Extract web platform service boundary

src/platform_api/platform_services.cpp

@@ -1,7 +1,66 @@
 #include "platform_api/platform_services.h"
 
+#include "platform_api/platform_policy.h"
+
 namespace pp::platform {
 namespace {
+
+class DefaultWebPlatformServices final : public WebPlatformServices {
+public:
+    void publish_exported_image(std::string_view path) override
+    {
+        (void)path;
+    }
+
+    void flush_persistent_storage() override
+    {
+    }
+
+    [[nodiscard]] int default_canvas_resolution() override
+    {
+        return platform_default_canvas_resolution(PlatformFamily::webgl);
+    }
+
+    void save_prepared_file(
+        std::string_view path,
+        std::string_view suggested_name,
+        PreparedFileCallback callback) override
+    {
+        (void)suggested_name;
+        callback(std::string(path), false);
+    }
+};
+
+WebPlatformServices* g_injected_web_platform_services = nullptr;
+
 static_assert(sizeof(PlatformServices*) == sizeof(void*));
 }
+
+WebPlatformServices& default_web_platform_services()
+{
+    static DefaultWebPlatformServices services;
+    return services;
+}
+
+WebPlatformServices* injected_web_platform_services() noexcept
+{
+    return g_injected_web_platform_services;
+}
+
+void set_injected_web_platform_services(WebPlatformServices* services) noexcept
+{
+    g_injected_web_platform_services = services;
+}
+
+WebPlatformServices& resolve_web_platform_services(WebPlatformServices& fallback) noexcept
+{
+    if (auto* services = injected_web_platform_services())
+        return *services;
+    return fallback;
+}
+
+WebPlatformServices& active_web_platform_services()
+{
+    return resolve_web_platform_services(default_web_platform_services());
+}
 }

src/platform_api/platform_services.h

@@ -90,4 +90,23 @@ public:
         PreparedFileCallback callback) = 0;
 };
 
+class WebPlatformServices {
+public:
+    virtual ~WebPlatformServices() = default;
+
+    virtual void publish_exported_image(std::string_view path) = 0;
+    virtual void flush_persistent_storage() = 0;
+    [[nodiscard]] virtual int default_canvas_resolution() = 0;
+    virtual void save_prepared_file(
+        std::string_view path,
+        std::string_view suggested_name,
+        PreparedFileCallback callback) = 0;
+};
+
+[[nodiscard]] WebPlatformServices& default_web_platform_services();
+[[nodiscard]] WebPlatformServices* injected_web_platform_services() noexcept;
+void set_injected_web_platform_services(WebPlatformServices* services) noexcept;
+[[nodiscard]] WebPlatformServices& resolve_web_platform_services(WebPlatformServices& fallback) noexcept;
+[[nodiscard]] WebPlatformServices& active_web_platform_services();
+
 }

src/platform_legacy/legacy_platform_services.cpp

@@ -60,6 +60,48 @@ void invoke_picked_path_if_selected(
         callback(path);
 }
 
+#ifdef __WEB__
+class RetainedWebPlatformServices final : public pp::platform::WebPlatformServices {
+public:
+    void publish_exported_image(std::string_view path) override
+    {
+        (void)path;
+    }
+
+    void flush_persistent_storage() override
+    {
+        webgl_sync();
+    }
+
+    [[nodiscard]] int default_canvas_resolution() override
+    {
+        return pp::platform::platform_default_canvas_resolution(pp::platform::PlatformFamily::webgl);
+    }
+
+    void save_prepared_file(
+        std::string_view path,
+        std::string_view suggested_name,
+        pp::platform::PreparedFileCallback callback) override
+    {
+        const std::string value(path);
+        const std::string name(suggested_name);
+        webgl_pick_file_save(value, name, [callback = std::move(callback), value](bool success) {
+            callback(value, success);
+        });
+    }
+};
+#endif
+
+[[nodiscard]] pp::platform::WebPlatformServices& active_legacy_web_platform_services()
+{
+#ifdef __WEB__
+    static RetainedWebPlatformServices services;
+    return pp::platform::resolve_web_platform_services(services);
+#else
+    return pp::platform::active_web_platform_services();
+#endif
+}
+
 // DEBT-0017: fallback for platforms that do not inject PlatformServices yet.
 class LegacyPlatformServices final : public pp::platform::PlatformServices {
 public:
@@ -300,7 +342,13 @@ public:
 
     void publish_exported_image(std::string_view path) override
     {
-        if (!pp::platform::platform_publishes_exported_images(pp::platform::current_platform_family()))
+        const auto family = pp::platform::current_platform_family();
+        if (family == pp::platform::PlatformFamily::webgl)
+        {
+            active_legacy_web_platform_services().publish_exported_image(path);
+            return;
+        }
+        if (!pp::platform::platform_publishes_exported_images(family))
         {
             (void)path;
             return;
@@ -314,11 +362,14 @@ public:
 
     void flush_persistent_storage() override
     {
-        if (!pp::platform::platform_flushes_persistent_storage(pp::platform::current_platform_family()))
+        const auto family = pp::platform::current_platform_family();
+        if (family == pp::platform::PlatformFamily::webgl)
+        {
+            active_legacy_web_platform_services().flush_persistent_storage();
+            return;
+        }
+        if (!pp::platform::platform_flushes_persistent_storage(family))
             return;
-#ifdef __WEB__
-        webgl_sync();
-#endif
     }
 
     [[nodiscard]] std::vector<std::string> document_browse_roots(
@@ -501,8 +552,10 @@ public:
 
     [[nodiscard]] int default_canvas_resolution() override
     {
-        return pp::platform::platform_default_canvas_resolution(
-            pp::platform::current_platform_family());
+        const auto family = pp::platform::current_platform_family();
+        if (family == pp::platform::PlatformFamily::webgl)
+            return active_legacy_web_platform_services().default_canvas_resolution();
+        return pp::platform::platform_default_canvas_resolution(family);
     }
 
     [[nodiscard]] bool draws_canvas_tip_for_pointer(
@@ -591,6 +644,16 @@ public:
         std::string_view suggested_name,
         pp::platform::PreparedFileCallback callback) override
     {
+        const auto family = pp::platform::current_platform_family();
+        if (family == pp::platform::PlatformFamily::webgl)
+        {
+            active_legacy_web_platform_services().save_prepared_file(
+                path,
+                suggested_name,
+                std::move(callback));
+            return;
+        }
+
         const std::string value(path);
         const std::string name(suggested_name);
 #ifdef __IOS__
@@ -599,10 +662,6 @@ public:
             [App::I->ios_view pick_file_save:value];
         });
         callback(value, true);
-#elif __WEB__
-        webgl_pick_file_save(value, name, [callback = std::move(callback), value](bool success) {
-            callback(value, success);
-        });
 #else
         (void)name;
         callback(value, false);