Don't render Markdown when attempting to navigate above first cell (#119)

* Don't render md in first cell in vim:select-above

* Don't render md when pressing k in first cell

* Revise with cell loc context per review

* Lint

Author: firai

src/codemirrorCommands.ts

@@ -43,6 +43,11 @@ interface IUndoOptions {
   registerName: unknown;
 }
 
+export interface ICellContext {
+  index?: number;
+  cellCount?: number;
+}
+
 export class VimEditorManager {
   constructor({ enabled, userKeybindings }: VimEditorManager.IOptions) {
     this.enabled = enabled;
@@ -167,21 +172,29 @@ export class VimCellManager extends VimEditorManager {
     tracker: INotebookTracker,
     activeCell: Cell<ICellModel> | null
   ): void {
-    this.modifyCell(activeCell).catch(console.error);
+    const activeCellContext = {
+      index: tracker.currentWidget?.content.activeCellIndex,
+      cellCount: tracker.currentWidget?.content.widgets.length
+    } as ICellContext;
+    this.modifyCell(activeCell, activeCellContext).catch(console.error);
   }
 
   updateLastActive() {
-    if (!this._lastActiveCell) {
+    if (!this._lastActiveCell || !this._lastActiveCellContext) {
       return;
     }
-    this.modifyCell(this._lastActiveCell);
+    this.modifyCell(this._lastActiveCell, this._lastActiveCellContext);
   }
 
-  async modifyCell(activeCell: Cell<ICellModel> | null): Promise<void> {
-    if (!activeCell) {
+  async modifyCell(
+    activeCell: Cell<ICellModel> | null,
+    activeCellContext: ICellContext
+  ): Promise<void> {
+    if (!activeCell || !activeCellContext) {
       return;
     }
     this._lastActiveCell = activeCell;
+    this._lastActiveCellContext = activeCellContext;
     await activeCell.ready;
 
     if (activeCell.isDisposed) {
@@ -190,11 +203,14 @@ export class VimCellManager extends VimEditorManager {
     }
     const wasEnabled = this.modifyEditor(activeCell.editor);
     if (wasEnabled) {
-      this._modifyEdgeNavigation(activeCell);
+      this._modifyEdgeNavigation(activeCell, activeCellContext);
     }
   }
 
-  private _modifyEdgeNavigation(activeCell: Cell<ICellModel>) {
+  private _modifyEdgeNavigation(
+    activeCell: Cell<ICellModel>,
+    activeCellContext: ICellContext
+  ) {
     // Define a function to use as Vim motion
     // This replaces the codemirror moveByLines function to
     // for jumping between notebook cells.
@@ -254,7 +270,11 @@ export class VimCellManager extends VimEditorManager {
         // var key = '';
         // `currentCell !== null should not be needed since `activeCell`
         // is already check against null (row 61). Added to avoid warning.
-        if (currentCell !== null && currentCell.model.type === 'markdown') {
+        if (
+          currentCell !== null &&
+          currentCell.model.type === 'markdown' &&
+          !(!motionArgs.forward && activeCellContext.index === 0)
+        ) {
           if (!motionArgs.handleArrow) {
             // markdown cells tends to improperly handle arrow keys movement,
             //  on the way up the cell is rendered, but down movement is ignored
@@ -368,4 +388,5 @@ export class VimCellManager extends VimEditorManager {
 
   private _commands: CommandRegistry;
   private _lastActiveCell: Cell<ICellModel> | null = null;
+  private _lastActiveCellContext: ICellContext | undefined;
 }

src/index.ts

@@ -20,7 +20,8 @@ import { Prec } from '@codemirror/state';
 import {
   VimEditorManager,
   VimCellManager,
-  IKeybinding
+  IKeybinding,
+  ICellContext
 } from './codemirrorCommands';
 import { addNotebookCommands } from './labCommands';
 import { PartialJSONObject } from '@lumino/coreutils';
@@ -97,8 +98,13 @@ async function activateCellVim(
       } else if (editorTracker.currentWidget === current) {
         editorManager.modifyEditor(editorTracker.currentWidget.content.editor);
       } else if (notebookTracker.currentWidget === current) {
+        const activeCellContext = {
+          index: notebookTracker.currentWidget.content.activeCellIndex,
+          cellCount: notebookTracker.currentWidget.content.widgets.length
+        } as ICellContext;
         cellManager.modifyCell(
-          notebookTracker.currentWidget.content.activeCell
+          notebookTracker.currentWidget.content.activeCell,
+          activeCellContext
         );
       } else {
         console.warn('Current widget is not vim-enabled');
@@ -156,7 +162,14 @@ async function activateCellVim(
     } else if (editorTracker.currentWidget === current) {
       editorManager.modifyEditor(editorTracker.currentWidget.content.editor);
     } else if (notebookTracker.currentWidget === current) {
-      cellManager.modifyCell(notebookTracker.currentWidget.content.activeCell);
+      const activeCellContext = {
+        index: notebookTracker.currentWidget.content.activeCellIndex,
+        cellCount: notebookTracker.currentWidget.content.widgets.length
+      } as ICellContext;
+      cellManager.modifyCell(
+        notebookTracker.currentWidget.content.activeCell,
+        activeCellContext
+      );
     } else {
       // no-op
     }

src/labCommands.ts

@@ -210,15 +210,16 @@ export function addNotebookCommands(
       isEnabled
     }),
     commands.addCommand('vim:select-above-execute-markdown', {
-      label: 'Execute Markdown and Select Cell Below',
+      label: 'Execute Markdown and Select Cell Above',
       execute: args => {
         const current = getCurrent(args);
 
         if (current) {
           const { content } = current;
           if (
             content.activeCell !== null &&
-            content.activeCell.model.type === 'markdown'
+            content.activeCell.model.type === 'markdown' &&
+            content.activeCellIndex !== 0
           ) {
             (current.content.activeCell as MarkdownCell).rendered = true;
           }