Add support for loading projects from URL

Author: adazem009

include/scratchcpp/project.h

@@ -3,6 +3,7 @@
 #pragma once
 
 #include <memory>
+#include <functional>
 #include "spimpl.h"
 
 #include "global.h"
@@ -14,7 +15,11 @@ class ProjectPrivate;
 
 class IEngine;
 
-/*! \brief The Project class provides API for reading and running Scratch projects. */
+/*!
+ * \brief The Project class provides API for reading and running Scratch projects.
+ *
+ * \note Loading online projects is supported if the LIBSCRATCHCPP_NETWORK_SUPPORT option is set, just use setFileName("some URL")
+ */
 class LIBSCRATCHCPP_EXPORT Project
 {
     public:
@@ -37,6 +42,8 @@ class LIBSCRATCHCPP_EXPORT Project
 
         std::shared_ptr<IEngine> engine() const;
 
+        void setDownloadProgressCallback(const std::function<void(unsigned int, unsigned int)> &&f);
+
     private:
         spimpl::unique_impl_ptr<ProjectPrivate> impl;
 };

src/project.cpp

@@ -65,16 +65,17 @@ void Project::runEventLoop()
     impl->runEventLoop();
 }
 
-/*! Returns the project file name. */
+/*! Returns the project file name or URL. */
 const std::string &Project::fileName() const
 {
     return impl->fileName;
 }
 
-/*! Sets the project file name. */
+/*! Sets the project file name or URL. */
 void Project::setFileName(const std::string &newFileName)
 {
     impl->fileName = newFileName;
+    impl->detectScratchVersion();
 }
 
 /*! Returns the version of Scratch used for the project. */
@@ -97,3 +98,12 @@ std::shared_ptr<IEngine> Project::engine() const
 {
     return impl->engine;
 }
+
+/*!
+ * Sets the function which will be called when the asset download progress changes.
+ * \note The first parameter is the number of downloaded assets and the latter is the number of all assets to download.
+ */
+void Project::setDownloadProgressCallback(const std::function<void(unsigned int, unsigned int)> &&f)
+{
+    impl->setDownloadProgressCallback(f);
+}

src/project_p.cpp

@@ -1,31 +1,36 @@
 // SPDX-License-Identifier: Apache-2.0
 
+#include <scratchcpp/costume.h>
+#include <scratchcpp/sound.h>
 #include <iostream>
 
 #include "project_p.h"
 #include "internal/scratch3reader.h"
+#include "internal/projectdownloaderfactory.h"
+#include "internal/projectdownloader.h"
+#include "internal/projecturl.h"
 #include "engine/internal/engine.h"
 
 using namespace libscratchcpp;
 
+IProjectDownloaderFactory *ProjectPrivate::downloaderFactory = nullptr;
+
 ProjectPrivate::ProjectPrivate() :
     engine(std::make_shared<Engine>())
 {
+    if (!downloaderFactory)
+        downloaderFactory = ProjectDownloaderFactory::instance().get();
+
+    downloader = downloaderFactory->create();
 }
 
 ProjectPrivate::ProjectPrivate(const std::string &fileName) :
-    fileName(fileName),
-    engine(std::make_shared<Engine>())
+    ProjectPrivate()
 {
-    // Auto detect Scratch version
-    scratchVersion = ScratchVersion::Invalid;
-    Scratch3Reader scratch3;
-    scratch3.setFileName(fileName);
-    if (scratch3.isValid())
-        scratchVersion = ScratchVersion::Scratch3;
+    this->fileName = fileName;
 
-    if (scratchVersion == ScratchVersion::Invalid)
-        std::cerr << "Unable to determine Scratch version." << std::endl;
+    // Auto detect Scratch version
+    detectScratchVersion();
 }
 
 ProjectPrivate::ProjectPrivate(const std::string &fileName, ScratchVersion scratchVersion) :
@@ -47,16 +52,77 @@ bool ProjectPrivate::load()
             break;
     }
 
-    reader->setFileName(fileName);
-    if (!reader->isValid()) {
-        scratchVersion = ScratchVersion::Invalid;
-        std::cerr << "Could not read the project." << std::endl;
-        return false;
-    }
+    // Load from URL
+    ProjectUrl url(fileName);
+
+    if (url.isProjectUrl()) {
+        // Download JSON
+        if (!downloader->downloadJson(url.projectId())) {
+            std::cerr << "Failed to download the project file." << std::endl;
+            return false;
+        }
+
+        bool ret = reader->loadData(downloader->json());
+
+        if (!ret)
+            return false;
+
+        // Get asset file names
+        std::vector<std::string> assetNames;
+        std::unordered_map<std::string, Asset *> assets;
+        const auto &targets = reader->targets();
+
+        for (auto target : targets) {
+            const auto &costumes = target->costumes();
+            const auto &sounds = target->sounds();
+
+            for (auto costume : costumes) {
+                auto it = std::find(assetNames.begin(), assetNames.end(), costume->fileName());
+                if (it == assetNames.end()) {
+                    assetNames.push_back(costume->fileName());
+                    assets[assetNames.back()] = costume.get();
+                } else
+                    assets[*it] = costume.get();
+            }
+
+            for (auto sound : sounds) {
+                auto it = std::find(assetNames.begin(), assetNames.end(), sound->fileName());
+                if (it == assetNames.end()) {
+                    assetNames.push_back(sound->fileName());
+                    assets[assetNames.back()] = sound.get();
+                } else
+                    assets[*it] = sound.get();
+            }
+        }
+
+        // Download assets
+        if (!downloader->downloadAssets(assetNames)) {
+            std::cerr << "Failed to download the project assets." << std::endl;
+            return false;
+        }
 
-    bool ret = reader->load();
-    if (!ret)
-        return false;
+        const auto &assetData = downloader->assets();
+        assert(assetData.size() == assetNames.size());
+
+        // Load asset data
+        for (size_t i = 0; i < assets.size(); i++) {
+            const std::string &data = assetData[i];
+            assets[assetNames[i]]->setData(data.size(), static_cast<void *>(const_cast<char *>(data.c_str())));
+        }
+
+    } else {
+        // Load from file
+        reader->setFileName(fileName);
+        if (!reader->isValid()) {
+            scratchVersion = ScratchVersion::Invalid;
+            std::cerr << "Could not read the project." << std::endl;
+            return false;
+        }
+
+        bool ret = reader->load();
+        if (!ret)
+            return false;
+    }
 
     engine->clear();
     engine->setTargets(reader->targets());
@@ -81,6 +147,30 @@ void ProjectPrivate::runEventLoop()
     engine->runEventLoop();
 }
 
+void ProjectPrivate::detectScratchVersion()
+{
+    ProjectUrl url(fileName);
+
+    scratchVersion = ScratchVersion::Invalid;
+    Scratch3Reader scratch3;
+
+    if (url.isProjectUrl()) {
+        if (!downloader->downloadJson(url.projectId())) {
+            std::cerr << "Failed to download the project file." << std::endl;
+            return;
+        }
+
+        scratch3.loadData(downloader->json());
+    } else
+        scratch3.setFileName(fileName);
+
+    if (scratch3.isValid())
+        scratchVersion = ScratchVersion::Scratch3;
+
+    if (scratchVersion == ScratchVersion::Invalid)
+        std::cerr << "Unable to determine Scratch version." << std::endl;
+}
+
 void ProjectPrivate::setScratchVersion(ScratchVersion version)
 {
     // TODO: Use this when more versions become supported
@@ -90,3 +180,8 @@ void ProjectPrivate::setScratchVersion(ScratchVersion version)
     else
         std::cerr << "Unsupported Scratch version: " << static_cast<int>(version) << std::endl;
 }
+
+void ProjectPrivate::setDownloadProgressCallback(const std::function<void(unsigned int, unsigned int)> &f)
+{
+    downloader->setDownloadProgressCallback(f);
+}

src/project_p.h

@@ -9,6 +9,8 @@ namespace libscratchcpp
 {
 
 class IEngine;
+class IProjectDownloaderFactory;
+class IProjectDownloader;
 
 struct ProjectPrivate
 {
@@ -23,11 +25,17 @@ struct ProjectPrivate
         void run();
         void runEventLoop();
 
+        void detectScratchVersion();
         void setScratchVersion(ScratchVersion version);
 
+        void setDownloadProgressCallback(const std::function<void(unsigned int, unsigned int)> &f);
+
         ScratchVersion scratchVersion = ScratchVersion::Invalid;
         std::string fileName;
         std::shared_ptr<IEngine> engine = nullptr;
+
+        static IProjectDownloaderFactory *downloaderFactory;
+        std::shared_ptr<IProjectDownloader> downloader;
 };
 
 }; // namespace libscratchcpp

test/load_project/CMakeLists.txt

@@ -6,7 +6,9 @@ add_executable(
 target_link_libraries(
   load_project_test
   GTest::gtest_main
+  GTest::gmock_main
   scratchcpp
+  scratchcpp_mocks
 )
 
 gtest_discover_tests(load_project_test)