign to or destroy other. Any other operation will result in undefined behavior.
This function was introduced in Qt 5.4.
QPalette::QPalette(const QPalette &p)
Constructs a copy of p.
This constructor is fast thanks to implicit sharing.
QPalette::QPalette(const QBrush &windowText, const QBrush &button, const QBrush &light, const QBrush &dark, const QBrush &mid, const QBrush &text, const QBrush &bright_text, const QBrush &base, const QBrush &window)
Constructs a palette. You can pass either brushes, pixmaps or plain colors for windowText, button, light, dark, mid, text, bright_text, base and window.
See also QBrush.
QPalette::QPalette(const QColor &button, const QColor &window)
Constructs a palette from a button color and a window. The other colors are automatically calculated, based on these colors.
QPalette::QPalette(Qt::GlobalColor button)
Constructs a palette from the button color. The other colors are automatically calculated, based on this color. Window will be the button color as well.
QPalette::QPalette(const QColor &button)
Constructs a palette from the button color. The other colors are automatically calculated, based on this color. Window will be the button color as well.
QPalette::QPalette()
Constructs an empty palette object with no color roles set.
When used as the palette of a QWidget the colors are resolved as described by QWidget::setPalette().
See also QApplication::setPalette() and QApplication::palette().
QPalette &QPalette::operator=(QPalette &&other)
Move-assigns other to this QPalette instance.
This function was introduced in Qt 5.2.
QPalette &QPalette::operator=(const QPalette &p)
Assigns p to this palette and returns a reference to this palette.
This operation is fast thanks to implicit sharing.
QPalette::~QPalette()
Destroys the palette.
const QBrush &QPalette::alternateBase() const
Returns the alternate base brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::base() const
Returns the base brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::brightText() const
Returns the bright text foreground brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::brush(ColorGroup group, ColorRole role) const
Returns the brush in the specified color group, used for the given color role.
See also color(), setBrush(), and ColorRole.
const QBrush &QPalette::brush(ColorRole role) const
This is an overloaded function.
Returns the brush that has been set for the given color role in the current ColorGroup.
See also color(), setBrush(), and ColorRole.
const QBrush &QPalette::button() const
Returns the button brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::buttonText() const
Returns the button text foreground brush of the current color group.
See also ColorRole and brush().
qint64 QPalette::cacheKey() const
Returns a number that identifies the contents of this QPalette object. Distinct QPalette objects can have the same key if they refer to the same contents.
The cacheKey() will change when the palette is altered.
const QColor &QPalette::color(ColorGroup group, ColorRole role) const
Returns the color in the specified color group, used for the given color role.
See also brush(), setColor(), and ColorRole.
const QColor &QPalette::color(ColorRole role) const
This is an overloaded function.
Returns the color that has been set for the given color role in the current ColorGroup.
See also brush() and ColorRole.
ColorGroup QPalette::currentColorGroup() const
Returns the palette's current color group.
See also setCurrentColorGroup().
const QBrush &QPalette::dark() const
Returns the dark brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::highlight() const
Returns the highlight brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::highlightedText() const
Returns the highlighted text brush of the current color group.
See also ColorRole and brush().
bool QPalette::isBrushSet(ColorGroup cg, ColorRole cr) const
Returns true if the ColorGroup cg and ColorRole cr has been set previously on this palette; otherwise returns false.
This function was introduced in Qt 4.2.
See also setBrush().
bool QPalette::isCopyOf(const QPalette &p) const
Returns true if this palette and p are copies of each other, i.e. one of them was created as a copy of the other and neither was subsequently modified; otherwise returns false. This is much stricter than equality.
See also operator=() and operator==().
bool QPalette::isEqual(ColorGroup cg1, ColorGroup cg2) const
Returns true (usually quickly) if color group cg1 is equal to cg2; otherwise returns false.
const QBrush &QPalette::light() const
Returns the light brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::link() const
Returns the unvisited link text brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::linkVisited() const
Returns the visited link text brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::mid() const
Returns the mid brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::midlight() const
Returns the midlight brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::placeholderText() const
Returns the placeholder text brush of the current color group.
Note: Before Qt 5.12, the placeholder text color was hard-coded in the code as QPalette::text().color() where an alpha of 128 was applied. We continue to support this behavior by default, unless you set your own brush. One can get back the original placeholder color setting the special QBrush default constructor as placeholder brush.
This function was introduced in Qt 5.12.
See also ColorRole and brush().
QPalette QPalette::resolve(const QPalette &other) const
Returns a new QPalette that is a union of this instance and other. Color roles set in this instance take precedence.
void QPalette::setBrush(ColorRole role, const QBrush &brush)
Sets the brush for the given color role to the specified brush for all groups in the palette.
See also brush(), setColor(), and ColorRole.
void QPalette::setBrush(ColorGroup group, ColorRole role, const QBrush &brush)
This is an overloaded function.
Sets the brush in the specified color group, used for the given color role, to brush.
See also brush(), setColor(), and ColorRole.
void QPalette::setColor(ColorGroup group, ColorRole role, const QColor &color)
Sets the color in the specified color group, used for the given color role, to the specified solid color.
See also setBrush(), color(), and ColorRole.
void QPalette::setColor(ColorRole role, const QColor &color)
This is an overloaded function.
Sets the color used for the given color role, in all color groups, to the specified solid color.
See also brush(), setColor(), and ColorRole.
void QPalette::setColorGroup(ColorGroup cg, const QBrush &windowText, const QBrush &button, const QBrush &light, const QBrush &dark, const QBrush &mid, const QBrush &text, const QBrush &bright_text, const QBrush &base, const QBrush &window)
Sets a the group at cg. You can pass either brushes, pixmaps or plain colors for windowText, button, light, dark, mid, text, bright_text, base and window.
See also QBrush.
void QPalette::setCurrentColorGroup(ColorGroup cg)
Set the palette's current color group to cg.
See also currentColorGroup().
const QBrush &QPalette::shadow() const
Returns the shadow brush of the current color group.
See also ColorRole and brush().
void QPalette::swap(QPalette &other)
Swaps this palette instance with other. This function is very fast and never fails.
This function was introduced in Qt 5.0.
const QBrush &QPalette::text() const
Returns the text foreground brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::toolTipBase() const
Returns the tool tip base brush of the current color group. This brush is used by QToolTip and QWhatsThis.
Note: Tool tips use the Inactive color group of QPalette, because tool tips are not active windows.
This function was introduced in Qt 4.4.
See also ColorRole and brush().
const QBrush &QPalette::toolTipText() const
Returns the tool tip text brush of the current color group. This brush is used by QToolTip and QWhatsThis.
Note: Tool tips use the Inactive color group of QPalette, because tool tips are not active windows.
This function was introduced in Qt 4.4.
See also ColorRole and brush().
const QBrush &QPalette::window() const
Returns the window (general background) brush of the current color group.
See also ColorRole and brush().
const QBrush &QPalette::windowText() const
Returns the window text (general foreground) brush of the current color group.
See also ColorRole and brush().
QVariant QPalette::operator QVariant() const
Returns the palette as a QVariant
bool QPalette::operator!=(const QPalette &p) const
Returns true (slowly) if this palette is different from p; otherwise returns false (usually quickly).
Note: The current ColorGroup is not taken into account when comparing palettes
See also operator==().
bool QPalette::operator==(const QPalette &p) const
Returns true (usually quickly) if this palette is equal to p; otherwise returns false (slowly).
Note: The current ColorGroup is not taken into account when comparing palettes
See also operator!=().
Related Non-Members
QDataStream &operator<<(QDataStream &s, const QPalette &p)
Writes the palette, p to the stream s and returns a reference to the stream.
See also Format of the QDataStream operators.
QDataStream &operator>>(QDataStream &s, QPalette &p)
Reads a palette from the stream, s into the palette p, and returns a reference to the stream.
See also Format of the QDataStream operators.