Open Save in the project folder and offer the last name with a number counted on

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/core/project.cpp

@@ -672,4 +672,22 @@ Project loadProject(const std::string& path) {
     }
 }
 
+std::string nextExportPath(const std::string& previous) {
+    const std::filesystem::path path(previous);
+    std::string stem = path.stem().string();
+    long count = 0;
+    const auto dash = stem.rfind('-');
+    if (dash != std::string::npos && dash + 1 < stem.size() && stem.size() - dash <= 10 &&
+        stem.find_first_not_of("0123456789", dash + 1) == std::string::npos) {
+        count = std::strtol(stem.c_str() + dash + 1, nullptr, 10);
+        stem.resize(dash);
+    }
+    std::filesystem::path next;
+    std::error_code error;
+    do {
+        next = path.parent_path() / (stem + "-" + std::to_string(++count) + path.extension().string());
+    } while (std::filesystem::exists(next, error));
+    return next.string();
+}
+
 }  // namespace effector

src/core/project.hpp

@@ -54,4 +54,9 @@ Project projectFromJson(const std::string& text, const std::string& directory =
 void saveProject(const std::string& path, const Project& project);
 Project loadProject(const std::string& path);
 
+// The name to offer for the next export after `previous`: its stem with the
+// trailing `-N` counted on (`city.png` → `city-1.png`, `city-4.png` →
+// `city-5.png`), skipping any that already exist in its folder.
+std::string nextExportPath(const std::string& previous);
+
 }  // namespace effector

src/gui/window.cpp

@@ -2476,6 +2476,7 @@ void EffectorWindow::applyProject(const Project& project, const std::string& pat
     seedEntry_.set_text(std::to_string(seed_));
 
     projectPath_ = path;
+    lastExport_.clear();
     updateTitle();
     clearError();
     suspendRender_ = false;
@@ -2801,8 +2802,27 @@ void EffectorWindow::onSave() {
 
     auto dialog = Gtk::FileDialog::create();
     dialog->set_title(video ? "Save video" : "Save image");
-    dialog->set_initial_name("effector-" + chainSlug(stages_, video) + "-" + std::to_string(seed_) +
-                             (video ? ".mp4" : ".png"));
+    // The project's own folder when it has one, else where the last save went.
+    std::filesystem::path folder;
+    if (!projectPath_.empty()) {
+        folder = std::filesystem::path(projectPath_).parent_path();
+    } else if (!lastExport_.empty()) {
+        folder = std::filesystem::path(lastExport_).parent_path();
+    }
+    if (!folder.empty()) dialog->set_initial_folder(Gio::File::create_for_path(folder.string()));
+    // The last save's name counted on, so saving again never offers to
+    // overwrite it; its extension only when it is the same kind of file.
+    std::string name;
+    if (lastExport_.empty()) {
+        name = "effector-" + chainSlug(stages_, video) + "-" + std::to_string(seed_) +
+               (video ? ".mp4" : ".png");
+    } else {
+        std::filesystem::path last(lastExport_);
+        if (isVideoPath(last.string()) != video) last.replace_extension(video ? ".mp4" : ".png");
+        if (!folder.empty()) last = folder / last.filename();
+        name = std::filesystem::path(nextExportPath(last.string())).filename().string();
+    }
+    dialog->set_initial_name(name);
     dialog->save(*this, [this, dialog](const Glib::RefPtr<Gio::AsyncResult>& result) {
         onSaveChosen(result, dialog);
     });
@@ -2838,6 +2858,7 @@ void EffectorWindow::onSaveChosen(const Glib::RefPtr<Gio::AsyncResult>& result,
         return;
     }
     clearError();
+    lastExport_ = path.string();
     status_.set_text("Saved " + path.string());
     status_.set_tooltip_text("Saved " + path.string());
 }
@@ -2956,6 +2977,7 @@ void EffectorWindow::onExportFinished() {
         return;
     }
     clearError();
+    lastExport_ = exportPath_;
     status_.set_text("Saved " + exportPath_);
     status_.set_tooltip_text("Saved " + exportPath_);
 }

src/gui/window.hpp

@@ -206,6 +206,9 @@ private:
     Image result_;
     std::uint64_t seed_ = 0;
     std::string projectPath_;  // empty until the project has been saved once
+    // The last image or video saved from this project, which the next Save
+    // offers again with its number counted on; empty until one is saved.
+    std::string lastExport_;
     Glib::RefPtr<Gio::Menu> recentMenu_;
     sigc::connection recentChanged_;  // the recent list outlives the window
     bool suspendRender_ = true;