Skip to content

realworld-expo-clipboard.md

Latest commit

 

History

History
93 lines (81 loc) · 5.11 KB

realworld-expo-clipboard.md

File metadata and controls

93 lines (81 loc) · 5.11 KB
Raw

Real-app harness: expo-clipboard via GdkClipboard

expo-clipboard for text is a thin wrapper over the existing rnLinux.clipboard* JSI bindings (added during the device-info work). Those talk to GdkClipboard on the active display — the same surface every GTK app uses. Cross-app paste works because the display clipboard is shared with the rest of the desktop.

Architecture

JS app
  ↓ require('expo-clipboard')    ← metro/esbuild rewrite, linux only
@lucid-softworks/react-native-linux-expo/expo-clipboard.js
  ├─ setStringAsync(text)        →  rnLinux.clipboardSetString
  │                                    ↓ gdk_clipboard_set_text
  │                                    GdkClipboard on display
  └─ getStringAsync() / hasStringAsync()
                                 →  rnLinux.clipboardGetStringSync
                                      ↓ gdk_clipboard_get_content
                                      → GdkContentProvider value

VM / host setup

None. GTK4 is already a runtime dep; GdkClipboard is bundled.

Running the smoke demo

cd apps/playground
RN_ENTRY=smoke-demo.tsx node bundle.mjs
scripts/vm/sh.sh 'scripts/vm/run-playground.sh'

Scroll to the expo-clipboard section. The probe row already shows a successful set+get round-trip (roundtripped 22 chars). The demo exposes two buttons: copy timestamp writes a fresh ISO timestamp to the clipboard; paste reads back whatever's on the clipboard and displays it inline.

API surface

API Behavior on Linux
setStringAsync(text) / setString Real — gdk_clipboard_set_text on the display
getStringAsync() Real for values WE wrote (sync read of gdk_clipboard_get_content)
hasStringAsync() True iff getStringAsync() returns a non-empty string
getUrlAsync / setUrlAsync / hasUrl… Aliases for the text path — no separate Linux URL clip type
getImageAsync / setImageAsync Real — base64 PNG/JPEG round-trip through GdkTexture + gdk_clipboard_set_texture
getHtmlAsync / setHtmlAsync Real — unioned text/html + text/plain provider; plaintext extracted in JS
hasImageAsync / hasHtmlAsync Real — non-empty result from the matching async getter
setContentAsync({files: [...]}) Real — GdkFileList content provider; file managers paste real file refs
addClipboardListener Real — fan-out over GdkClipboard::changed (cross-app writes fire it too)
ContentType / StringFormat / ImageFormat enums Match upstream's numeric values

Known gaps

  • Cross-app paste reads — DONE. getStringAsync / hasStringAsync now route through rnLinux.clipboardGetStringAsync → gdk_clipboard_read_text_async, which negotiates the MIME transfer with whichever app put the text on the clipboard. The legacy sync clipboardGetStringSync is still there for the fast in-process round-trip but only sees this process's own writes.
  • Images — DONE. setImageAsync(base64) decodes via gdk_texture_new_from_bytes and calls gdk_clipboard_set_texture; getImageAsync() reads through gdk_clipboard_read_texture_async and re-encodes as PNG via gdk_texture_save_to_png_bytes so the base64 payload is self-describing.
  • HTML — DONE. setHtmlAsync(html) publishes a gdk_content_provider_new_union over both text/html and text/plain;charset=utf-8 (plaintext extracted in JS) so non-rich consumers still get something readable. getHtmlAsync() asks for text/html specifically via gdk_clipboard_read_async and drains the returned GInputStream.
  • File lists — DONE. Clipboard.setContentAsync({files: [...]}) builds a GdkFileList (gdk_file_list_new_from_list) and publishes a typed GDK_TYPE_FILE_LIST content provider; file managers paste real file refs, not just text URIs.
  • Change listener — DONE. g_signal_connect(clip, "changed", ...) is bound through a single native trampoline; the JS shim multiplexes all addClipboardListener subscribers behind it and tears the subscription down when the last listener unsubscribes. The signal fires on every clipboard write — including ones from other apps — so this is a real cross-app subscription, not a same-process echo. The payload is {} (iOS/Android pass content-type metadata; we don't carry that without an extra async read) — consumers re-call getStringAsync() to fetch the new value, matching the expo idiom.