keyboard-height/lib/android.js

calaculate the height of soft keyboard in mobile phone and emit on changes

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true,
});
exports.default = _default;
exports.getAndroidHeight = getAndroidHeight;
exports.getAndroidInnerHight = getAndroidInnerHight;

/**
 * android 下用 innerHeight 对于新开 tab 会有问题，会把上面的导航条也算进去, toolbar 大约在 150 px 以内
 * 即便在 DCL 下获取，也是有问题的，我们尝试在 1s 内轮训获取真实的 innerHeight
 * 同时要避免 autoFocus 导致页面刚打开就谈键盘，引起计算 bug，同理，部分键盘上有刷新按钮，导致页面刚打开的 innerHeight 就不对
 */
var initialHeight = innerHeight;
var realInnerHeight = innerHeight; // 键盘未弹起时的高度

function reset() {
  initialHeight = innerHeight;
  realInnerHeight = innerHeight;
}

var lastScreenHeight = screen.height; // 用于探测是否旋转屏幕，只要是容器变了都算

var maxCheckTime = 10;
var toolbarMaxSize = 150;
var checkCnt = 0;

var callback = function callback() {};

var intval = setInterval(function () {
  checkCnt++;
  if (checkCnt > maxCheckTime) clearInterval(intval);
  else {
    var currentInnerHeight = innerHeight;
    if (initialHeight - currentInnerHeight > toolbarMaxSize) return; // 可能键盘已经弹起

    if (realInnerHeight === currentInnerHeight) return; // 无变化

    realInnerHeight = currentInnerHeight; // 通知

    callback();
  }
}, 100);

function isOrientationChanged() {
  var changed = false;
  if (!isSame(lastScreenHeight, screen.height)) {
    changed = true;
    lastScreenHeight = screen.height;
  }
  return changed;
}

function isSame(a, b) {
  return Math.abs(a - b) < 0.01;
}

var lastHeight = -1;

function _default(cbArr) {
  [];

  callback = function callback() {
    if (isOrientationChanged()) {
      reset();
      if (lastHeight > 0) realInnerHeight = innerHeight + lastHeight;
    } else {
      var delta = getAndroidHeight();
      if (isSame(delta, lastHeight)) return;
      lastHeight = delta;
      cbArr.forEach(function (cb) {
        cb.call(null, lastHeight);
      });
    }
  };

  window.addEventListener("resize", callback);
}

function getAndroidHeight() {
  var currentInnerHeight = innerHeight;
  if (currentInnerHeight > realInnerHeight && checkCnt >= maxCheckTime)
    realInnerHeight = currentInnerHeight;
  return realInnerHeight - currentInnerHeight;
}

function getAndroidInnerHight() {
  return realInnerHeight;
}