QGIS API Documentation
3.18.1-Zürich (202f1bf7e5)
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Management of styles for use with one map layer. More...
#include <qgsmaplayerstylemanager.h>
Signals | |
void | currentStyleChanged (const QString ¤tName) |
Emitted when the current style has been changed. More... | |
void | styleAdded (const QString &name) |
Emitted when a new style has been added. More... | |
void | styleRemoved (const QString &name) |
Emitted when a style has been removed. More... | |
void | styleRenamed (const QString &oldName, const QString &newName) |
Emitted when a style has been renamed. More... | |
Public Member Functions | |
QgsMapLayerStyleManager (QgsMapLayer *layer) | |
Construct a style manager associated with a map layer (must not be nullptr ). More... | |
bool | addStyle (const QString &name, const QgsMapLayerStyle &style) |
Add a style with given name and data. More... | |
bool | addStyleFromLayer (const QString &name) |
Add style by cloning the current one. More... | |
void | copyStylesFrom (QgsMapLayerStyleManager *other) |
Copies all styles from other. More... | |
QString | currentStyle () const |
Returns name of the current style. More... | |
bool | isDefault (const QString &styleName) const |
Returns true if this is the default style. More... | |
QgsMapLayer * | layer () const |
Gets pointer to the associated map layer. More... | |
QMap< QString, QgsMapLayerStyle > | mapLayerStyles () const |
Gets available styles for the associated map layer. More... | |
void | readXml (const QDomElement &mgrElement) |
Read configuration (for project loading) More... | |
bool | removeStyle (const QString &name) |
Remove a stored style. More... | |
bool | renameStyle (const QString &name, const QString &newName) |
Rename a stored style to a different name. More... | |
void | reset () |
Reset the style manager to a basic state - with one default style which is set as current. More... | |
bool | restoreOverrideStyle () |
Restore the original store after a call to setOverrideStyle() More... | |
bool | setCurrentStyle (const QString &name) |
Set a different style as the current style - will apply it to the layer. More... | |
bool | setOverrideStyle (const QString &styleDef) |
Temporarily apply a different style to the layer. More... | |
QgsMapLayerStyle | style (const QString &name) const |
Returns data of a stored style - accessed by its unique name. More... | |
QStringList | styles () const |
Returns list of all defined style names. More... | |
void | writeXml (QDomElement &mgrElement) const |
Write configuration (for project saving) More... | |
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).
Definition at line 57 of file qgsmaplayerstylemanager.h.
QgsMapLayerStyleManager::QgsMapLayerStyleManager | ( | QgsMapLayer * | layer | ) |
Construct a style manager associated with a map layer (must not be nullptr
).
The style manager will be parented to layer.
Definition at line 25 of file qgsmaplayerstylemanager.cpp.
bool QgsMapLayerStyleManager::addStyle | ( | const QString & | name, |
const QgsMapLayerStyle & | style | ||
) |
Add a style with given name and data.
true
on success (name is unique and style is valid) Definition at line 109 of file qgsmaplayerstylemanager.cpp.
bool QgsMapLayerStyleManager::addStyleFromLayer | ( | const QString & | name | ) |
Add style by cloning the current one.
true
on success Definition at line 121 of file qgsmaplayerstylemanager.cpp.
void QgsMapLayerStyleManager::copyStylesFrom | ( | QgsMapLayerStyleManager * | other | ) |
Copies all styles from other.
In case there is already a style with the same name it will be overwritten.
Definition at line 234 of file qgsmaplayerstylemanager.cpp.
QString QgsMapLayerStyleManager::currentStyle | ( | ) | const |
Returns name of the current style.
Definition at line 164 of file qgsmaplayerstylemanager.cpp.
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signal |
Emitted when the current style has been changed.
bool QgsMapLayerStyleManager::isDefault | ( | const QString & | styleName | ) | const |
Returns true
if this is the default style.
Definition at line 229 of file qgsmaplayerstylemanager.cpp.
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inline |
Gets pointer to the associated map layer.
Definition at line 69 of file qgsmaplayerstylemanager.h.
QMap< QString, QgsMapLayerStyle > QgsMapLayerStyleManager::mapLayerStyles | ( | ) | const |
Gets available styles for the associated map layer.
Definition at line 91 of file qgsmaplayerstylemanager.cpp.
void QgsMapLayerStyleManager::readXml | ( | const QDomElement & | mgrElement | ) |
Read configuration (for project loading)
Definition at line 44 of file qgsmaplayerstylemanager.cpp.
bool QgsMapLayerStyleManager::removeStyle | ( | const QString & | name | ) |
Remove a stored style.
true
on success (style exists and it is not the last one) Definition at line 128 of file qgsmaplayerstylemanager.cpp.
bool QgsMapLayerStyleManager::renameStyle | ( | const QString & | name, |
const QString & | newName | ||
) |
Rename a stored style to a different name.
true
on success (style exists and new name is unique) Definition at line 150 of file qgsmaplayerstylemanager.cpp.
void QgsMapLayerStyleManager::reset | ( | ) |
Reset the style manager to a basic state - with one default style which is set as current.
Definition at line 38 of file qgsmaplayerstylemanager.cpp.
bool QgsMapLayerStyleManager::restoreOverrideStyle | ( | ) |
Restore the original store after a call to setOverrideStyle()
Definition at line 215 of file qgsmaplayerstylemanager.cpp.
bool QgsMapLayerStyleManager::setCurrentStyle | ( | const QString & | name | ) |
Set a different style as the current style - will apply it to the layer.
true
on success Definition at line 169 of file qgsmaplayerstylemanager.cpp.
bool QgsMapLayerStyleManager::setOverrideStyle | ( | const QString & | styleDef | ) |
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()
Definition at line 187 of file qgsmaplayerstylemanager.cpp.
QgsMapLayerStyle QgsMapLayerStyleManager::style | ( | const QString & | name | ) | const |
Returns data of a stored style - accessed by its unique name.
Definition at line 96 of file qgsmaplayerstylemanager.cpp.
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signal |
Emitted when a new style has been added.
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signal |
Emitted when a style has been removed.
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signal |
Emitted when a style has been renamed.
QStringList QgsMapLayerStyleManager::styles | ( | ) | const |
Returns list of all defined style names.
Definition at line 86 of file qgsmaplayerstylemanager.cpp.
void QgsMapLayerStyleManager::writeXml | ( | QDomElement & | mgrElement | ) | const |
Write configuration (for project saving)
Definition at line 71 of file qgsmaplayerstylemanager.cpp.