Area of preview on hover should be shrink to the size of the text displayed

CHANGELOG.md

@@ -50,6 +50,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 - We fixed the fallback window height (786 → 768) in JabRefGUI. [#14295](https://github.com/JabRef/jabref/pull/14295)
 - We fixed localization of the "New Entries" dialog. [#14455](https://github.com/JabRef/jabref/pull/14455)
 - We fixed an issue where keybindings could not be edited and saved. [#14237](https://github.com/JabRef/jabref/issues/14237)
+- Fixed the entry-table tooltip appearing oversized when preview was enabled. The tooltip now adapts to its content. [#12351](https://github.com/JabRef/jabref/issues/12351)
 - We readded the missing gui commands for importing and exporting preferences. [#14492](https://github.com/JabRef/jabref/pull/14492)
 
 ### Removed

jabgui/src/main/java/org/jabref/gui/maintable/MainTableTooltip.java

@@ -12,8 +12,11 @@
 import org.jabref.model.database.BibDatabaseContext;
 import org.jabref.model.entry.BibEntry;
 
-public class MainTableTooltip extends Tooltip {
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
+public class MainTableTooltip extends Tooltip {
+    private static final Logger LOGGER = LoggerFactory.getLogger(MainTableTooltip.class);
     private final PreviewViewer preview;
     private final GuiPreferences preferences;
     private final VBox tooltipContent = new VBox();
@@ -22,11 +25,49 @@ public class MainTableTooltip extends Tooltip {
     public MainTableTooltip(DialogService dialogService, GuiPreferences preferences, ThemeManager themeManager, TaskExecutor taskExecutor) {
         this.preferences = preferences;
         this.preview = new PreviewViewer(dialogService, preferences, themeManager, taskExecutor);
-        this.tooltipContent.getChildren().addAll(fieldValueLabel, preview);
+
+        fieldValueLabel.setWrapText(true);
+        fieldValueLabel.setMaxWidth(Double.MAX_VALUE);
+
+        tooltipContent.getChildren().addAll(fieldValueLabel, preview);
+        tooltipContent.setSpacing(5);
+
+        this.setMaxWidth(500);
+        this.setWrapText(true);
+
+        final double PREVIEW_WIDTH_PADDING = 16.0;
+        final double PREVIEW_HEIGHT_PADDING = 8.0;  // Padding to avoid bottom clipping of the preview
+        final double MIN_TOOLTIP_WIDTH = 200.0; // Minimum width of the tooltip to keep layout stable even with small content
+
+        preview.contentHeightProperty().addListener((_, _, val) -> {
+            double contentHeight = val == null ? 0 : val.doubleValue();
+            if (contentHeight <= 0) {
+                LOGGER.debug("contentHeightProperty emitted non-positive value: {}", contentHeight);
+                return;
+            }
+
+            preview.setPrefHeight(contentHeight + PREVIEW_HEIGHT_PADDING);
+        });
+
+        preview.contentWidthProperty().addListener((_, _, val) -> {
+            double contentWidth = val == null ? 0 : val.doubleValue();
+            if (contentWidth <= 0) {
+                LOGGER.debug("contentWidthProperty emitted non-positive value: {}", contentWidth);
+                return;
+            }
+
+            double desired = Math.max(contentWidth + PREVIEW_WIDTH_PADDING, MIN_TOOLTIP_WIDTH);
+
+            // We set a very large max width so that JavaFX does not artificially clamp the tooltip.
+            // The effective width is still limited by the window and screen bounds.
+            this.setMaxWidth(Double.MAX_VALUE);
+            this.setPrefWidth(desired);
+        });
     }
 
     public Tooltip createTooltip(BibDatabaseContext databaseContext, BibEntry entry, String fieldValue) {
-        fieldValueLabel.setText(fieldValue + "\n");
+        fieldValueLabel.setText(fieldValue);
+
         if (preferences.getPreviewPreferences().shouldShowPreviewEntryTableTooltip()) {
             preview.setLayout(preferences.getPreviewPreferences().getSelectedPreviewLayout());
             preview.setDatabaseContext(databaseContext);

jabgui/src/main/java/org/jabref/gui/preview/PreviewViewer.java

@@ -4,9 +4,12 @@
 import java.net.MalformedURLException;
 import java.util.List;
 import java.util.Objects;
+import java.util.Optional;
 
 import javafx.beans.InvalidationListener;
 import javafx.beans.Observable;
+import javafx.beans.property.ReadOnlyDoubleProperty;
+import javafx.beans.property.ReadOnlyDoubleWrapper;
 import javafx.beans.property.SimpleStringProperty;
 import javafx.beans.property.StringProperty;
 import javafx.concurrent.Worker;
@@ -85,6 +88,8 @@ function getSelectionHtml() {
     private @Nullable BibEntry entry;
     private PreviewLayout layout;
     private String layoutText;
+    private final ReadOnlyDoubleWrapper contentHeight = new ReadOnlyDoubleWrapper(0);
+    private final ReadOnlyDoubleWrapper contentWidth = new ReadOnlyDoubleWrapper(0);
 
     public PreviewViewer(DialogService dialogService,
                          GuiPreferences preferences,
@@ -105,8 +110,11 @@ public PreviewViewer(DialogService dialogService,
         this.searchQueryProperty = searchQueryProperty;
         this.searchQueryProperty.addListener((_, _, _) -> highlightLayoutText());
 
-        setFitToHeight(true);
-        setFitToWidth(true);
+        setFitToHeight(false);
+        setFitToWidth(false);
+
+        setHbarPolicy(ScrollBarPolicy.NEVER);
+        setVbarPolicy(ScrollBarPolicy.NEVER);
         previewView = WebViewStore.get();
         setContent(previewView);
 
@@ -144,9 +152,57 @@ private void configurePreviewView(ThemeManager themeManager) {
                     evt.preventDefault();
                 }, false);
             }
+
+            try {
+                Object heightObj = previewView.getEngine().executeScript("document.getElementById('content').scrollHeight || document.body.scrollHeight");
+                Object widthObj = previewView.getEngine().executeScript("document.getElementById('content').scrollWidth || document.body.scrollWidth");
+
+                Double height = null;
+                if (heightObj instanceof java.lang.Number heightNum) {
+                    height = heightNum.doubleValue();
+                }
+
+                Double width = null;
+                if (widthObj instanceof java.lang.Number widthNum) {
+                    width = widthNum.doubleValue();
+                }
+
+                // Use a single runLater to update both properties at once. We store the
+                // measured values as Optionals to make the intent explicit.
+                Optional<Double> optHeight = Optional.ofNullable(height);
+                Optional<Double> optWidth = Optional.ofNullable(width);
+
+                javafx.application.Platform.runLater(() -> {
+                    optHeight.ifPresent(measuredHeight -> {
+                        contentHeight.set(measuredHeight);
+                        // small padding so the rendered content is not clipped at edges
+                        this.setPrefHeight(measuredHeight + 8);
+                    });
+                    optWidth.ifPresent(measuredWidth -> {
+                        contentWidth.set(measuredWidth);
+                        this.setPrefWidth(measuredWidth + 8);
+                    });
+                });
+
+                setHvalue(0);
+            } catch (NullPointerException e) {
+                LOGGER.debug("Null value encountered while computing preview content size", e);
+            } catch (ClassCastException e) {
+                LOGGER.debug("Unexpected type returned from JavaScript while computing preview content size", e);
+            } catch (IllegalStateException e) {
+                LOGGER.debug("JavaFX thread not ready while computing preview content size", e);
+            }
         });
     }
 
+    public ReadOnlyDoubleProperty contentHeightProperty() {
+        return contentHeight.getReadOnlyProperty();
+    }
+
+    public ReadOnlyDoubleProperty contentWidthProperty() {
+        return contentWidth.getReadOnlyProperty();
+    }
+
     public void setLayout(PreviewLayout newLayout) {
         // Change listeners might set the layout to null while the update method is executing, therefore, we need to prevent this here
         if ((newLayout == null) || newLayout.equals(layout)) {