[GIS] How to iterate over selected layers

pyqgispythonqgis

In QGis by pressing shift or ctrl keys a user can select multiple layers in toc.
How can a python script iterate over selected layers?

I'd expect a iface.selectedLayers() but I can find only iface.activeLayer() which return only one layer.

Best Answer

I have added a QgsLegend::selectedLayers() binding to QgsLegendInterface in master branch. You can now do the following when using a current master build (might have to wait a day or two, unless compiling yourself; not going to be backported to QGIS 1.8):

# iface.legendInterface().selectedLayers(bool inDrawOrder)
# param inDrawOrder False returns QTreeWidget::selectedItems() order
#                   True returns render drawing order (Legend or Layer Order)
# returns list of selected QgsMapLayer(s), or empty list

from qgis.utils import iface
li = iface.legendInterface()
sl = li.selectedLayers(True)
for lyr in sl:
    print lyr.name()

QGIS 3.x

To get the layers selected in the TOC in QGIS 3.x check this answer.

with the iface object, it is possible to get the layerTreeView, which has a method selectedLayers():
iface.layerTreeView().selectedLayers()
more methods on QgsLayerTreeView in the docs:

QGIS 2.x

You can get the layers selected in the TOC with something like this

selectedLayers = iface.legendInterface().selectedLayers()

the selectedLayers() method in QgsLegendInterface does the trick. But take into account that:

If a group is selected neither the group itself, neither the layers within are returned by selectedLayers(). You must select it in the GUI one by one.
Probably you want to filter the layers by their type (TileLayer, QgsRasterLayer, QgsVectorLayer, ...)

A more complete example:

selectedLayers = iface.legendInterface().selectedLayers()
for layer in selectedLayers:
    if layer.type() == QgsMapLayer.VectorLayer:
        print(layer.name())
    elif layer.type() == QgsMapLayer.RasterLayer:
        print(layer.name())
    elif layer.type() == QgsMapLayer.PluginLayer:
        print(layer.name())
    else:
        raise Exception('Should never happen')

QGIS – Accessing Menu Functions Like Copy Paste Style Using Python and PyQGIS

I'll answer the concrete question of copying/pasting layer styles with PyQGIS:

Select the source layer in the QGIS layer tree either by hand or by code.
Run the following command to copy the style:
```
iface.actionCopyLayerStyle().trigger()
```
Select another layer either by hand or by code (as you mentioned, it could be a layer in another QGIS window).
Run the following command to paste the style:
```
iface.actionPasteLayerStyle().trigger()
```

In general, some QGIS functionality is exposed through iface object. Have a look at the different actions that you could call (trigger) at http://www.qgis.org/api/classQgisInterface.html

For your specific use case, since you seem to be managing the clipboard, I suggest you to do this:

Save the layer style into a temporary QML file (using layer.saveNamedStyle( pathToQMLFile )),
Copy the path to that file into the clipboard,
When pasting, load the style from the QML file path in the clipboard (using layer.loadNamedStyle( pathToQMLFile ) and then layer.triggerRepaint()).

Best Answer

Related Solutions

Programmatically Get Selected Layers from QGIS Legend

QGIS 3.x

QGIS 2.x

QGIS – Accessing Menu Functions Like Copy Paste Style Using Python and PyQGIS

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