4 files changed, 56 insertions, 17 deletions

diff --git a/src/plugins/platforms/wasm/qtloader.js b/src/plugins/platforms/wasm/qtloader.js
index 84694c7b9f..203213db56 100644
--- a/src/plugins/platforms/wasm/qtloader.js
+++ b/src/plugins/platforms/wasm/qtloader.js
@@ -168,7 +168,14 @@ function QtLoader(config)
             removeChildren(container);
             var canvas = document.createElement("canvas");
             canvas.className = "QtCanvas"
-            canvas.style = "height: 100%; width: 100%;"
+            canvas.style.height = "100%"
+            canvas.style.width = "100%"
+
+            // Set contentEditable in order to enable clipboard events; hide the resulting focus frame.
+            canvas.contentEditable = true;
+            canvas.style.outline = "0px solid transparent";
+            canvas.style.cursor = "default";
+
             return canvas;
         }
 
diff --git a/src/plugins/platforms/wasm/qwasmclipboard.cpp b/src/plugins/platforms/wasm/qwasmclipboard.cpp
index ec058f05dd..63fea7738d 100644
--- a/src/plugins/platforms/wasm/qwasmclipboard.cpp
+++ b/src/plugins/platforms/wasm/qwasmclipboard.cpp
@@ -67,23 +67,42 @@ static void qClipboardPromiseResolve(emscripten::val something)
     pasteClipboardData(emscripten::val("text/plain"), something);
 }
 
-static void qClipboardCopyTo(val event)
+static void qClipboardCutTo(val event)
 {
-    val target = event["target"];
-    val clipboard = event["clipboardData"];
+    if (!QWasmIntegration::get()->getWasmClipboard()->hasClipboardApi) {
+        // Send synthetic Ctrl+X to make the app cut data to Qt's clipboard
+        QWindowSystemInterface::handleKeyEvent<QWindowSystemInterface::SynchronousDelivery>(
+            0, QEvent::KeyPress, Qt::Key_X,  Qt::ControlModifier, "X");
+    }
 
     val module = val::global("Module");
     val clipdata = module.call<val>("getClipboardData");
     val clipFormat = module.call<val>("getClipboardFormat");
-    clipboard.call<void>("setData", clipFormat, clipdata);
-    target.call<void>("preventDefault");
+    event["clipboardData"].call<void>("setData", clipFormat, clipdata);
+    event.call<void>("preventDefault");
 }
 
-static void qClipboardPasteTo(val event)
+static void qClipboardCopyTo(val event)
 {
-    val target = event["clipboardData"];
+    if (!QWasmIntegration::get()->getWasmClipboard()->hasClipboardApi) {
+        // Send synthetic Ctrl+C to make the app copy data to Qt's clipboard
+        QWindowSystemInterface::handleKeyEvent<QWindowSystemInterface::SynchronousDelivery>(
+            0, QEvent::KeyPress, Qt::Key_C,  Qt::ControlModifier, "C");
+    }
+
     val module = val::global("Module");
     val clipdata = module.call<val>("getClipboardData");
+    val clipFormat = module.call<val>("getClipboardFormat");
+    event["clipboardData"].call<void>("setData", clipFormat, clipdata);
+    event.call<void>("preventDefault");
+}
+
+static void qClipboardPasteTo(val event)
+{
+    bool hasClipboardApi = QWasmIntegration::get()->getWasmClipboard()->hasClipboardApi;
+    val clipdata = hasClipboardApi ?
+        val::global("Module").call<val>("getClipboardData") :
+        event["clipboardData"].call<val>("getData", std::string("text"));
 
     const std::string data = clipdata.as<std::string>();
     if (data.length() > 0) {
@@ -99,6 +118,7 @@ EMSCRIPTEN_BINDINGS(clipboard_module) {
     function("getClipboardFormat", &getClipboardFormat);
     function("pasteClipboardData", &pasteClipboardData);
     function("qClipboardPromiseResolve", &qClipboardPromiseResolve);
+    function("qClipboardCutTo", &qClipboardCutTo);
     function("qClipboardCopyTo", &qClipboardCopyTo);
     function("qClipboardPasteTo", &qClipboardPasteTo);
 }
@@ -161,7 +181,7 @@ void QWasmClipboard::initClipboardEvents()
     val permissions = navigator["permissions"];
     val clipboard = navigator["clipboard"];
 
-    hasClipboardApi = (!clipboard.isUndefined());
+    hasClipboardApi = (!clipboard.isUndefined() && !clipboard["readText"].isUndefined());
     if (hasClipboardApi) {
         val readPermissionsMap = val::object();
         readPermissionsMap.set("name", val("clipboard-read"));
@@ -172,13 +192,13 @@ void QWasmClipboard::initClipboardEvents()
         permissions.call<val>("query", writePermissionsMap);
 
     } else {
-
-        val window = val::global("window");
-        window.call<void>("addEventListener", std::string("paste"),
-                          val::module_property("qClipboardPasteTo"));
-
-        window.call<void>("addEventListener", std::string("copy"),
+        val canvas = val::module_property("canvas");
+        canvas.call<void>("addEventListener", std::string("cut"),
+                          val::module_property("qClipboardCutTo"));
+        canvas.call<void>("addEventListener", std::string("copy"),
                           val::module_property("qClipboardCopyTo"));
+        canvas.call<void>("addEventListener", std::string("paste"),
+                          val::module_property("qClipboardPasteTo"));
     }
 }
 
diff --git a/src/plugins/platforms/wasm/qwasmeventtranslator.cpp b/src/plugins/platforms/wasm/qwasmeventtranslator.cpp
index 3fc8f600a1..05c09ec9a0 100644
--- a/src/plugins/platforms/wasm/qwasmeventtranslator.cpp
+++ b/src/plugins/platforms/wasm/qwasmeventtranslator.cpp
@@ -832,6 +832,14 @@ bool QWasmEventTranslator::processKeyboard(int eventType, const EmscriptenKeyboa
         return 0;
 
     QFlags<Qt::KeyboardModifier> mods = translateKeyboardEventModifier(keyEvent);
+
+    // Clipboard fallback path: cut/copy/paste are handled by clipboard event
+    // handlers if direct clipboard access is not available.
+    if (!QWasmIntegration::get()->getWasmClipboard()->hasClipboardApi && modifiers & Qt::ControlModifier &&
+        (qtKey == Qt::Key_X || qtKey == Qt::Key_C || qtKey == Qt::Key_V)) {
+            return 0;
+    }
+
     bool accepted = false;
 
     if (keyType == QEvent::KeyPress &&
diff --git a/src/plugins/platforms/wasm/wasm_shell.html b/src/plugins/platforms/wasm/wasm_shell.html
index 67bfcdfbdc..110d45e036 100644
--- a/src/plugins/platforms/wasm/wasm_shell.html
+++ b/src/plugins/platforms/wasm/wasm_shell.html
@@ -7,7 +7,11 @@
     <style>
       html, body { padding: 0; margin : 0; overflow:hidden; height: 100% }
       /* the canvas *must not* have any border or padding, or mouse coords will be wrong */
-      canvas { border: 0px none; background-color: white; height:100%; width:100%; }
+      canvas { border: 0px none; background-color: white; height:100%; width:100%;  }
+      /* The contenteditable property is set to true for the canvas in order to support
+         clipboard events. Hide the resulting focus frame and set the cursor back to
+         the default cursor. */
+      canvas { outline: 0px solid transparent; cursor:default }
     </style>
   </head>
   <body onload="init()">
@@ -19,7 +23,7 @@
         <noscript>JavaScript is disabled. Please enable JavaScript to use this application.</noscript>
       </center>
     </figure>
-    <canvas id="canvas" oncontextmenu="event.preventDefault()"></canvas>
+    <canvas id="canvas" oncontextmenu="event.preventDefault()" contenteditable="true"></canvas>
 
     <script type='text/javascript'>
         function init() {