wasm: extend qstdweb to support objectUrls in File

Change-Id: If346f8afcf4578dedccce6f768e85c7750a9de3e
Done-with: Mikolaj.Boc@qt.io
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>

src/corelib/platform/wasm/qstdweb.cpp

@@ -578,6 +578,17 @@ File::File(const emscripten::val &file)
 
 }
 
+File::~File() = default;
+
+File::File(const File &other) = default;
+
+File::File(File &&other) = default;
+
+File &File::operator=(const File &other) = default;
+
+File &File::operator=(File &&other) = default;
+
+
 Blob File::slice(uint64_t begin, uint64_t end) const
 {
     return Blob(m_file.call<emscripten::val>("slice", uint53_t(begin), uint53_t(end)));
@@ -623,6 +634,22 @@ emscripten::val File::val() const
     return m_file;
 }
 
+FileUrlRegistration::FileUrlRegistration(File file)
+{
+    m_path = QString::fromStdString(emscripten::val::global("window")["URL"].call<std::string>(
+        "createObjectURL", file.file()));
+}
+
+FileUrlRegistration::~FileUrlRegistration()
+{
+    emscripten::val::global("window")["URL"].call<void>("revokeObjectURL",
+                                                        emscripten::val(m_path.toStdString()));
+}
+
+FileUrlRegistration::FileUrlRegistration(FileUrlRegistration &&other) = default;
+
+FileUrlRegistration &FileUrlRegistration::operator=(FileUrlRegistration &&other) = default;
+
 FileList::FileList(const emscripten::val &fileList)
     :m_fileList(fileList)
 {
@@ -902,7 +929,7 @@ namespace Promise {
 //
 //  haveJspi(): returns true if asyncify 2 (JSPI) is available.
 //
-//  canBlockCallingThread(): returns true if the calling thread can block on 
+//  canBlockCallingThread(): returns true if the calling thread can block on
 //      QEventLoop::exec(), using either asyncify or as a seconarday thread.
 bool haveJspi()
 {

src/corelib/platform/wasm/qstdweb_p.h

@@ -88,6 +88,12 @@ namespace qstdweb {
     public:
         File() = default;
         explicit File(const emscripten::val &file);
+        ~File();
+
+        File(const File &other);
+        File(File &&other);
+        File &operator=(const File &other);
+        File &operator=(File &&other);
 
         Blob slice(uint64_t begin, uint64_t end) const;
         std::string name() const;
@@ -97,11 +103,34 @@ namespace qstdweb {
                     std::function<void()> completed) const;
         void stream(char *buffer, std::function<void()> completed) const;
         emscripten::val val() const;
+        void fileUrlRegistration() const;
+        const QString &fileUrlPath() const { return m_urlPath; }
+        emscripten::val file() const { return m_file; }
 
     private:
         emscripten::val m_file = emscripten::val::undefined();
+        QString m_urlPath;
     };
 
+    class Q_CORE_EXPORT FileUrlRegistration
+    {
+    public:
+        explicit FileUrlRegistration(File file);
+        ~FileUrlRegistration();
+
+        FileUrlRegistration(const FileUrlRegistration &other) = delete;
+        FileUrlRegistration(FileUrlRegistration &&other);
+        FileUrlRegistration &operator=(const FileUrlRegistration &other) = delete;
+        FileUrlRegistration &operator=(FileUrlRegistration &&other);
+
+        const QString &path() const { return m_path; }
+
+    private:
+        QString m_path;
+    };
+
+    using FileUrlRegistrations = std::vector<std::unique_ptr<FileUrlRegistration>>;
+
     class Q_CORE_EXPORT FileList {
     public:
         FileList() = default;