refactor: abstract away the text bound aspect of the ControlFlowLines…

… feature

recaf-ui/src/main/java/software/coley/recaf/ui/control/richtext/linegraphics/AbstractTextBoundLineGraphicFactory.java

@@ -0,0 +1,76 @@
+package software.coley.recaf.ui.control.richtext.linegraphics;
+
+import jakarta.annotation.Nonnull;
+import javafx.beans.binding.Bindings;
+import javafx.beans.value.ObservableValue;
+import javafx.geometry.Pos;
+import javafx.scene.layout.StackPane;
+import org.openrewrite.jgit.annotations.NonNull;
+import software.coley.recaf.ui.control.VirtualizedScrollPaneWrapper;
+import software.coley.recaf.ui.control.richtext.Editor;
+import software.coley.recaf.util.FxThreadUtil;
+import software.coley.recaf.util.SceneUtils;
+
+public abstract class AbstractTextBoundLineGraphicFactory extends AbstractLineGraphicFactory {
+
+    protected Editor editor;
+
+    protected final int containerHeight = 16; // Each line graphic region is only 16px tall
+    protected final int containerWidth = 16;
+
+    /**
+     * @param priority Priority dictating the order of graphics displayed in {@link RootLineGraphicFactory}.
+     *                 See {@link LineGraphicFactory} for constants.
+     */
+    protected AbstractTextBoundLineGraphicFactory(int priority) {
+        super(priority);
+    }
+
+    @Override
+    public void install(@Nonnull Editor editor) {
+        this.editor = editor;
+    }
+
+    @Override
+    public void uninstall(@Nonnull Editor editor) {
+        this.editor = null;
+    }
+
+    @Override
+    public void apply(@Nonnull LineContainer container, int paragraph) {
+
+        // To keep the ordering of the line graphic factory priority we need to add the stack pane now
+        // since the rest of the work is done async below. We want this to have zero width so that it doesn't
+        // shit the editor around when the content becomes active/inactive.
+        StackPane stack = new StackPane();
+        stack.setManaged(false);
+        stack.setPrefWidth(0);
+        stack.setMouseTransparent(true);
+        container.addHorizontal(stack);
+
+        FxThreadUtil.delayedRun(0, () -> {
+            stack.setPrefSize(containerHeight, containerHeight);
+            stack.setAlignment(Pos.CENTER_LEFT);
+            SceneUtils.getParentOfTypeLater(container, VirtualizedScrollPaneWrapper.class).whenComplete((parentScroll, error) -> {
+                ObservableValue<? extends Number> translateX;
+                if (parentScroll != null) {
+                    translateX = Bindings.add(container.widthProperty().subtract(containerHeight), parentScroll.horizontalScrollProperty().negate());
+                } else {
+                    // Should never happen since the 'VirtualizedScrollPaneWrapper' is mandated internally by 'Editor'.
+                    translateX = container.widthProperty().subtract(containerHeight);
+                }
+                stack.translateXProperty().bind(translateX);
+            });
+
+            apply(stack, paragraph);
+        });
+    }
+
+    /**
+     * Apply the line graphic to the given pane,
+     * the pane is always bound to the beginning of the line.
+     * @param pane The pane to apply the graphic to.
+     * @param paragraph The paragraph index.
+     */
+    protected abstract void apply(@NonNull StackPane pane, int paragraph);
+}