Remap the Keyboard in macOS: Karabiner-Elements

karabiner.json

{
    "profiles": [
        {
            "complex_modifications": {
                "rules": [
                    {
                        "description": "⌃-J to switch between english and 倉頡",
                        "manipulators": [
                            {
                                "conditions": [
                                    {
                                        "input_sources": [
                                            {
                                                "input_mode_id": "com.apple.inputmethod.TCIM.Cangjie",
                                                "input_source_id": "com.apple.inputmethod.TCIM.Cangjie",
                                                "language": "zh-Hant"
                                            }
                                        ],
                                        "type": "input_source_if"
                                    }
                                ],
                                "from": {
                                    "key_code": "j",
                                    "modifiers": {
                                        "mandatory": "left_control",
                                        "optional": ["any"]
                                    }
                                },
                                "to": [
                                    {
                                        "select_input_source": {
                                            "input_source_id": "com.apple.keylayout.ABC",
                                            "language": "en"
                                        }
                                    }
                                ],
                                "type": "basic"
                            },
                            {
                                "conditions": [
                                    {
                                        "input_sources": [
                                            {
                                                "input_source_id": "com.apple.keylayout.ABC",
                                                "language": "en"
                                            }
                                        ],
                                        "type": "input_source_if"
                                    }
                                ],
                                "from": {
                                    "key_code": "j",
                                    "modifiers": {
                                        "mandatory": "left_control",
                                        "optional": ["any"]
                                    }
                                },
                                "to": [
                                    {
                                        "select_input_source": {
                                            "input_mode_id": "com.apple.inputmethod.TCIM.Cangjie",
                                            "input_source_id": "com.apple.inputmethod.TCIM.Cangjie",
                                            "language": "zh-Hant"
                                        }
                                    }
                                ],
                                "type": "basic"
                            }
                        ]
                    },
                    {
                        "description": "Change left_option+hjkl to arrow keys",
                        "manipulators": [
                            {
                                "from": {
                                    "key_code": "h",
                                    "modifiers": {
                                        "mandatory": ["left_option"],
                                        "optional": ["any"]
                                    }
                                },
                                "to": [{ "key_code": "left_arrow" }],
                                "type": "basic"
                            },
                            {
                                "from": {
                                    "key_code": "j",
                                    "modifiers": {
                                        "mandatory": ["left_option"],
                                        "optional": ["any"]
                                    }
                                },
                                "to": [{ "key_code": "down_arrow" }],
                                "type": "basic"
                            },
                            {
                                "from": {
                                    "key_code": "k",
                                    "modifiers": {
                                        "mandatory": ["left_option"],
                                        "optional": ["any"]
                                    }
                                },
                                "to": [{ "key_code": "up_arrow" }],
                                "type": "basic"
                            },
                            {
                                "from": {
                                    "key_code": "l",
                                    "modifiers": {
                                        "mandatory": ["left_option"],
                                        "optional": ["any"]
                                    }
                                },
                                "to": [{ "key_code": "right_arrow" }],
                                "type": "basic"
                            }
                        ]
                    }
                ]
            },
            "devices": [
                {
                    "identifiers": {
                        "is_keyboard": true,
                        "product_id": 34050,
                        "vendor_id": 2652
                    },
                    "simple_modifications": [
                        {
                            "from": { "key_code": "caps_lock" },
                            "to": [{ "key_code": "escape" }]
                        }
                    ]
                }
            ],
            "name": "Default profile",
            "selected": true
        }
    ]
}