def __init__(self, iface):
"""Constructor.
:param iface: An interface instance that will be passed to this class
which provides the hook by which you can manipulate the QGIS
application at run time.
:type iface: QgsInterface
"""
# Save reference to the QGIS interface
self.iface = iface
# initialize plugin directory
self.plugin_dir = os.path.dirname(__file__)
# initialize locale
locale = QSettings().value('locale/userLocale')[0:2]
locale_path = os.path.join(
self.plugin_dir,
'i18n',
'Ellipse_{}.qm'.format(locale))
if os.path.exists(locale_path):
self.translator = QTranslator()
self.translator.load(locale_path)
if qVersion() > '4.3.3':
QCoreApplication.installTranslator(self.translator)
# Create the dialog (after translation) and keep reference
self.dlg = EllipseDialog()
# Declare instance attributes
self.actions = []
self.menu = self.tr(u'&Ellipse')
# TODO: We are going to let the user set this up in a future iteration
self.toolbar = self.iface.addToolBar(u'Ellipse')
self.toolbar.setObjectName(u'Ellipse')
class Ellipse:
"""QGIS Plugin Implementation."""
def __init__(self, iface):
"""Constructor.
:param iface: An interface instance that will be passed to this class
which provides the hook by which you can manipulate the QGIS
application at run time.
:type iface: QgsInterface
"""
# Save reference to the QGIS interface
self.iface = iface
# initialize plugin directory
self.plugin_dir = os.path.dirname(__file__)
# initialize locale
locale = QSettings().value('locale/userLocale')[0:2]
locale_path = os.path.join(
self.plugin_dir,
'i18n',
'Ellipse_{}.qm'.format(locale))
if os.path.exists(locale_path):
self.translator = QTranslator()
self.translator.load(locale_path)
if qVersion() > '4.3.3':
QCoreApplication.installTranslator(self.translator)
# Create the dialog (after translation) and keep reference
self.dlg = EllipseDialog()
# Declare instance attributes
self.actions = []
self.menu = self.tr(u'&Ellipse')
# TODO: We are going to let the user set this up in a future iteration
self.toolbar = self.iface.addToolBar(u'Ellipse')
self.toolbar.setObjectName(u'Ellipse')
# noinspection PyMethodMayBeStatic
def tr(self, message):
"""Get the translation for a string using Qt translation API.
We implement this ourselves since we do not inherit QObject.
:param message: String for translation.
:type message: str, QString
:returns: Translated version of message.
:rtype: QString
"""
# noinspection PyTypeChecker,PyArgumentList,PyCallByClass
return QCoreApplication.translate('Ellipse', message)
def add_action(
self,
icon_path,
text,
callback,
enabled_flag=True,
add_to_menu=False,
add_to_toolbar=True,
status_tip=None,
whats_this=None,
parent=None):
"""Add a toolbar icon to the toolbar.
:param icon_path: Path to the icon for this action. Can be a resource
path (e.g. ':/plugins/foo/bar.png') or a normal file system path.
:type icon_path: str
:param text: Text that should be shown in menu items for this action.
:type text: str
:param callback: Function to be called when the action is triggered.
:type callback: function
:param enabled_flag: A flag indicating if the action should be enabled
by default. Defaults to True.
:type enabled_flag: bool
:param add_to_menu: Flag indicating whether the action should also
be added to the menu. Defaults to True.
:type add_to_menu: bool
:param add_to_toolbar: Flag indicating whether the action should also
be added to the toolbar. Defaults to True.
:type add_to_toolbar: bool
:param status_tip: Optional text to show in a popup when mouse pointer
hovers over the action.
:type status_tip: str
:param parent: Parent widget for the new action. Defaults None.
:type parent: QWidget
:param whats_this: Optional text to show in the status bar when the
mouse pointer hovers over the action.
:returns: The action that was created. Note that the action is also
added to self.actions list.
:rtype: QAction
"""
icon = QIcon(icon_path)
action = QAction(icon, text, parent)
action.triggered.connect(callback)
action.setEnabled(enabled_flag)
if status_tip is not None:
action.setStatusTip(status_tip)
if whats_this is not None:
action.setWhatsThis(whats_this)
if add_to_toolbar:
self.toolbar.addAction(action)
if add_to_menu:
self.iface.addPluginToMenu(
self.menu,
action)
self.actions.append(action)
return action
def initGui(self):
"""Create the menu entries and toolbar icons inside the QGIS GUI."""
icon_path = ':/plugins/Ellipse/icon.png'
self.add_action(
icon_path,
text=self.tr(u'Create Ellipse'),
callback=self.run,
parent=self.iface.mainWindow())
self.iface.addPluginToVectorMenu("Ellipse", self.actions[0])
def unload(self):
"""Removes the plugin menu item and icon from QGIS GUI."""
for action in self.actions:
self.iface.removePluginMenu(
self.tr(u'&Ellipse'),
action)
self.iface.removeToolBarIcon(action)
# remove the toolbar
del self.toolbar
self.iface.removePluginVectorMenu("Ellipse", self.actions[0])
def run(self):
"""Run method that performs all the real work"""
from PyQt4.QtGui import QMessageBox
# Get the current layer
cur_layer = self.iface.mapCanvas().currentLayer()
#Ensure that the layer exists
if cur_layer is None:
problem = 'No layer selected'
QMessageBox.information(None, "Invalid target layer:", problem)
return False
# Ensure it's a vector layer
if cur_layer.type() != QgsMapLayer.VectorLayer:
problem = 'Selected layer is not a vector layer'
QMessageBox.information(None, "Invalid target layer:", problem)
return False
#Ensure it's a polygon layer
if cur_layer.geometryType() != QGis.Polygon:
problem = 'Selected layer is not a polygon vector layer'
QMessageBox.information(None, "Invalid target layer:", problem)
return False
# Ensure it's editable
if not cur_layer.isEditable():
problem = 'Selected layer is not editable'
QMessageBox.information(None, "Invalid target layer:", problem)
return False
# show the dialog
self.dlg.show()
# Run the dialog event loop
result = self.dlg.exec_()
# See if OK was pressed
if result:
#"""
#A function for working with ellipses
#"""
import math
import sys
def draw_ellipse(min_diam=150, maj_diam=250, angle_deg=45):
#"""
#
#Adds an ellipse to the current layer
#
#:param iface: A QgsInterface object
#:param min_diam: Minor ellipse axis diameter (float, map units)
#:param maj_diam: Major ellipse axis diameter (float, map units)
#:param angle_deg: Angle of rotation (float, degrees, clockwise)
#:return:
#"""
# Draw the ellipse around 0, 0
vert_count = 100
coords = []
for i in range(vert_count):
angle = i * 2 * math.pi / vert_count
x = (min_diam/2) * math.cos(angle)
y = (maj_diam/2) * math.sin(angle)
coords.append( QgsPoint(x, y) )
coords.append( QgsPoint(x, y) )
# Make a geometry from the points
ellipse_geom = QgsGeometry().fromPolygon( [coords] )
ellipse_geom.rotate( angle_deg, QgsPoint(0,0) )
# Get the canvas centroid position
# Translate (shift) the new geometry to that location
canvas_center = self.iface.mapCanvas().center()
ellipse_geom.translate( canvas_center.x(),
canvas_center.y())
# Create and add the new feature
new_f = QgsFeature()
new_f.setGeometry( ellipse_geom )
cur_layer.dataProvider().addFeatures( [ new_f ] )
cur_layer.updateExtents()
self.iface.mapCanvas().refresh()
return True
#Validate ellipse dimensions entered by user and call the ellipse function if dimensions are valid
if self.dlg.txtMinDiameter.text().replace('.','',1).isdigit() and self.dlg.txtMajDiameter.text().replace('.','',1).isdigit() and self.dlg.txtRotation.text().replace('.','',1).isdigit():
draw_ellipse(float(self.dlg.txtMinDiameter.text()), float(self.dlg.txtMajDiameter.text()), float(self.dlg.txtRotation.text()))
else:
QMessageBox.information(None, "Invalid ellipse dimensions:", "Please enter valid ellipse dimensions")
