gistfile1.txt

from PyQt4.QtCore import QPointF, QRectF, QTimer, QObject, pyqtProperty, QPropertyAnimation, Qt
from PyQt4.QtGui import QPainter, QBrush, QColor
from qgis.gui import QgsMapCanvasItem
from qgis.core import QgsPoint
 
class PingLocationMarker(QgsMapCanvasItem):
    """
    Position marker for the current location in the viewer.
    """
    class AniObject(QObject):
        def __init__(self):
            super(PingLocationMarker.AniObject, self).__init__()
            self._size = 0
            self.startsize = 0
            self.maxsize = 32
 
        @pyqtProperty(int)
        def size(self):
            return self._size
 
        @size.setter
        def size(self, value):
            self._size = value
 
    def __init__(self, canvas):
        self.canvas = canvas
        self.map_pos = QgsPoint(0.0, 0.0)
        self.aniobject = PingLocationMarker.AniObject()
        QgsMapCanvasItem.__init__(self, canvas)
        self.anim = QPropertyAnimation(self.aniobject, "size")
        self.anim.setDuration(1000)
        self.anim.setStartValue(self.aniobject.startsize)
        self.anim.setEndValue(self.aniobject.maxsize)
        self.anim.setLoopCount(-1)
        self.anim.valueChanged.connect(self.value_changed)
        self.anim.start()
 
    @property
    def size(self):
        return self.aniobject.size
 
    @property
    def halfsize(self):
        return self.aniobject.maxsize / 2.0
 
    @property
    def maxsize(self):
        return self.aniobject.maxsize
 
    def value_changed(self, value):
        self.update()
 
    def paint(self, painter, xxx, xxx2):
        self.setCenter(self.map_pos)
 
        rect = QRectF(0 - self.halfsize, 0 - self.halfsize, self.size, self.size)
        painter.setRenderHint(QPainter.Antialiasing)
        painter.setBrush(Qt.green)
        painter.setPen(Qt.green)
        painter.drawEllipse(QPointF(0,0), self.size, self.size)
 
    def boundingRect(self):
        return QRectF(-self.halfsize * 2.0, -self.halfsize * 2.0, 2.0 * self.maxsize, 2.0 * self.maxsize)
 
    def setCenter(self, map_pos):
        self.map_pos = map_pos
        self.setPos(self.toCanvasCoordinates(self.map_pos))
 
    def updatePosition(self):
        self.setCenter(self.map_pos)
 
marker = PingLocationMarker(iface.mapCanvas())