Setting different context menu actions for each layer type with PyQGIS

Question

I want to set different actions(context menu) for vectors, rasters, etc.

class MyMenuProvider(QgsLayerTreeViewMenuProvider):
    def __init__(self, view):
        QgsLayerTreeViewMenuProvider.__init__(self)
        self.view = view
    
      def createContextMenu(self):
        if not self.view.currentLayer():
          return None
        m = QMenu()
        m.addAction("Show Attribute Table", self.openAttributeTable)
        return m
    
      def openAttributeTable(self):
        #iface1.openFeatureForm(iface1.activeLayer(), feature, False)
        iface1.showAttributeTable(iface1.activeLayer())

then using it as

view = iface1.layerTreeView()
provider = MyMenuProvider(view)
view.setMenuProvider(provider)

But this sets the menu provider for all layers, I want to have different actions for different layers.

Answer 1

You can always have a look at how QGIS does it to get an idea.

In your case, you can use a conditional expression to evaluate the layer type. If the current layer is a vector you add certain actions, if not, you add others.

This is a basic example (see the createContextMenu function):

from qgis.PyQt.QtWidgets import QMenu
from qgis.core import QgsVectorLayer, QgsRasterLayer
from qgis.gui import QgsLayerTreeViewMenuProvider

class MyMenuProvider(QgsLayerTreeViewMenuProvider):

    def __init__(self, view):
        QgsLayerTreeViewMenuProvider.__init__(self)
        self.view = view
        self.defaultActions = view.defaultActions()

    def createContextMenu(self):
        if not self.view.currentLayer():
            return None
        m = QMenu()
        m.addAction("Open layer properties", self.openLayerProperties)
        m.addSeparator()

        if type(self.view.currentLayer()) == QgsVectorLayer:
            m.addAction("Show Feature Count", self.featureCount)
            m.addAction("Another vector-specific action", self.vectorAction)
        elif type(self.view.currentLayer()) == QgsRasterLayer:
            m.addAction("Zoom 100%", self.zoom100)
            m.addAction("Another raster-specific action", self.rasterAction)
        return m

    def openLayerProperties(self):
        iface.showLayerProperties(self.view.currentLayer())

    def featureCount(self):
        self.defaultActions.actionShowFeatureCount().trigger()

    def vectorAction(self):
        pass

    def zoom100(self):
        iface.actionZoomActualSize().trigger()

    def rasterAction(self):
        pass

view = iface.layerTreeView()
provider = MyMenuProvider(view)
view.setMenuProvider(provider)

Which produces:

Answer 2

If you want to keep the default elements and behaviour of the context menu and just add new actions to it, you can use the contextMenuAboutToShow signal of QgsLayerTreeView as a trigger for a function that generates a QAction.

from PyQt5.QtWidgets import QMenu
from qgis.utils import iface
from qgis.core import QgsMapLayer


def generate_qaction(menu: QMenu) -> None:
    menu.addSeparator()
    menu.addAction('MyAction', on_click_behaviour)


def on_click_behaviour() -> None:
    layer = iface.activeLayer()
    if not layer:
        return
    if layer.type() == QgsMapLayer.VectorLayer:
        print('do vector layer stuff')
    else:
        ...


ltv = iface.layerTreeView()
ltv.contextMenuAboutToShow.connect(generate_qaction)

Make sure to disconnect the signal, when you dont need it anymore:

ltv.contextMenuAboutToShow.disconnect(add_action_layer_context_menu)