1 files changed, 66 insertions, 0 deletions
diff --git a/web/src/widget-api.js b/web/src/widget-api.js
new file mode 100644
index 0000000..3efca0e
--- /dev/null
+++ b/web/src/widget-api.js
@@ -0,0 +1,66 @@
+// Copyright (c) 2020 Tulir Asokan
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+let widgetId = null
+
+window.onmessage = event => {
+	if (!window.parent || !event.data) {
+		return
+	}
+
+	const request = event.data
+	if (!request.requestId || !request.widgetId || !request.action || request.api !== "toWidget") {
+		return
+	}
+
+	if (widgetId) {
+		if (widgetId !== request.widgetId) {
+			return
+		}
+	} else {
+		widgetId = request.widgetId
+	}
+
+	let response
+
+	if (request.action === "visibility") {
+		response = {}
+	} else if (request.action === "capabilities") {
+		response = { capabilities: ["m.sticker"] }
+	} else {
+		response = { error: { message: "Action not supported" } }
+	}
+
+	window.parent.postMessage({ ...request, response }, event.origin)
+}
+
+export function sendSticker(content) {
+	const data = {
+		content: { ...content },
+		// `name` is for Element Web (and also the spec)
+		// Element Android uses content -> body as the name
+		name: content.body,
+	}
+	// Custom field that stores the ID even for non-telegram stickers
+	delete data.content.id
+
+	// This is for Element iOS
+	const widgetData = {
+		...data,
+		description: content.body,
+		file: `${content.id}.png`,
+	}
+	// Element iOS explodes if there are extra fields present
+	delete widgetData.content["net.maunium.telegram.sticker"]
+
+	window.parent.postMessage({
+		api: "fromWidget",
+		action: "m.sticker",
+		requestId: `sticker-${Date.now()}`,
+		widgetId,
+		data,
+		widgetData,
+	}, "*")
+}