Add pixel size warning and minor linting

src/main/java/qupath/ext/instanseg/core/InstanSeg.java

@@ -173,10 +173,16 @@ private InstanSegResults runInstanSeg(ImageData<BufferedImage> imageData, Collec
         String layoutOutput = "CHW";
 
         // Get the downsample - this may be specified by the user, or determined from the model spec
+        if (!imageData.getServerMetadata().pixelSizeCalibrated()) {
+            logger.warn("Running InstanSeg without pixel calibration --- results may not be as expected!");
+        }
         double downsample;
         if (this.downsample > 0) {
             downsample = this.downsample;
             logger.debug("Calling InstanSeg with user-specified downsample {}", downsample);
+        } else if (!imageData.getServerMetadata().pixelSizeCalibrated()) {
+            downsample = 1.0;
+            logger.debug("No pixel calibration - defaulting to a downsample of 1.0");
         } else {
             downsample = this.model.getPreferredDownsample(imageData.getServer().getPixelCalibration());
             logger.debug("Calling InstanSeg with calculated downsample {}", downsample);

src/main/java/qupath/ext/instanseg/ui/InstanSegController.java

@@ -137,7 +137,7 @@ public class InstanSegController extends BorderPane {
     private List<InstanSegModel> remoteModels;
 
     // Listener for property changes in the current ImageData; these can be required to update the input channels
-    private PropertyChangeListener imageDataPropertyChangeListener = this::handleImageDataPropertyChange;
+    private final PropertyChangeListener imageDataPropertyChangeListener = this::handleImageDataPropertyChange;
 
     /**
      * Create an instance of the InstanSeg GUI pane.
@@ -715,6 +715,9 @@ private void runInstanSeg(InstanSegModel model) {
             Dialogs.showErrorNotification(resources.getString("title"), resources.getString("error.no-imagedata"));
             return;
         }
+        if (!imageData.getServerMetadata().pixelSizeCalibrated()) {
+            Dialogs.showWarningNotification(resources.getString("title"), resources.getString("error.no-pixel-size"));
+        }
 
         if (!PytorchManager.hasPyTorchEngine()) {
             if (!Dialogs.showConfirmDialog(resources.getString("title"), resources.getString("ui.pytorch"))) {

src/main/java/qupath/ext/instanseg/ui/InstanSegUtils.java

@@ -18,10 +18,10 @@
 class InstanSegUtils {
 
     private InstanSegUtils() {
-        // Prevent instantiation
+        throw new UnsupportedOperationException("This class should not be instantiated.");
     }
 
-    private static ObjectBinding<Path> modelDirectoryBinding = Bindings.createObjectBinding(
+    private static final ObjectBinding<Path> modelDirectoryBinding = Bindings.createObjectBinding(
                 () -> tryToGetPath(InstanSegPreferences.modelDirectoryProperty().get()),
                 InstanSegPreferences.modelDirectoryProperty()
         );

src/main/resources/qupath/ext/instanseg/ui/strings.properties

@@ -109,6 +109,7 @@ ui.prefs.permit-online.description = Allow QuPath to check for new InstanSeg mod
 ## Errors
 error.window = Error initializing InstanSeg window.\nAn internet connection is required when running for the first time.
 error.no-imagedata = Cannot run InstanSeg without an image available.
+error.no-pixel-size = Pixel size is not set in this image! Results may be inaccurate.
 error.downloading = Error downloading files
 error.querying-local = Error querying local files
 error.localModel = Can't find file in user model directory