Initial Commit

include/EmscriptenHelpers/emscripten_browser_clipboard.h

@@ -0,0 +1,96 @@
+#pragma once
+
+#include <string>
+#include <emscripten.h>
+
+#define _EM_JS_INLINE(ret, c_name, js_name, params, code)                          \
+  extern "C" {                                                                     \
+  ret c_name params EM_IMPORT(js_name);                                            \
+  EMSCRIPTEN_KEEPALIVE                                                             \
+  __attribute__((section("em_js"), aligned(1))) inline char __em_js__##js_name[] = \
+    #params "<::>" code;                                                           \
+  }
+
+#define EM_JS_INLINE(ret, name, params, ...) _EM_JS_INLINE(ret, name, name, params, #__VA_ARGS__)
+
+namespace emscripten_browser_clipboard {
+
+/////////////////////////////////// Interface //////////////////////////////////
+
+using paste_handler = void(*)(std::string&&, void*);
+using copy_handler = char const*(*)(void*);
+
+inline void paste(paste_handler callback, void *callback_data = nullptr);
+inline void copy(copy_handler callback, void *callback_data = nullptr);
+inline void copy(std::string const &content);
+
+///////////////////////////////// Implementation ///////////////////////////////
+
+namespace detail {
+
+EM_JS_INLINE(void, paste_js, (paste_handler callback, void *callback_data), {
+  /// Register the given callback to handle paste events. Callback data pointer is passed through to the callback.
+  /// Paste handler callback signature is:
+  ///   void my_handler(std::string const &paste_data, void *callback_data = nullptr);
+  document.addEventListener('paste', (event) => {
+    Module["ccall"]('emscripten_browser_clipboard_detail_paste_return', 'number', ['string', 'number', 'number'], [event.clipboardData.getData('text/plain'), callback, callback_data]);
+  });
+});
+
+EM_JS_INLINE(void, copy_js, (copy_handler callback, void *callback_data), {
+  /// Register the given callback to handle copy events. Callback data pointer is passed through to the callback.
+  /// Copy handler callback signature is:
+  ///   char const *my_handler(void *callback_data = nullptr);
+  document.addEventListener('copy', (event) => {
+    const content_ptr = Module["ccall"]('emscripten_browser_clipboard_detail_copy_return', 'number', ['number', 'number'], [callback, callback_data]);
+    event.clipboardData.setData('text/plain', UTF8ToString(content_ptr));
+    event.preventDefault();
+  });
+});
+
+EM_JS_INLINE(void, copy_async_js, (char const *content_ptr), {
+  /// Attempt to copy the provided text asynchronously
+  navigator.clipboard.writeText(UTF8ToString(content_ptr));
+});
+
+} // namespace detail
+
+inline void paste(paste_handler callback, void *callback_data) {
+  /// C++ wrapper for javascript paste call
+  detail::paste_js(callback, callback_data);
+}
+
+inline void copy(copy_handler callback, void *callback_data) {
+  /// C++ wrapper for javascript copy call
+  detail::copy_js(callback, callback_data);
+}
+
+inline void copy(std::string const &content) {
+  /// C++ wrapper for javascript copy call
+  detail::copy_async_js(content.c_str());
+}
+
+namespace detail {
+
+extern "C" {
+
+EMSCRIPTEN_KEEPALIVE inline int emscripten_browser_clipboard_detail_paste_return(char const *paste_data, paste_handler callback, void *callback_data);
+
+EMSCRIPTEN_KEEPALIVE inline int emscripten_browser_clipboard_detail_paste_return(char const *paste_data, paste_handler callback, void *callback_data) {
+  /// Call paste callback - this function is called from javascript when the paste event occurs
+  callback(paste_data, callback_data);
+  return 1;
+}
+
+EMSCRIPTEN_KEEPALIVE inline char const *emscripten_browser_clipboard_detail_copy_return(copy_handler callback, void *callback_data);
+
+EMSCRIPTEN_KEEPALIVE inline char const *emscripten_browser_clipboard_detail_copy_return(copy_handler callback, void *callback_data) {
+  /// Call paste callback - this function is called from javascript when the paste event occurs
+  return callback(callback_data);
+}
+
+}
+
+} // namespace detail
+
+} // namespace emscripten_browser_clipboard