block based eval

packages/codemirror/widget.mjs

@@ -1,55 +1,111 @@
 import { StateEffect, StateField } from '@codemirror/state';
-import { Decoration, EditorView, WidgetType } from '@codemirror/view';
+import { Decoration, EditorView, WidgetType, ViewPlugin } from '@codemirror/view';
 import { getWidgetID, registerWidgetType } from '@strudel/transpiler';
 import { Pattern } from '@strudel/core';
 
-export const addWidget = StateEffect.define({
-  map: ({ from, to }, change) => {
-    return { from: change.mapPos(from), to: change.mapPos(to) };
-  },
-});
+export const setWidgets = StateEffect.define();
 
-export const updateWidgets = (view, widgets) => {
-  view.dispatch({ effects: addWidget.of(widgets) });
+export const setWidgetsInRange = StateEffect.define();
+
+export const updateWidgets = (view, widgets, range = null) => {
+  if (range) {
+    // range argument passed for block-based evaluation
+    view.dispatch({ effects: setWidgetsInRange.of({ widgets, range }) });
+  } else {
+    view.dispatch({ effects: setWidgets.of(widgets) });
+  }
 };
 
-function getWidgets(widgetConfigs) {
-  return (
-    widgetConfigs
-      // codemirror throws an error if we don't sort
-      .sort((a, b) => a.to - b.to)
-      .map((widgetConfig) => {
+function getWidgets(widgetConfigs, view) {
+  const filtered = widgetConfigs
+    // Filter to widget configs only (exclude sliders)
+    .filter((w) => w && w.type && w.type !== 'slider')
+    // Deduplicate widgets by ID, matching slider behavior for stable widget identity
+    .filter((widget, index, self) => index === self.findIndex((w) => w.type === widget.type && w.id === widget.id));
+
+  // Filter out widgets whose range is encompassed by another widget
+  // const nonEncompassed = filterEncompassedWidgets(filtered);
+
+  return filtered
+    .sort((a, b) => (a.to || 0) - (b.to || 0))
+    .map((widgetConfig) => {
+      try {
         return Decoration.widget({
-          widget: new BlockWidget(widgetConfig),
+          widget: new BlockWidget(widgetConfig, view),
           side: 0,
-          block: true,
-        }).range(widgetConfig.to);
-      })
-  );
+        }).range(widgetConfig.to || widgetConfig.from || 0);
+      } catch (error) {
+        console.error('error creating widget', error);
+        return null;
+      }
+    })
+    .filter(Boolean); // Remove any null results from failed creations
 }
 
-const widgetField = StateField.define(
-  /* <DecorationSet> */ {
-    create() {
-      return Decoration.none;
-    },
-    update(widgets, tr) {
-      widgets = widgets.map(tr.changes);
-      for (let e of tr.effects) {
-        if (e.is(addWidget)) {
-          try {
-            widgets = widgets.update({
-              filter: () => false,
-              add: getWidgets(e.value),
-            });
-          } catch (error) {
-            console.log('err', error);
+export const widgetPlugin = ViewPlugin.fromClass(
+  class {
+    decorations; //: DecorationSet
+
+    constructor(view /* : EditorView */) {
+      this.decorations = Decoration.set([]);
+    }
+
+    update(update /* : ViewUpdate */) {
+      update.transactions.forEach((tr) => {
+        if (tr.docChanged) {
+          this.decorations = this.decorations.map(tr.changes);
+          const iterator = this.decorations.iter();
+          // Apply changes to iterator.from and iterator.to if docChanged
+          while (iterator.value) {
+            // when the widgets are moved, we need to tell the dom node the current position
+            // this is important because the widget functions have to work with the dom node
+            if (iterator.value?.widget instanceof BlockWidget) {
+              iterator.value.widget.from = iterator.from;
+              iterator.value.widget.to = iterator.to;
+            }
+            iterator.next();
           }
         }
-      }
-      return widgets;
-    },
-    provide: (f) => EditorView.decorations.from(f),
+        for (let e of tr.effects) {
+          if (e.is(setWidgetsInRange)) {
+            // Block-aware widget update logic
+            const { widgets, range } = e.value;
+            const [rangeStart, rangeEnd] = range;
+
+            // Get existing widget widgets that should be preserved
+            const existingWidgets = [];
+            this.decorations.between(0, update.view.state.doc.length, (from, to, decoration) => {
+              if (decoration.widget instanceof BlockWidget) {
+                // Preserve widgets outside the evaluation range
+                // Use strict > for rangeEnd because when code is deleted, widget positions
+                // map to the deletion boundary (rangeEnd), and those should be removed, not preserved
+                if (from < rangeStart || from > rangeEnd) {
+                  existingWidgets.push({
+                    from: decoration.widget.from,
+                    to: decoration.widget.to,
+                    type: decoration.widget.type,
+                    index: decoration.widget.index,
+                    id: decoration.widget.id,
+                  });
+                }
+              }
+            });
+
+            // Merge preserved widgets with new widgets, deduplicating by ID
+            const mergedWidgets = [...existingWidgets, ...widgets].filter(
+              (widget, index, self) => index === self.findIndex((w) => w.type === widget.type && w.id === widget.id),
+            );
+
+            this.decorations = Decoration.set(getWidgets(mergedWidgets, update.view));
+          } else if (e.is(setWidgets)) {
+            this.decorations = Decoration.set(getWidgets(e.value, update.view));
+          }
+        }
+      });
+    }
+  },
+  {
+    decorations: (v) => v.decorations,
   },
 );
 
@@ -60,24 +116,116 @@ export function setWidget(id, el) {
 }
 
 export class BlockWidget extends WidgetType {
-  constructor(widgetConfig) {
+  constructor(widgetConfig, view) {
     super();
+
+    // Graceful handling of invalid configs like sliders
+    if (!widgetConfig || typeof widgetConfig !== 'object') {
+      widgetConfig = { type: 'unknown', from: 0, to: 0 };
+    }
+
+    this.from = widgetConfig.from || 0;
+    this.originalFrom = widgetConfig.from || 0;
+    this.to = widgetConfig.to || this.from;
+    this.originalTo = widgetConfig.to || this.from;
+    this.type = widgetConfig.type || 'unknown';
+    this.index = widgetConfig.index || 0;
+    this.view = view;
+
+    // Use range-based ID for stability, similar to sliders
+    this.id = widgetConfig.id || getWidgetID?.(widgetConfig);
     this.widgetConfig = widgetConfig;
   }
-  eq() {
-    return true;
+
+  eq(other) {
+    if (!(other instanceof BlockWidget)) {
+      return false;
+    }
+    return (
+      this.id === other.id &&
+      this.from === other.from &&
+      this.to === other.to &&
+      this.type === other.type &&
+      this.index === other.index
+    );
   }
+
   toDOM() {
-    const id = getWidgetID(this.widgetConfig);
-    const el = widgetElements[id];
-    return el;
+    let wrap = document.createElement('span');
+    wrap.setAttribute('aria-hidden', 'true');
+    wrap.className = 'cm-widget-container';
+
+    let el = widgetElements[this.id];
+    if (el) {
+      // Ensure the element has the correct ID
+      el.id = this.id;
+      wrap.appendChild(el);
+    } else {
+      // Create a placeholder element if the widget element doesn't exist
+      // This prevents CodeMirror errors when widget is missing
+      const placeholder = document.createElement('span');
+      placeholder.setAttribute('aria-hidden', 'true');
+      placeholder.className = 'cm-widget-placeholder';
+      placeholder.style.cssText = 'display: none;'; // Hide placeholder
+      placeholder.id = this.id;
+      wrap.appendChild(placeholder);
+    }
+
+    return wrap;
   }
+
   ignoreEvent(e) {
     return true;
   }
 }
 
-export const widgetPlugin = [widgetField];
+export function getActiveWidgets(view) {
+  if (!view || !view.state) {
+    return [];
+  }
+
+  const widgetPluginInstance = view.plugin(widgetPlugin);
+  if (!widgetPluginInstance || !widgetPluginInstance.decorations) {
+    return [];
+  }
+
+  const widgets = [];
+
+  widgetPluginInstance.decorations.between(0, view.state.doc.length, (from, to, decoration) => {
+    if (decoration.widget instanceof BlockWidget) {
+      widgets.push({
+        type: decoration.widget.type,
+        from: decoration.widget.from,
+        to: decoration.widget.to,
+        index: decoration.widget.index,
+        id: decoration.widget.id,
+      });
+    }
+  });
+
+  return widgets;
+}
+
+export function getAllWidgetIds(view) {
+  if (!view || !view.state) {
+    return [];
+  }
+
+  const widgetPluginInstance = view.plugin(widgetPlugin);
+  if (!widgetPluginInstance || !widgetPluginInstance.decorations) {
+    return [];
+  }
+
+  const widgetIds = [];
+
+  widgetPluginInstance.decorations.between(0, view.state.doc.length, (from, to, decoration) => {
+    if (decoration.widget instanceof BlockWidget) {
+      widgetIds.push(decoration.widget.id);
+    }
+  });
+
+  return widgetIds;
+}
 
 // widget implementer API to create a new widget type
 export function registerWidget(type, fn) {