fix: support native clipboard image paste on mobile (#181)

Co-authored-by: Khushvendra <khushvendras99@gmail.com>
Co-committed-by: Khushvendra <khushvendras99@gmail.com>

src/app/editor/clipboard.ts

@@ -0,0 +1,81 @@
+import {Clipboard} from "@capacitor/clipboard"
+import {Capacitor} from "@capacitor/core"
+import {Extension} from "@tiptap/core"
+import {Plugin, PluginKey} from "@tiptap/pm/state"
+
+const nativeClipboardAvailable = () =>
+  Capacitor.isNativePlatform() && Capacitor.isPluginAvailable("Clipboard")
+
+const hasStandardPastePayload = (event: ClipboardEvent) => {
+  const clipboardData = event.clipboardData
+
+  if (!clipboardData) {
+    return false
+  }
+
+  if (Array.from(clipboardData.items).some(item => item.kind === "file")) {
+    return true
+  }
+
+  if (clipboardData.types.includes("text/html")) {
+    return true
+  }
+
+  return clipboardData.getData("text/plain") !== ""
+}
+
+const getNativeClipboardImage = async () => {
+  try {
+    const {type, value} = await Clipboard.read()
+
+    if (!type.startsWith("image/") || value === "") {
+      return undefined
+    }
+
+    const imageData = value.startsWith("data:") ? value : `data:${type};base64,${value}`
+    const blob = await fetch(imageData).then(res => res.blob())
+
+    if (!blob.type.startsWith("image/")) {
+      return undefined
+    }
+
+    const extension = type.split("/")[1]?.split("+")[0] || "png"
+
+    return new File([blob], `clipboard-image.${extension}`, {type: blob.type || type})
+  } catch {
+    return undefined
+  }
+}
+
+export const NativeClipboardPasteExtension = Extension.create({
+  name: "nativeClipboardPaste",
+
+  addProseMirrorPlugins() {
+    const editor = this.editor
+
+    return [
+      new Plugin({
+        key: new PluginKey("nativeClipboardPaste"),
+        props: {
+          handlePaste: (_view, event) => {
+            if (!nativeClipboardAvailable() || hasStandardPastePayload(event)) {
+              return false
+            }
+
+            event.preventDefault()
+
+            void getNativeClipboardImage().then(file => {
+              if (!file) {
+                return
+              }
+
+              editor.commands.addFile(file, editor.state.selection.from + 1)
+            })
+
+            return true
+          },
+        },
+      }),
+    ]
+  },
+})

src/app/editor/index.ts

@@ -15,6 +15,7 @@ import {
 } from "@welshman/app"
 import type {FileAttributes} from "@welshman/editor"
 import {Editor, MentionSuggestion, WelshmanExtension, editorProps} from "@welshman/editor"
+import {NativeClipboardPasteExtension} from "@app/editor/clipboard"
 import {escapeHtml} from "@lib/html"
 import {makeMentionNodeView} from "@app/editor/MentionNodeView"
 import ProfileSuggestion from "@app/editor/ProfileSuggestion.svelte"
@@ -137,6 +138,7 @@ export const makeEditor = async ({
           },
         },
       }),
+      NativeClipboardPasteExtension,
     ],
     onUpdate({editor}) {
       wordCount?.set(editor.storage.wordCount.words)