Route collection export targets through platform policy

src/app.h

@@ -185,6 +185,7 @@ public:
         std::function<void(std::string path)> writer, std::function<void(const std::string& path, bool saved)> callback);
     void pick_file_save(std::vector<std::string> types, std::function<void(std::string path)> callback);
     [[nodiscard]] bool uses_prepared_file_writes() const;
+    [[nodiscard]] bool uses_work_directory_document_export_collections() const;
     void pick_dir(std::function<void(std::string path)> callback);
     void display_file(std::string path);
     void share_file(std::string path);

src/app_core/document_export.h

@@ -26,6 +26,11 @@ struct DocumentExportSuggestedName {
     std::string name;
 };
 
+enum class DocumentExportCollectionDestination {
+    work_directory_collection,
+    picked_directory_stem,
+};
+
 enum class DocumentExportStartDecision {
     start_now,
     show_license_disabled,
@@ -72,6 +77,12 @@ struct DocumentExportMenuPlan {
     bool opens_dialog = true;
 };
 
+struct DocumentExportCollectionTargetPlan {
+    DocumentExportCollectionKind kind = DocumentExportCollectionKind::layers;
+    DocumentExportCollectionDestination destination = DocumentExportCollectionDestination::picked_directory_stem;
+    std::string_view suffix;
+};
+
 class DocumentExportMenuServices {
 public:
     virtual ~DocumentExportMenuServices() = default;
@@ -193,6 +204,32 @@ public:
     return plan;
 }
 
+[[nodiscard]] constexpr std::string_view document_export_collection_suffix(
+    DocumentExportCollectionKind kind) noexcept
+{
+    switch (kind) {
+    case DocumentExportCollectionKind::layers:
+        return "_layers";
+    case DocumentExportCollectionKind::animation_frames:
+        return "_frames";
+    }
+
+    return {};
+}
+
+[[nodiscard]] constexpr DocumentExportCollectionTargetPlan plan_document_export_collection_target(
+    DocumentExportCollectionKind kind,
+    bool use_work_directory_collection) noexcept
+{
+    return {
+        kind,
+        use_work_directory_collection
+            ? DocumentExportCollectionDestination::work_directory_collection
+            : DocumentExportCollectionDestination::picked_directory_stem,
+        document_export_collection_suffix(kind),
+    };
+}
+
 [[nodiscard]] inline pp::foundation::Result<DocumentExportFileTarget> make_document_export_file_target(
     std::string_view work_directory,
     std::string_view document_name,

src/app_dialogs.cpp

@@ -53,6 +53,57 @@ namespace {
     return false;
 }
 
+void start_document_export_collection(
+    App& app,
+    pp::app::DocumentExportCollectionKind kind,
+    const char* message_title,
+    const char* collection_log_message,
+    const char* stem_log_message)
+{
+    const auto plan = pp::app::plan_document_export_collection_target(
+        kind,
+        app.uses_work_directory_document_export_collections());
+
+    if (plan.destination == pp::app::DocumentExportCollectionDestination::work_directory_collection) {
+        const auto target = pp::app::make_document_export_collection_target(
+            app.work_path,
+            app.doc_name,
+            plan.suffix);
+        if (!target) {
+            app.message_box(message_title, target.status().message);
+            return;
+        }
+
+        const auto status = pp::panopainter::execute_legacy_document_export_collection(
+            app,
+            plan.kind,
+            target.value());
+        if (!status.ok())
+            LOG("%s: %s", collection_log_message, status.message);
+        return;
+    }
+
+    app.pick_dir([
+        &app,
+        kind = plan.kind,
+        title = std::string(message_title),
+        log_message = std::string(stem_log_message)
+    ](std::string path) {
+        const auto target = pp::app::make_document_export_stem_target(path, app.doc_name);
+        if (!target) {
+            app.message_box(title, target.status().message);
+            return;
+        }
+
+        const auto status = pp::panopainter::execute_legacy_document_export_stem(
+            app,
+            kind,
+            target.value());
+        if (!status.ok())
+            LOG("%s: %s", log_message.c_str(), status.message);
+    });
+}
+
 }
 
 std::shared_ptr<NodeProgressBar> App::show_progress(const std::string& title, int total /*= 0*/)
@@ -361,35 +412,12 @@ void App::dialog_export_layers()
     if (!can_start_document_export(*this, true))
         return;
 
-#if defined(__IOS__)
-    const auto target = pp::app::make_document_export_collection_target(work_path, doc_name, "_layers");
-    if (!target) {
-        message_box("Export Layers", target.status().message);
-        return;
-    }
-
-    const auto status = pp::panopainter::execute_legacy_document_export_collection(
+    start_document_export_collection(
         *this,
         pp::app::DocumentExportCollectionKind::layers,
-        target.value());
-    if (!status.ok())
-        LOG("Document layer collection export failed: %s", status.message);
-#else
-    pick_dir([this](std::string path) {
-        const auto target = pp::app::make_document_export_stem_target(path, doc_name);
-        if (!target) {
-            message_box("Export Layers", target.status().message);
-            return;
-        }
-
-        const auto status = pp::panopainter::execute_legacy_document_export_stem(
-            *this,
-            pp::app::DocumentExportCollectionKind::layers,
-            target.value());
-        if (!status.ok())
-            LOG("Document layer stem export failed: %s", status.message);
-    });
-#endif
+        "Export Layers",
+        "Document layer collection export failed",
+        "Document layer stem export failed");
 }
 
 void App::dialog_export_anim_frames()
@@ -397,35 +425,12 @@ void App::dialog_export_anim_frames()
     if (!can_start_document_export(*this, true))
         return;
 
-#if defined(__IOS__)
-    const auto target = pp::app::make_document_export_collection_target(work_path, doc_name, "_frames");
-    if (!target) {
-        message_box("Export Layers", target.status().message);
-        return;
-    }
-
-    const auto status = pp::panopainter::execute_legacy_document_export_collection(
+    start_document_export_collection(
         *this,
         pp::app::DocumentExportCollectionKind::animation_frames,
-        target.value());
-    if (!status.ok())
-        LOG("Document animation frame collection export failed: %s", status.message);
-#else
-    pick_dir([this](std::string path) {
-        const auto target = pp::app::make_document_export_stem_target(path, doc_name);
-        if (!target) {
-            message_box("Export Layers", target.status().message);
-            return;
-        }
-
-        const auto status = pp::panopainter::execute_legacy_document_export_stem(
-            *this,
-            pp::app::DocumentExportCollectionKind::animation_frames,
-            target.value());
-        if (!status.ok())
-            LOG("Document animation frame stem export failed: %s", status.message);
-    });
-#endif
+        "Export Layers",
+        "Document animation frame collection export failed",
+        "Document animation frame stem export failed");
 }
 
 void App::dialog_export_depth()

src/app_events.cpp

@@ -186,6 +186,11 @@ bool App::uses_prepared_file_writes() const
     return active_platform_services().uses_prepared_file_writes();
 }
 
+bool App::uses_work_directory_document_export_collections() const
+{
+    return active_platform_services().uses_work_directory_document_export_collections();
+}
+
 void App::pick_dir(std::function<void(std::string path)> callback)
 {
     redraw = true;

src/platform_api/platform_services.h

@@ -64,6 +64,7 @@ public:
     virtual void pick_save_file(std::vector<std::string> file_types, PickedPathCallback callback) = 0;
     virtual void pick_directory(PickedPathCallback callback) = 0;
     [[nodiscard]] virtual bool uses_prepared_file_writes() = 0;
+    [[nodiscard]] virtual bool uses_work_directory_document_export_collections() = 0;
     [[nodiscard]] virtual PreparedFileTarget prepare_writable_file(
         std::string_view type,
         std::string_view default_name,

src/platform_legacy/legacy_platform_services.cpp

@@ -440,6 +440,15 @@ public:
 #endif
     }
 
+    [[nodiscard]] bool uses_work_directory_document_export_collections() override
+    {
+#if __IOS__
+        return true;
+#else
+        return false;
+#endif
+    }
+
     [[nodiscard]] pp::platform::PreparedFileTarget prepare_writable_file(
         std::string_view type,
         std::string_view default_name,

src/platform_windows/windows_platform_services.cpp

@@ -453,6 +453,11 @@ public:
         return false;
     }
 
+    [[nodiscard]] bool uses_work_directory_document_export_collections() override
+    {
+        return false;
+    }
+
     [[nodiscard]] pp::platform::PreparedFileTarget prepare_writable_file(
         std::string_view type,
         std::string_view default_name,