android 物理鍵盤 關鍵因素

參考PhoneWindowManager.java的adjustConfigurationLw()方法，可以找出以下關鍵因素：

config_lidKeyboardAccessibility：在frameworks/base/core/res/res/values/config.xml中定義，含義如下：

 Indicate whether the lid state impacts the accessibility of the physical keyboard. 

0 means it doesn't,

1 means it is accessible when the lid is open,

2 means it is accessible when the lid is closed.

The default is 1.

意爲物理鍵盤是否受滑蓋影響，0表示不受滑蓋影響，1表示當滑蓋打開時物理鍵盤可用，2表示滑蓋關閉時物理鍵盤可用。

 

另外PhoneWindowManager.java還有個常量也對物理鍵盤的狀態有影響：

// Debugging: set this to have the system act like there is no hard keyboard.
static final boolean KEYBOARD_ALWAYS_HIDDEN = false;

 

InputMethodService.java: 判斷是否顯示軟鍵盤的代碼：

onShowInputRequested() {

        if (!onEvaluateInputViewShown()) {
            return false;
        }
       ......................

}

    public boolean onEvaluateInputViewShown() {
        Configuration config = getResources().getConfiguration();
        return config.keyboard == Configuration.KEYBOARD_NOKEYS
                || config.hardKeyboardHidden == Configuration.KEYBOARDHIDDEN_YES;
    }

其中兩項config.hardKeyboardHidden就是framworks中config.xml的config_lidKeyboardAccessibility取值

 

 

物理鍵盤映射過程：
手機/system/usr/keylayout/*.kl ：內核將keyCode映射成有含義的字符串
KeycodeLabels.h ： framework 將字符串映射成keyEvent的keyCode
frameworks/.../res/values/attrs.xml