Add a restore geopackage button to restore plugin state from QGIS pro…

…ject

Fixes #127

plugin/qgistim/widgets/dataset_widget.py

@@ -21,6 +21,7 @@
     QCheckBox,
     QComboBox,
     QFileDialog,
+    QGroupBox,
     QHBoxLayout,
     QHeaderView,
     QLineEdit,
@@ -272,14 +273,16 @@ def __init__(self, parent):
         self.new_geopackage_button = QPushButton("New")
         self.open_geopackage_button = QPushButton("Open")
         self.copy_geopackage_button = QPushButton("Copy")
+        self.restore_geopackage_button = QPushButton("Restore")
         self.transient_combo_box = QComboBox()
         self.transient_combo_box.addItems(["Steady-state", "Transient"])
         self.transient_combo_box.currentTextChanged.connect(self.on_transient_changed)
-        self.remove_button = QPushButton("Remove from GeoPackage")
+        self.remove_button = QPushButton("Remove from Model")
         self.add_button = QPushButton("Add to QGIS")
         self.new_geopackage_button.clicked.connect(self.new_geopackage)
         self.open_geopackage_button.clicked.connect(self.open_geopackage)
         self.copy_geopackage_button.clicked.connect(self.copy_geopackage)
+        self.restore_geopackage_button.clicked.connect(self.restore_geopackage)
         self.suppress_popup_checkbox = QCheckBox("Suppress attribute form pop-up")
         self.suppress_popup_checkbox.stateChanged.connect(self.suppress_popup_changed)
         self.remove_button.clicked.connect(self.remove_geopackage_layer)
@@ -288,18 +291,29 @@ def __init__(self, parent):
         self.convert_button.clicked.connect(self.convert_to_python)
         # Layout
         dataset_layout = QVBoxLayout()
+
+        # Add geopackage management
+        geopackage_group = QGroupBox("GeoPackage")
+        geopackage_layout = QVBoxLayout()
+        geopackage_group.setLayout(geopackage_layout)
+        geopackage_layout.addWidget(self.dataset_line_edit)
+        geopackage_row = QHBoxLayout()
+        geopackage_row.addWidget(self.open_geopackage_button)
+        geopackage_row.addWidget(self.new_geopackage_button)
+        geopackage_row.addWidget(self.copy_geopackage_button)
+        geopackage_row.addWidget(self.restore_geopackage_button)
+        geopackage_layout.addLayout(geopackage_row)
+        dataset_layout.addWidget(geopackage_group)
+
+        # Transient versus steady-state selector
         mode_row = QHBoxLayout()
-        dataset_row = QHBoxLayout()
-        layer_row = QHBoxLayout()
-        dataset_row.addWidget(self.dataset_line_edit)
-        dataset_row.addWidget(self.open_geopackage_button)
-        dataset_row.addWidget(self.new_geopackage_button)
-        dataset_row.addWidget(self.copy_geopackage_button)
-        dataset_layout.addLayout(dataset_row)
         mode_row.addWidget(self.transient_combo_box)
         dataset_layout.addLayout(mode_row)
+        # Dataset table and suppression checkbox
         dataset_layout.addWidget(self.dataset_tree)
+        # Assorted widgets
         dataset_layout.addWidget(self.suppress_popup_checkbox)
+        layer_row = QHBoxLayout()
         layer_row.addWidget(self.add_button)
         layer_row.addWidget(self.remove_button)
         dataset_layout.addLayout(layer_row)
@@ -348,15 +362,17 @@ def add_selection_to_qgis(self) -> None:
             self.add_item_to_qgis(item)
         return
 
-    def load_geopackage(self) -> None:
+    def load_geopackage(
+        self, input_group: str = None, output_group: str = None
+    ) -> None:
         """
         Load the layers of a GeoPackage into the Layers Panel
         """
         self.dataset_tree.clear()
 
         name = str(Path(self.path).stem)
-        self.parent.create_input_group(name)
-        self.parent.create_output_group(name)
+        self.parent.create_input_group(name, input_group)
+        self.parent.create_output_group(name, output_group)
 
         elements = load_elements_from_geopackage(self.path)
         for element in elements:
@@ -372,6 +388,7 @@ def load_geopackage(self) -> None:
         self.on_transient_changed()
 
         self.model_crs = self.domain_item().element.timml_layer.crs()
+        self.parent.qgs_project.writeEntry("qgistim", "geopackage_path", self.path)
         return
 
     def new_geopackage(self) -> None:
@@ -420,6 +437,9 @@ def copy_geopackage(self) -> None:
         """
         Copy a GeoPackage file, containing qgis-tim, and open it.
         """
+        # Do nothing if there's nothing to copy.
+        if self.path == "":
+            return
         self.dataset_tree.clear()
         target_path, _ = QFileDialog.getSaveFileName(self, "Select file", "", "*.gpkg")
         if target_path != "":  # Empty string in case of cancel button press
@@ -437,6 +457,30 @@ def copy_geopackage(self) -> None:
             self.load_geopackage()
         return
 
+    def restore_geopackage(self) -> None:
+        qgs_project = self.parent.qgs_project
+        geopackage_path, success = qgs_project.readEntry("qgistim", "geopackage_path")
+        if not success:
+            self.parent.message_bar.pushMessage(
+                title="Error",
+                text="Could not find a QGIS-Tim GeoPackage in this QGS Project.",
+                level=Qgis.Critical,
+            )
+            return
+
+        if not Path(geopackage_path).exists():
+            self.parent.message_bar.pushMessage(
+                title="Error",
+                text=f"QGIS-Tim Geopackage {geopackage_path} does not exist.",
+                level=Qgis.Critical,
+            )
+
+        input_group_name, _ = qgs_project.readEntry("qgistim", "input_group")
+        output_group_name, _ = qgs_project.readEntry("qgistim", "output_group")
+        self.dataset_line_edit.setText(geopackage_path)
+        self.load_geopackage(input_group_name, output_group_name)
+        return
+
     def remove_geopackage_layer(self) -> None:
         """
         Remove layers from:

plugin/qgistim/widgets/tim_widget.py

@@ -1,11 +1,11 @@
 """
 This module forms the high level DockWidget.
 
-It ensures the underlying widgets can talk to each other.  It also manages the
+It ensures the underlying widgets can talk to each other. It also manages the
 connection to the QGIS Layers Panel, and ensures there is a group for the Tim
 layers there.
 """
-from typing import Any, Dict, Union
+from typing import Any, Dict, Optional, Union
 
 from PyQt5.QtCore import Qt
 from PyQt5.QtWidgets import (
@@ -15,7 +15,13 @@
     QVBoxLayout,
     QWidget,
 )
-from qgis.core import QgsApplication, QgsEditFormConfig, QgsMapLayer, QgsProject
+from qgis.core import (
+    QgsApplication,
+    QgsEditFormConfig,
+    QgsLayerTreeGroup,
+    QgsMapLayer,
+    QgsProject,
+)
 from qgistim.core.server_handler import ServerHandler
 from qgistim.core.task import BaseServerTask
 from qgistim.widgets.compute_widget import ComputeWidget
@@ -32,13 +38,19 @@ def __init__(
         self,
         root,
         name: str,
+        group_name: Optional[QgsLayerTreeGroup] = None,
     ):
         self.name = name
         self.root = root
         self.subgroups = {}
-        self.create_group()
-
-    def create_group(self):
+        self.create_group(group_name)
+
+    def _create_group(self, group_name: str):
+        if group_name is not None:
+            self.group = self.root.findGroup(group_name)
+            if self.group is not None:
+                self.group.removeAllChildren()
+                return
         self.group = self.root.addGroup(self.name)
         return
 
@@ -147,6 +159,18 @@ def add_layer(
         return maplayer
 
 
+class InputGroup(LayersPanelGroup):
+    def create_group(self, group=None):
+        QgsProject.instance().writeEntry("qgistim", "input_group", self.name)
+        self._create_group(group)
+
+
+class OutputGroup(LayersPanelGroup):
+    def create_group(self, group=None):
+        QgsProject.instance().writeEntry("qgistim", "output_group", self.name)
+        self._create_group(group)
+
+
 class StartTask(BaseServerTask):
     @property
     def task_description(self):
@@ -208,6 +232,10 @@ def __init__(self, parent, iface):
         # QGIS Layers Panel groups
         self.input_group = None
         self.output_group = None
+
+        # Connect to the project saved signal.
+        # Note that the project is a singleton instance, so it's always up to date.
+        self.qgs_project = QgsProject.instance()
         return
 
     # Inter-widget communication
@@ -293,16 +321,16 @@ def add_element(self, element: Any):
 
     # QGIS layers
     # -----------
-    def create_input_group(self, name: str) -> None:
-        root = QgsProject.instance().layerTreeRoot()
-        self.input_group = LayersPanelGroup(root, f"{name} input")
+    def create_input_group(self, name: str, group: str = None) -> None:
+        root = self.qgs_project.layerTreeRoot()
+        self.input_group = InputGroup(root, f"{name} input", group)
         self.input_group.create_subgroup("timml")
         self.input_group.create_subgroup("ttim")
         return
 
-    def create_output_group(self, name: str) -> None:
-        root = QgsProject.instance().layerTreeRoot()
-        self.output_group = LayersPanelGroup(root, f"{name} output")
+    def create_output_group(self, name: str, group: str = None) -> None:
+        root = self.qgs_project.layerTreeRoot()
+        self.output_group = OutputGroup(root, f"{name} output", group)
         # Pre-create the groups here to make sure the vector group ends up on top.
         # Apparently moving it destroys the group?
         self.output_group.create_subgroup("vector")