(core) Readonly editors

Summary:
Grist should not prevent read-only viewers from opening cell editors since they usually provide much more information than is visible in a cell.

Every editor was enhanced with a read-only mode that provides the same information available for an editor but doesn't allow to change the underlying data.

Test Plan: Browser tests

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2842

app/client/components/AceEditor.js

@@ -26,6 +26,7 @@ function AceEditor(options) {
   this.calcSize = (options && options.calcSize) || ((elem, size) => size);
   this.gristDoc = (options && options.gristDoc) || null;
   this.editorState = (options && options.editorState) || null;
+  this._readonly = options.readonly || false;
 
   this.editor = null;
   this.editorDom = null;
@@ -112,6 +113,11 @@ AceEditor.prototype.attachCommandGroup = function(commandGroup) {
   _.each(commandGroup.knownKeys, (command, key) => {
     this.editor.commands.addCommand({
       name: command,
+      // We are setting readonly as true to enable all commands
+      // in a readonly mode.
+      // Because FieldEditor in readonly mode will rewire all commands that
+      // modify state, we are safe to enable them.
+      readOnly: this._readonly,
       bindKey: {
         win: key,
         mac: key,

app/client/components/BaseView.js

@@ -278,16 +278,12 @@ BaseView.prototype.activateEditorAtCursor = function(options) {
   // LazyArrayModel row model which is also used to build the cell dom. Needed since
   // it may be used as a key to retrieve the cell dom, which is useful for editor placement.
   var lazyRow = this.getRenderedRowModel(rowId);
-  if (builder.field.disableEditData() || this.gristDoc.isReadonly.get()) {
-    builder.flashCursorReadOnly(lazyRow);
-  } else {
-    if (!lazyRow) {
-      // TODO scroll into view. For now, just don't activate the editor.
-      return;
-    }
-    this.editRowModel.assign(rowId);
-    builder.buildEditorDom(this.editRowModel, lazyRow, options || {});
+  if (!lazyRow) {
+    // TODO scroll into view. For now, just don't activate the editor.
+    return;
   }
+  this.editRowModel.assign(rowId);
+  builder.buildEditorDom(this.editRowModel, lazyRow, options || {});
 };
 
 /**

app/client/components/EditorMonitor.ts

@@ -58,6 +58,9 @@ export class EditorMonitor extends Disposable {
     // will be invoked only once
     let executed = false;
 
+    // don't restore on readonly mode
+    if (doc.isReadonly.get()) { return; }
+
     // on view shown
     this._currentViewListener.autoDispose(doc.currentView.addListener(async view => {
       if (executed) {