Fix grid views to show without measurements

Fixes qupath#1472
Also speeds up the animations a bit (as they were quite sluggish) and sets a 'No measurements!' placeholder in the combo box when there are no measurements available.

qupath-gui-fx/src/main/java/qupath/lib/gui/commands/PathObjectGridView.java

@@ -211,9 +211,10 @@ private static List<PathObject> getAnnotations(PathObjectHierarchy hierarchy) {
 	 * @return
 	 */
 	public Stage getStage() {
-		if (stage == null)
+		if (stage == null) {
 			initializeGUI();
 			stage.setWidth(600);
+		}
 		return stage;
 	}
 
@@ -306,9 +307,7 @@ private void initializeData(ImageData<BufferedImage> imageData) {
 
 		String m = measurement.getValue();
 		sortPathObjects(backingList, model, m, descending.get());
-		filteredList.setPredicate(p -> {
-			return !(isMissingCore(p) || Double.isNaN(model.getNumericValue(p, m)));
-		});
+		filteredList.setPredicate(p -> m == null || !(isMissingCore(p) || Double.isNaN(model.getNumericValue(p, m))));
 		grid.getItems().setAll(filteredList);
 
 		// Select the first measurement if necessary
@@ -345,6 +344,7 @@ private void initializeGUI() {
 
 
 		comboMeasurement = new ComboBox<>();
+		comboMeasurement.setPlaceholder(createPlaceholderText("No measurements!"));
 		comboMeasurement.setItems(model.getMeasurementNames());
 		if (!comboMeasurement.getItems().isEmpty())
 			comboMeasurement.getSelectionModel().select(0);
@@ -375,14 +375,7 @@ private void initializeGUI() {
 
 		CheckBox cbShowMeasurement = new CheckBox("Show measurement");
 		showMeasurement.bind(cbShowMeasurement.selectedProperty());
-		showMeasurement.addListener(c -> {
-			String m = measurement.getValue();
-			sortPathObjects(backingList, model, m, descending.get());
-			filteredList.setPredicate(p -> {
-				return m == null || !(isMissingCore(p) || Double.isNaN(model.getNumericValue(p, m)));
-			});
-			grid.getItems().setAll(filteredList);
-		}); // Force an update
+		showMeasurement.addListener(c -> updateMeasurement()); // Force an update
 
 
 		CheckBox cbAnimation = new CheckBox("Animate");
@@ -440,6 +433,14 @@ private void initializeGUI() {
 		stage.setOnShowing(e -> refresh());
 		stage.show();
 	}
+
+
+	private void updateMeasurement() {
+		String m = measurement.getValue();
+		sortPathObjects(backingList, model, m, descending.get());
+		filteredList.setPredicate(p -> m == null || !(isMissingCore(p) || Double.isNaN(model.getNumericValue(p, m))));
+		grid.getItems().setAll(filteredList);
+	}
 
 
 	/**
@@ -479,8 +480,13 @@ public void hierarchyChanged(PathObjectHierarchyEvent event) {
 			requestUpdate(imageData);
 		}
 	}
-
-
+
+
+	private static Text createPlaceholderText(String text) {
+		var textNode = new Text(text);
+		textNode.setStyle("-fx-fill: -fx-text-base-color;");
+		return textNode;
+	}
 
 	class QuPathGridView extends StackPane {
 
@@ -490,7 +496,7 @@ class QuPathGridView extends StackPane {
 
 		private IntegerProperty imageSize = new SimpleIntegerProperty();
 
-		private Text textEmpty = new Text("No objects available!");
+		private Text textEmpty = createPlaceholderText("No objects available!");
 
 		QuPathGridView() {
 			imageSize.addListener(v -> {
@@ -503,7 +509,6 @@ public void onChanged(javafx.collections.ListChangeListener.Change<? extends Pat
                 }
             });
 			updateChildren();
-			textEmpty.setStyle("-fx-fill: -fx-text-base-color;");
 			StackPane.setAlignment(textEmpty, Pos.CENTER);
 		}
 
@@ -603,15 +608,15 @@ protected void layoutChildren() {
 					TranslateTransition translate = translationMap.get(node);
 					boolean doChanges = false;
 					if (translate == null) {
-						translate = new TranslateTransition(Duration.seconds(0.5));
+						translate = new TranslateTransition(Duration.seconds(0.25));
 						translate.setNode(node);
 						translationMap.put(node, translate);
 						doChanges = true;
 					} else {
 						if (!GeneralTools.almostTheSame(x, translate.getToX(), 0.001)
 								|| !GeneralTools.almostTheSame(y, translate.getToY(), 0.001)) {
 							translate.stop();
-							translate.setDuration(Duration.seconds(0.5));
+							translate.setDuration(Duration.seconds(0.25));
 							doChanges = true;
 						}
 					}