ExtensionInterfaceCompat.kt

/*
 * Copyright 2021 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

import android.app.Activity

/**
 * Base interface for different extension versions that serves as an API compatibility wrapper.
 * @see SidecarCompat
 */
internal interface ExtensionInterfaceCompat {
    /**
     * Verifies if the extension interface conforms to the declared version.
     */
    fun validateExtensionInterface(): Boolean

    /**
     * Sets the callback that is used by the extension to inform about hardware state changes.
     */
    fun setExtensionCallback(extensionCallback: ExtensionCallbackInterface)

    /**
     * Notifies extension that a listener for display feature layout changes was registered for the
     * given activity context. Should notify the [ExtensionCallbackInterface] of
     * the initial [WindowLayoutInfo] when it is available.
     */
    fun onWindowLayoutChangeListenerAdded(activity: Activity)

    /**
     * Notifies extension that a listener for display feature layout changes was removed for the
     * given activity context.
     */
    fun onWindowLayoutChangeListenerRemoved(activity: Activity)

    /**
     * Callback that will be registered with the WindowManager library, and that the extension
     * should use to report all state changes.
     */
    interface ExtensionCallbackInterface {
        /**
         * Called by extension when the feature layout inside the window changes.
         */
        fun onWindowLayoutChanged(activity: Activity, newLayout: WindowLayoutInfo)
    }
}