ContextUtils.kt
/*
* Copyright 2022 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.window.layout.util
import android.app.Activity
import android.content.Context
import android.content.ContextWrapper
import android.inputmethodservice.InputMethodService
import androidx.annotation.UiContext
internal object ContextUtils {
/**
* Given a [UiContext], check if it is a [ContextWrapper]. If so, we need to unwrap it and
* return the actual [UiContext] within.
*/
@UiContext
internal fun unwrapUiContext(@UiContext context: Context): Context {
var iterator = context
while (iterator is ContextWrapper) {
if (iterator is Activity) {
// Activities are always ContextWrappers
return iterator
} else if (iterator is InputMethodService) {
// InputMethodService are always ContextWrappers
return iterator
} else if (iterator.baseContext == null) {
return iterator
}
iterator = iterator.baseContext
}
// TODO(b/259148796): This code path is not needed for APIs R and above. However, that is
// not clear and also not enforced anywhere. Once we move to version-based implementations,
// this ambiguity will no longer exist. Again for clarity, on APIs before R, UiContexts are
// Activities or InputMethodServices, so we should never reach this point.
throw IllegalArgumentException("Context $context is not a UiContext")
}
}