Finalize markdown tree tooltip and resolveTreeItem

Fixes #100741

src/vs/vscode.d.ts

@@ -8809,6 +8809,25 @@ declare module 'vscode' {
  * @return Parent of `element`.
  */
  getParent?(element: T): ProviderResult<T>;
+
+ /**
+ * Called only on hover to resolve the [TreeItem](#TreeItem.tooltip) property if it is undefined.
+ * Only properties that were undefined can be resolved in `resolveTreeItem`.
+ * Functionality may be expanded later to include being called to resolve other missing
+ * properties on selection and/or on open.
+ *
+ * Will only ever be called once per TreeItem.
+ *
+ * *Note* that this function is called when tree items are already showing in the UI.
+ * Because of that, no property that changes the presentation (label, description, command, etc.)
+ * can be changed.
+ *
+ * @param element The object associated with the TreeItem
+ * @param item Undefined properties of `item` should be set then `item` should be returned.
+ * @return The resolved tree item or a thenable that resolves to such. It is OK to return the given
+ * `item`. When no result is returned, the given `item` will be used.
+ */
+ resolveTreeItem?(item: TreeItem, element: T): ProviderResult<TreeItem>;
  }
 
  export class TreeItem {
@@ -8848,7 +8867,7 @@ declare module 'vscode' {
  /**
  * The tooltip text when you hover over this item.
  */
- tooltip?: string | undefined;
+ tooltip?: string | MarkdownString | undefined;
 
  /**
  * The [command](#Command) that should be executed when the tree item is selected.

src/vs/vscode.proposed.d.ts

@@ -943,29 +943,6 @@ declare module 'vscode' {
  //#endregion
 
  //#region Tree View: https://github.com/microsoft/vscode/issues/61313
-
- // https://github.com/microsoft/vscode/issues/100741
- export interface TreeDataProvider<T> {
- /**
- * Called only on hover to resolve the TreeItem2#tooltip property if it is undefined.
- * Only properties that were undefined can be resolved in `resolveTreeItem`.
- * Will only ever be called once per TreeItem.
- * Functionality may be expanded later to include being called to resolve other missing
- * properties on selection and/or on open.
- *
- * @param element
- * @param item Undefined properties of `item` should be set then `item` should be returned.
- */
- resolveTreeItem?(item: TreeItem2, element: T): ProviderResult<TreeItem2>;
- }
-
- export class TreeItem2 extends TreeItem {
- /**
- * Content to be shown when you hover over the tree item.
- */
- tooltip?: string | MarkdownString | /* for compilation */ any;
- }
-
  export interface TreeView<T> extends Disposable {
  reveal(element: T | undefined, options?: { select?: boolean, focus?: boolean, expand?: boolean | number }): Thenable<void>;
  }

src/vs/workbench/api/common/extHostTreeViews.ts

@@ -17,7 +17,6 @@ import { TreeItemCollapsibleState, ThemeIcon, MarkdownString as MarkdownStringTy
 import { isUndefinedOrNull, isString } from 'vs/base/common/types';
 import { equals, coalesce } from 'vs/base/common/arrays';
 import { ILogService } from 'vs/platform/log/common/log';
-import { checkProposedApiEnabled } from 'vs/workbench/services/extensions/common/extensions';
 import { IExtensionDescription } from 'vs/platform/extensions/common/extensions';
 import { MarkdownString } from 'vs/workbench/api/common/extHostTypeConverters';
 import { IMarkdownString } from 'vs/base/common/htmlContent';
@@ -182,7 +181,7 @@ type TreeData<T> = { message: boolean, element: T | Root | false };
 
 interface TreeNode extends IDisposable {
  item: ITreeItem;
- extensionItem: vscode.TreeItem2;
+ extensionItem: vscode.TreeItem;
  parent: TreeNode | Root;
  children?: TreeNode[];
 }
@@ -569,13 +568,12 @@ class ExtHostTreeView<T> extends Disposable {
 
  private getTooltip(tooltip?: string | vscode.MarkdownString): string | IMarkdownString | undefined {
  if (MarkdownStringType.isMarkdownString(tooltip)) {
- checkProposedApiEnabled(this.extension);
  return MarkdownString.from(tooltip);
  }
  return tooltip;
  }
 
- private createTreeNode(element: T, extensionTreeItem: vscode.TreeItem2, parent: TreeNode | Root): TreeNode {
+ private createTreeNode(element: T, extensionTreeItem: vscode.TreeItem, parent: TreeNode | Root): TreeNode {
  const disposable = new DisposableStore();
  const handle = this.createHandle(element, extensionTreeItem, parent);
  const icon = this.getLightIconPath(extensionTreeItem);
@@ -604,7 +602,7 @@ class ExtHostTreeView<T> extends Disposable {
  };
  }
 
- private getThemeIcon(extensionTreeItem: vscode.TreeItem2): ThemeIcon | undefined {
+ private getThemeIcon(extensionTreeItem: vscode.TreeItem): ThemeIcon | undefined {
  return extensionTreeItem.iconPath instanceof ThemeIcon ? extensionTreeItem.iconPath : undefined;
  }