(core) Restore default context menu out of std views

Summary:
Also fix few clode glitches
- Attach events handler to the scrollPane using `onMatch` instead of
  the cell itself. This streamline cell dom creation a bit while
  scrolling.
- Fix memory leaks on contextMenu.
- Also fix Importer and ColumnOps nbrowser test

see:
https://phab.getgrist.com/D3237#inline-36376
https://phab.getgrist.com/D3237#inline-36375

Restore default context menu for where there's no custom one

It appears that default context menu adds some value, in particular
for links and for editing text. This diff restores it.

Test Plan: Should not break anything.

Reviewers: paulfitz

Reviewed By: paulfitz

Differential Revision: https://phab.getgrist.com/D3256

app/client/components/GridView.js

@@ -224,6 +224,9 @@ function GridView(gristDoc, viewSectionModel, isPreview = false) {
   //--------------------------------------------------
   // Set up DOM event handling.
   onDblClickMatchElem(this.scrollPane, '.field', () => this.activateEditorAtCursor());
+  if (!this.isPreview) {
+    grainjsDom.onMatchElem(this.scrollPane, '.field:not(.column_name)', 'contextmenu', (ev, elem) => this.onCellContextMenu(ev, elem), {useCapture: true});
+  }
   this.onEvent(this.scrollPane, 'scroll', this.onScroll);
 
   //--------------------------------------------------
@@ -1117,7 +1120,7 @@ GridView.prototype.buildDom = function() {
             self.changeHover(-1);
           }
         }),
-        contextMenu((ctx) => {
+        self.isPreview ? null : contextMenu((ctx) => {
           // We need to close the menu when the row is removed, but the dom of the row is not
           // disposed when the record is removed (this is probably due to how scrolly work). Hence,
           // we need to subscribe to `isRowActive` to close the menu.
@@ -1169,20 +1172,6 @@ GridView.prototype.buildDom = function() {
 
             kd.toggleClass('selected', isSelected),
             fieldBuilder.buildDomWithCursor(row, isCellActive, isCellSelected),
-
-            grainjsDom.on('contextmenu', (ev, elem) => {
-              let row = self.domToRowModel(elem, selector.CELL);
-              let col = self.domToColModel(elem, selector.CELL);
-
-              if (self.cellSelector.containsCell(row._index(), col._index())) {
-                // contextmenu event could be preceded by a mousedown event (ie: when ctrl+click on
-                // mac) which triggers a cursor assignment that we need to prevent.
-                self.preventAssignCursor();
-              } else {
-                self.assignCursor(elem, selector.NONE);
-              }
-            })
-
           );
         })
       )
@@ -1215,6 +1204,19 @@ GridView.prototype.onLinkFilterChange = function(rowId) {
   this.clearSelection();
 };
 
+GridView.prototype.onCellContextMenu = function(ev, elem) {
+  let row = this.domToRowModel(elem, selector.CELL);
+  let col = this.domToColModel(elem, selector.CELL);
+
+  if (this.cellSelector.containsCell(row._index(), col._index())) {
+    // contextmenu event could be preceded by a mousedown event (ie: when ctrl+click on
+    // mac) which triggers a cursor assignment that we need to prevent.
+    this.preventAssignCursor();
+  } else {
+    this.assignCursor(elem, selector.NONE);
+  }
+}
+
 // ======================================================================================
 // SELECTOR STUFF
 

app/client/ui/AppUI.ts

@@ -30,10 +30,7 @@ export function createAppUI(topAppModel: TopAppModel, appObj: App): IDisposable
   dom.update(document.body, content, {
     // Cancel out bootstrap's overrides.
     style: 'font-family: inherit; font-size: inherit; line-height: inherit;'
-  },
-  // prevent default context menu to show
-  dom.on('contextmenu', (ev) => ev.preventDefault())
-  );
+  });
 
   function dispose() {
     // Return value of dom.maybe() / dom.domComputed() is a pair of markers with a function that

app/client/ui/contextMenu.ts

@@ -7,7 +7,7 @@
  * context menu) dont forget to prevent it by including below line at the root of the dom:
  *   `dom.on('contextmenu', ev => ev.preventDefault())`
  */
-import { Disposable, dom, DomArg, DomContents } from "grainjs";
+import { Disposable, dom, DomArg, DomContents, Holder } from "grainjs";
 import { cssMenuElem } from 'app/client/ui2018/menus';
 import { IOpenController, Menu } from 'popweasel';
 
@@ -77,22 +77,17 @@ class ContextMenuController extends Disposable implements IOpenController {
   }
 }
 
-/**
- * Show the return value of contentFunc() in a context menu next to the mouse.
- */
-function showContextMenu(ev: MouseEvent, contentFunc: IContextMenuContentFunc) {
-  return ContextMenuController.create(null, ev, contentFunc);
-}
-
 /**
  * Show a context menu on contextmenu.
  */
 export function contextMenu(contentFunc: IContextMenuContentFunc): DomArg {
   return (elem) => {
+    const holder = Holder.create(null);
+    dom.autoDisposeElem(elem, holder);
     dom.onElem(elem, 'contextmenu', (ev) => {
       ev.preventDefault();
       ev.stopPropagation();
-      dom.autoDisposeElem(elem, showContextMenu(ev, contentFunc));
+      ContextMenuController.create(holder, ev, contentFunc);
     });
   };
 }