Also, a key event has 3 different form of the Key objects. Normally a input method engine may only want to consider only the key() property. origKey() and rawKey() properties are less used. Key property is in a normalized form of key event. That removes "Shift" modifier for certain cases, which makes it easier to handle by the input method engine. For example, upper case A produced by Shift+A and Capslocked A will be the same after normalization. You may refer to the implementation to learn about how this normalization works.
此外，一个按键事件有 3 种不同形式的 Key 对象。通常输入法引擎可能只想考虑 key() 属性。origKey() 和 rawKey() 属性使用较少。键属性是键事件的规范化形式。这删除了某些情况下的“Shift”修饰符，这使得输入法引擎更容易处理。例如，通过 Shift+A 和 Capslocked A 生成的大写字母 A 在归一化后将相同。您可以参考实现以了解此规范化的工作原理。