How do I change the input method programatically?

Question

I have a requirement of changing the keyboard based on the change of language.

I have done a bit of research and found that it can be done using these APIs

1. InputMethodManager setInputMethod(android.os.IBinder, java.lang.String)
2. InputMethodService switchInputMethod(java.lang.String)

For the 1st API, I need an IBinder token which can be taken from InputMethodService instance by calling

mInputMethodService.getWindow().getWindow().getAttributes().token

or if I have the reference to InputMethodService object I can simply call

mInputMethodService.switchInputMethod(id)

to change the input method.

The real problem is how do I get a reference to InputMethodService object.

PS: I don't want to use InputMethodManager's showInputMethodPicker() because for my requirement I want to change it from my existing dialog which has a list of languages.

I know that this is not possible for a user app but not sure if it's also not possible for a system app or not.

Answer 1

Succeded!!!

The only way I have figured out of changing the current IME is by customizing it.

For my resp. problem I have to change the keyboard to chinese if I change the system language to chinese from my custom Settings application.

The approach discussed below was used for a custom LatinIME app.

Every IME has a class that extends InputMethodService class. In this class we can override a method called onInitializeInterface. This method gets called everytime when the configuration changes i.e. when you change your system Locale it will be called.

Here we can check whether the Locale that's currently been selected is supported by the current IME or not. If not then we can load its respective IME by calling the method switchInputMethod(id).

To get the id, we can query through inputMethodManager and get a list of available ids

    String pinyinId = "";

    InputMethodManager inputMethodManager = (InputMethodManager) getApplicationContext()
                    .getSystemService(INPUT_METHOD_SERVICE);
    List<InputMethodInfo> inputMethodInfos = inputMethodManager.getInputMethodList();

    for (InputMethodInfo inputMethodInfo : inputMethodInfos) {
            if (inputMethodInfo.getId().contains("pinyin")) {
                    pinyinId = inputMethodInfo.getId();
            }
    }

After getting the id we can call switchInputMethod(pinyinId) and it will change the IME.

Answer 2

This is an old question, but I was directed here from Google in 2019. I was facing the same problem & here is my solution:

NOTE: You need to install your app as system app OR signed with platform key.

1. Add write secure setting permission in AndroidManifest.xml:

   <uses-permission android:name="android.permission.WRITE_SECURE_SETTINGS" />
   

2. Use InputMethodService switchInputMethod(String inputMethodId) where applicable. Example: switchInputMethod("com.google.android.inputmethod.latin/com.android.inputmethod.latin.LatinIME");