Merge pull request #175 from oleksandr-danylchenko/#169-fix-repeated-…

…update-emission

#169 Fixed repeated updates for the unchanged target

packages/text-annotator/src/SelectionHandler.ts

@@ -73,9 +73,12 @@ export const SelectionHandler = (
   const onSelectionChange = debounce((evt: Event) => {
     const sel = document.getSelection();
 
-    // This is to handle cases where the selection is "hijacked" by another element
-    // in a not-annotatable area. A rare case in theory. But rich text editors
-    // will like Quill do it...
+    /**
+     * This is to handle cases where the selection is "hijacked"
+     * by another element in a not-annotatable area.
+     * A rare case in theory.
+     * But rich text editors will like Quill do it.
+     */
     if (isNotAnnotatable(sel.anchorNode)) {
       currentTarget = undefined;
       return;
@@ -130,7 +133,6 @@ export const SelectionHandler = (
     const hasChanged =
       annotatableRanges.length !== currentTarget.selector.length ||
       annotatableRanges.some((r, i) => r.toString() !== currentTarget.selector[i]?.quote);
-
     if (!hasChanged) return;
 
     currentTarget = {
@@ -140,8 +142,8 @@ export const SelectionHandler = (
     };
 
     /**
-     * During mouse selection on the desktop, annotation won't usually exist while the selection is being edited.
-     * But it will be typical during keyboard or mobile handlebars selection!
+     * During mouse selection on the desktop, the annotation won't usually exist while the selection is being edited.
+     * But it'll be typical during selection via the keyboard or mobile's handlebars.
      */
     if (store.getAnnotation(currentTarget.annotation)) {
       store.updateTarget(currentTarget, Origin.LOCAL);
@@ -152,7 +154,7 @@ export const SelectionHandler = (
   });
 
   /**
-   * Select events don't carry information about the mouse button
+   * Select events don't carry information about the mouse button.
    * Therefore, to prevent right-click selection, we need to listen
    * to the initial pointerdown event and remember the button
    */
@@ -167,20 +169,6 @@ export const SelectionHandler = (
     isLeftClick = lastDownEvent.button === 0;
   };
 
-  // Helper
-  const upsertCurrentTarget = () => {
-    const exists = store.getAnnotation(currentTarget.annotation);
-    if (exists) {
-      store.updateTarget(currentTarget);
-    } else {
-      store.addAnnotation({
-        id: currentTarget.annotation,
-        bodies: [],
-        target: currentTarget
-      });
-    }
-  }
-
   const onPointerUp = (evt: PointerEvent) => {
     if (isNotAnnotatable(evt.target as Node) || !isLeftClick) return;
 
@@ -317,6 +305,29 @@ export const SelectionHandler = (
 
   hotkeys(ARROW_KEYS.join(','), { keydown: true, keyup: false }, handleArrowKeyPress);
 
+  // Helper
+  const upsertCurrentTarget = () => {
+    const existingAnnotation = store.getAnnotation(currentTarget.annotation);
+    if (!existingAnnotation) {
+      store.addAnnotation({
+        id: currentTarget.annotation,
+        bodies: [],
+        target: currentTarget
+      });
+      return;
+    }
+
+    const { target: { updated: existingTargetUpdated } } = existingAnnotation;
+    const { updated: currentTargetUpdated } = currentTarget;
+    if (
+      !existingTargetUpdated ||
+      !currentTargetUpdated ||
+      existingTargetUpdated < currentTargetUpdated
+    ) {
+      store.updateTarget(currentTarget);
+    }
+  };
+
   container.addEventListener('pointerdown', onPointerDown);
   document.addEventListener('pointerup', onPointerUp);
   document.addEventListener('contextmenu', onContextMenu);