pgraster_import.py

# -*- coding: utf-8 -*-
"""
/***************************************************************************
 PGRasterImport
                                 A QGIS plugin
 Import Raster to PgRaster
 Generated by Plugin Builder: http://g-sherman.github.io/Qgis-Plugin-Builder/
                              -------------------
        begin                : 2021-06-24
        git sha              : $Format:%H$
        copyright            : (C) 2021 by Dr. Horst Duester / Sourcepols
        email                : horst.duester@sourcepole.ch
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
"""

import os.path

from qgis.core import QgsApplication
from qgis.PyQt.QtCore import (
    QSettings,
    QTranslator,
    QCoreApplication
)
from qgis.PyQt.QtGui import QIcon
from qgis.PyQt.QtWidgets import QAction, QMenu

# Initialize Qt resources from file resources.py
from .resources_rc import *
# Import the code for the dialog
from .pgraster_import_dialog_base import PGRasterImportDialog
from .pgraster_create_overviews_dialog import PGRasterCreateOverviewsDialog


class PGRasterImport:
    """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',
            'PGRasterImport_{}.qm'.format(locale))

        if os.path.exists(locale_path):
            self.translator = QTranslator()
            self.translator.load(locale_path)
            QCoreApplication.installTranslator(self.translator)

        # Declare instance attributes
        self.actions = []
        self.menu = None

        # Check if plugin was started the first time in current QGIS session
        # Must be set in initGui() to survive plugin reloads
        self.first_start = 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('PGRasterImport', 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:
            # Adds plugin icon to Plugins toolbar
            self.iface.addDatabaseToolBarIcon(action)

        if add_to_menu:
            self.menu.addAction(action)

        self.actions.append(action)

        return action

    def initGui(self):
        """Create the menu entries and toolbar icons inside the QGIS GUI."""

        resource_prefix = ':/plugins/pgraster_import/icons'        
        self.menu = QMenu(self.tr('&PostGIS Raster Import'))
        self.menu.setIcon(QIcon(resource_prefix + '/icon.png'))
        self.add_action(
            resource_prefix + '/NewRasterLayer.svg',
            text=self.tr('Import raster into database'),
            callback=self.raster_import,
            parent=self.iface.mainWindow())
        self.add_action(
            QgsApplication.getThemeIcon('/mIconPyramid.svg'),
            text=self.tr('Create overviews for existing layer'),
            callback=self.create_overviews,
            parent=self.iface.mainWindow())
        self.iface.databaseMenu().addMenu(self.menu)

        self.first_start = True
        self.dlg_create_overviews = None

    def unload(self):
        """Removes the plugin menu item and icon from QGIS GUI."""
        for action in self.actions:
            if self.menu:
                self.menu.removeAction(action)
            self.iface.removeDatabaseToolBarIcon(action)
        self.iface.databaseMenu().removeAction(self.menu.menuAction())
        self.menu = None

    def raster_import(self):
        """Run method that performs all the real work"""

        # Create the dialog with elements (after translation) and keep reference
        # Only create GUI ONCE in callback, so that it will only load when the plugin is started
        if self.first_start == True:
            self.first_start = False
            self.dlg = PGRasterImportDialog(self.iface)

        # show the dialog
        self.dlg.show()
        # Run the dialog event loop
        result = self.dlg.exec_()
        # See if OK was pressed
        if result:
            # Do something useful here - delete the line containing pass and
            # substitute with your code.
            pass

    def create_overviews(self):
        if not self.dlg_create_overviews:
            self.dlg_create_overviews = PGRasterCreateOverviewsDialog(self.iface)
        self.dlg_create_overviews.open_dialog()