Merge branch 'sidebar-tabs'

CLAUDE.md

@@ -12,7 +12,7 @@ ctest --test-dir build --output-on-failure
 
 Everything is warning-clean under `-Wall -Wextra -Wpedantic`; keep it that way.
 
-The test suite is a single hand-rolled binary (no framework), so there is no
+The core test suite is a single hand-rolled binary (no framework), so there is no
 per-test filter: run `./build/tests/effector_tests` directly to see the section
 headings (`rng`, `registry`, `scanlines`, `tiles`, `blur`, `chain`, `project`,
 `image io`, `batch loading`) and the `ok`/`FAIL` lines. To iterate on one area, comment
@@ -20,6 +20,13 @@ out the other blocks in `tests/core_tests.cpp` or add a new
 `std::cout << "section\n"` block — checks are plain
 `check(condition, "description")` calls and `main()` returns the failure count.
 
+The interface has its own binary, `./build/tests/effector_gui_tests`
+(`tests/gui_tests.cpp`, same `check()` style), which opens the real window and
+drives it by widget names and tooltips (`chain-list`, `add-effect`,
+`sources`, "Move up", ...). It needs a display: ctest runs it under `xvfb-run`
+when that is installed and otherwise reports it skipped (exit 77). To run it by
+hand, use the Xvfb invocation below.
+
 Headless render (no display needed, the fastest end-to-end smoke test):
 
 ```bash
@@ -148,8 +155,9 @@ is discarded rather than mixed into the new project (`dropLoadedImages_`).
 
 `effector_core` (static) holds image IO, params, effects, rng and links only
 `gdk-pixbuf-2.0`, `pangocairo` (the text effect's glyphs; Pango and Cairo need
-no display) + Threads — **no gtkmm, no display**. The `effector` executable
-adds `src/main.cpp`, `src/cli/`, `src/gui/` and links gtkmm. Keep GTK out of
+no display) + Threads — **no gtkmm, no display**. `effector_gui` (static) adds
+`src/cli/` and `src/gui/` and links gtkmm, and the `effector` executable is
+`src/main.cpp` on top of it; the GUI tests link `effector_gui` too. Keep GTK out of
 `src/core/` and `src/effects/`; the tests link the core alone and rely on this.
 
 ### Determinism is a contract

CMakeLists.txt

@@ -54,14 +54,18 @@ target_include_directories(effector_core PUBLIC src)
 target_link_libraries(effector_core PUBLIC PkgConfig::GDKPIXBUF PkgConfig::PANGOCAIRO Threads::Threads)
 target_compile_options(effector_core PRIVATE -Wall -Wextra -Wpedantic)
 
-# --- application --------------------------------------------------------------
-add_executable(effector
-    src/main.cpp
+# --- interface: the GTK window, split out so the GUI tests can link it --------
+add_library(effector_gui STATIC
     src/cli/options.cpp
     src/gui/app.cpp
     src/gui/window.cpp
 )
-target_link_libraries(effector PRIVATE effector_core PkgConfig::GTKMM)
+target_link_libraries(effector_gui PUBLIC effector_core PkgConfig::GTKMM)
+target_compile_options(effector_gui PRIVATE -Wall -Wextra -Wpedantic)
+
+# --- application --------------------------------------------------------------
+add_executable(effector src/main.cpp)
+target_link_libraries(effector PRIVATE effector_gui)
 target_compile_options(effector PRIVATE -Wall -Wextra -Wpedantic)
 
 install(TARGETS effector RUNTIME DESTINATION bin)

src/gui/window.cpp

@@ -118,29 +118,63 @@ void EffectorWindow::buildUi() {
     root->append(*paned);
 }
 
-// The chain is what the interface is about, so it comes first and the params
-// of the selected stage sit right below it. The sources are a prerequisite,
-// not the subject: they live at the bottom in a collapsed expander.
+// The sidebar is two tabs. "Chain" is what the interface is about: the stages
+// and the params of the selected one, with the whole height to themselves.
+// "Setup" holds what is set once per project -- the sources, the canvas and
+// the seed -- so it never takes room from the chain however long that grows.
 Gtk::Widget& EffectorWindow::buildSidebar() {
+    auto* stack = Gtk::make_managed<Gtk::Stack>();
+    stack->set_vexpand(true);
+    stack->set_transition_type(Gtk::StackTransitionType::CROSSFADE);
+    stack->add(buildChainTab(), "chain", "Chain");
+    stack->add(buildSetupTab(), "setup", "Setup");
+
+    auto* switcher = Gtk::make_managed<Gtk::StackSwitcher>();
+    switcher->set_stack(*stack);
+    switcher->set_halign(Gtk::Align::CENTER);
+
     auto* sidebar = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::VERTICAL, 12);
     sidebar->set_margin(12);
+    sidebar->append(*switcher);
+    sidebar->append(*stack);
+    return *sidebar;
+}
 
-    sidebar->append(buildChainSection());
-
+// The chain and the params of the selected stage share the tab through a
+// split the user drags: a long chain wants the list, a stage with many params
+// wants the grid, and no fixed share suits both.
+Gtk::Widget& EffectorWindow::buildChainTab() {
+    auto* params = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::VERTICAL, 12);
+    params->set_margin_top(12);
     paramHeading_.set_xalign(0.0F);
     paramHeading_.add_css_class("heading");
-    sidebar->append(paramHeading_);
+    params->append(paramHeading_);
     paramGrid_.set_column_spacing(8);
     paramGrid_.set_row_spacing(6);
     auto* paramScroller = Gtk::make_managed<Gtk::ScrolledWindow>();
     paramScroller->set_policy(Gtk::PolicyType::NEVER, Gtk::PolicyType::AUTOMATIC);
     paramScroller->set_child(paramGrid_);
     paramScroller->set_vexpand(true);
-    sidebar->append(*paramScroller);
+    params->append(*paramScroller);
+
+    auto& chain = buildChainSection();
+    chain.set_margin_bottom(6);
+
+    auto* split = Gtk::make_managed<Gtk::Paned>(Gtk::Orientation::VERTICAL);
+    split->set_start_child(chain);
+    split->set_end_child(*params);
+    split->set_shrink_start_child(false);
+    split->set_shrink_end_child(false);
+    split->set_position(300);
     rebuildChainRows();
     buildParamWidgets();
+    return *split;
+}
 
-    sidebar->append(*Gtk::make_managed<Gtk::Separator>(Gtk::Orientation::HORIZONTAL));
+// The sources come first because they are the first thing a project needs;
+// their list takes whatever height the canvas and seed leave over.
+Gtk::Widget& EffectorWindow::buildSetupTab() {
+    auto* tab = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::VERTICAL, 12);
 
     sourceList_.set_selection_mode(Gtk::SelectionMode::NONE);
     sourceList_.add_css_class("boxed-list");
@@ -153,10 +187,16 @@ Gtk::Widget& EffectorWindow::buildSidebar() {
     scroller->set_policy(Gtk::PolicyType::NEVER, Gtk::PolicyType::AUTOMATIC);
     scroller->set_child(sourceList_);
     scroller->set_size_request(-1, 140);
-    scroller->set_margin_top(6);
+    scroller->set_vexpand(true);
 
-    auto* sourcesBox = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::VERTICAL, 6);
-    sourcesBox->append(*scroller);
+    sourcesHeading_.set_xalign(0.0F);
+    sourcesHeading_.add_css_class("heading");
+    sourcesSection_.set_name("sources");
+    sourcesSection_.set_orientation(Gtk::Orientation::VERTICAL);
+    sourcesSection_.set_spacing(6);
+    sourcesSection_.set_vexpand(true);
+    sourcesSection_.append(sourcesHeading_);
+    sourcesSection_.append(*scroller);
 
     // Same shape as "Add effect": the icon and the text are put together by
     // hand because set_label() and set_icon_name() replace one another.
@@ -169,16 +209,14 @@ Gtk::Widget& EffectorWindow::buildSidebar() {
     addButton->set_halign(Gtk::Align::START);
     addButton->set_tooltip_text("Add source images");
     addButton->signal_clicked().connect(sigc::mem_fun(*this, &EffectorWindow::onAddImages));
-    sourcesBox->append(*addButton);
+    sourcesSection_.append(*addButton);
     addButton_ = addButton;
 
-    sourcesExpander_.set_child(*sourcesBox);
-    sourcesExpander_.set_expanded(false);
     updateSourcesLabel();
-    sidebar->append(sourcesExpander_);
+    tab->append(sourcesSection_);
 
-    sidebar->append(*sectionLabel("Canvas"));
-    sidebar->append(buildCanvasSection());
+    tab->append(*sectionLabel("Canvas"));
+    tab->append(buildCanvasSection());
 
     auto* seedBox = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::HORIZONTAL, 8);
     auto* seedLabel = Gtk::make_managed<Gtk::Label>("Seed");
@@ -188,9 +226,9 @@ Gtk::Widget& EffectorWindow::buildSidebar() {
     seedEntry_.set_text(std::to_string(seed_));
     seedEntry_.signal_activate().connect(sigc::mem_fun(*this, &EffectorWindow::onSeedEntered));
     seedBox->append(seedEntry_);
-    sidebar->append(*seedBox);
+    tab->append(*seedBox);
 
-    return *sidebar;
+    return *tab;
 }
 
 // Only the first stage is ever handed the sources, so whether the chain wants
@@ -199,15 +237,14 @@ Gtk::Widget& EffectorWindow::buildSidebar() {
 // rather than left there to be filled in vain. This is the same declarative
 // answer the render gate uses -- no effect is named here.
 void EffectorWindow::updateSourcesVisible() {
-    sourcesExpander_.set_visible(chainNeedsSources(stages_));
+    sourcesSection_.set_visible(chainNeedsSources(stages_));
 }
 
-// The expander is collapsed by default, so its label carries the count that
-// used to be plain to see in the list.
+// The heading carries the count, which a long list scrolled away would hide.
 void EffectorWindow::updateSourcesLabel() {
     int count = 0;
     while (sourceList_.get_row_at_index(count) != nullptr) ++count;
-    sourcesExpander_.set_label(count == 0 ? "Source images"
+    sourcesHeading_.set_text(count == 0 ? "Source images"
                                           : "Source images (" + std::to_string(count) + ")");
 }
 
@@ -331,7 +368,7 @@ Gtk::Widget& EffectorWindow::buildPreview() {
     picture_.set_can_shrink(true);
     picture_.set_content_fit(Gtk::ContentFit::CONTAIN);
 
-    placeholder_.set_text("Add source images to start.");
+    placeholder_.set_text("Add source images under Setup to start.");
     placeholder_.set_wrap(true);
     placeholder_.add_css_class("dim-label");
 
@@ -1135,10 +1172,44 @@ void EffectorWindow::onImagesChosen(const Glib::RefPtr<Gio::AsyncResult>& result
 
 // ---------------------------------------------------------------- chain ---
 
-Gtk::Widget& EffectorWindow::buildChainSection() {
-    auto* box = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::VERTICAL, 6);
-    box->append(*sectionLabel("Effect chain"));
+// The move and remove buttons are faded out until the pointer is over their
+// row, or the row is selected or focused, so a long chain reads as a list of
+// names rather than a column of icons. They keep their place while hidden,
+// so the names do not jump as the pointer moves.
+const char* const stageRowCss = R"css(
+row.stage-row .stage-action {
+    min-width: 24px;
+    min-height: 24px;
+    padding: 0;
+    opacity: 0;
+    transition: opacity 120ms;
+}
+row.stage-row:hover .stage-action,
+row.stage-row:selected .stage-action,
+row.stage-row:focus-within .stage-action {
+    opacity: 1;
+}
+)css";
 
+Gtk::Widget& EffectorWindow::buildChainSection() {
+    auto css = Gtk::CssProvider::create();
+    css->load_from_string(stageRowCss);
+    Gtk::StyleProvider::add_provider_for_display(Gdk::Display::get_default(), css,
+                                                 GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+
+    auto* box = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::VERTICAL, 6);
+
+    // "Add effect" sits beside the heading rather than under the list: under
+    // it, the split could drag it so far down the screen that the menu of
+    // effects had no room left to open.
+    auto* heading = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::HORIZONTAL, 6);
+    auto* title = sectionLabel("Effect chain");
+    title->set_hexpand(true);
+    heading->append(*title);
+    heading->append(addEffectButton_);
+    box->append(*heading);
+
+    chainList_.set_name("chain-list");
     chainList_.add_css_class("boxed-list");
     chainList_.set_selection_mode(Gtk::SelectionMode::SINGLE);
     auto* empty = Gtk::make_managed<Gtk::Label>("No effects yet");
@@ -1151,7 +1222,10 @@ Gtk::Widget& EffectorWindow::buildChainSection() {
     auto* scroller = Gtk::make_managed<Gtk::ScrolledWindow>();
     scroller->set_policy(Gtk::PolicyType::NEVER, Gtk::PolicyType::AUTOMATIC);
     scroller->set_child(chainList_);
-    scroller->set_size_request(-1, 150);
+    // The split above the params decides the height; this is only the least
+    // it may be dragged down to.
+    scroller->set_size_request(-1, 100);
+    scroller->set_vexpand(true);
     box->append(*scroller);
 
     // set_label() and set_icon_name() replace one another, so the icon and the
@@ -1164,12 +1238,14 @@ Gtk::Widget& EffectorWindow::buildChainSection() {
     addEffectButton_.set_always_show_arrow(true);
     addEffectButton_.set_tooltip_text("Append an effect, applied to the output so far");
     addEffectButton_.set_popover(static_cast<Gtk::Popover&>(buildAddMenu()));
-    addEffectButton_.set_halign(Gtk::Align::START);
-    box->append(addEffectButton_);
+    addEffectButton_.set_name("add-effect");
 
     return *box;
 }
 
+// The tallest the menu of effects grows before it scrolls, in pixels.
+constexpr int addMenuMaxHeight = 480;
+
 // One entry per registered effect, so a new effect shows up here without this
 // file knowing anything about it.
 Gtk::Widget& EffectorWindow::buildAddMenu() {
@@ -1188,7 +1264,15 @@ Gtk::Widget& EffectorWindow::buildAddMenu() {
         list->append(*item);
     }
 
-    popover->set_child(*list);
+    // A popover that does not fit on the screen is not shown at all, and the
+    // list grows with every effect registered, so past a point it scrolls.
+    auto* scroller = Gtk::make_managed<Gtk::ScrolledWindow>();
+    scroller->set_policy(Gtk::PolicyType::NEVER, Gtk::PolicyType::AUTOMATIC);
+    scroller->set_propagate_natural_height(true);
+    scroller->set_max_content_height(addMenuMaxHeight);
+    scroller->set_child(*list);
+
+    popover->set_child(*scroller);
     return *popover;
 }
 
@@ -1239,9 +1323,10 @@ void EffectorWindow::rebuildChainRows() {
     for (std::size_t i = 0; i < stages_.size(); ++i) {
         const int index = static_cast<int>(i);
         auto* row = Gtk::make_managed<Gtk::ListBoxRow>();
-        auto* box = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::HORIZONTAL, 4);
-        box->set_margin_top(4);
-        box->set_margin_bottom(4);
+        row->add_css_class("stage-row");
+        auto* box = Gtk::make_managed<Gtk::Box>(Gtk::Orientation::HORIZONTAL, 2);
+        box->set_margin_top(1);
+        box->set_margin_bottom(1);
         box->set_margin_start(8);
         box->set_margin_end(4);
 
@@ -1281,6 +1366,8 @@ void EffectorWindow::rebuildChainRows() {
             button->set_icon_name(action.icon);
             button->set_tooltip_text(action.tip);
             button->add_css_class("flat");
+            button->add_css_class("stage-action");
+            button->set_valign(Gtk::Align::CENTER);
             const int delta = action.delta;
             button->signal_clicked().connect([this, index, delta] {
                 if (delta == 0) {
@@ -1397,7 +1484,7 @@ bool EffectorWindow::canRender() const {
 std::string EffectorWindow::missingText() const {
     if (stages_.empty()) return "Add an effect to start.";
     if (enabledStages(stages_).empty()) return "Every effect is switched off.";
-    return "Add source images to start.";
+    return "Add source images under Setup to start.";
 }
 
 void EffectorWindow::showPlaceholder() {

src/gui/window.hpp

@@ -29,6 +29,8 @@ public:
 private:
     void buildUi();
     Gtk::Widget& buildSidebar();
+    Gtk::Widget& buildChainTab();
+    Gtk::Widget& buildSetupTab();
     Gtk::Widget& buildPreview();
     void buildParamWidgets();
     ParamValues paramValues() const;
@@ -72,7 +74,7 @@ private:
     void closeLoadWindow();
     void cancelLoad();
     void appendSourceRow(const std::string& path);
-    void updateSourcesLabel();  // the collapsed expander shows the count
+    void updateSourcesLabel();  // the heading shows the count
     // The whole sources section only shows while the chain asks for sources.
     void updateSourcesVisible();
 
@@ -183,7 +185,8 @@ private:
     std::unique_ptr<Gtk::Window> loadWindow_;
     Gtk::ProgressBar* loadBar_ = nullptr;
     Gtk::Label* loadFileLabel_ = nullptr;
-    Gtk::Expander sourcesExpander_;
+    Gtk::Box sourcesSection_;  // hidden while the chain needs no sources
+    Gtk::Label sourcesHeading_;
     Gtk::ListBox sourceList_;
     Gtk::DropDown formatDrop_;
     Gtk::SpinButton widthSpin_;

tests/CMakeLists.txt

@@ -5,3 +5,19 @@ target_link_libraries(effector_tests PRIVATE effector_core)
 target_compile_options(effector_tests PRIVATE -Wall -Wextra -Wpedantic)
 
 add_test(NAME core COMMAND effector_tests)
+
+# The interface drives the real window, so it needs a display. Under ctest it
+# gets a private Xvfb one when xvfb-run is installed; without it, or without a
+# display of its own, the test reports itself skipped rather than failed.
+add_executable(effector_gui_tests gui_tests.cpp)
+target_link_libraries(effector_gui_tests PRIVATE effector_gui)
+target_compile_options(effector_gui_tests PRIVATE -Wall -Wextra -Wpedantic)
+
+find_program(XVFB_RUN xvfb-run)
+if(XVFB_RUN)
+    add_test(NAME gui COMMAND ${XVFB_RUN} -a -s "-screen 0 1400x900x24"
+             env -u WAYLAND_DISPLAY GDK_BACKEND=x11 $<TARGET_FILE:effector_gui_tests>)
+else()
+    add_test(NAME gui COMMAND effector_gui_tests)
+endif()
+set_tests_properties(gui PROPERTIES SKIP_RETURN_CODE 77)

tests/gui_tests.cpp

@@ -0,0 +1,275 @@
+// Checks for the interface, driven through the real window: the widgets are
+// found by what a user sees (a name, a tooltip, a label) and pressed the way a
+// click would press them. Needs a display; exits 77 (skipped) without one.
+
+#include <gtkmm.h>
+
+#include <chrono>
+#include <cstdlib>
+#include <iostream>
+#include <memory>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include "cli/options.hpp"
+#include "core/registry.hpp"
+#include "gui/window.hpp"
+
+namespace {
+
+int failures = 0;
+
+void check(bool condition, const std::string& what) {
+    if (condition) {
+        std::cout << "  ok   " << what << "\n";
+    } else {
+        std::cout << "  FAIL " << what << "\n";
+        ++failures;
+    }
+}
+
+// Lets the main loop run for a while: popovers map, renders come back, and
+// the rows rebuilt by a click are laid out.
+void pump(int milliseconds = 100) {
+    auto context = Glib::MainContext::get_default();
+    const auto until = std::chrono::steady_clock::now() + std::chrono::milliseconds(milliseconds);
+    while (std::chrono::steady_clock::now() < until) {
+        while (context->pending()) context->iteration(false);
+        std::this_thread::sleep_for(std::chrono::milliseconds(5));
+    }
+}
+
+template <typename T, typename Pred>
+void collect(Gtk::Widget& root, Pred pred, std::vector<T*>& out) {
+    for (auto* child = root.get_first_child(); child != nullptr; child = child->get_next_sibling()) {
+        if (auto* match = dynamic_cast<T*>(child); match != nullptr && pred(*match)) out.push_back(match);
+        collect<T>(*child, pred, out);
+    }
+}
+
+template <typename T>
+std::vector<T*> all(Gtk::Widget& root) {
+    std::vector<T*> out;
+    collect<T>(root, [](T&) { return true; }, out);
+    return out;
+}
+
+template <typename T>
+T* named(Gtk::Widget& root, const std::string& name) {
+    std::vector<T*> out;
+    collect<T>(root, [&](T& w) { return w.get_name() == name; }, out);
+    return out.empty() ? nullptr : out.front();
+}
+
+Gtk::Button* withTooltip(Gtk::Widget& root, const std::string& tip) {
+    std::vector<Gtk::Button*> out;
+    collect<Gtk::Button>(root, [&](Gtk::Button& b) { return b.get_tooltip_text() == tip; }, out);
+    return out.empty() ? nullptr : out.front();
+}
+
+bool isAncestor(const Gtk::Widget& ancestor, const Gtk::Widget& widget) {
+    for (auto* w = widget.get_parent(); w != nullptr; w = w->get_parent()) {
+        if (w == &ancestor) return true;
+    }
+    return false;
+}
+
+int rowCount(Gtk::ListBox& list) {
+    int count = 0;
+    while (list.get_row_at_index(count) != nullptr) ++count;
+    return count;
+}
+
+std::string rowTitle(Gtk::ListBox& list, int index) {
+    auto* row = list.get_row_at_index(index);
+    if (row == nullptr) return {};
+    const auto labels = all<Gtk::Label>(*row);
+    return labels.empty() ? std::string{} : std::string(labels.front()->get_text());
+}
+
+// The top of `widget` in the window's coordinates.
+double topIn(Gtk::Widget& widget, Gtk::Widget& window) {
+    graphene_rect_t bounds;
+    if (!gtk_widget_compute_bounds(widget.gobj(), window.gobj(), &bounds)) return -1.0;
+    return bounds.origin.y;
+}
+
+// The menu of effects: the popover the "Add effect" button opens, and the
+// entry in it for one effect.
+Gtk::Button* menuEntry(Gtk::Popover& menu, const std::string& title) {
+    for (auto* button : all<Gtk::Button>(menu)) {
+        if (button->get_label() == title) return button;
+    }
+    return nullptr;
+}
+
+// Presses a button the way the keyboard does. GTK shows the press for a
+// quarter of a second before the button reports the click, so wait it out.
+void press(Gtk::Button& button) {
+    button.activate();
+    pump(400);
+}
+
+bool addFromMenu(Gtk::MenuButton& add, const std::string& title) {
+    auto* menu = add.get_popover();
+    if (menu == nullptr) return false;
+    add.popup();
+    pump();
+    auto* entry = menuEntry(*menu, title);
+    if (entry == nullptr || !menu->get_mapped()) return false;
+    press(*entry);
+    return true;
+}
+
+void runTests(Gtk::Window& window) {
+    const auto& effects = effector::effects();
+
+    std::cout << "sidebar\n";
+    auto* stack = all<Gtk::Stack>(window).empty() ? nullptr : all<Gtk::Stack>(window).front();
+    check(stack != nullptr && stack->get_child_by_name("chain") != nullptr &&
+              stack->get_child_by_name("setup") != nullptr,
+          "the sidebar has a Chain and a Setup tab");
+    check(stack != nullptr && stack->get_visible_child_name() == "chain",
+          "it opens on the Chain tab");
+
+    auto* chainList = named<Gtk::ListBox>(window, "chain-list");
+    auto* add = named<Gtk::MenuButton>(window, "add-effect");
+    auto* sources = named<Gtk::Box>(window, "sources");
+    check(chainList != nullptr && add != nullptr && sources != nullptr,
+          "the chain list, the Add effect button and the sources are there");
+    if (chainList == nullptr || add == nullptr || sources == nullptr) return;
+
+    std::vector<Gtk::Paned*> panes;
+    collect<Gtk::Paned>(window, [&](Gtk::Paned& p) { return isAncestor(p, *chainList); }, panes);
+    auto* split = panes.empty() ? nullptr : panes.back();
+    check(split != nullptr && split->get_orientation() == Gtk::Orientation::VERTICAL,
+          "the Chain tab is a vertical split");
+    check(split != nullptr && split->get_start_child() != nullptr &&
+              isAncestor(*split->get_start_child(), *chainList),
+          "the chain list is above the split");
+    check(split != nullptr && split->get_end_child() != nullptr &&
+              !isAncestor(*split->get_end_child(), *chainList),
+          "the params are below it, apart from the list");
+    check(split != nullptr && !split->get_shrink_start_child() && !split->get_shrink_end_child(),
+          "neither side can be dragged below its minimum");
+    check(topIn(*add, window) >= 0.0 && topIn(*add, window) < topIn(*chainList, window),
+          "Add effect sits above the chain list, not under it");
+    check(isAncestor(*stack->get_child_by_name("setup"), *sources),
+          "the sources are on the Setup tab");
+
+    std::cout << "add effect\n";
+    auto* menu = add->get_popover();
+    check(menu != nullptr, "Add effect has a menu");
+    if (menu == nullptr) return;
+    bool listed = true;
+    for (const auto& effect : effects) listed = listed && menuEntry(*menu, effect->title()) != nullptr;
+    check(listed, "the menu has an entry for every registered effect");
+    check(all<Gtk::Button>(*menu).size() == effects.size(), "and nothing else");
+
+    add->popup();
+    pump();
+    check(menu->get_mapped(), "the menu opens");
+    // A popover taller than the room below its button is not shown at all --
+    // though GTK still calls it mapped -- which is what broke the button once
+    // there were enough effects: the entries have to scroll instead, in a
+    // menu short enough to open below a button near the top of a 768-pixel
+    // screen.
+    const auto scrollers = all<Gtk::ScrolledWindow>(*menu);
+    const int cap = scrollers.empty() ? -1 : scrollers.front()->get_max_content_height();
+    check(!scrollers.empty() && isAncestor(*scrollers.front(), *menuEntry(*menu, effects.front()->title())),
+          "the entries scroll");
+    check(cap > 0 && cap <= 480, "past a height that fits a small screen");
+    check(menu->get_height() > 0 && menu->get_height() <= cap + 40,
+          "and the menu stays within it however many effects there are");
+    add->popdown();
+    pump();
+
+    // With the split dragged all the way down, the button must still work.
+    if (split != nullptr) split->set_position(10000);
+    pump();
+    add->popup();
+    pump();
+    check(menu->get_mapped(), "the menu opens with the split dragged to the bottom");
+    add->popdown();
+    pump();
+    if (split != nullptr) split->set_position(300);
+    pump();
+
+    check(rowCount(*chainList) == 0, "the chain starts empty");
+    check(addFromMenu(*add, "Blur"), "picking Blur from the menu");
+    check(!menu->get_mapped(), "closes the menu");
+    check(rowCount(*chainList) == 1 && rowTitle(*chainList, 0) == "1. Blur",
+          "and appends a Blur stage");
+    check(chainList->get_selected_row() == chainList->get_row_at_index(0),
+          "the new stage is selected");
+    check(!sources->get_visible(), "a chain led by blur hides the sources");
+
+    check(addFromMenu(*add, "Scanlines"), "picking Scanlines");
+    check(rowCount(*chainList) == 2 && rowTitle(*chainList, 1) == "2. Scanlines",
+          "appends it after Blur");
+    check(chainList->get_selected_row() == chainList->get_row_at_index(1),
+          "and selects it");
+
+    std::cout << "stage rows\n";
+    if (rowCount(*chainList) != 2) return;
+    auto* second = chainList->get_row_at_index(1);
+    check(second->has_css_class("stage-row"), "a row is a stage row");
+    std::vector<Gtk::Button*> actions;
+    collect<Gtk::Button>(*second, [](Gtk::Button& b) { return b.has_css_class("stage-action"); }, actions);
+    check(actions.size() == 3, "with a move up, a move down and a remove action");
+    auto* first = chainList->get_row_at_index(0);
+    auto* firstUp = withTooltip(*first, "Move up");
+    auto* lastDown = withTooltip(*second, "Move down");
+    check(firstUp != nullptr && !firstUp->get_sensitive(), "the first stage cannot move up");
+    check(lastDown != nullptr && !lastDown->get_sensitive(), "the last stage cannot move down");
+
+    auto* up = withTooltip(*second, "Move up");
+    check(up != nullptr, "the second stage has Move up");
+    if (up != nullptr) press(*up);
+    check(rowTitle(*chainList, 0) == "1. Scanlines" && rowTitle(*chainList, 1) == "2. Blur",
+          "Move up swaps the stages");
+    check(chainList->get_selected_row() == chainList->get_row_at_index(0),
+          "and the moved stage stays selected");
+    check(sources->get_visible(), "a chain led by scanlines shows the sources");
+
+    auto* remove = withTooltip(*chainList->get_row_at_index(0), "Remove");
+    if (remove != nullptr) press(*remove);
+    check(rowCount(*chainList) == 1 && rowTitle(*chainList, 0) == "1. Blur",
+          "Remove drops the stage and renumbers the rest");
+    check(!sources->get_visible(), "and the sources hide again");
+
+    std::cout << "many stages\n";
+    for (int i = 0; i < 12; ++i) addFromMenu(*add, effects[static_cast<std::size_t>(i) % effects.size()]->title());
+    check(rowCount(*chainList) == 13, "the menu still works with a long chain");
+    check(addFromMenu(*add, effects.back()->title()) && rowCount(*chainList) == 14,
+          "including for the last effect in the menu");
+}
+
+}  // namespace
+
+int main(int argc, char** argv) {
+    // A crash should still leave every check before it on the screen.
+    std::cout << std::unitbuf;
+    const char* x11 = std::getenv("DISPLAY");
+    const char* wayland = std::getenv("WAYLAND_DISPLAY");
+    if ((x11 == nullptr || *x11 == '\0') && (wayland == nullptr || *wayland == '\0')) {
+        std::cout << "no display, skipped\n";
+        return 77;
+    }
+
+    auto app = Gtk::Application::create("org.effector.GuiTests",
+                                        Gio::Application::Flags::NON_UNIQUE);
+    app->signal_activate().connect([&app] {
+        auto window = std::make_unique<effector::EffectorWindow>(effector::Options{});
+        app->add_window(*window);
+        window->present();
+        pump(300);
+        runTests(*window);
+        app->remove_window(*window);
+    });
+    const int status = app->run(argc > 0 ? 1 : 0, argv);
+    if (status != 0) return status;
+    std::cout << (failures == 0 ? "all passed\n" : std::to_string(failures) + " failed\n");
+    return failures;
+}