freehandeditingtool.py

# -*- coding: utf-8 -*-

from PyQt5.QtCore import *
from PyQt5.QtGui import *
from PyQt5.QtWidgets import *
from qgis.core import *
from qgis.gui import *


class FreehandEditingTool(QgsMapTool):

    rbFinished = pyqtSignal('QgsGeometry*')

    def __init__(self, canvas):
        QgsMapTool.__init__(self, canvas)
        self.canvas = canvas
        self.rb = None
        self.mCtrl = None
        self.drawing = False
        self.ignoreclick = False
        #our own fancy cursor
        self.cursor = QCursor(QPixmap(["16 16 3 1",
                                       "      c None",
                                       ".     c #FF0000",
                                       "+     c #faed55",
                                       "                ",
                                       "       +.+      ",
                                       "      ++.++     ",
                                       "     +.....+    ",
                                       "    +.  .  .+   ",
                                       "   +.   .   .+  ",
                                       "  +.    .    .+ ",
                                       " ++.    .    .++",
                                       " ... ...+... ...",
                                       " ++.    .    .++",
                                       "  +.    .    .+ ",
                                       "   +.   .   .+  ",
                                       "   ++.  .  .+   ",
                                       "    ++.....+    ",
                                       "      ++.++     ",
                                       "       +.+      "]))

    def keyPressEvent(self, event):
        if event.key() == Qt.Key_Control:
            self.mCtrl = True
            print("ctrl")

    def keyReleaseEvent(self, event):
        if event.key() == Qt.Key_Control:
            self.mCtrl = False
            print("ctrl release")

    def canvasPressEvent(self, event):

        if self.ignoreclick or self.drawing:

            # ignore secondary canvasPressEvents if already drag-drawing
            # NOTE: canvasReleaseEvent will still occur (ensures rb is deleted)
            # click on multi-button input device will halt drag-drawing
            return
        layer = self.canvas.currentLayer()
        if layer is None:
            return
        self.drawing = True
        self.type = layer.geometryType()
        self.isPolygon = (self.type != 1)
        if self.isPolygon:

            self.rb = QgsRubberBand(self.canvas, QgsWkbTypes.PolygonGeometry)
            self.rb.setColor(QColor(255, 0, 0, 63))
            self.rb.setWidth(2)
        else:

            self.rb = QgsRubberBand(self.canvas)
            self.rb.setColor(QColor(255, 0, 0, 150))
            self.rb.setWidth(1)
        x = event.pos().x()
        y = event.pos().y()
        if self.type == 1:
            if self.mCtrl:

                startingPoint = QPoint(x, y)
                snapper = QgsMapCanvasSnappingUtils(self.canvas)
                result = snapper.snapToCurrentLayer(startingPoint,QgsPointLocator.Vertex)

                if result.point().x() != 0 and result.point().y() != 0:

                    point = QgsPointXY()
                    point.setX(result.point().x())
                    point.setY(result.point().y())

                else:

                    point = self.toLayerCoordinates(layer, event.pos())
            else:
                point = self.toLayerCoordinates(layer, event.pos())

            pointMap = self.toMapCoordinates(layer, point)
            self.rb.addPoint(pointMap)
        else:
            point = self.toLayerCoordinates(layer, event.pos())
            pointMap = self.toMapCoordinates(layer, point)
            self.rb.addPoint(pointMap)

    def canvasMoveEvent(self, event):
        if self.ignoreclick or not self.rb:
            return
        self.rb.addPoint(self.toMapCoordinates(event.pos()))


    def canvasReleaseEvent(self, event):
        if self.ignoreclick:
            return
        self.drawing = False
        if not self.rb:
            return
        if self.rb.numberOfVertices() > 2:
            geom = self.rb.asGeometry()
            self.rbFinished.emit(geom)

        # reset rubberband and refresh the canvas
        self.rb.reset()
        self.rb = None
        self.isPolygon = (self.type != 1)
        self.canvas.refresh()

    def setIgnoreClick(self, ignore):
        """Used to keep the tool from registering clicks during modal dialogs"""
        self.ignoreclick = ignore

    def showSettingsWarning(self):
        pass

    def activate(self):
        mc = self.canvas
        mc.setCursor(self.cursor)
        # Check whether Geometry is a Line or a Polygon
        layer = mc.currentLayer()
        self.type = layer.geometryType()
        # toolbar button is only active with editable line and polygon layers
        self.isPolygon = (self.type != 1)

    def deactivate(self):
        pass

    def isZoomTool(self):
        return False

    def isTransient(self):
        return False

    def isEditTool(self):
        return True