Remove old diffs when a new diff is created

Author: Zsailer

package.json

@@ -63,7 +63,7 @@
         "@jupyterlab/services": "^7.0.0",
         "@jupyterlab/ui-components": "^4.0.0",
         "@lumino/widgets": "^2.0.0",
-        "jupyterlab-cell-input-footer": "^0.2.0",
+        "jupyterlab-cell-input-footer": "^0.3.0",
         "nbdime": "^7.0.1"
     },
     "devDependencies": {

src/command.ts

@@ -40,18 +40,24 @@ export function showCellDiff(data: ShowDiff.ICommandArgs, cellFooterTracker: ICe
 
   let mergeView: MergeView;
   mergeView = new MergeView({ remote: diff });
+  // 
+  mergeView.addClass("jp-cell-diff");
+  // Add the classes below to pick up the styling from nbdime.
   mergeView.addClass("nbdime-root");
   mergeView.addClass("jp-Notebook-diff");
   mergeView.hide();
 
   let footer = cellFooterTracker.getFooter(data.cell_id);
+  // Try removing any old widget that exists.
+  try { footer?.removeWidget("jp-cell-diff") } catch {}
+
   footer?.addWidget(mergeView);
 
   if (footer?.isHidden) {
     footer.show();
     footer.update();
   }
-  footer?.addItemOnLeft(
+  footer?.addToolbarItemOnLeft(
     'compare',
     new ToolbarButton({
       // icon: wandIcon,

yarn.lock

@@ -3727,7 +3727,7 @@ __metadata:
     eslint: ^8.36.0
     eslint-config-prettier: ^8.8.0
     eslint-plugin-prettier: ^5.0.0
-    jupyterlab-cell-input-footer: ^0.2.0
+    jupyterlab-cell-input-footer: ^0.3.0
     mkdirp: ^1.0.3
     nbdime: ^7.0.1
     npm-run-all2: ^7.0.1
@@ -3745,13 +3745,13 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"jupyterlab-cell-input-footer@npm:^0.2.0":
-  version: 0.2.0
-  resolution: "jupyterlab-cell-input-footer@npm:0.2.0"
+"jupyterlab-cell-input-footer@npm:^0.3.0":
+  version: 0.3.0
+  resolution: "jupyterlab-cell-input-footer@npm:0.3.0"
   dependencies:
     "@jupyterlab/services": ^7.0.0
     "@lumino/coreutils": ^2.1.2
-  checksum: b298f6ba525668ce18c25c1e1bd5c1f515d2c76f9611092b88e1ae2769e2966784455c4d7e80f10061a8482d8c938264af15436faf0234bada101fa0a42d62ef
+  checksum: 88e8a420022a9228a09271f7b7e5ddc15f2bab9f9cf4e11541364a4060d8907ebdee2174efe0ecbbbdfa56d649fda25380e7a0f9d6dbe4d3486b3c0ab2e55a4c
   languageName: node
   linkType: hard