webView 键盘遮挡输入框处理

package com.hconline.iso.uicore.utils

import android.app.Activity
import android.graphics.Rect
import android.os.Build
import android.provider.Settings
import android.util.Log
import android.view.View
import android.view.WindowManager
import android.widget.FrameLayout

/**
 * webView 键盘遮挡输入框处理
 * 适用于 全屏/非全屏/有底部导航栏/无底部导航栏
 */
class WebViewKeyBoardListener(
    private val activity: Activity
) {
    private var mChildOfContent: View? = null
    private var usableHeightPrevious: Int = 0
    private var frameLayoutParams: FrameLayout.LayoutParams? = null


    fun init() {
        val content = activity
            .findViewById<View>(android.R.id.content) as FrameLayout
        mChildOfContent = content.getChildAt(0)
        mChildOfContent!!.viewTreeObserver.addOnGlobalLayoutListener { possiblyResizeChildOfContent() }
        frameLayoutParams = mChildOfContent!!
            .layoutParams as FrameLayout.LayoutParams
    }

    private fun possiblyResizeChildOfContent() {
        val usableHeightNow = computeUsableHeight()
        if (usableHeightNow != usableHeightPrevious) {
            val usableHeightSansKeyboard = mChildOfContent!!.rootView
                .height - getNavHeight()
            val heightDifference = usableHeightSansKeyboard - usableHeightNow
            if (heightDifference > usableHeightSansKeyboard / 4) {
                // keyboard probably just became visible
                frameLayoutParams!!.height = usableHeightSansKeyboard - heightDifference
            } else {
                // keyboard probably just became hidden
                frameLayoutParams!!.height = usableHeightSansKeyboard
            }
            mChildOfContent!!.requestLayout()
            usableHeightPrevious = usableHeightNow
        }
    }


    private fun computeUsableHeight(): Int {
        val r = Rect()
        mChildOfContent!!.getWindowVisibleDisplayFrame(r)
        return r.bottom - r.top
    }


    private fun getNavHeight(): Int {
        val resources = activity.resources
        val resourceId = resources.getIdentifier("navigation_bar_height", "dimen", "android");
        if (resourceId > 0) {
            //判断底部导航栏是否为显示状态
            val navigationBarShowing = isNavigationBarShowing()
            if (navigationBarShowing) {
                val height = resources.getDimensionPixelSize(resourceId)
                return height
            }
        }
        return 0
    }

    private fun isNavigationBarShowing(): Boolean {
        //判断手机底部是否支持导航栏显示
        val haveNavigationBar = checkDeviceHasNavigationBar()
        if (haveNavigationBar) {
            if (Build.VERSION.SDK_INT >= 17) {
                val brand = Build.BRAND
                val mDeviceInfo = when {
                    brand.toUpperCase() == "HUAWEI" -> "navigationbar_is_min"
                    brand.toUpperCase() == "XIAOMI" -> "force_fsg_nav_bar"
                    brand.toUpperCase() == "VIVO" -> "navigation_gesture_on"
                    brand.toUpperCase() == "OPPO" -> "navigation_gesture_on"
                    else -> "navigationbar_is_min"
                }
                //是否全屏
                val isFullScree =
                    (activity.window.attributes.flags and WindowManager.LayoutParams.FLAG_FULLSCREEN) == WindowManager.LayoutParams.FLAG_FULLSCREEN
                if (Settings.Global.getInt(
                        activity.contentResolver,
                        mDeviceInfo,
                        0
                    ) == 0 && !isFullScree
                ) {
                    return true
                }
            }
        }
        return false
    }

    private fun checkDeviceHasNavigationBar(): Boolean {
        var hasNavigationBar = false
        val rs = activity.resources
        val id = rs.getIdentifier("config_showNavigationBar", "bool", "android")
        if (id > 0) {
            hasNavigationBar = rs.getBoolean(id)
        }
        try {
            val systemPropertiesClass = Class.forName("android.os.SystemProperties");
            val m = systemPropertiesClass.getMethod("get", String::class.java)
            val navBarOverride = m.invoke(systemPropertiesClass, "qemu.hw.mainkeys") as String
            if ("1" == navBarOverride) {
                hasNavigationBar = false
            } else if ("0" == navBarOverride) {
                hasNavigationBar = true
            }
        } catch (e: Exception) {
            e.printStackTrace()
        }
        return hasNavigationBar
    }


    companion object {

        fun getInstance(activity: Activity): WebViewKeyBoardListener {
            val keyBoardListener = WebViewKeyBoardListener(activity)
            return keyBoardListener
        }
    }
}