LibWeb: Implement WebDriver action extraction

There's a lot of parsing involved in action extraction. So this patch
implements only that - actually executing actions will be a future
patch.

Userland/Libraries/LibWeb/WebDriver/Actions.h

@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2024, Tim Flynn <trflynn89@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Function.h>
+#include <AK/Optional.h>
+#include <AK/String.h>
+#include <AK/Time.h>
+#include <AK/Variant.h>
+#include <AK/Vector.h>
+#include <LibJS/Heap/GCPtr.h>
+#include <LibWeb/Forward.h>
+#include <LibWeb/PixelUnits.h>
+#include <LibWeb/UIEvents/MouseButton.h>
+#include <LibWeb/WebDriver/Error.h>
+#include <LibWeb/WebDriver/InputSource.h>
+
+namespace Web::WebDriver {
+
+// https://w3c.github.io/webdriver/#dfn-action-object
+struct ActionObject {
+    enum class Subtype {
+        Pause,
+        KeyUp,
+        KeyDown,
+        PointerUp,
+        PointerDown,
+        PointerMove,
+        PointerCancel,
+        Scroll,
+    };
+
+    enum class OriginType {
+        Viewport,
+        Pointer,
+    };
+    using Origin = Variant<OriginType, String>;
+
+    struct PauseFields {
+        Optional<AK::Duration> duration;
+    };
+
+    struct KeyFields {
+        String value;
+    };
+
+    struct PointerFields {
+        PointerInputSource::Subtype pointer_type { PointerInputSource::Subtype::Mouse };
+        Optional<double> width;
+        Optional<double> height;
+        Optional<double> pressure;
+        Optional<double> tangential_pressure;
+        Optional<i32> tilt_x;
+        Optional<i32> tilt_y;
+        Optional<u32> twist;
+        Optional<double> altitude_angle;
+        Optional<double> azimuth_angle;
+    };
+
+    struct PointerUpDownFields : public PointerFields {
+        UIEvents::MouseButton button { UIEvents::MouseButton::None };
+    };
+
+    struct PointerMoveFields : public PointerFields {
+        Optional<AK::Duration> duration;
+        Origin origin { OriginType::Viewport };
+        CSSPixelPoint position;
+    };
+
+    struct PointerCancelFields {
+        PointerInputSource::Subtype pointer_type { PointerInputSource::Subtype::Mouse };
+    };
+
+    struct ScrollFields {
+        Origin origin { OriginType::Viewport };
+        Optional<AK::Duration> duration;
+        i64 x { 0 };
+        i64 y { 0 };
+        i64 delta_x { 0 };
+        i64 delta_y { 0 };
+    };
+
+    ActionObject(String id, InputSourceType type, Subtype subtype);
+
+    void set_pointer_type(PointerInputSource::Subtype);
+
+    PauseFields& pause_fields() { return fields.get<PauseFields>(); }
+    PauseFields const& pause_fields() const { return fields.get<PauseFields>(); }
+
+    KeyFields& key_fields() { return fields.get<KeyFields>(); }
+    KeyFields const& key_fields() const { return fields.get<KeyFields>(); }
+
+    PointerUpDownFields& pointer_up_down_fields() { return fields.get<PointerUpDownFields>(); }
+    PointerUpDownFields const& pointer_up_down_fields() const { return fields.get<PointerUpDownFields>(); }
+
+    PointerMoveFields& pointer_move_fields() { return fields.get<PointerMoveFields>(); }
+    PointerMoveFields const& pointer_move_fields() const { return fields.get<PointerMoveFields>(); }
+
+    PointerCancelFields& pointer_cancel_fields() { return fields.get<PointerCancelFields>(); }
+    PointerCancelFields const& pointer_cancel_fields() const { return fields.get<PointerCancelFields>(); }
+
+    ScrollFields& scroll_fields() { return fields.get<ScrollFields>(); }
+    ScrollFields const& scroll_fields() const { return fields.get<ScrollFields>(); }
+
+    String id;
+    InputSourceType type;
+    Subtype subtype;
+
+    using Fields = Variant<PauseFields, KeyFields, PointerUpDownFields, PointerMoveFields, PointerCancelFields, ScrollFields>;
+    Fields fields;
+};
+
+// https://w3c.github.io/webdriver/#dfn-actions-options
+struct ActionsOptions {
+    Function<bool(JsonObject const&)> is_element_origin;
+    Function<ErrorOr<JS::NonnullGCPtr<DOM::Element>, WebDriver::Error>(StringView)> get_element_origin;
+};
+
+ErrorOr<Vector<Vector<ActionObject>>, WebDriver::Error> extract_an_action_sequence(InputState&, JsonValue const&, ActionsOptions const&);
+
+}