Class: QgsMapLayerStyleManager

Management of styles for use with one map layer.

Stored styles are identified by their names. The manager always keep track of which style of the stored ones is currently active. When the current style is changed, the new style is applied to the associated layer.

The class takes care of updating itself when the layer’s current style configuration changes. When some of layer style’s properties change (e.g. opacity / colors), the style manager will record them in the currently active style without any extra effort required.

When an instance is created, it creates “default” style (with empty name) recorded from the associated map layer and it is set as the current style. The instance must always contain at least one style (which is the current).

The style which is marked as current has no style data stored in its entry. This is to avoid duplication of data as all data is stored in map layer and can be retrieved easily. Also when saving, the entry for the current style will be saved with no data because everything is already saved by the map layer itself.

The class also features support for temporary change of the layer’s style, ideal for short-term use of a custom style followed by restoration of the original style (for example, when rendering a map with a different than current style).

Class Hierarchy

Base classes

QObject

class qgis.core.QgsMapLayerStyleManager

Bases: QObject

__init__(layer: QgsMapLayer | None)

Construct a style manager associated with a map layer (must not be None). The style manager will be parented to layer.

Parameters:

layer (Optional[QgsMapLayer])

addStyle(self, name: str | None, style: QgsMapLayerStyle) → bool

Add a style with given name and data

Return type:

bool

Returns:

True on success (name is unique and style is valid)

Parameters:

• name (Optional[str])

• style (QgsMapLayerStyle)

addStyleFromLayer(self, name: str | None) → bool

Add style by cloning the current one

Return type:

bool

Returns:

True on success

Parameters:

name (Optional[str])

copyStylesFrom(self, other: QgsMapLayerStyleManager | None)

Copies all styles from other. In case there is already a style with the same name it will be overwritten.

Added in version 3.14.

Parameters:

other (Optional[QgsMapLayerStyleManager])

currentStyle(self) → str

Returns name of the current style

Return type:

str

signal currentStyleChanged

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

static isDefault(styleName: str | None) → bool

Returns True if this is the default style

Parameters:

styleName (Optional[str])

Return type:

bool

layer(self) → QgsMapLayer | None

Gets pointer to the associated map layer

Return type:

Optional[QgsMapLayer]

mapLayerStyles(self) → Dict[str, QgsMapLayerStyle]

Gets available styles for the associated map layer.

Return type:

Dict[str, QgsMapLayerStyle]

Returns:

A map of map layer style by style name

readXml(self, mgrElement: QDomElement)

Read configuration (for project loading)

Parameters:

mgrElement (QDomElement)

removeStyle(self, name: str | None) → bool

Remove a stored style

Return type:

bool

Returns:

True on success (style exists and it is not the last one)

Parameters:

name (Optional[str])

renameStyle(self, name: str | None, newName: str | None) → bool

Rename a stored style to a different name

Return type:

bool

Returns:

True on success (style exists and new name is unique)

Parameters:

• name (Optional[str])

• newName (Optional[str])

reset(self)

Reset the style manager to a basic state - with one default style which is set as current

restoreOverrideStyle(self) → bool

Restore the original store after a call to setOverrideStyle()

Return type:

bool

setCurrentStyle(self, name: str | None) → bool

Set a different style as the current style - will apply it to the layer

Return type:

bool

Returns:

True on success

Parameters:

name (Optional[str])

setOverrideStyle(self, styleDef: str | None) → bool

Temporarily apply a different style to the layer. The argument can be either a style name or a full QML style definition. Each call must be paired with restoreOverrideStyle()

Parameters:

styleDef (Optional[str])

Return type:

bool

style(self, name: str | None) → QgsMapLayerStyle

Returns data of a stored style - accessed by its unique name

Parameters:

name (Optional[str])

Return type:

QgsMapLayerStyle

signal styleAdded

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

signal styleRemoved

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

signal styleRenamed

pyqtSignal(*types, name: str = …, revision: int = …, arguments: Sequence = …) -> PYQT_SIGNAL

types is normally a sequence of individual types. Each type is either a type object or a string that is the name of a C++ type. Alternatively each type could itself be a sequence of types each describing a different overloaded signal. name is the optional C++ name of the signal. If it is not specified then the name of the class attribute that is bound to the signal is used. revision is the optional revision of the signal that is exported to QML. If it is not specified then 0 is used. arguments is the optional sequence of the names of the signal’s arguments.

styles(self) → List[str]

Returns list of all defined style names

Return type:

List[str]

writeXml(self, mgrElement: QDomElement)

Write configuration (for project saving)

Parameters:

mgrElement (QDomElement)