layer_style_loader.py

# -*- coding: utf-8 -*-
"""
/***************************************************************************
 LayerStyleLoader
                                 A QGIS plugin
 Load multiple layer styles based on layer names
                              -------------------
        begin                : 2016-09-16
        git sha              : $Format:%H$
        copyright            : (C) 2016 by Bernd Loigge
        email                : bernd.loigge@gmx.at
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
"""
from __future__ import absolute_import
from builtins import str
from builtins import object
from qgis.core import QgsProject
from qgis.PyQt.QtCore import QSettings, QTranslator, qVersion, QCoreApplication, Qt
from qgis.PyQt.QtWidgets import QAction, QFileDialog
from qgis.PyQt.QtGui import QIcon
# Initialize Qt resources from file resources.py
from . import resources

# Import the code for the DockWidget
from .layer_style_loader_dockwidget import LayerStyleLoaderDockWidget
import os.path
project = QgsProject.instance()


class LayerStyleLoader(object):
    """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',
            'LayerStyleLoader_{}.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)

        # Declare instance attributes
        self.actions = []
        self.menu = self.tr(u'&Layer Style Loader')
        # TODO: We are going to let the user set this up in a future iteration
        self.toolbar = self.iface.addToolBar(u'LayerStyleLoader')
        self.toolbar.setObjectName(u'LayerStyleLoader')

        #print "** INITIALIZING LayerStyleLoader"

        self.pluginIsActive = False
        self.dockwidget = None


    # 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('LayerStyleLoader', message)


    def add_action(
        self,
        icon_path,
        text,
        callback,
        enabled_flag=True,
        add_to_menu=True,
        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/LayerStyleLoader/icon.png'
        self.add_action(
            icon_path,
            text=self.tr(u'Load Layer Styles'),
            callback=self.run,
            parent=self.iface.mainWindow())

    #--------------------------------------------------------------------------

    def onClosePlugin(self):
        """Cleanup necessary items here when plugin dockwidget is closed"""

        #print "** CLOSING LayerStyleLoader"

        # disconnects
        self.dockwidget.closingPlugin.disconnect(self.onClosePlugin)
        self.iface.newProjectCreated.disconnect(self.loadFolderPathInProject)
        self.iface.projectRead.disconnect(self.loadFolderPathInProject)

        # remove this statement if dockwidget is to remain
        # for reuse if plugin is reopened
        # Commented next statement since it causes QGIS crashe
        # when closing the docked window:
        self.dockwidget = None

        self.pluginIsActive = False


    def unload(self):
        """Removes the plugin menu item and icon from QGIS GUI."""

        
        
        #print "** UNLOAD LayerStyleLoader"

        for action in self.actions:
            self.iface.removePluginMenu(
                self.tr(u'&Layer Style Loader'),
                action)
            self.iface.removeToolBarIcon(action)
        # remove the toolbar
        del self.toolbar


        
    #--------------------------------------------------------------------------

    def run(self):
        """Run method that loads and starts the plugin"""

        if not self.pluginIsActive:
            self.pluginIsActive = True

            #print "** STARTING LayerStyleLoader"

            # dockwidget may not exist if:
            #    first run of plugin
            #    removed on close (see self.onClosePlugin method)
            if self.dockwidget == None:
                # Create the dockwidget (after translation) and keep reference
                self.dockwidget = LayerStyleLoaderDockWidget()

            # connect to provide cleanup on closing of dockwidget
            self.dockwidget.closingPlugin.connect(self.onClosePlugin)

            # show the dockwidget
            # TODO: fix to allow choice of dock location
            self.iface.addDockWidget(Qt.LeftDockWidgetArea, self.dockwidget)
            self.dockwidget.show()
            
            # Check if new project gets opend or file loaded
            
            self.iface.newProjectCreated.connect(self.loadFolderPathInProject)
            self.iface.projectRead.connect(self.loadFolderPathInProject)
            
            # Load Init Stuff
            # Load Folder Path if exists
            self.loadFolderPathInProject()
            
            self.dockwidget.pushButton.clicked.connect(self.selectParentFolder)
            self.dockwidget.pushButton_2.clicked.connect(self.loadLayerStyles) 


    #--------------------------------------------------------------------------
    
    def selectParentFolder(self):
        global project
        cPath = project.readEntry("styles", "styleLayerPath", "nothing")[0]
        naming = "Select Parent Style Folder"
        if  cPath != "nothing":
            folderpath = QFileDialog.getExistingDirectory(self.dockwidget, naming, cPath)
        else:
            folderpath = QFileDialog.getExistingDirectory(self.dockwidget, naming, os.path.expanduser("~"))
        
        
        
        if folderpath != "":
            self.saveFolderPathInProject(folderpath)
            self.loadFolderPathInProject()
            self.updateStyleListComboBox()
        
    def saveFolderPathInProject(self, folderpath):
        global project
        project.writeEntry("styles", "styleLayerPath", folderpath)
        
    def loadFolderPathInProject(self):
        global project
        folderpath = project.readEntry("styles", "styleLayerPath", "nothing")[0]
        if folderpath != "nothing":
            self.dockwidget.lineEdit.setText(folderpath)
            self.updateStyleListComboBox()
        else:
            self.dockwidget.lineEdit.setText("")
        
    def updateStyleListComboBox(self):
        global project
        folderpath = project.readEntry("styles", "styleLayerPath", "nothing")[0]
        if folderpath != "":
            comboBox = self.dockwidget.comboBox
            comboBox.clear()
            data = os.listdir(folderpath)
            folder = []
            for content in data:
                if os.path.isdir(folderpath + os.path.normcase("/") + str(content)):
                    folder.append(content)
            comboBox.addItems(folder)
            
    def loadLayerStyles(self):
        global project
        folderpath = project.readEntry("styles", "styleLayerPath", "nothing")[0]
        styling = folderpath + os.path.normcase("/") + self.dockwidget.comboBox.currentText()
        
        # Check if any QML File in Folder
        for myFile in (os.listdir(styling)):
            layer = self.getLayerByName(os.path.splitext(myFile)[0])
            if layer != False:
                layer.loadNamedStyle(styling + os.path.normcase("/") + myFile)
                self.iface.mapCanvas().refresh()
                self.iface.mapCanvas().refreshAllLayers()          
    
    def getLayerByName(self, name):
        global project
        myLegendLayers = layers = [tree_layer.layer() for tree_layer in QgsProject.instance().layerTreeRoot().findLayers()]
        for myLayer in myLegendLayers:
            if name == myLayer.name():
                return myLayer
        return False