packages/SystemUI/src/com/android/systemui/statusbar/phone/PanelExpansionListener.java

/*
 * Copyright (C) 2019 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 com.android.systemui.statusbar.phone;

/**
 * Panel and QS expansion callbacks.
 */
public interface PanelExpansionListener {
    /**
     * Invoked whenever the notification panel expansion changes, at every animation frame.
     * This is the main expansion that happens when the user is swiping up to dismiss the
     * lock screen.
     *
     * @param expansion 0 when collapsed, 1 when expanded.
     * @param tracking {@code true} when the user is actively dragging the panel.
     */
    void onPanelExpansionChanged(float expansion, boolean tracking);

    /**
     * Invoked whenever the QS expansion changes, at every animation frame.
     * @param expansion 0 when collapsed, 1 when expanded.
     */
    default void onQsExpansionChanged(float expansion) {};
}