Add foundation event dispatcher tests

CMakeLists.txt

@@ -69,6 +69,7 @@ add_custom_target(panopainter_validate_shaders
 
 add_library(pp_foundation STATIC
     src/foundation/binary_stream.cpp
+    src/foundation/event.cpp
     src/foundation/log.cpp
     src/foundation/parse.cpp
     src/foundation/task_queue.cpp

docs/modernization/build-inventory.md

@@ -80,8 +80,8 @@ Known local toolchain state:
   `platform-build` automation wrapper for `pp_foundation`, `pp_assets`,
   `pp_paint`, `pp_document`, `pp_renderer_api`, `pp_paint_renderer`,
   `pp_ui_core`, `pano_cli`, and their current headless test binaries,
-  including foundation logging/task queue coverage, PPI header, paint stroke
-  sampling, and layout XML parse coverage.
+  including foundation event/logging/task queue coverage, PPI header, paint
+  stroke sampling, and layout XML parse coverage.
 - `panopainter_validate_shaders` validates the current combined GLSL shader
   files for one vertex stage marker, one fragment stage marker, valid marker
   order, and existing relative includes.

docs/modernization/roadmap.md

@@ -304,9 +304,10 @@ Goal: split libraries while keeping current app behavior.
 Status: started. `pp_foundation` exists with binary stream utilities and
 boundary/overread tests. It also owns strict decimal `uint32` parsing used by
 `pano_cli`, with rejection tests for empty, signed, mixed, and overflowing
-input. A structured logging facade, bounded FIFO task queue, and deterministic
-`TraceRecorder` now record component/name/thread/frame/stroke metadata with
-filtering, capacity, and invalid-end tests. `pp_assets` has started with
+input. A synchronous event dispatcher, structured logging facade, bounded FIFO
+task queue, and deterministic `TraceRecorder` now record
+component/name/thread/frame/stroke metadata with filtering, capacity, and
+invalid-end tests. `pp_assets` has started with
 PNG/JPEG signature detection plus PPI header recognition, with
 corrupt/truncated/unsupported tests.
 `pp_paint` has started with CPU reference math for the five current shader
@@ -524,7 +525,7 @@ Last verified on 2026-06-01:
 
 ```powershell
 cmake --preset windows-msvc-default
-cmake --build --preset windows-msvc-default --config Debug --target pp_foundation_binary_stream_tests pp_foundation_log_tests pp_foundation_parse_tests pp_foundation_task_queue_tests pp_foundation_trace_tests pp_assets_image_format_tests pp_assets_ppi_header_tests pp_paint_blend_tests pp_paint_stroke_tests pp_document_tests pp_renderer_api_tests pp_paint_renderer_compositor_tests pp_ui_core_layout_value_tests pp_ui_core_layout_xml_tests pano_cli PanoPainter
+cmake --build --preset windows-msvc-default --config Debug --target pp_foundation_binary_stream_tests pp_foundation_event_tests pp_foundation_log_tests pp_foundation_parse_tests pp_foundation_task_queue_tests pp_foundation_trace_tests pp_assets_image_format_tests pp_assets_ppi_header_tests pp_paint_blend_tests pp_paint_stroke_tests pp_document_tests pp_renderer_api_tests pp_paint_renderer_compositor_tests pp_ui_core_layout_value_tests pp_ui_core_layout_xml_tests pano_cli PanoPainter
 ctest --preset desktop-fast --build-config Debug
 powershell -ExecutionPolicy Bypass -File scripts\automation\test.ps1 -Preset desktop-fast -Configuration Debug
 powershell -ExecutionPolicy Bypass -File scripts\automation\build.ps1 -Preset windows-msvc-default -Configuration Debug -Target pano_cli
@@ -538,6 +539,7 @@ powershell -ExecutionPolicy Bypass -File scripts\automation\package-smoke.ps1 -P
 Results:
 
 - `pp_foundation_binary_stream_tests` passed.
+- `pp_foundation_event_tests` passed.
 - `pp_foundation_log_tests` passed.
 - `pp_foundation_parse_tests` passed.
 - `pp_foundation_task_queue_tests` passed.

scripts/automation/platform-build.ps1

@@ -1,7 +1,7 @@
 [CmdletBinding()]
 param(
     [string[]]$Presets = @("android-arm64"),
-    [string[]]$Targets = @("pp_foundation", "pp_assets", "pp_paint", "pp_document", "pp_renderer_api", "pp_paint_renderer", "pp_ui_core", "pano_cli", "pp_foundation_binary_stream_tests", "pp_foundation_log_tests", "pp_foundation_parse_tests", "pp_foundation_task_queue_tests", "pp_foundation_trace_tests", "pp_assets_image_format_tests", "pp_assets_ppi_header_tests", "pp_paint_blend_tests", "pp_paint_stroke_tests", "pp_document_tests", "pp_renderer_api_tests", "pp_paint_renderer_compositor_tests", "pp_ui_core_layout_value_tests", "pp_ui_core_layout_xml_tests")
+    [string[]]$Targets = @("pp_foundation", "pp_assets", "pp_paint", "pp_document", "pp_renderer_api", "pp_paint_renderer", "pp_ui_core", "pano_cli", "pp_foundation_binary_stream_tests", "pp_foundation_event_tests", "pp_foundation_log_tests", "pp_foundation_parse_tests", "pp_foundation_task_queue_tests", "pp_foundation_trace_tests", "pp_assets_image_format_tests", "pp_assets_ppi_header_tests", "pp_paint_blend_tests", "pp_paint_stroke_tests", "pp_document_tests", "pp_renderer_api_tests", "pp_paint_renderer_compositor_tests", "pp_ui_core_layout_value_tests", "pp_ui_core_layout_xml_tests")
 )
 
 $ErrorActionPreference = "Stop"

scripts/automation/platform-build.sh

@@ -3,7 +3,7 @@ set -u
 
 preset="${1:-android-arm64}"
 shift || true
-targets="${*:-pp_foundation pp_assets pp_paint pp_document pp_renderer_api pp_paint_renderer pp_ui_core pano_cli pp_foundation_binary_stream_tests pp_foundation_log_tests pp_foundation_parse_tests pp_foundation_task_queue_tests pp_foundation_trace_tests pp_assets_image_format_tests pp_assets_ppi_header_tests pp_paint_blend_tests pp_paint_stroke_tests pp_document_tests pp_renderer_api_tests pp_paint_renderer_compositor_tests pp_ui_core_layout_value_tests pp_ui_core_layout_xml_tests}"
+targets="${*:-pp_foundation pp_assets pp_paint pp_document pp_renderer_api pp_paint_renderer pp_ui_core pano_cli pp_foundation_binary_stream_tests pp_foundation_event_tests pp_foundation_log_tests pp_foundation_parse_tests pp_foundation_task_queue_tests pp_foundation_trace_tests pp_assets_image_format_tests pp_assets_ppi_header_tests pp_paint_blend_tests pp_paint_stroke_tests pp_document_tests pp_renderer_api_tests pp_paint_renderer_compositor_tests pp_ui_core_layout_value_tests pp_ui_core_layout_xml_tests}"
 start="$(date +%s)"
 
 cmake --preset "$preset"

src/foundation/event.cpp

@@ -0,0 +1,97 @@
+#include "foundation/event.h"
+
+#include <algorithm>
+
+namespace pp::foundation {
+
+EventDispatcher::EventDispatcher(std::size_t max_subscriptions) noexcept
+    : max_subscriptions_(max_subscriptions)
+{
+    subscriptions_.reserve(std::min(max_subscriptions_, max_event_subscriptions));
+}
+
+std::size_t EventDispatcher::size() const noexcept
+{
+    return subscriptions_.size();
+}
+
+bool EventDispatcher::empty() const noexcept
+{
+    return subscriptions_.empty();
+}
+
+std::size_t EventDispatcher::max_subscriptions() const noexcept
+{
+    return max_subscriptions_;
+}
+
+Result<std::uint64_t> EventDispatcher::subscribe(std::uint32_t type, EventCallback callback, void* user_data)
+{
+    if (max_subscriptions_ == 0U || max_subscriptions_ > max_event_subscriptions) {
+        return Result<std::uint64_t>::failure(
+            Status::out_of_range("event dispatcher capacity is outside the configured range"));
+    }
+
+    if (type == 0U) {
+        return Result<std::uint64_t>::failure(Status::invalid_argument("event type must not be zero"));
+    }
+
+    if (callback == nullptr) {
+        return Result<std::uint64_t>::failure(Status::invalid_argument("event callback must not be null"));
+    }
+
+    if (subscriptions_.size() >= max_subscriptions_) {
+        return Result<std::uint64_t>::failure(Status::out_of_range("event dispatcher is full"));
+    }
+
+    const auto id = next_subscription_id_++;
+    subscriptions_.push_back(EventSubscription {
+        .id = id,
+        .type = type,
+        .callback = callback,
+        .user_data = user_data,
+    });
+
+    return Result<std::uint64_t>::success(id);
+}
+
+Status EventDispatcher::unsubscribe(std::uint64_t subscription_id) noexcept
+{
+    const auto found = std::find_if(
+        subscriptions_.begin(),
+        subscriptions_.end(),
+        [subscription_id](const EventSubscription& subscription) {
+            return subscription.id == subscription_id;
+        });
+
+    if (found == subscriptions_.end()) {
+        return Status::out_of_range("event subscription id was not found");
+    }
+
+    subscriptions_.erase(found);
+    return Status::success();
+}
+
+std::size_t EventDispatcher::publish(const Event& event) const noexcept
+{
+    if (event.type == 0U) {
+        return 0;
+    }
+
+    std::size_t delivered = 0;
+    for (const auto& subscription : subscriptions_) {
+        if (subscription.type == event.type) {
+            subscription.callback(event, subscription.user_data);
+            ++delivered;
+        }
+    }
+
+    return delivered;
+}
+
+void EventDispatcher::clear() noexcept
+{
+    subscriptions_.clear();
+}
+
+}

src/foundation/event.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include "foundation/result.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <vector>
+
+namespace pp::foundation {
+
+constexpr std::size_t max_event_subscriptions = 65536;
+
+struct Event {
+    std::uint32_t type = 0;
+    std::uint64_t source_id = 0;
+    std::uint64_t frame_id = 0;
+    std::uint64_t payload_u64 = 0;
+};
+
+using EventCallback = void (*)(const Event& event, void* user_data) noexcept;
+
+struct EventSubscription {
+    std::uint64_t id = 0;
+    std::uint32_t type = 0;
+    EventCallback callback = nullptr;
+    void* user_data = nullptr;
+};
+
+class EventDispatcher {
+public:
+    explicit EventDispatcher(std::size_t max_subscriptions = max_event_subscriptions) noexcept;
+
+    [[nodiscard]] std::size_t size() const noexcept;
+    [[nodiscard]] bool empty() const noexcept;
+    [[nodiscard]] std::size_t max_subscriptions() const noexcept;
+
+    [[nodiscard]] Result<std::uint64_t> subscribe(std::uint32_t type, EventCallback callback, void* user_data);
+    [[nodiscard]] Status unsubscribe(std::uint64_t subscription_id) noexcept;
+    [[nodiscard]] std::size_t publish(const Event& event) const noexcept;
+    void clear() noexcept;
+
+private:
+    std::size_t max_subscriptions_ = max_event_subscriptions;
+    std::uint64_t next_subscription_id_ = 1;
+    std::vector<EventSubscription> subscriptions_;
+};
+
+}

tests/CMakeLists.txt

@@ -16,6 +16,16 @@ add_test(NAME pp_foundation_binary_stream_tests COMMAND pp_foundation_binary_str
 set_tests_properties(pp_foundation_binary_stream_tests PROPERTIES
     LABELS "foundation;desktop-fast")
 
+add_executable(pp_foundation_event_tests
+    foundation/event_tests.cpp)
+target_link_libraries(pp_foundation_event_tests PRIVATE
+    pp_foundation
+    pp_test_harness)
+
+add_test(NAME pp_foundation_event_tests COMMAND pp_foundation_event_tests)
+set_tests_properties(pp_foundation_event_tests PROPERTIES
+    LABELS "foundation;desktop-fast")
+
 add_executable(pp_foundation_log_tests
     foundation/log_tests.cpp)
 target_link_libraries(pp_foundation_log_tests PRIVATE

tests/foundation/event_tests.cpp

@@ -0,0 +1,136 @@
+#include "foundation/event.h"
+#include "test_harness.h"
+
+using pp::foundation::Event;
+using pp::foundation::EventDispatcher;
+using pp::foundation::StatusCode;
+using pp::foundation::max_event_subscriptions;
+
+namespace {
+
+struct Receiver {
+    int count = 0;
+    std::uint64_t payload_sum = 0;
+    std::uint64_t last_source = 0;
+};
+
+void receive_event(const Event& event, void* user_data) noexcept
+{
+    auto* receiver = static_cast<Receiver*>(user_data);
+    ++receiver->count;
+    receiver->payload_sum += event.payload_u64;
+    receiver->last_source = event.source_id;
+}
+
+void subscribe_and_publish_matching_events(pp::tests::Harness& h)
+{
+    EventDispatcher dispatcher(4);
+    Receiver receiver;
+
+    const auto subscription = dispatcher.subscribe(7, receive_event, &receiver);
+    PP_EXPECT(h, subscription.ok());
+    PP_EXPECT(h, subscription.value() == 1U);
+    PP_EXPECT(h, dispatcher.size() == 1U);
+    PP_EXPECT(h, dispatcher.max_subscriptions() == 4U);
+
+    const auto delivered = dispatcher.publish(Event {
+        .type = 7,
+        .source_id = 42,
+        .frame_id = 3,
+        .payload_u64 = 11,
+    });
+
+    PP_EXPECT(h, delivered == 1U);
+    PP_EXPECT(h, receiver.count == 1);
+    PP_EXPECT(h, receiver.payload_sum == 11U);
+    PP_EXPECT(h, receiver.last_source == 42U);
+}
+
+void ignores_non_matching_or_zero_events(pp::tests::Harness& h)
+{
+    EventDispatcher dispatcher(4);
+    Receiver receiver;
+
+    PP_EXPECT(h, dispatcher.subscribe(2, receive_event, &receiver).ok());
+    PP_EXPECT(h, dispatcher.publish(Event { .type = 3, .payload_u64 = 1 }) == 0U);
+    PP_EXPECT(h, dispatcher.publish(Event { .type = 0, .payload_u64 = 1 }) == 0U);
+    PP_EXPECT(h, receiver.count == 0);
+}
+
+void preserves_subscription_order_and_unsubscribes(pp::tests::Harness& h)
+{
+    EventDispatcher dispatcher(4);
+    Receiver first;
+    Receiver second;
+
+    const auto first_subscription = dispatcher.subscribe(9, receive_event, &first);
+    const auto second_subscription = dispatcher.subscribe(9, receive_event, &second);
+    PP_EXPECT(h, first_subscription.ok());
+    PP_EXPECT(h, second_subscription.ok());
+
+    PP_EXPECT(h, dispatcher.publish(Event { .type = 9, .payload_u64 = 5 }) == 2U);
+    PP_EXPECT(h, first.payload_sum == 5U);
+    PP_EXPECT(h, second.payload_sum == 5U);
+
+    PP_EXPECT(h, dispatcher.unsubscribe(first_subscription.value()).ok());
+    PP_EXPECT(h, dispatcher.publish(Event { .type = 9, .payload_u64 = 7 }) == 1U);
+    PP_EXPECT(h, first.payload_sum == 5U);
+    PP_EXPECT(h, second.payload_sum == 12U);
+
+    const auto missing = dispatcher.unsubscribe(first_subscription.value());
+    PP_EXPECT(h, !missing.ok());
+    PP_EXPECT(h, missing.code == StatusCode::out_of_range);
+}
+
+void rejects_invalid_subscriptions_and_capacity(pp::tests::Harness& h)
+{
+    EventDispatcher dispatcher(1);
+    EventDispatcher zero_capacity(0);
+    EventDispatcher excessive_capacity(max_event_subscriptions + 1U);
+    Receiver receiver;
+
+    const auto zero_type = dispatcher.subscribe(0, receive_event, &receiver);
+    const auto null_callback = dispatcher.subscribe(1, nullptr, &receiver);
+    PP_EXPECT(h, !zero_type.ok());
+    PP_EXPECT(h, zero_type.status().code == StatusCode::invalid_argument);
+    PP_EXPECT(h, !null_callback.ok());
+    PP_EXPECT(h, null_callback.status().code == StatusCode::invalid_argument);
+
+    PP_EXPECT(h, dispatcher.subscribe(1, receive_event, &receiver).ok());
+    const auto full = dispatcher.subscribe(2, receive_event, &receiver);
+    PP_EXPECT(h, !full.ok());
+    PP_EXPECT(h, full.status().code == StatusCode::out_of_range);
+
+    const auto zero_capacity_result = zero_capacity.subscribe(1, receive_event, &receiver);
+    const auto excessive_capacity_result = excessive_capacity.subscribe(1, receive_event, &receiver);
+    PP_EXPECT(h, !zero_capacity_result.ok());
+    PP_EXPECT(h, zero_capacity_result.status().code == StatusCode::out_of_range);
+    PP_EXPECT(h, !excessive_capacity_result.ok());
+    PP_EXPECT(h, excessive_capacity_result.status().code == StatusCode::out_of_range);
+}
+
+void clear_removes_all_subscriptions(pp::tests::Harness& h)
+{
+    EventDispatcher dispatcher(4);
+    Receiver receiver;
+
+    PP_EXPECT(h, dispatcher.subscribe(1, receive_event, &receiver).ok());
+    PP_EXPECT(h, dispatcher.subscribe(2, receive_event, &receiver).ok());
+    dispatcher.clear();
+    PP_EXPECT(h, dispatcher.empty());
+    PP_EXPECT(h, dispatcher.publish(Event { .type = 1, .payload_u64 = 5 }) == 0U);
+    PP_EXPECT(h, receiver.count == 0);
+}
+
+}
+
+int main()
+{
+    pp::tests::Harness harness;
+    harness.run("subscribe_and_publish_matching_events", subscribe_and_publish_matching_events);
+    harness.run("ignores_non_matching_or_zero_events", ignores_non_matching_or_zero_events);
+    harness.run("preserves_subscription_order_and_unsubscribes", preserves_subscription_order_and_unsubscribes);
+    harness.run("rejects_invalid_subscriptions_and_capacity", rejects_invalid_subscriptions_and_capacity);
+    harness.run("clear_removes_all_subscriptions", clear_removes_all_subscriptions);
+    return harness.finish();
+}