feat(input): add touch-action contact panning

docs/validation/code-oss-css-touch-action-799.md

@@ -0,0 +1,41 @@
+# Code OSS touch-action and contact pointer implementation (#799)
+
+## Product trigger
+
+Unchanged Code OSS authors 52 `touch-action` declarations across 27 files on
+editors, tabs, split views, sliders, terminal, and Chat surfaces. WebScene
+previously accepted only legacy mouse input and did not retain a native contact
+gesture policy.
+
+## Implemented slice
+
+- Adds generated native/managed CSS identity and CSSOM for non-inherited
+  `touch-action`: `auto`, `none`, `manipulation`, `pan-x`, `pan-y`, and the
+  two-axis combination, including CSS-wide values, mutation, and removal.
+- Decodes the versioned AppScene #298 pointer metadata from unused input flag
+  bits while preserving the 48-byte ABI and legacy primary-mouse behavior.
+- Exposes stable 1..15 pointer IDs, mouse/touch/pen identity, primary state,
+  pointer capture by ID, and terminal `pointercancel` teardown.
+- Freezes the intersected ancestor policy at contact start and performs
+  axis-qualified retained scrolling without synthetic mouse events.
+- Uses a fixed 16-entry gesture array. CSS mutation is interaction-only, adds
+  no layout invalidation, document scan, scene node, timer, browser shell, or
+  Code OSS patch.
+
+## Authored gates
+
+- `webscene_pointer_input_metadata_tests`: legacy fallback, touch identity,
+  stable ID, malformed input, and future-version rejection.
+- `contracts/css-touch-action.html`: non-inheritance, CSSOM, canonical axis
+  order, invalid-write preservation, CSS-wide inheritance, and removal.
+- Native input contract: frozen `pan-y`, touch/pen event fields, capture,
+  cancellation, no mouse compatibility events, and `none` suppression.
+- `css-touch-action-performance`: 4,096 nodes, 40,960 CSS mutations, 1,000
+  gestures, no layout passes, bounded scene publication, no animation-frame
+  leak, and a five-second guardrail.
+
+## Evidence state
+
+Implementation and gates are authored from source review. Per the active fast
+merge direction, no build, test, WPT, visual, package, memory, lifecycle, or
+performance command was executed. Evidence remains zero until full validation.

docs/validation/code-oss-web-api-ledger.md

@@ -29,7 +29,7 @@ Static matches establish source reachability only. Runtime claims require the ev
 | `form-data` | yes | blocked | linux-x64, macos-arm64, windows-x64 | WebScene#266 | 0 | FormData and multipart transport support exist in the runtime; bounded cross-platform webview/product evidence has not been accepted. |
 | `iframe` | yes | blocked | linux-x64, macos-arm64, windows-x64 | WebScene#253, WebScene#264, WebScene#265, WebScene#266, WebScene#267, WebScene#268 | 2 (12 pass, 0 fail, 0 skipped, 0 unavailable, 12 total) | Recorded evidence covers the earlier sandbox Wave 0 revision only. Current service-worker/resource/nested-frame stacks and packaged Markdown must still be promoted with revision-pinned results. |
 | `indexeddb` | yes | blocked | linux-x64, macos-arm64, windows-x64 | WebScene#56, WebScene#227 | 0 | Engine contracts exist, but Code OSS origin durability, quota, failure recovery, and package evidence are incomplete. |
-| `media-capture` | yes | blocked | linux-x64, macos-arm64, windows-x64 | WebScene#770, WebScene#773, WebScene#775, WebScene#776, WebScene#777, AppScene#289, WebScene#261 | 0 | MediaDevices, microphone tracks, analyser graph delivery, and the narrow Code OSS PCM AudioWorklet are implemented with authored gates. Windows/Linux providers, physical-device and exact-package evidence remain incomplete. |
+| `media-capture` | yes | blocked | linux-x64, macos-arm64, windows-x64 | WebScene#770, WebScene#773, WebScene#775, WebScene#776, WebScene#777, AppScene#289, WebScene#261 | 0 | WebScene exposes bounded MediaDevices enumeration, audio getUserMedia host handoff, microphone track lifecycle, graph delivery, and the narrow Code OSS PCM AudioWorklet/MessagePort path with authored but unexecuted gates. AppScene provides the bounded transport and macOS provider; Windows/Linux providers and physical-device evidence remain open. |
 | `message-port` | yes | blocked | linux-x64, macos-arm64, windows-x64 | WebScene#81 | 0 | Current implementation evidence has not yet been recorded as an accepted cross-platform run. |
 | `observers` | yes | blocked | linux-x64, macos-arm64, windows-x64 | WebScene#227, WebScene#258 | 0 | Observer scheduling, batching, disconnection, memory, and Code OSS panel-churn evidence are incomplete. |
 | `performance-timing` | yes | blocked | linux-x64, macos-arm64, windows-x64 | WebScene#227 | 0 | Monotonicity exists but accepted-scenario marks, observers, resource timing, bounds, and package evidence are not reconciled. |

experiments/WebScene.NativeEngine.Probe/CMakeLists.txt

@@ -5,6 +5,14 @@ include(CTest)
 include(FetchContent)
 
 if(BUILD_TESTING)
+    add_executable(webscene_pointer_input_metadata_tests
+        tests/pointer_input_metadata_tests.cpp)
+    target_compile_features(webscene_pointer_input_metadata_tests PRIVATE cxx_std_20)
+    target_include_directories(webscene_pointer_input_metadata_tests PRIVATE native)
+    add_test(NAME webscene_pointer_input_metadata_tests
+        COMMAND webscene_pointer_input_metadata_tests)
+    set_tests_properties(webscene_pointer_input_metadata_tests PROPERTIES
+        LABELS "native;input;pointer;abi;performance" TIMEOUT 10)
     add_executable(webscene_semantic_delta_header_tests
         tests/semantic_delta_header_tests.c)
     target_compile_features(webscene_semantic_delta_header_tests PRIVATE c_std_11)

experiments/WebScene.NativeEngine.Probe/native/css_property_metadata.json

@@ -159,7 +159,8 @@
     {"id": "isolation", "name": "isolation"},
     {"id": "will_change", "name": "will-change", "aliases": ["willchange"]},
     {"id": "text_wrap", "name": "text-wrap", "aliases": ["textwrap"]},
-    {"id": "caret_color", "name": "caret-color", "aliases": ["caretcolor"]}
+    {"id": "caret_color", "name": "caret-color", "aliases": ["caretcolor"]},
+    {"id": "touch_action", "name": "touch-action", "aliases": ["touchaction"]}
   ],
   "nativeStorageOnlyProperties": [
     "accent-color", "align-content", "animation-direction", "animation-fill-mode", "animation-play-state",
@@ -181,7 +182,7 @@
       "justify_content", "box_sizing", "vertical_align", "grid_auto_flow", "border_collapse", "table_layout", "border_style", "background_repeat",
       "visibility", "pointer_events", "text_anchor", "font_smoothing", "text_align", "text_transform", "white_space", "word_break", "overflow_wrap", "list_style_position",
       "list_style_type", "scrollbar_width", "container", "container_type", "content_visibility", "object_fit", "user_select",
-      "overscroll_behavior", "overscroll_behavior_x", "overscroll_behavior_y", "isolation", "will_change", "text_wrap"
+      "overscroll_behavior", "overscroll_behavior_x", "overscroll_behavior_y", "isolation", "will_change", "text_wrap", "touch_action"
     ],
     "componentList": [
       "container_name", "background_position", "background_size", "transition", "transition_property", "transition_duration",
@@ -225,7 +226,7 @@
     "outline", "outline_width", "outline_color", "animation", "animation_name", "animation_duration", "animation_delay",
     "animation_timing_function", "animation_iteration_count", "background_repeat", "background_position", "background_size",
     "font", "text_transform", "word_break", "overflow_wrap", "list_style", "list_style_position", "list_style_type",
-    "object_fit", "object_position", "user_select", "overscroll_behavior", "overscroll_behavior_x", "overscroll_behavior_y", "isolation", "will_change", "text_wrap", "caret_color"
+    "object_fit", "object_position", "user_select", "overscroll_behavior", "overscroll_behavior_x", "overscroll_behavior_y", "isolation", "will_change", "text_wrap", "caret_color", "touch_action"
   ],
   "managedKnownProperties": [
     "align-content", "align-items", "align-self", "all", "background", "background-color",
@@ -247,7 +248,7 @@
     "top", "transform", "visibility", "white-space", "word-break", "overflow-wrap", "width", "word-spacing", "z-index",
     "outline", "outline-color", "outline-offset", "outline-style", "outline-width",
     "grid-template-areas", "aspect-ratio", "object-fit", "object-position", "user-select",
-    "overscroll-behavior", "overscroll-behavior-x", "overscroll-behavior-y", "isolation", "will-change", "text-wrap", "caret-color"
+    "overscroll-behavior", "overscroll-behavior-x", "overscroll-behavior-y", "isolation", "will-change", "text-wrap", "caret-color", "touch-action"
   ],
   "supportedPropertyExtras": [
     "animation", "animation-delay", "animation-direction", "animation-duration", "animation-fill-mode",

experiments/WebScene.NativeEngine.Probe/native/generated/webscene_css_property_identity.inc

@@ -238,6 +238,8 @@ inline constexpr std::array native_typed_property_identity_catalog{
     native_typed_property_identity{"textwrap", css_property_id::text_wrap},
     native_typed_property_identity{"caret-color", css_property_id::caret_color},
     native_typed_property_identity{"caretcolor", css_property_id::caret_color},
+    native_typed_property_identity{"touch-action", css_property_id::touch_action},
+    native_typed_property_identity{"touchaction", css_property_id::touch_action},
 };
 
 inline constexpr std::array<std::string_view, 62> native_storage_only_property_catalog{
@@ -465,6 +467,7 @@ inline constexpr std::array native_modeled_property_mask_catalog{
     false,
     false,
     false,
+    false,
 };
 
 inline constexpr bool generated_property_has_modeled_mask(
@@ -673,6 +676,7 @@ inline constexpr std::array native_property_grammar_catalog{
     native_property_grammar::keyword,
     native_property_grammar::keyword,
     native_property_grammar::complex,
+    native_property_grammar::keyword,
 };
 
 inline constexpr native_property_grammar generated_property_grammar(
@@ -919,5 +923,7 @@ inline css_property_id generated_property_id_lowercase(std::string_view name) no
     if (name == "textwrap") return css_property_id::text_wrap;
     if (name == "caret-color") return css_property_id::caret_color;
     if (name == "caretcolor") return css_property_id::caret_color;
+    if (name == "touch-action") return css_property_id::touch_action;
+    if (name == "touchaction") return css_property_id::touch_action;
     return css_property_id::unknown;
 }

experiments/WebScene.NativeEngine.Probe/native/generated/webscene_css_property_ids.inc

@@ -158,3 +158,4 @@ isolation,
 will_change,
 text_wrap,
 caret_color,
+touch_action,

experiments/WebScene.NativeEngine.Probe/native/generated/webscene_css_supported_properties.inc

@@ -239,6 +239,7 @@ inline constexpr std::array cssom_supported_property_catalog{
     cssom_supported_property_metadata{"text-transform", "textTransform"},
     cssom_supported_property_metadata{"text-wrap", "textWrap"},
     cssom_supported_property_metadata{"top", "top"},
+    cssom_supported_property_metadata{"touch-action", "touchAction"},
     cssom_supported_property_metadata{"transform", "transform"},
     cssom_supported_property_metadata{"transform-origin", "transformOrigin"},
     cssom_supported_property_metadata{"transition", "transition"},
@@ -263,4 +264,4 @@ inline constexpr std::array cssom_supported_property_catalog{
     cssom_supported_property_metadata{"zoom", "zoom"},
 };
 
-inline constexpr auto cssom_style_template_property_accessor_count = 468U;
+inline constexpr auto cssom_style_template_property_accessor_count = 470U;

experiments/WebScene.NativeEngine.Probe/native/webscene_css_application.h

@@ -260,6 +260,7 @@ void apply_resolved_declaration(native_document& document,dom_node& node,
         } else if (css::apply_replaced_value(node,name,value,decision)) {
         } else if (css::apply_user_select_value(node,name,value,decision)) {
         } else if (css::apply_overscroll_behavior_value(node,name,value,decision)) {
+        } else if (css::apply_touch_action_value(node,name,value,decision)) {
         } else if (css::apply_isolation_value(node,name,value,decision)) {
         } else if (css::apply_will_change_value(node,name,value,decision)) {
         } else if (css::apply_text_value(node,name,value,decision,is_inline)) {

experiments/WebScene.NativeEngine.Probe/native/webscene_css_cascade_reset.h

@@ -233,6 +233,7 @@ inline void reset_cascaded_style(dom_node& node,
             textual->will_change.clear();
             textual->overscroll_x = overscroll_behavior::automatic;
             textual->overscroll_y = overscroll_behavior::automatic;
+            textual->touch_action_value = touch_action::automatic;
         }
         if ((node.style.inline_property_mask & inline_font_weight) == 0U) node.style.font_weight = 0;
         node.style.isolation_stacking_context = false;

experiments/WebScene.NativeEngine.Probe/native/webscene_css_interaction_values.h

@@ -5,6 +5,66 @@
 #include <utility>
 
 namespace webscene_native::css {
+inline std::string_view serialize_touch_action(touch_action value) noexcept
+{
+    switch (value) {
+    case touch_action::none: return "none";
+    case touch_action::manipulation: return "manipulation";
+    case touch_action::pan_x: return "pan-x";
+    case touch_action::pan_y: return "pan-y";
+    case touch_action::pan_x_y: return "pan-x pan-y";
+    default: return "auto";
+    }
+}
+
+inline uint8_t touch_action_axes(touch_action value) noexcept
+{
+    switch (value) {
+    case touch_action::none: return 0U;
+    case touch_action::pan_x: return 1U;
+    case touch_action::pan_y: return 2U;
+    default: return 3U;
+    }
+}
+
+inline std::optional<touch_action> parse_touch_action(
+    std::string_view value) noexcept
+{
+    if (value == "auto") return touch_action::automatic;
+    if (value == "none") return touch_action::none;
+    if (value == "manipulation") return touch_action::manipulation;
+    if (value == "pan-x") return touch_action::pan_x;
+    if (value == "pan-y") return touch_action::pan_y;
+    if (value == "pan-x pan-y" || value == "pan-y pan-x")
+        return touch_action::pan_x_y;
+    return std::nullopt;
+}
+
+template<typename Decision>
+bool apply_touch_action_value(dom_node& node,const std::string& name,
+    const std::string& raw_value,Decision& decision)
+{
+    if (canonical_property_name(name) != "touch-action") return false;
+    auto value = ascii_lower(trim_value(raw_value));
+    if (value == "inherit") {
+        node.style.mutable_textual().touch_action_value = node.parent == nullptr
+            ? touch_action::automatic
+            : node.parent->style.textual().touch_action_value;
+        return true;
+    }
+    if (value == "initial" || value == "unset" || value == "revert"
+        || value == "revert-layer") value = "auto";
+    const auto parsed = parse_touch_action(value);
+    if (!parsed.has_value()) {
+        decision.classification = "invalid-authoring";
+        return true;
+    }
+    if (*parsed == touch_action::automatic && !node.style.has_textual_data())
+        return true;
+    node.style.mutable_textual().touch_action_value = *parsed;
+    return true;
+}
+
 template<typename Decision>
 bool apply_user_select_value(dom_node& node,const std::string& name,
     const std::string& raw_value,Decision& decision)

experiments/WebScene.NativeEngine.Probe/native/webscene_css_reset.h

@@ -251,6 +251,10 @@ inline void apply_all_unset(
     if (has_inline({"overscroll-behavior", "overscroll-behavior-y"})) {
         reset.mutable_textual().overscroll_y = previous.textual().overscroll_y;
     }
+    if (has_inline({"touch-action"})) {
+        reset.mutable_textual().touch_action_value =
+            previous.textual().touch_action_value;
+    }
     if (has_inline({"isolation"})) {
         reset.isolation_stacking_context = previous.isolation_stacking_context;
     }

experiments/WebScene.NativeEngine.Probe/native/webscene_css_specified_coverage.h

@@ -15,6 +15,7 @@ inline constexpr auto specified_property_samples = std::to_array<specified_prope
         {"will-change","transform, opacity"},
         {"text-wrap","nowrap"},
         {"caret-color","#123456"},
+        {"touch-action","pan-y"},
     {"width","12px"},{"height","20%"},{"min-width","1rem"},{"min-height","2px"},
     {"max-width","none"},{"max-height","fit-content"},
     {"left","1px"},{"top","2px"},{"right","3px"},{"bottom","4px"},{"inset","1px 2px 3px 4px"},

experiments/WebScene.NativeEngine.Probe/native/webscene_native_dom.h

@@ -166,6 +166,15 @@ enum class overscroll_behavior : uint8_t {
     none
 };
 
+enum class touch_action : uint8_t {
+    automatic,
+    none,
+    manipulation,
+    pan_x,
+    pan_y,
+    pan_x_y
+};
+
 enum class float_mode : uint8_t {
     none,
     left,
@@ -812,6 +821,9 @@ struct node_style final {
         // walks exhausted scroll containers, so keep both axes in cold style.
         overscroll_behavior overscroll_x{overscroll_behavior::automatic};
         overscroll_behavior overscroll_y{overscroll_behavior::automatic};
+        // Native gesture admission is consulted only for active touch/pen
+        // contacts, so keep the non-inherited policy in cold style storage.
+        touch_action touch_action_value{touch_action::automatic};
         std::string contain_value;
         std::string container_type{"normal"};
         std::string container_name{"none"};

experiments/WebScene.NativeEngine.Probe/native/webscene_native_engine.h

@@ -68,7 +68,10 @@ typedef enum webscene_input_kind {
     WEBSCENE_INPUT_TEXT = 9,
     // A discrete host-surface exit, not a mousemove. Coordinates may still be
     // the last known position inside the surface. Does not cancel capture.
-    WEBSCENE_INPUT_POINTER_LEAVE = 10
+    WEBSCENE_INPUT_POINTER_LEAVE = 10,
+    // Terminal contact cancellation. Older consumers ignore this additive
+    // kind; current consumers retire capture and gesture state without click.
+    WEBSCENE_INPUT_POINTER_CANCEL = 17
 } webscene_input_kind;
 
 typedef enum webscene_cursor_kind {
@@ -478,9 +481,26 @@ enum {
     // target-offset animator. Unclassified legacy input remains immediate.
     WEBSCENE_INPUT_WHEEL_PRECISE = 1U << 20U,
     WEBSCENE_INPUT_WHEEL_NATIVE_MOMENTUM = 1U << 21U,
-    WEBSCENE_INPUT_WHEEL_DISCRETE = 1U << 22U
+    WEBSCENE_INPUT_WHEEL_DISCRETE = 1U << 22U,
+    // Binary-compatible pointer metadata. Version zero is a legacy primary
+    // mouse at ID 1. Version one occupies bits 23..31; consumers must reject
+    // unknown nonzero versions rather than reinterpret their payload.
+    WEBSCENE_INPUT_POINTER_METADATA_VERSION_SHIFT = 23U,
+    WEBSCENE_INPUT_POINTER_METADATA_VERSION_MASK = 3U << 23U,
+    WEBSCENE_INPUT_POINTER_METADATA_VERSION_1 = 1U << 23U,
+    WEBSCENE_INPUT_POINTER_DEVICE_SHIFT = 25U,
+    WEBSCENE_INPUT_POINTER_DEVICE_MASK = 3U << 25U,
+    WEBSCENE_INPUT_POINTER_PRIMARY = 1U << 27U,
+    WEBSCENE_INPUT_POINTER_ID_SHIFT = 28U,
+    WEBSCENE_INPUT_POINTER_ID_MASK = 15U << 28U
 };
 
+typedef enum webscene_pointer_device_kind {
+    WEBSCENE_POINTER_DEVICE_MOUSE = 0,
+    WEBSCENE_POINTER_DEVICE_TOUCH = 1,
+    WEBSCENE_POINTER_DEVICE_PEN = 2
+} webscene_pointer_device_kind;
+
 typedef struct webscene_input_event {
     uint32_t kind;
     uint32_t flags;

experiments/WebScene.NativeEngine.Probe/native/webscene_native_engine_input.inc

@@ -24,6 +24,7 @@
         case WEBSCENE_INPUT_POINTER_DOWN:
         case WEBSCENE_INPUT_POINTER_UP:
         case WEBSCENE_INPUT_POINTER_LEAVE:
+        case WEBSCENE_INPUT_POINTER_CANCEL:
             pointer_x_ = event.x;
             pointer_y_ = event.y;
 #if defined(WEBSCENE_NATIVE_ENGINE_WITH_V8)