dynamic-layout-inspector/agent/appinspection/src/main/com/android/tools/agent/appinspection/framework/ViewExtensions.kt

/*
 * 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.tools.agent.appinspection.framework

import android.content.res.Resources
import android.graphics.Bitmap
import android.graphics.Canvas
import android.util.Log
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import com.android.tools.agent.appinspection.util.ThreadUtils
import java.util.Stack
import kotlin.math.roundToInt

fun ViewGroup.getChildren(): List<View> {
    ThreadUtils.assertOnMainThread()
    return (0 until childCount).map { i -> getChildAt(i) }
}

/**
 * Return this node's text value, if it is a kind of node that has one.
 */
fun View.getTextValue(): String? {
    if (this !is TextView) return null
    return text.toString()
}

/**
 * Return a list of this view and all its children in depth-first order
 */
fun View.flatten(): Sequence<View> {
    ThreadUtils.assertOnMainThread()

    return sequence {
        val toProcess = Stack<View>()
        toProcess.push(this@flatten)

        while (toProcess.isNotEmpty()) {
            val curr = toProcess.pop()
            yield(curr)
            if (curr is ViewGroup) {
                toProcess.addAll(curr.getChildren())
            }
        }
    }
}

/**
 * Returns true if the view is contained in a layout generated by the platform / system.
 *
 * <ul>
 *   <li>DecorView, ViewStub, AndroidComposeView, View will have a null layout
 *   <li>Layouts from the "android" namespace are from the platform
 *   <li>AppCompat will typically use an "abc_" prefix for their layout names
 * </ul>
 */
fun View.isSystemView(): Boolean {
    return try {
        val layoutId = sourceLayoutResId
        if (layoutId == 0) {
            // Programmatically added Views are treated as system views:
            return true
        }
        val namespace = resources.getResourcePackageName(layoutId)
        val name = resources.getResourceEntryName(layoutId)

        namespace == "android" || name.startsWith("abc_")
    } catch (ignored: Resources.NotFoundException) {
        false
    }
}

/**
 * Convert this view into a bitmap.
 *
 * This method may return null if the app runs out of memory trying to create it.
 */
fun View.takeScreenshot(scale: Float): Bitmap? {
    val bitmap = Bitmap.createBitmap(
        (width * scale).roundToInt(),
        (height * scale).roundToInt(),
        Bitmap.Config.RGB_565
    )
    return try {
        val canvas = Canvas(bitmap)
        canvas.scale(scale, scale)
        ThreadUtils.runOnMainThread { draw(canvas) }.get()
        bitmap
    } catch (e: OutOfMemoryError) {
        Log.w("ViewLayoutInspector", "Out of memory for bitmap")
        null
    }
}