[core] Don't scroll when re-setting focus on widgets.

packages/core/src/browser/menu/browser-menu-plugin.ts

@@ -173,7 +173,7 @@ class DynamicMenuWidget extends MenuWidget {
         // we want to restore the focus after the menu closes.
         const previouslyActive = window.document.activeElement as HTMLElement;
         const cb = () => {
-            previouslyActive.focus();
+            previouslyActive.focus({ preventScroll: true });
             this.aboutToClose.disconnect(cb);
         };
         this.aboutToClose.connect(cb);

packages/core/src/browser/quick-open/quick-command-service.ts

@@ -246,7 +246,7 @@ export class CommandQuickOpenItem extends QuickOpenGroupItem {
         // allow the quick open widget to close itself
         setTimeout(() => {
             // reset focus on the previously active element.
-            this.activeElement.focus();
+            this.activeElement.focus({ preventScroll: true });
             this.commands.executeCommand(this.command.id);
         }, 50);
         return true;

packages/core/src/browser/tree/tree-widget.tsx

@@ -331,7 +331,7 @@ export class TreeWidget extends ReactWidget implements StatefulWidget {
 
     protected onActivateRequest(msg: Message): void {
         super.onActivateRequest(msg);
-        this.node.focus();
+        this.node.focus({ preventScroll: true });
     }
 
     /**

packages/core/src/browser/view-container.ts

@@ -528,7 +528,7 @@ export class ViewContainer extends BaseWidget implements StatefulWidget, Applica
         if (this.currentPart) {
             this.currentPart.activate();
         } else {
-            this.panel.node.focus();
+            this.panel.node.focus({ preventScroll: true });
         }
     }
 

packages/git/src/browser/diff/git-diff-widget.tsx

@@ -437,7 +437,7 @@ export class GitDiffListContainer extends React.Component<GitDiffListContainer.P
 
     focus(): void {
         if (this.listContainer) {
-            this.listContainer.focus();
+            this.listContainer.focus({ preventScroll: true });
         }
     }
 }

packages/monaco/src/browser/monaco-quick-open-service.ts

@@ -219,7 +219,7 @@ export class MonacoQuickOpenService extends QuickOpenService {
             },
             onCancel: () => {
                 if (this.previousActiveElement instanceof HTMLElement) {
-                    this.previousActiveElement.focus();
+                    this.previousActiveElement.focus({ preventScroll: true });
                 }
                 this.previousActiveElement = undefined;
                 this.contextKeyService.activeContext = undefined;

packages/plugin-ext/src/main/browser/quick-open-main.ts

@@ -77,7 +77,7 @@ export class QuickOpenMainImpl implements QuickOpenMain, QuickOpenModel, Disposa
         this.items = undefined;
         this.acceptor = undefined;
         if (this.activeElement) {
-            this.activeElement.focus();
+            this.activeElement.focus({ preventScroll: true });
         }
         this.activeElement = undefined;
     }

packages/plugin-ext/src/main/browser/workspace-main.ts

@@ -150,7 +150,7 @@ export class WorkspaceMainImpl implements WorkspaceMain, Disposable {
                 placeholder: options.placeHolder,
                 onClose: () => {
                     if (activeElement) {
-                        activeElement.focus();
+                        activeElement.focus({ preventScroll: true });
                     }
 
                     resolve(returnValue);