bbox

from qgis.utils import iface
from qgis.core import QGis
from qgiscommand.command import command

@command()
def bbox():
    layer = iface.activeLayer()

    def pbounds (Lextent,s):
        e = Lextent
        if s =='no':
            iface.messageBar().pushInfo("bbox layer\n",'x,y\n%s,%s\n%s,%s' %(e.xMinimum(), e.yMinimum(), e.xMaximum(), e.yMaximum()))
        else:
            iface.messageBar().pushInfo("bbox selected features\n",'x,y\n%s,%s\n%s,%s' %(e.xMinimum(), e.yMinimum(), e.xMaximum(), e.yMaximum()))

    if layer.wkbType()== QGis.WKBPolygon or layer.wkbType() == QGis.WKBMultiPolygon or layer.wkbType() == QGis.WKBLineString:
        if layer.selectedFeatureCount() < 1:
            s = 'no'
            e = layer.extent()
        else:
            s = 'yes'
            e = layer.boundingBoxOfSelected()
        pbounds(e, s)

    else:
        if layer.featureCount() <=1:
                iface.messageBar().pushInfo("point layer",'less than 2 points')
        else:
            if layer.selectedFeatureCount() <2:
                s = 'no'
                e = layer.extent()
                pbounds(e, s)
            else:
                s = 'yes'
                e = layer.boundingBoxOfSelected()
                pbounds(e, s)

from qgis.utils import iface
from qgis.core import QGis
from qgiscommand.command import command

@command()
def bbox():
    layer = iface.activeLayer()

    usingselection = not layer.selectedFeatureCount()
    if not usingselection:
        e = layer.extent()
    else:
        e = layer.boundingBoxOfSelected()

    title = "bbx layer"
    if usingselection:
        title = "bbox selected features"

    iface.messageBar().pushInfo(title,"x,y {}".format(extent.toString()))

:)