QGIS/python/plugins/processing/gui/ExtentSelectionPanel.py

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

"""
***************************************************************************
    ExtentSelectionPanel.py
    ---------------------
    Date                 : August 2012
    Copyright            : (C) 2012 by Victor Olaya
    Email                : volayaf at gmail dot com
***************************************************************************
*                                                                         *
*   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.                                   *
*                                                                         *
***************************************************************************
"""

__author__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

from qgis.core import *
from PyQt4 import QtGui, QtCore
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from processing import interface
from processing.gui.RectangleMapTool import RectangleMapTool
from processing.parameters.ParameterRaster import ParameterRaster
from processing.parameters.ParameterVector import ParameterVector
from processing.parameters.ParameterMultipleInput import ParameterMultipleInput
from processing.tools import dataobjects


class ExtentSelectionPanel(QtGui.QWidget):

    def __init__(self, dialog, alg, default):
        super(ExtentSelectionPanel, self).__init__(None)
        self.dialog = dialog
        self.params = alg.parameters
        self.horizontalLayout = QtGui.QHBoxLayout(self)
        self.horizontalLayout.setSpacing(2)
        self.horizontalLayout.setMargin(0)
        self.text = QtGui.QLineEdit()
        self.text.setSizePolicy(QtGui.QSizePolicy.Expanding,
                                QtGui.QSizePolicy.Expanding)
        if self.canUseAutoExtent():
            if hasattr(self.text, 'setPlaceholderText'):
                self.text.setPlaceholderText(
                        '[Leave blank to use min covering extent]')
        self.horizontalLayout.addWidget(self.text)
        self.pushButton = QtGui.QPushButton()
        self.pushButton.setText('...')
        self.pushButton.clicked.connect(self.buttonPushed)
        self.horizontalLayout.addWidget(self.pushButton)
        self.setLayout(self.horizontalLayout)
        canvas = interface.iface.mapCanvas()
        self.prevMapTool = canvas.mapTool()
        self.tool = RectangleMapTool(canvas)
        self.connect(self.tool, SIGNAL('rectangleCreated()'), self.fillCoords)

    def canUseAutoExtent(self):
        for param in self.params:
            if isinstance(param, (ParameterRaster, ParameterVector)):
                return True
            if isinstance(param, ParameterMultipleInput):
                return True

        return False

    def buttonPushed(self):
        popupmenu = QMenu()
        useLayerExtentAction = QtGui.QAction('Use layer/canvas extent',
                self.pushButton)
        useLayerExtentAction.triggered.connect(self.useLayerExtent)
        popupmenu.addAction(useLayerExtentAction)
        selectOnCanvasAction = QtGui.QAction('Select extent on canvas',
                self.pushButton)
        selectOnCanvasAction.triggered.connect(self.selectOnCanvas)
        popupmenu.addAction(selectOnCanvasAction)
        if self.canUseAutoExtent():
            useMincoveringExtentAction = \
                QtGui.QAction('Use min convering extent from input layers',
                              self.pushButton)
            useMincoveringExtentAction.triggered.connect(
                    self.useMinCoveringExtent)
            popupmenu.addAction(useMincoveringExtentAction)

        popupmenu.exec_(QtGui.QCursor.pos())

    def useMinCoveringExtent(self):
        self.text.setText('')

    def getMinCoveringExtent(self):
        first = True
        found = False
        for param in self.params:
            if param.value:
                if isinstance(param, (ParameterRaster, ParameterVector)):
                    if isinstance(param.value, (QgsRasterLayer,
                                  QgsVectorLayer)):
                        layer = param.value
                    else:
                        layer = dataobjects.getObjectFromUri(param.value)
                    if layer:
                        found = True
                        self.addToRegion(layer, first)
                        first = False
                elif isinstance(param, ParameterMultipleInput):
                    layers = param.value.split(';')
                    for layername in layers:
                        layer = dataobjects.getObjectFromUri(layername, first)
                        if layer:
                            found = True
                            self.addToRegion(layer, first)
                            first = False
        if found:
            return str(self.xmin) + ',' + str(self.xmax) + ',' \
                + str(self.ymin) + ',' + str(self.ymax)
        else:
            return None

    def useNewAlg(self, alg):
        self.params = alg.parameters

    def addToRegion(self, layer, first):
        if first:
            self.xmin = layer.extent().xMinimum()
            self.xmax = layer.extent().xMaximum()
            self.ymin = layer.extent().yMinimum()
            self.ymax = layer.extent().yMaximum()
        else:
            self.xmin = min(self.xmin, layer.extent().xMinimum())
            self.xmax = max(self.xmax, layer.extent().xMaximum())
            self.ymin = min(self.ymin, layer.extent().yMinimum())
            self.ymax = max(self.ymax, layer.extent().yMaximum())

    def useLayerExtent(self):
        CANVAS_KEY = 'Use canvas extent'
        extentsDict = {}
        extentsDict[CANVAS_KEY] = interface.iface.mapCanvas().extent()
        extents = [CANVAS_KEY]
        layers = dataobjects.getAllLayers()
        for layer in layers:
            extents.append(layer.name())
            extentsDict[layer.name()] = layer.extent()
        (item, ok) = QtGui.QInputDialog.getItem(self, 'Select extent',
                'Use extent from', extents, False)
        if ok:
            self.setValueFromRect(extentsDict[item])

    def selectOnCanvas(self):
        canvas = interface.iface.mapCanvas()
        canvas.setMapTool(self.tool)
        self.dialog.showMinimized()

    def fillCoords(self):
        r = self.tool.rectangle()
        self.setValueFromRect(r)

    def setValueFromRect(self, r):
        s = str(r.xMinimum()) + ',' + str(r.xMaximum()) + ',' \
            + str(r.yMinimum()) + ',' + str(r.yMaximum())
        self.text.setText(s)
        self.tool.reset()
        canvas = interface.iface.mapCanvas()
        canvas.setMapTool(self.prevMapTool)
        self.dialog.showNormal()
        self.dialog.raise_()
        self.dialog.activateWindow()

    def getValue(self):
        if str(self.text.text()).strip() != '':
            return str(self.text.text())
        else:
            return self.getMinCoveringExtent()