From a32915b23a5ac92c92b68e39e978ed20fd1acbc8 Mon Sep 17 00:00:00 2001
From: Johan Groth <johan.groth@lime.tech>
Date: Thu, 29 Aug 2019 13:40:29 +0200
Subject: [PATCH] feat(menu-surface): new menu-surface component

---
 src/components/menu-surface/menu-surface.scss |   7 +
 src/components/menu-surface/menu-surface.tsx  | 172 ++++++++++++++++++
 2 files changed, 179 insertions(+)
 create mode 100644 src/components/menu-surface/menu-surface.scss
 create mode 100644 src/components/menu-surface/menu-surface.tsx

diff --git a/src/components/menu-surface/menu-surface.scss b/src/components/menu-surface/menu-surface.scss
new file mode 100644
index 0000000000..acac731590
--- /dev/null
+++ b/src/components/menu-surface/menu-surface.scss
@@ -0,0 +1,7 @@
+@import '../../style/variables';
+@import "@limetech/mdc-menu-surface/mdc-menu-surface";
+
+.mdc-menu-surface {
+    width: 100%;
+    max-height: 100%;
+}
diff --git a/src/components/menu-surface/menu-surface.tsx b/src/components/menu-surface/menu-surface.tsx
new file mode 100644
index 0000000000..c1ab7635d4
--- /dev/null
+++ b/src/components/menu-surface/menu-surface.tsx
@@ -0,0 +1,172 @@
+import { Corner, MDCMenuSurface } from '@limetech/mdc-menu-surface';
+import {
+    Component,
+    Element,
+    Event,
+    EventEmitter,
+    h,
+    Prop,
+} from '@stencil/core';
+import { isDescendant } from '../../util/dom';
+import {
+    ESCAPE,
+    ESCAPE_KEY_CODE,
+    TAB,
+    TAB_KEY_CODE,
+} from '../../util/keycodes';
+
+@Component({
+    tag: 'limel-menu-surface',
+    shadow: true,
+    styleUrl: 'menu-surface.scss',
+})
+export class MenuSurface {
+    /**
+     * True if the menu surface is open, false otherwise
+     */
+    @Prop()
+    public open = false;
+
+    /**
+     * Emitted when the menu surface is dismissed and should be closed
+     */
+    @Event()
+    public dismiss: EventEmitter<void>;
+
+    @Element()
+    private host: HTMLElement;
+
+    private menuSurface: MDCMenuSurface;
+
+    constructor() {
+        this.handleDocumentClick = this.handleDocumentClick.bind(this);
+        this.handleDocumentScroll = this.handleDocumentScroll.bind(this);
+        this.handleKeyDown = this.handleKeyDown.bind(this);
+        this.handleResize = this.handleResize.bind(this);
+    }
+
+    public connectedCallback() {
+        this.setup();
+    }
+
+    public disconnectedCallback() {
+        this.teardown();
+    }
+
+    public componentDidLoad() {
+        this.setup();
+    }
+
+    public render() {
+        return (
+            <div
+                class={{
+                    'mdc-menu-surface': true,
+                    'mdc-menu-surface--open': this.open,
+                }}
+                tabindex="-1"
+            >
+                <slot />
+            </div>
+        );
+    }
+
+    private setup() {
+        const menuElement = this.host.shadowRoot.querySelector(
+            '.mdc-menu-surface'
+        );
+        if (!menuElement) {
+            return;
+        }
+
+        this.menuSurface = new MDCMenuSurface(menuElement);
+        this.menuSurface.setAnchorCorner(Corner.TOP_START);
+
+        document.addEventListener('mousedown', this.handleDocumentClick, {
+            capture: true,
+        });
+        document.addEventListener('wheel', this.handleDocumentScroll, {
+            passive: true,
+        });
+        this.host.addEventListener('keydown', this.handleKeyDown);
+        window.addEventListener('resize', this.handleResize, {
+            passive: true,
+        });
+    }
+
+    private teardown() {
+        this.menuSurface.destroy();
+        document.removeEventListener('mousedown', this.handleDocumentClick, {
+            capture: true,
+        });
+        document.removeEventListener('wheel', this.handleDocumentScroll);
+        this.host.removeEventListener('keydown', this.handleKeyDown);
+        window.removeEventListener('resize', this.handleResize);
+    }
+
+    private handleDocumentClick(event) {
+        if (this.open && !isDescendant(event.target, this.host)) {
+            this.dismiss.emit();
+            this.preventClickEventPropagation();
+        }
+    }
+
+    private handleDocumentScroll(event) {
+        if (this.open && !isDescendant(event.target, this.host)) {
+            this.dismiss.emit();
+        }
+    }
+
+    private handleResize() {
+        if (this.open) {
+            this.dismiss.emit();
+        }
+    }
+
+    private preventClickEventPropagation() {
+        // When the menu surface is open, we want to stop the `click` event from propagating
+        // when clicking outside the surface itself. This is to prevent any dialog that might
+        // be open from closing, etc. However, when dragging a scrollbar no `click` event is emitted,
+        // only mousedown and mouseup. So we listen for `mousedown` and attach a one-time listener
+        // for `click`, so we can capture and "kill" it.
+        document.addEventListener('click', this.stopEvent, {
+            capture: true,
+            once: true,
+        });
+        // We also capture and "kill" the next `mouseup` event.
+        document.addEventListener('mouseup', this.stopEvent, {
+            capture: true,
+            once: true,
+        });
+        // If the user dragged the scrollbar, no `click` event happens. So when we get the
+        // `mouseup` event, remove the handler for `click` if it's still there.
+        // Otherwise, we would catch the next click even though the menu is no longer open.
+        document.addEventListener(
+            'mouseup',
+            () => {
+                document.removeEventListener('click', this.stopEvent, {
+                    capture: true,
+                });
+            },
+            {
+                once: true,
+            }
+        );
+    }
+
+    private stopEvent(event) {
+        event.stopPropagation();
+        event.preventDefault();
+    }
+
+    private handleKeyDown(event: KeyboardEvent) {
+        const isEscape =
+            event.key === ESCAPE || event.keyCode === ESCAPE_KEY_CODE;
+        const isTab = event.key === TAB || event.keyCode === TAB_KEY_CODE;
+
+        if (this.open && (isEscape || isTab)) {
+            event.stopPropagation();
+            this.dismiss.emit();
+        }
+    }
+}