QDS-9900 Update the design viewer app to work with Qt 6.5 / emsdk 3.1.25

Use new API in Qt, adapt to changes in Qt and Emscripten.

Incremental step towards Qt 6.6 support (see QDS-9900).

design-viewer/src/dv_wasm.cpp

@@ -26,64 +26,23 @@
 #include "dv_wasm.h"
 #if defined(Q_OS_WASM)
 
+#include <emscripten/val.h>
+
 #include <emscripten.h>
 #include <functional>
 
 #include <QFile>
-
-std::function<void(char *, size_t, char *)> g_setFileDataCallback;
-extern "C" EMSCRIPTEN_KEEPALIVE void qt_callSetFileData(char *content,
-                                                        size_t contentSize,
-                                                        char *fileName)
-{
-    if (g_setFileDataCallback == nullptr)
-        return;
-
-    g_setFileDataCallback(content, contentSize, fileName);
-    g_setFileDataCallback = nullptr;
-}
+#include <QTimer>
 
 void DvWasm::fetchProject(QByteArray *data, QString *fileName)
 {
-    // Call qt_callSetFileData to make sure the emscripten linker does not
-    // optimize it away, which may happen if the function is called from JavaScript
-    // only. Set g_setFileDataCallback to null to make it a no-op.
-    ::g_setFileDataCallback = nullptr;
-    ::qt_callSetFileData(nullptr, 0, nullptr);
-
-    auto setFileDataCallback =
-        [data, fileName](char *content, size_t contentSize, char *projectFilename) {
-            data->setRawData(content, contentSize);
-            *fileName = QString::fromUtf8(projectFilename);
-        };
-    g_setFileDataCallback = setFileDataCallback;
-
-    EM_ASM_({
-        // Copy the file file content to the C++ heap.
-        // Note: this could be simplified by passing the content as an
-        // "array" type to ccall and then let it copy to C++ memory.
-        // However, this built-in solution does not handle files larger
-        // than ~15M (Chrome). Instead, allocate memory manually and
-        // pass a pointer to the C++ side (which will free() it when done).
+    // Access global variables set by index.html
+    emscripten::val jsData = emscripten::val::global("contentArray");
+    emscripten::val jsFileName = emscripten::val::global("projectfileName");
 
-        // TODO: consider slice()ing the file to read it picewise and
-        // then assembling it in a QByteArray on the C++ side.
-
-        const contentSize = contentArray.byteLength;
-        const heapPointer = _malloc(contentSize);
-        const heapBytes = new Uint8Array(Module.HEAPU8.buffer, heapPointer, contentSize);
-        heapBytes.set(contentArray);
-
-        // Null out the first data copy to enable GC
-        reader = null;
-        contentArray = null;
-
-        // Call the C++ file data ready callback
-        ccall("qt_callSetFileData",
-              null,
-              ["number", "number", "string"],
-              [heapPointer, contentSize, projectfileName]);
-    });
+    // Copy project data to the C++ heap and convert string
+    *data = QByteArray::fromEcmaUint8Array(jsData);
+    *fileName = QString::fromStdString(jsFileName.as<std::string>());
 }
 
 void DvWasm::printLog(const QString &message)
@@ -96,22 +55,41 @@ void DvWasm::printWarn(const QString &message)
     QString escaped = message;
     escaped.replace("'", "\'");
     escaped.replace("\n", "\\n");
-    emscripten_run_script("alert('" + escaped.toUtf8() + "');");
+    emscripten::val::global("window").call<void>("alert", escaped.toStdString());
 }
 
 void DvWasm::printError(const QString &message, const QString &fileName, int line)
 {
     printWarn(message);
-    emscripten_run_script("location.hash = ''; location.reload();");
+    emscripten::val location = emscripten::val::global("window")["location"];
+    location.set("hash", std::string());
+    location.call<void>("reload");
 }
 
 void DvWasm::showAppWindow()
 {
     printLog("Resizing the QML app window");
     const QSize size;
-    const QString command
-        = QString::fromLatin1("setScreenSize(%1, %2);").arg(size.width()).arg(size.height());
-    emscripten_run_script(command.toUtf8());
+    emscripten::val qtContainer = emscripten::val::global("container"); // global from index.html
+    emscripten::val qtContainerStyle = qtContainer["style"];
+
+    if (size.isEmpty()) {
+        qtContainerStyle.set("width", std::string("100%"));
+        qtContainerStyle.set("height",
+                             std::string(
+                                 "100%")); // ### FIXME: 100% height gives 0px height for some reason
+    } else {
+        qtContainerStyle.set("width", QString("%1px").arg(size.width()).toStdString());
+        qtContainerStyle.set("height", QString("%1px").arg(size.height()).toStdString());
+    }
+
+    // Make Qt pick up the new container size by calling the resizeCanvasElement()
+    // qtloader API. This needs to be done on delay after initial setup to make
+    // sure qtloader is initialized.
+    QTimer::singleShot(0, [qtContainer]() {
+        emscripten::val qtLoader = emscripten::val::global("qtLoader");
+        qtLoader.call<void>("resizeCanvasElement", qtContainer);
+    });
     printLog("Showing the QML app window");
     m_quickWindow->show();
 }