fix(overlay): vend a VirtualTrigger for overlays with no element trigger

packages/overlay/local.d.ts

@@ -20,9 +20,9 @@ declare module '@popperjs/core/dist/esm/popper-lite.js' {
 }
 
 declare module '@popperjs/core/dist/esm/types.js' {
-    import { Instance } from '@popperjs/core/lib/types.js';
+    import { Instance, VirtualElement } from '@popperjs/core/lib/types.js';
 
-    export { Instance };
+    export { Instance, VirtualElement };
 }
 
 declare module '@popperjs/core/dist/esm/enums.js' {

packages/overlay/src/ActiveOverlay.ts

@@ -28,6 +28,7 @@ import {
     TriggerInteractions,
 } from './overlay-types.js';
 import { applyMaxSize, createPopper, Instance, maxSize } from './popper.js';
+import { VirtualTrigger } from './VirtualTrigger.js';
 
 export interface PositionResult {
     arrowOffsetLeft: number;
@@ -115,6 +116,7 @@ export class ActiveOverlay extends SpectrumElement {
     public overlayContent!: HTMLElement;
     public overlayContentTip?: HTMLElement;
     public trigger!: HTMLElement;
+    public virtualTrigger?: VirtualTrigger;
 
     private popper?: Instance;
 
@@ -250,25 +252,29 @@ export class ActiveOverlay extends SpectrumElement {
         if (!this.overlayContent || !this.trigger) return;
 
         if (this.placement && this.placement !== 'none') {
-            this.popper = createPopper(this.trigger, this, {
-                placement: this.placement,
-                modifiers: [
-                    maxSize,
-                    applyMaxSize,
-                    {
-                        name: 'arrow',
-                        options: {
-                            element: this.overlayContentTip,
+            this.popper = createPopper(
+                this.virtualTrigger || this.trigger,
+                this,
+                {
+                    placement: this.placement,
+                    modifiers: [
+                        maxSize,
+                        applyMaxSize,
+                        {
+                            name: 'arrow',
+                            options: {
+                                element: this.overlayContentTip,
+                            },
                         },
-                    },
-                    {
-                        name: 'offset',
-                        options: {
-                            offset: [0, this.offset],
+                        {
+                            name: 'offset',
+                            options: {
+                                offset: [0, this.offset],
+                            },
                         },
-                    },
-                ],
-            });
+                    ],
+                }
+            );
         }
 
         this.state = 'active';
@@ -324,6 +330,7 @@ export class ActiveOverlay extends SpectrumElement {
         this.overlayContent = detail.content;
         this.overlayContentTip = detail.contentTip;
         this.trigger = detail.trigger;
+        this.virtualTrigger = detail.virtualTrigger;
         this.placement = detail.placement;
         this.offset = detail.offset;
         this.interaction = detail.interaction;

packages/overlay/src/VirtualTrigger.ts

@@ -0,0 +1,45 @@
+/*
+Copyright 2020 Adobe. All rights reserved.
+This file is licensed to you under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License. You may obtain a copy
+of the License at http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software distributed under
+the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+OF ANY KIND, either express or implied. See the License for the specific language
+governing permissions and limitations under the License.
+*/
+
+import type { VirtualElement } from './popper.js';
+import { Overlay } from './overlay.js';
+
+export class VirtualTrigger implements VirtualElement {
+    private x = 0;
+    private y = 0;
+
+    public constructor(x: number, y: number) {
+        this.x = x;
+        this.y = y;
+    }
+
+    public updateBoundingClientRect(x: number, y: number): void {
+        this.x = x;
+        this.y = y;
+        Overlay.update();
+    }
+
+    public getBoundingClientRect(): DOMRect {
+        return {
+            width: 0,
+            height: 0,
+            top: this.y,
+            right: this.x,
+            y: this.y,
+            x: this.x,
+            bottom: this.y,
+            left: this.x,
+            toJSON() {
+                return;
+            },
+        };
+    }
+}

packages/overlay/src/index.ts

@@ -14,3 +14,4 @@ export * from './OverlayTrigger.js';
 export * from './overlay-types.js';
 export * from './ActiveOverlay.js';
 export * from './loader.js';
+export * from './VirtualTrigger.js';

packages/overlay/src/overlay-types.ts

@@ -12,6 +12,7 @@ governing permissions and limitations under the License.
 
 import { ThemeData } from '@spectrum-web-components/theme';
 import { Placement as PopperPlacement } from './popper';
+import { VirtualTrigger } from './VirtualTrigger.js';
 
 export type TriggerInteractions =
     | 'click'
@@ -29,6 +30,7 @@ export interface OverlayOpenDetail {
     offset: number;
     placement?: Placement;
     receivesFocus?: 'auto';
+    virtualTrigger?: VirtualTrigger;
     trigger: HTMLElement;
     interaction: TriggerInteractions;
     theme: ThemeData;
@@ -59,6 +61,7 @@ export type OverlayOptions = {
     receivesFocus?: 'auto';
     notImmediatelyClosable?: boolean;
     abortPromise?: Promise<boolean>;
+    virtualTrigger?: VirtualTrigger;
 };
 
 declare global {

packages/overlay/src/overlay.ts

@@ -96,6 +96,7 @@ export class Overlay {
         placement = 'top',
         receivesFocus,
         notImmediatelyClosable,
+        virtualTrigger,
     }: OverlayOptions): Promise<boolean> {
         /* c8 ignore next */
         if (this.isOpen) return true;
@@ -140,6 +141,7 @@ export class Overlay {
             theme: queryThemeDetail,
             receivesFocus,
             notImmediatelyClosable,
+            virtualTrigger,
             ...overlayDetailQuery,
         });
         this.isOpen = true;

packages/overlay/src/popper.ts

@@ -24,7 +24,10 @@ import {
     defaultModifiers,
     popperGenerator,
 } from '@popperjs/core/dist/esm/popper-lite.js';
-import type { Instance } from '@popperjs/core/dist/esm/types.js';
+import type {
+    Instance,
+    VirtualElement,
+} from '@popperjs/core/dist/esm/types.js';
 import maxSize from 'popper-max-size-modifier';
 import { applyMaxSize } from './apply-max-size.js';
 
@@ -38,5 +41,5 @@ export const createPopper = popperGenerator({
     ],
 });
 
-export type { Instance, Placement };
+export type { Instance, Placement, VirtualElement };
 export { maxSize, applyMaxSize };

packages/overlay/stories/overlay.stories.ts

@@ -9,7 +9,13 @@ OF ANY KIND, either express or implied. See the License for the specific languag
 governing permissions and limitations under the License.
 */
 import { html, TemplateResult, ifDefined } from '@spectrum-web-components/base';
-import { OverlayContentTypes, OverlayTrigger, Placement } from '../';
+import {
+    openOverlay,
+    OverlayContentTypes,
+    OverlayTrigger,
+    Placement,
+    VirtualTrigger,
+} from '../';
 import '@spectrum-web-components/action-button/sp-action-button.js';
 import '@spectrum-web-components/action-group/sp-action-group.js';
 import '@spectrum-web-components/button/sp-button.js';
@@ -20,6 +26,7 @@ import '@spectrum-web-components/icons-workflow/icons/sp-icon-magnify.js';
 import '@spectrum-web-components/overlay/overlay-trigger.js';
 import { Picker } from '@spectrum-web-components/picker';
 import '@spectrum-web-components/picker/sp-picker.js';
+import '@spectrum-web-components/menu/sp-menu.js';
 import '@spectrum-web-components/menu/sp-menu-item.js';
 import '@spectrum-web-components/menu/sp-menu-divider.js';
 import '@spectrum-web-components/popover/sp-popover.js';
@@ -637,3 +644,51 @@ export const superComplexModal = (): TemplateResult => {
         </overlay-trigger>
     `;
 };
+
+export const virtualElement = (args: Properties): TemplateResult => {
+    const pointerenter = async (event: PointerEvent): Promise<void> => {
+        event.preventDefault();
+        const trigger = event.target as HTMLElement;
+        const virtualTrigger = new VirtualTrigger(event.clientX, event.clientY);
+        openOverlay(
+            trigger,
+            'modal',
+            trigger.nextElementSibling as HTMLElement,
+            {
+                placement: args.placement,
+                receivesFocus: 'auto',
+                virtualTrigger,
+            }
+        );
+    };
+    return html`
+        <style>
+            .app-root {
+                position: absolute;
+                inset: 0;
+            }
+        </style>
+        <div class="app-root" @contextmenu=${pointerenter}></div>
+        <sp-popover
+            style="max-width: 33vw;"
+            @click=${(event: Event) =>
+                event.target?.dispatchEvent(
+                    new Event('close', { bubbles: true })
+                )}
+        >
+            <sp-menu>
+                <sp-menu-item>Deselect</sp-menu-item>
+                <sp-menu-item>Select inverse</sp-menu-item>
+                <sp-menu-item>Feather...</sp-menu-item>
+                <sp-menu-item>Select and mask...</sp-menu-item>
+                <sp-menu-divider></sp-menu-divider>
+                <sp-menu-item>Save selection</sp-menu-item>
+                <sp-menu-item disabled>Make work path</sp-menu-item>
+            </sp-menu>
+        </sp-popover>
+    `;
+};
+
+virtualElement.args = {
+    placement: 'right-end',
+};