Fix toolbar stealing focus (microsoft#6888)

* Fix toolbar stealing focus

* Implement suggestion by @scomea

* Add test

* Use 'getRootActiveElement'

* Change files

* Apply review comment

---------

Co-authored-by: Frédéric Collonval <[email protected]>
Co-authored-by: Stephane Comeau <[email protected]>

change/@microsoft-fast-foundation-65238abc-a169-4169-a830-9dcdb4e9af99.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "Fix toolbar stealing focus",
+  "packageName": "@microsoft/fast-foundation",
+  "email": "[email protected]",
+  "dependentChangeType": "prerelease"
+}

packages/web-components/fast-foundation/src/toolbar/toolbar.pw.spec.ts

@@ -479,4 +479,66 @@ test.describe("Toolbar", () => {
         await button3.click();
         await expect(button3).toBeFocused();
     });
+
+    test("should not focus clicked item when focus is moved outside of the toolbar by an event handler", async () => {
+        await root.evaluate(node => {
+            node.innerHTML = /* html */ `
+                <fast-toolbar>
+                    <button slot="start">Start Slot Button</button>
+                    <button id="toolbar-button-1">Button 1</button>
+                    <button id="toolbar-button-1">Button 2</button>
+                    <button>Button 3</button>
+                    <button>Button 4</button>
+                    <button>Button 5</button>
+                    <button slot="end">End Slot Button</button>
+                </fast-toolbar>
+                <button id="outside-button">Button Outside Toolbar</button>
+            `;
+        });
+
+        const buttonOutsideToolbar = page.locator("button", { hasText: "Button Outside Toolbar"});
+        const button1 = element.locator("button", { hasText: "Button 1" });
+        const button2 = element.locator("button", { hasText: "Button 2" });
+        const button3 = element.locator("button", { hasText: "Button 3" });
+
+        const wasButton1Clicked = await button1.evaluate(node => new Promise(resolve => {
+                node.addEventListener("mousedown", (e: MouseEvent) => {
+                    document.querySelector<HTMLButtonElement>('#outside-button')?.focus();
+                    resolve(true)
+                })
+
+                node.dispatchEvent(new MouseEvent("mousedown", {bubbles: true, cancelable: true}))
+            }))
+
+        expect.soft(wasButton1Clicked).toEqual(true)
+        await expect.soft(buttonOutsideToolbar).toBeFocused();
+        buttonOutsideToolbar.evaluate(node => {node.blur()})
+
+        const [wasButton2Clicked] = await Promise.all([
+            button2.evaluate(node => new Promise(resolve => {
+                node.addEventListener("click", () => {
+                    document.querySelector<HTMLButtonElement>('#outside-button')?.focus();
+                    resolve(true)
+                })
+            })),
+            button2.click()
+        ])
+
+        expect.soft(wasButton2Clicked).toEqual(true)
+        await expect.soft(buttonOutsideToolbar).toBeFocused();
+        buttonOutsideToolbar.evaluate(node => {node.blur()})
+
+        const [wasButton3Clicked] = await Promise.all([
+            button3.evaluate(node => new Promise(resolve => {
+                node.addEventListener("click", () => {
+                    resolve(true)
+                })
+            })),
+            button3.click()
+        ])
+
+        expect.soft(wasButton3Clicked).toEqual(true)
+        await expect.soft(buttonOutsideToolbar).not.toBeFocused();
+        await expect(button3).toBeFocused();
+    });
 });

packages/web-components/fast-foundation/src/toolbar/toolbar.ts

@@ -4,6 +4,7 @@ import { isFocusable } from "tabbable";
 import { ARIAGlobalStatesAndProperties, StartEnd } from "../patterns/index.js";
 import { applyMixins } from "../utilities/apply-mixins.js";
 import { getDirection } from "../utilities/direction.js";
+import { getRootActiveElement } from "../utilities/root-active-element.js";
 import { ToolbarOrientation } from "./toolbar.options.js";
 
 /**
@@ -246,7 +247,14 @@ export class FASTToolbar extends FASTElement {
     private setFocusedElement(activeIndex: number = this.activeIndex): void {
         this.activeIndex = activeIndex;
         this.setFocusableElements();
-        this.focusableElements[this.activeIndex]?.focus();
+        if (
+            this.focusableElements[this.activeIndex] &&
+            // Don't focus the toolbar element if some event handlers moved
+            // the focus on another element in the page.
+            this.contains(getRootActiveElement(this))
+        ) {
+            this.focusableElements[this.activeIndex].focus();
+        }
     }
 
     /**