Fix channel selector when duplicate channels present (resolve #11)

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

@@ -0,0 +1,26 @@
+package qupath.ext.instanseg.core;
+
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+public class InstanSegUtils {
+    private static final Logger logger = LoggerFactory.getLogger(InstanSegUtils.class);
+
+    private InstanSegUtils() {
+        throw new AssertionError("Do not instantiate this class");
+    }
+
+    public static boolean isValidModel(Path path) {
+        // return path.toString().endsWith(".pt"); // if just looking at pt files
+        if (Files.isDirectory(path)) {
+            return Files.exists(path.resolve("instanseg.pt")) && Files.exists(path.resolve("rdf.yaml"));
+        }
+        return false;
+    }
+
+}

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

@@ -0,0 +1,34 @@
+package qupath.ext.instanseg.ui;
+
+import qupath.lib.images.servers.ColorTransforms;
+
+/**
+ * Super simple class to deal with channel selection dropdown items that have different display and selection names.
+ * e.g., the first channel in non-RGB images is shown as "Channel 1 (C1)" but the actual name is "Channel 1".
+ */
+class ChannelSelectItem {
+    private final String name;
+    private final ColorTransforms.ColorTransform transform;
+    ChannelSelectItem(String name) {
+        this.name = name;
+        this.transform = ColorTransforms.createChannelExtractor(name);
+    }
+
+    ChannelSelectItem(String name, ColorTransforms.ColorTransform transform) {
+        this.name = name;
+        this.transform = transform;
+    }
+
+    @Override
+    public String toString() {
+        return this.name;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public ColorTransforms.ColorTransform getTransform() {
+        return transform;
+    }
+}