feat: Add metadata viewer as napari widget (#1195)

<!-- Generated by sourcery-ai[bot]: start summary -->

## Summary by Sourcery

Add a new LayerMetadata widget to the napari viewer for displaying layer
metadata, update the DictViewer class to use a set_data method, and
include tests for the new widget.

New Features:
- Introduce a new LayerMetadata widget for viewing metadata of layers in
the napari viewer.

Enhancements:
- Modify the DictViewer class to use a set_data method for initializing
data.

Tests:
- Add tests for the LayerMetadata widget to verify its initialization
and functionality with and without layers.

<!-- Generated by sourcery-ai[bot]: end summary -->

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

## Release Notes

- **New Features**
- Introduced the "View Layer Metadata" feature in the Napari interface,
allowing users to view metadata associated with image layers.
- Added a new `LayerMetadata` widget for selecting layers and displaying
their metadata.

- **Bug Fixes**
- Enhanced metadata handling for image layers, ensuring relevant
information is included in layer configurations.

- **Tests**
- Added a new test class for the `LayerMetadata` widget to ensure proper
functionality during initialization and layer updates.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

package/PartSeg/common_gui/dict_viewer.py

@@ -16,7 +16,7 @@ def __init__(self, data: dict | None = None):
         self.layout.addWidget(self.tree)
         self.setLayout(self.layout)
         self.tree.setHeaderLabels(["Key", "Value"])
-        self.data = data
+        self.set_data(data)
 
     def set_data(self, data: dict | None):
         if data is None:

package/PartSeg/napari.yaml

@@ -74,6 +74,9 @@ contributions:
   - id: PartSeg.CopyLabels
     title: Create Copy Labels
     python_name: PartSeg.plugins.napari_widgets:CopyLabelsWidget
+  - id: PartSeg.Metadata
+    title: View Layer Metadata
+    python_name: PartSeg.plugins.napari_widgets:LayerMetadata
   readers:
   - command: PartSeg.load_roi_project
     filename_patterns:
@@ -157,3 +160,5 @@ contributions:
     display_name: Threshold
   - command: PartSeg.Watershed
     display_name: Watershed
+  - command: PartSeg.Metadata
+    display_name: Layer Metadata

package/PartSeg/plugins/napari_widgets/__init__.py

@@ -12,6 +12,7 @@
 from PartSeg.plugins.napari_widgets.copy_labels import CopyLabelsWidget
 from PartSeg.plugins.napari_widgets.lables_control import LabelSelector
 from PartSeg.plugins.napari_widgets.mask_create_widget import MaskCreate
+from PartSeg.plugins.napari_widgets.metadata_viewer import LayerMetadata
 from PartSeg.plugins.napari_widgets.roi_extraction_algorithms import ROIAnalysisExtraction, ROIMaskExtraction
 from PartSeg.plugins.napari_widgets.search_label_widget import SearchLabel
 
@@ -27,6 +28,7 @@
     "Watershed",
     "ImageColormap",
     "LabelSelector",
+    "LayerMetadata",
     "MaskCreate",
     "ROIAnalysisExtraction",
     "ROIMaskExtraction",

package/PartSeg/plugins/napari_widgets/metadata_viewer.py

@@ -0,0 +1,29 @@
+import napari
+from magicgui.widgets import create_widget
+from napari.layers import Image as NapariImage
+from qtpy.QtWidgets import QVBoxLayout, QWidget
+
+from PartSeg.common_gui.dict_viewer import DictViewer
+
+
+class LayerMetadata(QWidget):
+    def __init__(self, viewer: napari.Viewer):
+        super().__init__()
+        self._viewer = viewer
+        self.layer_selector = create_widget(annotation=NapariImage, label="Layer", options={})
+        self._dict_viewer = DictViewer()
+        layout = QVBoxLayout()
+        layout.addWidget(self.layer_selector.native)
+        layout.addWidget(self._dict_viewer)
+
+        self.setLayout(layout)
+        self.update_metadata()
+        self.layer_selector.changed.connect(self.update_metadata)
+
+    def reset_choices(self):
+        self.layer_selector.reset_choices()
+
+    def update_metadata(self):
+        if self.layer_selector.value is None:
+            return
+        self._dict_viewer.set_data(self.layer_selector.value.metadata)

package/PartSegCore/napari_plugins/loader.py

@@ -26,6 +26,7 @@ def _image_to_layers(project_info, scale, translate):
                     "name": project_info.image.channel_names[i],
                     "blending": "additive",
                     "translate": translate,
+                    "metadata": project_info.image.metadata,
                 },
                 "image",
             )

package/tests/test_PartSeg/test_napari_widgets.py

@@ -22,6 +22,7 @@
 from PartSeg.plugins.napari_widgets import (
     CopyLabelsWidget,
     ImageColormap,
+    LayerMetadata,
     MaskCreate,
     ROIAnalysisExtraction,
     ROIMaskExtraction,
@@ -600,6 +601,41 @@ def test_check_uncheck(self, copy_labels, qtbot):
         assert not copy_labels.checkbox_layout.itemAt(0).widget().isChecked()
 
 
+class TestLayerMetadata:
+    def test_init(self, make_napari_viewer, qtbot):
+        viewer = make_napari_viewer()
+        widget = LayerMetadata(viewer)
+        qtbot.addWidget(widget)
+        assert widget._dict_viewer._data == {}
+
+    def test_init_with_layer(self, make_napari_viewer, qtbot):
+        viewer = make_napari_viewer()
+        viewer.add_image(
+            np.ones((10, 10)),
+            contrast_limits=[0, 1],
+            metadata={"foo": "bar"},
+        )
+        widget = LayerMetadata(viewer)
+        viewer.window.add_dock_widget(widget)
+        widget.reset_choices()
+        assert widget.layer_selector.value is not None
+        assert widget._dict_viewer._data == {"foo": "bar"}
+
+    def test_add_layer_post_init(self, make_napari_viewer, qtbot):
+        viewer = make_napari_viewer()
+        widget = LayerMetadata(viewer)
+        viewer.window.add_dock_widget(widget)
+        assert widget._dict_viewer._data == {}
+        viewer.add_image(
+            np.ones((10, 10)),
+            contrast_limits=[0, 1],
+            metadata={"foo": "bar"},
+        )
+        widget.reset_choices()
+        assert widget.layer_selector.value is not None
+        assert widget._dict_viewer._data == {"foo": "bar"}
+
+
 def test_enum():
     assert " " in str(CompareType.lower_threshold)
     assert " " in str(FlowType.dark_center)