LibWeb: Add a basic KeyboardEvent and fire "keydown" events :^)

Userland/Libraries/LibWeb/UIEvents/KeyboardEvent.cpp

@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2021, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/CharacterTypes.h>
+#include <LibWeb/UIEvents/KeyboardEvent.h>
+
+namespace Web::UIEvents {
+
+// https://www.w3.org/TR/uievents/#determine-keydown-keyup-keyCode
+static unsigned long determine_key_code(KeyCode platform_key, u32 code_point)
+{
+    // If input key when pressed without modifiers would insert a numerical character (0-9), return the ASCII code of that numerical character.
+    if (is_ascii_digit(code_point))
+        return code_point;
+
+    // If input key when pressed without modifiers would insert a lower case character in the a-z alphabetical range, return the ASCII code of the upper case equivalent.
+    if (is_ascii_lower_alpha(code_point))
+        return to_ascii_uppercase(code_point);
+
+    // If the key’s function, as determined in an implementation-specific way, corresponds to one of the keys in the §8.3.3 Fixed virtual key codes table, return the corresponding key code.
+    // https://www.w3.org/TR/uievents/#fixed-virtual-key-codes
+    switch (platform_key) {
+    case KeyCode::Key_Backspace:
+        return 8;
+    case KeyCode::Key_Tab:
+        return 9;
+    case KeyCode::Key_Return:
+        return 13;
+    case KeyCode::Key_Shift:
+        return 16;
+    case KeyCode::Key_Control:
+        return 17;
+    case KeyCode::Key_Alt:
+        return 18;
+    case KeyCode::Key_CapsLock:
+        return 20;
+    case KeyCode::Key_Escape:
+        return 27;
+    case KeyCode::Key_Space:
+        return 32;
+    case KeyCode::Key_PageUp:
+        return 33;
+    case KeyCode::Key_PageDown:
+        return 34;
+    case KeyCode::Key_End:
+        return 35;
+    case KeyCode::Key_Home:
+        return 36;
+    case KeyCode::Key_Left:
+        return 37;
+    case KeyCode::Key_Up:
+        return 38;
+    case KeyCode::Key_Right:
+        return 39;
+    case KeyCode::Key_Down:
+        return 40;
+    default:
+        break;
+    }
+
+    // Return the virtual key code from the operating system.
+    return platform_key;
+}
+
+NonnullRefPtr<KeyboardEvent> KeyboardEvent::create_from_platform_event(FlyString event_name, KeyCode platform_key, unsigned modifiers, u32 code_point)
+{
+    // FIXME: Figure out what these should actually contain.
+    String event_key = key_code_to_string(platform_key);
+    String event_code = "FIXME";
+
+    auto key_code = determine_key_code(platform_key, code_point);
+    return KeyboardEvent::create(move(event_name), move(event_key), move(event_code), 0, modifiers & Mod_Ctrl, modifiers & Mod_Shift, modifiers & Mod_Alt, false, false, false, key_code, code_point);
+}
+
+KeyboardEvent::KeyboardEvent(FlyString event_name, String key, String code, unsigned long location, bool ctrl_key, bool shift_key, bool alt_key, bool meta_key, bool repeat, bool is_composing, unsigned long key_code, unsigned long char_code)
+    : UIEvent(move(event_name))
+    , m_key(move(key))
+    , m_code(move(code))
+    , m_location(location)
+    , m_ctrl_key(ctrl_key)
+    , m_shift_key(shift_key)
+    , m_alt_key(alt_key)
+    , m_meta_key(meta_key)
+    , m_repeat(repeat)
+    , m_is_composing(is_composing)
+    , m_key_code(key_code)
+    , m_char_code(char_code)
+{
+}
+
+KeyboardEvent::~KeyboardEvent()
+{
+}
+
+bool KeyboardEvent::get_modifier_state(String const& key_arg)
+{
+    if (key_arg == "Alt")
+        return m_alt_key;
+    if (key_arg == "Control")
+        return m_ctrl_key;
+    if (key_arg == "Shift")
+        return m_shift_key;
+    if (key_arg == "Meta")
+        return m_meta_key;
+    return false;
+}
+}