android 关于软键盘遮挡webView底部输入框问题（解决方案）

软键盘挡住了输入框这个坑      填坑方法：来吧，小伙伴们  keyboarder，多亏我的名字了

为什么说它是个坑？"issue 5497"

上面表格的这种情况并非是Google所期望的，理想的情况当然是它们都能正常生效才对——所以这其实是Android系统本身的一个BUG。

为什么文章开头说这是个坑呢？
——因为这个BUG从Android1.x时代（2009年）就被报告了，而一直到了如今的Android7.0（2016年）还是没有修复……/(ㄒoㄒ)/
可以说这不仅是个坑，而且还是个官方挖的坑~

"issue 5497"，详情传送门 ☞ Issue 5497 - android -WebView adjustResize windowSoftInputMode breaks when activity is fullscreen - Android Open Source Project - Issue Tracker - Google Project Hosting

当然了，不管坑是谁挖的，最终还是要开发者来解决。

遇到坑之后，有两种方法可以过去：躲，或者填。

public static void assistActivity(Activity activity) {
    new AndroidBug5497Workaround(activity);
}

private View mChildOfContent;
private int usableHeightPrevious;
private FrameLayout.LayoutParams frameLayoutParams;

private AndroidBug5497Workaround(Activity activity) {
    FrameLayout content = (FrameLayout) activity.findViewById(android.R.id.content);
    mChildOfContent = content.getChildAt(0);
    mChildOfContent.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
        public void onGlobalLayout() {
            possiblyResizeChildOfContent();
        }
    });
    frameLayoutParams = (FrameLayout.LayoutParams) mChildOfContent.getLayoutParams();
}

private void possiblyResizeChildOfContent() {
    int usableHeightNow = computeUsableHeight();
    if (usableHeightNow != usableHeightPrevious) {
        int usableHeightSansKeyboard = mChildOfContent.getRootView().getHeight();
        int 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 int computeUsableHeight() {
    Rect r = new Rect();
    mChildOfContent.getWindowVisibleDisplayFrame(r);
    return (r.bottom - r.top);// 全屏模式下： return r.bottom
}

AndroidBug5497Workaround.assistActivity(this);