/*
 * Copyright (C) 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 com.android.launcher3.taskbar;

import static com.android.systemui.shared.system.ViewTreeObserverWrapper.InsetsInfo.TOUCHABLE_INSETS_FRAME;
import static com.android.systemui.shared.system.ViewTreeObserverWrapper.InsetsInfo.TOUCHABLE_INSETS_REGION;

import android.content.Context;
import android.util.AttributeSet;
import android.widget.FrameLayout;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;

import com.android.launcher3.anim.AlphaUpdateListener;
import com.android.systemui.shared.system.ViewTreeObserverWrapper;

/**
 * Top-level ViewGroup that hosts the TaskbarView as well as Views created by it such as Folder.
 */
public class TaskbarContainerView extends FrameLayout {

    // Initialized in init.
    private TaskbarView mTaskbarView;
    private ViewTreeObserverWrapper.OnComputeInsetsListener mTaskbarInsetsComputer;

    public TaskbarContainerView(@NonNull Context context) {
        this(context, null);
    }

    public TaskbarContainerView(@NonNull Context context, @Nullable AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public TaskbarContainerView(@NonNull Context context, @Nullable AttributeSet attrs,
            int defStyleAttr) {
        this(context, attrs, defStyleAttr, 0);
    }

    public TaskbarContainerView(@NonNull Context context, @Nullable AttributeSet attrs,
            int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
    }

    protected void init(TaskbarView taskbarView) {
        mTaskbarView = taskbarView;
        mTaskbarInsetsComputer = createTaskbarInsetsComputer();
    }

    private ViewTreeObserverWrapper.OnComputeInsetsListener createTaskbarInsetsComputer() {
        return insetsInfo -> {
            if (getAlpha() < AlphaUpdateListener.ALPHA_CUTOFF_THRESHOLD) {
                // We're invisible, let touches pass through us.
                insetsInfo.touchableRegion.setEmpty();
                insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_REGION);
            } else {
                 // We're visible again, accept touches anywhere in our bounds.
                insetsInfo.setTouchableInsets(TOUCHABLE_INSETS_FRAME);
            }
        };
    }

    protected void cleanup() {
        ViewTreeObserverWrapper.removeOnComputeInsetsListener(mTaskbarInsetsComputer);
    }

    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();

        ViewTreeObserverWrapper.addOnComputeInsetsListener(getViewTreeObserver(),
                mTaskbarInsetsComputer);
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();

        cleanup();
    }
}