QGIS » QGIS Application

"""

/***************************************************************************

         Value Tool       - A QGIS plugin to get values at the mouse pointer

                             -------------------

    begin                : 2008-08-26

    copyright            : (C) 2008 by G. Picard

    email                : 

 ***************************************************************************/

/***************************************************************************

 *                                                                         *

 *   This program is free software; you can redistribute it and/or modify  *

 *   it under the terms of the GNU General Public License as published by  *

 *   the Free Software Foundation; either version 2 of the License, or     *

 *   (at your option) any later version.                                   *

 *                                                                         *

 ***************************************************************************/

 This script initializes the plugin, making it known to QGIS.

"""

from PyQt4.QtCore import *

from PyQt4.QtGui import *

from qgis.core import *

hasqwt=True

try:

    from PyQt4.Qwt5 import QwtPlot,QwtPlotCurve,QwtScaleDiv,QwtSymbol

except:

    hasqwt=False

from valuewidgetbase import Ui_Form

class ValueWidget(QWidget,Ui_Form):

    def __init__(self, iface, canvas):

        QWidget.__init__(self)

        Ui_Form.__init__(self)

        self.setupUi(self)

        self.iface=iface

        self.canvas=canvas

        QObject.connect(self.checkBox_2,SIGNAL("stateChanged(int)"),self.changeActive)

        self.changeActive(Qt.Checked)

        QObject.connect(self.checkBox,SIGNAL("stateChanged(int)"),self.changePage)

        QObject.connect(self.canvas, SIGNAL( "keyPressed( QKeyEvent * )" ), self.pauseDisplay )

        if (hasqwt):

            self.curve = QwtPlotCurve()

            self.curve.setSymbol(

                QwtSymbol(QwtSymbol.Ellipse,

                          QBrush(Qt.white),

                          QPen(Qt.red, 2),

                          QSize(9, 9)))

            self.curve.attach(self.qwtPlot)

    def disconnect(self):

        self.changeActive(False)

        QObject.disconnect(self.canvas, SIGNAL( "keyPressed( QKeyEvent * )" ), self.pauseDisplay )

    def pauseDisplay(self,e):

      if ( e.modifiers() == Qt.ShiftModifier or e.modifiers() == Qt.MetaModifier ) and e.key() == Qt.Key_A:

        self.checkBox_2.toggle()

        return True

      return False

    def keyPressEvent( self, e ):

      if ( e.modifiers() == Qt.ControlModifier or e.modifiers() == Qt.MetaModifier ) and e.key() == Qt.Key_C:

        items = QString()

        for rec in range( self.tableWidget.rowCount() ):

          items.append( '"' + self.tableWidget.item( rec, 0 ).text() + '",' + self.tableWidget.item( rec, 1 ).text() + "\n" )

        if not items.isEmpty():

          clipboard = QApplication.clipboard()

          clipboard.setText( items )

      elif (self.pauseDisplay(e)):

        pass

      else:

        QWidget.keyPressEvent( self, e )

    def changePage(self,state):

        if (state==Qt.Checked):

            self.stackedWidget.setCurrentIndex(1)

        else:

            self.stackedWidget.setCurrentIndex(0)

    def changeActive(self,state):

        if (state==Qt.Checked):

            if int(QGis.QGIS_VERSION[2]) > 2: # for QGIS >= 1.3

                QObject.connect(self.canvas, SIGNAL("xyCoordinates(const QgsPoint &)"), self.printValue)

            else:

                QObject.connect(self.canvas, SIGNAL("xyCoordinates(QgsPoint &)"), self.printValue)

        else:

            if int(QGis.QGIS_VERSION[2]) > 2: # for QGIS >= 1.3

                QObject.disconnect(self.canvas, SIGNAL("xyCoordinates(const QgsPoint &)"), self.printValue)

            else:

                QObject.disconnect(self.canvas, SIGNAL("xyCoordinates(QgsPoint &)"), self.printValue)

    def printValue(self,position):

        mapPos = position

        needextremum= self.checkBox.isChecked() # if plot is checked

        layers=self.iface

        # count the number of requires rows and remember the raster layers

        nrow=0

        rasterlayers=[]

        layersWOStatistics=[]

        for i in range(self.canvas.layerCount()):

            layer = self.canvas.layer(i)

            if (layer!=None and layer.isValid() and layer.type()==QgsMapLayer.RasterLayer):

              if layer.providerKey()=="wms":

                continue

              if layer.providerKey()=="grassraster":

                nrow+=1

                rasterlayers.append(layer)

              else: # normal raster layer

                nrow+=layer.bandCount()

                rasterlayers.append(layer)

              # check statistics for each band

              if needextremum:

                for i in range( 1,layer.bandCount()+1 ):

                  if not layer.hasStatistics(i):

                    layersWOStatistics.append((layer,i))

        if layersWOStatistics:

          self.calculateStatistics(layersWOStatistics)

        # create the row if necessary

        self.tableWidget.setRowCount(nrow)

        irow=0

        self.values=[]

        self.ymin=1e38

        self.ymax=-1e38

        mapCanvasSrs = self.iface.mapCanvas().mapRenderer().destinationSrs()

        for layer in rasterlayers:

            layerSrs = layer.srs()

            pos = mapPos

            if not mapCanvasSrs == layerSrs:

              srsTransform = QgsCoordinateTransform(mapCanvasSrs, layerSrs)

              pos = srsTransform.transform(mapPos)

            isok,ident = layer.identify(pos)

            if not isok:

              continue

            layername=unicode(layer.name())

            if layer.providerKey()=="grassraster":

              if not ident.has_key(QString("value")):

                continue

              cstr = ident[QString("value")]

              if cstr.isNull():

                continue

              value = cstr.toDouble()

              if not value[1]:

                continue

              self.values.append((layername,cstr))

              if needextremum:

                self.ymin = min(self.ymin,value[0])

                self.ymax = max(self.ymax,value[0])

            else:

              for iband in range(1,layer.bandCount()+1): # loop over the bands

                bandvalue=ident[layer.bandName(iband)]

                layernamewithband=layername

                if len(ident)>1:

                    layernamewithband+=' '+layer.bandName(iband)

                self.values.append((layernamewithband,bandvalue))

                if needextremum:

                  cstr=layer.bandStatistics(iband)

                  self.ymin=min(self.ymin,cstr.minimumValue)

                  self.ymax=max(self.ymax,cstr.maximumValue)

        if self.checkBox.isChecked():

          self.plot()

        else:

          self.printInTable()

    def calculateStatistics(self,layersWOStatistics):

      lays= [l[0].name() for l in layersWOStatistics]

      lays = list(set( lays ))

      lays = QStringList() << lays

      res = QMessageBox.warning( self, self.tr( 'Warning' ),

                                 self.tr( 'There are no statistics in the following rasters:\n%1\n\nCalculate?' ).arg(lays.join('\n')),

                                 QMessageBox.Yes | QMessageBox.No )

      if res != QMessageBox.Yes:

        self.checkBox_2.setCheckState(Qt.Unchecked)

        return

      # calculate statistics

      save_state=self.checkBox_2.isChecked()

      self.changeActive(Qt.Unchecked) # deactivate

      for layerband in layersWOStatistics:

        layer,iband=layerband

        stat = layer.bandStatistics(iband)

      if save_state:

        self.changeActive(Qt.Checked) # activate if necessary

    def printInTable(self):

        irow=0

        for row in self.values:

          layername,value=row

          if (self.tableWidget.item(irow,0)==None):

              # create the item

              self.tableWidget.setItem(irow,0,QTableWidgetItem())

              self.tableWidget.setItem(irow,1,QTableWidgetItem())

          self.tableWidget.item(irow,0).setText(layername)

          self.tableWidget.item(irow,1).setText(value)

          irow+=1

    def plot(self):

        if (hasqwt):

            numvalues=[]

            self.qwtPlot.setAxisMaxMinor(QwtPlot.xBottom,0)

            #self.qwtPlot.setAxisMaxMajor(QwtPlot.xBottom,0)

            self.qwtPlot.setAxisScale(QwtPlot.xBottom,1,len(self.values))

            self.qwtPlot.setAxisScale(QwtPlot.yLeft,self.ymin,self.ymax)

            for row in self.values:

                layername,value=row

                try:

                    numvalues.append(float(value))

                except:

                    numvalues.append(0)

            self.curve.setData(range(1,len(numvalues)+1), numvalues)

            self.qwtPlot.replot()

        #try:

                #    attr = float(ident[j])

                #except:

                #    attr = 0

                #    print "Null cell value catched as zero!"  # For none values, profile height = 0. It's not elegant...

                    #nr = rastLayer.getRasterBandNumber(self.rastItems[field[1]][field[2]][0])

                    #print ident

            #for j in ident:

                #print j

                #if j.right(1) == str(nr):

       #attr = int(ident[j])

       #attr = float(ident[j])  ##### I MUST IMPLEMENT RASTER TYPE HANDLING!!!!

       #outFeat.addAttribute(i, QVariant(attr))