The QGradient class is used in combination with QBrush to specify gradient fills. More...
#include <qbrush.h>
Classes | |
| union | QGradientData |
Public Member Functions | |
| QGradient () | |
| QGradient (Preset) | |
| ~QGradient () | |
| Type | type () const |
| void | setSpread (Spread spread) |
| Spread | spread () const |
| void | setColorAt (qreal pos, const QColor &color) |
| void | setStops (const QGradientStops &stops) |
| QGradientStops | stops () const |
| CoordinateMode | coordinateMode () const |
| void | setCoordinateMode (CoordinateMode mode) |
| InterpolationMode | interpolationMode () const |
| void | setInterpolationMode (InterpolationMode mode) |
| bool | operator== (const QGradient &gradient) const |
| bool | operator!= (const QGradient &other) const |
Friends | |
| class | QLinearGradient |
| class | QRadialGradient |
| class | QConicalGradient |
| class | QBrush |
Related Functions | |
(Note that these are not member functions.) | |
| QGradientStop | |
| QGradientStops | |
Detailed Description
The QGradient class is used in combination with QBrush to specify gradient fills.
\inmodule QtGui
Qt currently supports three types of gradient fills:
\list
- Linear gradients interpolate colors between start and end points.
- Simple radial gradients interpolate colors between a focal point and end points on a circle surrounding it.
- Extended radial gradients interpolate colors between a center and a focal circle.
- Conical gradients interpolate colors around a center point. \endlist
A gradient's type can be retrieved using the type() function. Each of the types is represented by a subclass of QGradient:
\table \header
- QLinearGradient
- QRadialGradient
- QConicalGradient \row
- \inlineimage qgradient-linear.png
- \inlineimage qgradient-radial.png
- \inlineimage qgradient-conical.png \endtable
The colors in a gradient are defined using stop points of the QGradientStop type; i.e., a position and a color. Use the setColorAt() function to define a single stop point. Alternatively, use the setStops() function to define several stop points in one go. Note that the latter function replaces the current set of stop points.
It is the gradient's complete set of stop points (accessible through the stops() function) that describes how the gradient area should be filled. If no stop points have been specified, a gradient of black at 0 to white at 1 is used.
A diagonal linear gradient from black at (100, 100) to white at (200, 200) could be specified like this:
A gradient can have an arbitrary number of stop points. The following would create a radial gradient starting with red in the center, blue and then green on the edges:
It is possible to repeat or reflect the gradient outside its area by specifying the \l {QGradient::Spread}{spread method} using the setSpread() function. The default is to pad the outside area with the color at the closest stop point. The currently set \l {QGradient::Spread}{spread method} can be retrieved using the spread() function. The QGradient::Spread enum defines three different methods:
\table \row
- \inlineimage qradialgradient-pad.png
- \inlineimage qradialgradient-repeat.png
- \inlineimage qradialgradient-reflect.png \row
- \l {QGradient::PadSpread}{PadSpread}
- \l {QGradient::RepeatSpread}{RepeatSpread}
- \l {QGradient::ReflectSpread}{ReflectSpread} \endtable
Note that the setSpread() function only has effect for linear and radial gradients. The reason is that the conical gradient is closed by definition, i.e. the conical gradient fills the entire circle from 0 - 360 degrees, while the boundary of a radial or a linear gradient can be specified through its radius or final stop points, respectively.
The gradient coordinates can be specified in logical coordinates, relative to device coordinates, or relative to object bounding box coordinates. The \l {QGradient::CoordinateMode}{coordinate mode} can be set using the setCoordinateMode() function. The default is LogicalMode, where the gradient coordinates are specified in the same way as the object coordinates. To retrieve the currently set \l {QGradient::CoordinateMode} {coordinate mode} use coordinateMode().
- See also
- {painting/gradients}{The Gradients Example}, QBrush
Member Enumeration Documentation
◆ CoordinateMode
- Since
- 4.4
This enum specifies how gradient coordinates map to the paint device on which the gradient is used.
\value LogicalMode This is the default mode. The gradient coordinates are specified logical space just like the object coordinates. \value ObjectMode In this mode the gradient coordinates are relative to the bounding rectangle of the object being drawn, with (0,0) in the top left corner, and (1,1) in the bottom right corner of the object's bounding rectangle. This value was added in Qt 5.12. \value StretchToDeviceMode In this mode the gradient coordinates are relative to the bounding rectangle of the paint device, with (0,0) in the top left corner, and (1,1) in the bottom right corner of the paint device. \value ObjectBoundingMode This mode is the same as ObjectMode, except that the {QBrush::transform()} {brush transform}, if any, is applied relative to the logical space instead of the object space. This enum value is deprecated and should not be used in new code.
| Enumerator | |
|---|---|
| LogicalMode | |
| StretchToDeviceMode | |
| ObjectBoundingMode | |
| ObjectMode | |
◆ InterpolationMode
◆ Preset
| enum QGradient::Preset |
- Since
- 5.12
This enum specifies a set of predefined presets for QGradient, based on the gradients from \l {https://webgradients.com/}.
\value WarmFlame \value NightFade \value SpringWarmth \value JuicyPeach \value YoungPassion \value LadyLips \value SunnyMorning \value RainyAshville \value FrozenDreams \value WinterNeva \value DustyGrass \value TemptingAzure \value HeavyRain \value AmyCrisp \value MeanFruit \value DeepBlue \value RipeMalinka \value CloudyKnoxville \value MalibuBeach \value NewLife \value TrueSunset \value MorpheusDen \value RareWind \value NearMoon \value WildApple \value SaintPetersburg \value PlumPlate \value EverlastingSky \value HappyFisher \value Blessing \value SharpeyeEagle \value LadogaBottom \value LemonGate \value ItmeoBranding \value ZeusMiracle \value OldHat \value StarWine \value HappyAcid \value AwesomePine \value NewYork \value ShyRainbow \value MixedHopes \value FlyHigh \value StrongBliss \value FreshMilk \value SnowAgain \value FebruaryInk \value KindSteel \value SoftGrass \value GrownEarly \value SharpBlues \value ShadyWater \value DirtyBeauty \value GreatWhale \value TeenNotebook \value PoliteRumors \value SweetPeriod \value WideMatrix \value SoftCherish \value RedSalvation \value BurningSpring \value NightParty \value SkyGlider \value HeavenPeach \value PurpleDivision \value AquaSplash \value SpikyNaga \value LoveKiss \value CleanMirror \value PremiumDark \value ColdEvening \value CochitiLake \value SummerGames \value PassionateBed \value MountainRock \value DesertHump \value JungleDay \value PhoenixStart \value OctoberSilence \value FarawayRiver \value AlchemistLab \value OverSun \value PremiumWhite \value MarsParty \value EternalConstance \value JapanBlush \value SmilingRain \value CloudyApple \value BigMango \value HealthyWater \value AmourAmour \value RiskyConcrete \value StrongStick \value ViciousStance \value PaloAlto \value HappyMemories \value MidnightBloom \value Crystalline \value PartyBliss \value ConfidentCloud \value LeCocktail \value RiverCity \value FrozenBerry \value ChildCare \value FlyingLemon \value NewRetrowave \value HiddenJaguar \value AboveTheSky \value Nega \value DenseWater \value Seashore \value MarbleWall \value CheerfulCaramel \value NightSky \value MagicLake \value YoungGrass \value ColorfulPeach \value GentleCare \value PlumBath \value HappyUnicorn \value AfricanField \value SolidStone \value OrangeJuice \value GlassWater \value NorthMiracle \value FruitBlend \value MillenniumPine \value HighFlight \value MoleHall \value SpaceShift \value ForestInei \value RoyalGarden \value RichMetal \value JuicyCake \value SmartIndigo \value SandStrike \value NorseBeauty \value AquaGuidance \value SunVeggie \value SeaLord \value BlackSea \value GrassShampoo \value LandingAircraft \value WitchDance \value SleeplessNight \value AngelCare \value CrystalRiver \value SoftLipstick \value SaltMountain \value PerfectWhite \value FreshOasis \value StrictNovember \value MorningSalad \value DeepRelief \value SeaStrike \value NightCall \value SupremeSky \value LightBlue \value MindCrawl \value LilyMeadow \value SugarLollipop \value SweetDessert \value MagicRay \value TeenParty \value FrozenHeat \value GagarinView \value FabledSunset \value PerfectBlue
◆ Spread
| enum QGradient::Spread |
Specifies how the area outside the gradient area should be filled.
\value PadSpread The area is filled with the closest stop color. This is the default.
\value RepeatSpread The gradient is repeated outside the gradient area.
\value ReflectSpread The gradient is reflected outside the gradient area.
- See also
- spread(), setSpread()
| Enumerator | |
|---|---|
| PadSpread | |
| ReflectSpread | |
| RepeatSpread | |
◆ Type
| enum QGradient::Type |
Specifies the type of gradient.
\value LinearGradient Interpolates colors between start and end points (QLinearGradient).
\value RadialGradient Interpolate colors between a focal point and end points on a circle surrounding it (QRadialGradient).
\value ConicalGradient Interpolate colors around a center point (QConicalGradient). \value NoGradient No gradient is used.
- See also
- type()
| Enumerator | |
|---|---|
| LinearGradient | |
| RadialGradient | |
| ConicalGradient | |
| NoGradient | |
Constructor & Destructor Documentation
◆ QGradient() [1/2]
| QGradient::QGradient | ( | ) |
Definition at line 1316 of file qbrush.cpp.
◆ QGradient() [2/2]
| QGradient::QGradient | ( | QGradient::Preset | preset | ) |
- Since
- 5.12
Constructs a gradient based on a predefined preset.
The coordinate mode of the resulting gradient is QGradient::ObjectMode, allowing the preset to be applied to arbitrary object sizes.
Definition at line 1510 of file qbrush.cpp.
◆ ~QGradient()
| QGradient::~QGradient | ( | ) |
Definition at line 1521 of file qbrush.cpp.
Member Function Documentation
◆ coordinateMode()
| QGradient::CoordinateMode QGradient::coordinateMode | ( | ) | const |
- Since
- 4.4
Returns the coordinate mode of this gradient. The default mode is LogicalMode.
Definition at line 1705 of file qbrush.cpp.
◆ interpolationMode()
| QGradient::InterpolationMode QGradient::interpolationMode | ( | ) | const |
- Since
- 4.5
Definition at line 1739 of file qbrush.cpp.
◆ operator!=()
|
inline |
- Since
- 4.2
Returns true if the gradient is the same as the other gradient specified; otherwise returns false.
- See also
- operator==()
Definition at line 397 of file qbrush.h.
◆ operator==()
Returns true if the gradient is the same as the other gradient specified; otherwise returns false.
- See also
- operator!=()
Definition at line 1772 of file qbrush.cpp.
◆ setColorAt()
Creates a stop point at the given position with the given color. The given position must be in the range 0 to 1.
- See also
- setStops(), stops()
Definition at line 1596 of file qbrush.cpp.
◆ setCoordinateMode()
| void QGradient::setCoordinateMode | ( | CoordinateMode | mode | ) |
- Since
- 4.4
Sets the coordinate mode of this gradient to mode. The default mode is LogicalMode.
Definition at line 1716 of file qbrush.cpp.
◆ setInterpolationMode()
| void QGradient::setInterpolationMode | ( | InterpolationMode | mode | ) |
◆ setSpread()
◆ setStops()
| void QGradient::setStops | ( | const QGradientStops & | stopPoints | ) |
Replaces the current set of stop points with the given stopPoints. The positions of the points must be in the range 0 to 1, and must be sorted with the lowest point first.
- See also
- setColorAt(), stops()
Definition at line 1641 of file qbrush.cpp.
◆ spread()
|
inline |
Returns the spread method use by this gradient. The default is PadSpread.
- See also
- setSpread()
Definition at line 383 of file qbrush.h.
◆ stops()
| QGradientStops QGradient::stops | ( | ) | const |
Returns the stop points for this gradient.
If no stop points have been specified, a gradient of black at 0 to white at 1 is used.
- See also
- setStops(), setColorAt()
Definition at line 1664 of file qbrush.cpp.
◆ type()
|
inline |
Friends And Related Function Documentation
◆ QBrush
◆ QConicalGradient
|
friend |
◆ QGradientStop()
|
related |
◆ QGradientStops()
|
related |
Typedef for QList<QGradientStop>.
◆ QLinearGradient
|
friend |
◆ QRadialGradient
|
friend |
The documentation for this class was generated from the following files:
- src/gui/painting/qbrush.h
- src/gui/painting/qbrush.cpp
