Class: QgsLayerTreeModel¶
-
class
qgis.core.
QgsLayerTreeModel
(rootNode: QgsLayerTree, parent: QObject = None)¶ Bases:
PyQt5.QtCore.QAbstractItemModel
Construct a new tree model with given layer tree (root node must not be null pointer). The root node is not transferred by the model.
The QgsLayerTreeModel class is model implementation for Qt item views framework. The model can be used in any QTreeView, it is however recommended to use it with QgsLayerTreeView which brings additional functionality specific to layer tree handling.
The model listens to the changes in the layer tree and signals the changes as appropriate, so that any view that uses the model is updated accordingly.
Behavior of the model can be customized with flags. For example, whether to show legend or whether to allow changes to the layer tree.
See also
New in version 2.4: Enums
Methods
Returns at what number of legend nodes the layer node should be collapsed.
Gets index of the item marked as current.
Filter nodes from QgsMapLayerLegend according to the current filtering rules
Searches through the layer tree to find a legend node with a matching layer ID and rule key.
flags(self) -> QgsLayerTreeModel.Flags Returns OR-ed combination of model flags
Returns legend node for given index.
Returns layer tree node for given index.
Convert a
list
of indexes to a list of layer tree nodes.Returns filtered list of active legend nodes attached to a particular layer node (by default it returns also legend node embedded in parent layer node (if any) unless skipNodeEmbeddedInParent is true)
Returns original (unfiltered) list of legend nodes attached to a particular layer node
Gets map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one
Gets font for a particular type of layer tree node.
Returns the scale which restricts the legend nodes which are visible.
Returns the current map settings used for the current legend filter (or null if none is enabled)
Gets hints about map view - to be used in legend nodes.
Returns index for a given legend node.
Returns legend node that may be embedded in parent (i.e.
Returns index for a given node.
Updates model when node’s name has changed
emit dataChanged() for layer tree node items
Force a refresh of legend nodes of a layer node.
Updates layer data for scale dependent layers, should be called when map scale changes.
Returns pointer to the root node of the layer tree.
Scales an layer tree model icon size to compensate for display pixel density, making the icon size hi-dpi friendly, whilst still resulting in pixel-perfect sizes for low-dpi displays.
Sets at what number of legend nodes the layer node should be collapsed.
Sets index of the current item.
Enable or disable a model flag
Sets OR-ed combination of model flags
Sets map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one
Sets font for a particular type of layer tree node.
Filter display of legend nodes for given map settings
Force only display of legend nodes which are valid for given map settings.
Force only display of legend nodes which are valid for a given
scale
.Give the layer tree model hints about the currently associated map view so that legend nodes that use map units can be scaled currectly
Reset the model and use a new root group node
Check whether a flag is enabled
Signals
Attributes
-
ActionHierarchical
= 65536¶
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AllowLegendChangeState
= 32768¶
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AllowNodeChangeVisibility
= 16384¶
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AllowNodeRename
= 8192¶
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AllowNodeReorder
= 4096¶
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DeferredLegendInvalidation
= 8¶
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class
Flag
¶ Bases:
int
-
class
Flags
¶ Bases:
sip.wrapper
QgsLayerTreeModel.Flags(Union[QgsLayerTreeModel.Flags, QgsLayerTreeModel.Flag]) QgsLayerTreeModel.Flags(QgsLayerTreeModel.Flags)
-
ShowLegend
= 1¶
-
ShowLegendAsTree
= 4¶
-
UseEmbeddedWidgets
= 16¶
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addLegendToLayer
(self, nodeL: QgsLayerTreeLayer)¶
-
autoCollapseLegendNodes
(self) → int¶ Returns at what number of legend nodes the layer node should be collapsed. -1 means no auto-collapse (default).
-
beginInsertColumns
()¶
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beginInsertRows
()¶
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beginMoveColumns
()¶
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beginMoveRows
()¶
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beginRemoveColumns
()¶
-
beginRemoveRows
()¶
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beginResetModel
()¶
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changePersistentIndex
()¶
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changePersistentIndexList
()¶
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childEvent
()¶
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columnCount
(self, parent: QModelIndex = QModelIndex()) → int¶
-
connectNotify
()¶
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connectToLayer
(self, nodeLayer: QgsLayerTreeLayer)¶
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connectToLayers
(self, parentGroup: QgsLayerTreeGroup)¶
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connectToRootNode
(self)¶
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createIndex
()¶
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currentIndex
(self) → QModelIndex¶ Gets index of the item marked as current. Item marked as current is underlined.
-
customEvent
()¶
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data
(self, index: QModelIndex, role: int = Qt.DisplayRole) → Any¶
-
decodeData
()¶
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disconnectFromLayer
(self, nodeLayer: QgsLayerTreeLayer)¶
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disconnectFromLayers
(self, parentGroup: QgsLayerTreeGroup)¶
-
disconnectFromRootNode
(self)¶
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disconnectNotify
()¶
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dropMimeData
(self, data: QMimeData, action: Qt.DropAction, row: int, column: int, parent: QModelIndex) → bool¶
-
encodeData
()¶
-
endInsertColumns
()¶
-
endInsertRows
()¶
-
endMoveColumns
()¶
-
endMoveRows
()¶
-
endRemoveColumns
()¶
-
endRemoveRows
()¶
-
endResetModel
()¶
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filterLegendNodes
(self, nodes: Iterable[QgsLayerTreeModelLegendNode]) → List[QgsLayerTreeModelLegendNode]¶ Filter nodes from QgsMapLayerLegend according to the current filtering rules
-
findLegendNode
(self, layerId: str, ruleKey: str) → QgsLayerTreeModelLegendNode¶ Searches through the layer tree to find a legend node with a matching layer ID and rule key.
- Parameters
layerId – map layer ID
ruleKey – legend node rule key
- Returns
QgsLayerTreeModelLegendNode if found
New in version 2.14.
-
flags
(self, index: QModelIndex) → Qt.ItemFlags¶ flags(self) -> QgsLayerTreeModel.Flags Returns OR-ed combination of model flags
-
iconGroup
() → QIcon¶
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index
(self, row: int, column: int, parent: QModelIndex = QModelIndex()) → QModelIndex¶
-
index2legendNode
(index: QModelIndex) → QgsLayerTreeModelLegendNode¶ Returns legend node for given index. Returns null for invalid index
New in version 2.6.
-
index2node
(self, index: QModelIndex) → QgsLayerTreeNode¶ Returns layer tree node for given index. Returns root node for invalid index. Returns null pointer if index does not refer to a layer tree node (e.g. it is a legend node)
-
indexOfParentLayerTreeNode
(self, parentNode: QgsLayerTreeNode) → QModelIndex¶
-
indexes2nodes
(self, list: object, skipInternal: bool = False) → List[QgsLayerTreeNode]¶ Convert a
list
of indexes to a list of layer tree nodes. Indices that do not represent layer tree nodes are skipped. IfskipInternal
is true, a node is included in the output list only if no parent node is in the list.
-
invalidateLegendMapBasedData
(self)¶
-
isSignalConnected
()¶
-
layerLegendChanged
(self)¶
-
layerLegendNodes
(self, nodeLayer: QgsLayerTreeLayer, skipNodeEmbeddedInParent: bool = False) → List[QgsLayerTreeModelLegendNode]¶ Returns filtered list of active legend nodes attached to a particular layer node (by default it returns also legend node embedded in parent layer node (if any) unless skipNodeEmbeddedInParent is true)
Note
Parameter skipNodeEmbeddedInParent added in QGIS 2.18
See also
New in version 2.6.
-
layerNeedsUpdate
(self)¶
-
layerOriginalLegendNodes
(self, nodeLayer: QgsLayerTreeLayer) → List[QgsLayerTreeModelLegendNode]¶ Returns original (unfiltered) list of legend nodes attached to a particular layer node
See also
New in version 2.14.
-
layerStyleOverrides
(self) → Dict[str, str]¶ Gets map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one
New in version 2.10.
-
layerTreeNodeFont
(self, nodeType: int) → QFont¶ Gets font for a particular type of layer tree node. nodeType should come from QgsLayerTreeNode.NodeType enumeration
-
legendCleanup
(self)¶
-
legendEmbeddedInParent
(self, nodeLayer: QgsLayerTreeLayer) → bool¶
-
legendFilterByScale
(self) → float¶ Returns the scale which restricts the legend nodes which are visible. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map. A scale <= 0 indicates that no scale filtering is being performed.
See also
New in version 2.6.
-
legendFilterMapSettings
(self) → QgsMapSettings¶ Returns the current map settings used for the current legend filter (or null if none is enabled)
New in version 2.14.
-
legendIconEmbeddedInParent
(self, nodeLayer: QgsLayerTreeLayer) → QIcon¶
-
legendInvalidateMapBasedData
(self)¶
-
legendMapViewData
(self) → Tuple[float, int, float]¶ Gets hints about map view - to be used in legend nodes. Arguments that are not null will receive values. If there are no valid map view data (from previous call to setLegendMapViewData()), returned values are zeros.
New in version 2.6.
-
legendNode2index
(self, legendNode: QgsLayerTreeModelLegendNode) → QModelIndex¶ Returns index for a given legend node. If the legend node does not belong to the layer tree, the result is undefined. If the legend node is belongs to the tree but it is filtered out, invalid model index is returned.
New in version 2.6.
-
legendNodeData
(self, node: QgsLayerTreeModelLegendNode, role: int) → Any¶
-
legendNodeDataChanged
(self)¶
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legendNodeEmbeddedInParent
(self, nodeLayer: QgsLayerTreeLayer) → QgsLayerTreeModelLegendNode¶ Returns legend node that may be embedded in parent (i.e. its icon will be used for layer’s icon).
New in version 2.18.
-
legendNodeFlags
(self, node: QgsLayerTreeModelLegendNode) → Qt.ItemFlags¶
-
legendNodeIndex
(self, row: int, column: int, node: QgsLayerTreeModelLegendNode) → QModelIndex¶
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legendNodeRowCount
(self, node: QgsLayerTreeModelLegendNode) → int¶
-
legendParent
(self, legendNode: QgsLayerTreeModelLegendNode) → QModelIndex¶
-
legendRootIndex
(self, row: int, column: int, nL: QgsLayerTreeLayer) → QModelIndex¶
-
legendRootRowCount
(self, nL: QgsLayerTreeLayer) → int¶
-
mimeData
(self, indexes: object) → QMimeData¶
-
mimeTypes
(self) → List[str]¶
-
node2index
(self, node: QgsLayerTreeNode) → QModelIndex¶ Returns index for a given node. If the node does not belong to the layer tree, the result is undefined
-
nodeAddedChildren
(self, node: QgsLayerTreeNode, indexFrom: int, indexTo: int)¶
-
nodeCustomPropertyChanged
(self, node: QgsLayerTreeNode, key: str)¶
-
nodeLayerLoaded
(self)¶
-
nodeLayerWillBeUnloaded
(self)¶
-
nodeNameChanged
(self, node: QgsLayerTreeNode, name: str)¶ Updates model when node’s name has changed
New in version 3.0.
-
nodeRemovedChildren
(self)¶
-
nodeVisibilityChanged
(self, node: QgsLayerTreeNode)¶
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nodeWillAddChildren
(self, node: QgsLayerTreeNode, indexFrom: int, indexTo: int)¶
-
nodeWillRemoveChildren
(self, node: QgsLayerTreeNode, indexFrom: int, indexTo: int)¶
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parent
(self, child: QModelIndex) → QModelIndex¶
-
persistentIndexList
()¶
-
receivers
()¶
-
recursivelyEmitDataChanged
(self, index: QModelIndex = QModelIndex())¶ emit dataChanged() for layer tree node items
-
refreshLayerLegend
(self, nodeLayer: QgsLayerTreeLayer)¶ Force a refresh of legend nodes of a layer node. Not necessary to call when layer’s renderer is changed as the model listens to these events.
-
refreshScaleBasedLayers
(self, index: QModelIndex = QModelIndex())¶ Updates layer data for scale dependent layers, should be called when map scale changes. Emits dataChanged() for all scale dependent layers.
New in version 2.16.
-
removeLegendFromLayer
(self, nodeLayer: QgsLayerTreeLayer)¶
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removeRows
(self, row: int, count: int, parent: QModelIndex = QModelIndex()) → bool¶
-
resetInternalData
()¶
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rootGroup
(self) → QgsLayerTree¶ Returns pointer to the root node of the layer tree. Always a non-null pointer.
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rowCount
(self, parent: QModelIndex = QModelIndex()) → int¶
-
scaleIconSize
(standardSize: int) → int¶ Scales an layer tree model icon size to compensate for display pixel density, making the icon size hi-dpi friendly, whilst still resulting in pixel-perfect sizes for low-dpi displays.
standardSize
should be set to a standard icon size, e.g. 16, 24, 48, etc.New in version 3.6.
-
sender
()¶
-
senderSignalIndex
()¶
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setAutoCollapseLegendNodes
(self, nodeCount: int)¶ Sets at what number of legend nodes the layer node should be collapsed. Setting -1 disables the auto-collapse (default).
-
setCurrentIndex
(self, currentIndex: QModelIndex)¶ Sets index of the current item. May be used by view. Item marked as current is underlined.
-
setData
(self, index: QModelIndex, value: Any, role: int = Qt.EditRole) → bool¶
-
setFlag
(self, f: QgsLayerTreeModel.Flag, on: bool = True)¶ Enable or disable a model flag
-
setFlags
(self, f: Union[QgsLayerTreeModel.Flags, QgsLayerTreeModel.Flag])¶ Sets OR-ed combination of model flags
-
setLayerStyleOverrides
(self, overrides: Dict[str, str])¶ Sets map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one
New in version 2.10.
-
setLayerTreeNodeFont
(self, nodeType: int, font: QFont)¶ Sets font for a particular type of layer tree node. nodeType should come from QgsLayerTreeNode.NodeType enumeration
-
setLegendFilter
(self, settings: QgsMapSettings, useExtent: bool = True, polygon: QgsGeometry = QgsGeometry(), useExpressions: bool = True)¶ Filter display of legend nodes for given map settings
- Parameters
settings – Map settings. Setting a null pointer or invalid settings will disable any filter. Ownership is not changed, a copy is made
useExtent – Whether to use the extent of the map settings as a first spatial filter on legend nodes
polygon – If not empty, this polygon will be used instead of the map extent to filter legend nodes
useExpressions – Whether to use legend node filter expressions
New in version 2.14.
-
setLegendFilterByMap
(self, settings: QgsMapSettings)¶ Force only display of legend nodes which are valid for given map settings. Setting null pointer or invalid map settings will disable the functionality. Ownership of map settings pointer does not change, a copy is made.
New in version 2.6.
-
setLegendFilterByScale
(self, scale: float)¶ Force only display of legend nodes which are valid for a given
scale
. Thescale
value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map. Settingscale
<= 0 will disable the functionality.See also
New in version 2.6.
-
setLegendMapViewData
(self, mapUnitsPerPixel: float, dpi: int, scale: float)¶ Give the layer tree model hints about the currently associated map view so that legend nodes that use map units can be scaled currectly
New in version 2.6.
-
setRootGroup
(self, newRootGroup: QgsLayerTree)¶ Reset the model and use a new root group node
New in version 2.6.
-
supportedDropActions
(self) → Qt.DropActions¶
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testFlag
(self, f: QgsLayerTreeModel.Flag) → bool¶ Check whether a flag is enabled
-
timerEvent
()¶
-