Android4.4 为什么有的window设置SIM为adjustPan不起作用？？

android:gravity="center_horizontal"的EditText为什么设置了adjustPan之后不能调整View的位置。

今天遇到一个问题，当这个edittext同时设置        android:gravity="center_horizontal"      android:singleLine="true"这两个属性时会导致当 edittext第二次呼出输入法的时候，整个window不能adjust..

1》先附上 TestDemo的Layout如下：

2》解答：这个问题经过分析是android4.4 TextView的一个共性的bug.

center_horizontal的TextView的宽度在计算时得到了一个超大的数，详见下述方法的最后一个else.

    public float getLineRight(int line) {
        int dir = getParagraphDirection(line);
        Alignment align = getParagraphAlignment(line);

        if (align == Alignment.ALIGN_LEFT) {
            return getParagraphLeft(line) + getLineMax(line);
        } else if (align == Alignment.ALIGN_NORMAL) {
            if (dir == DIR_RIGHT_TO_LEFT)
                return mWidth;
            else
                return getParagraphLeft(line) + getLineMax(line);
        } else if (align == Alignment.ALIGN_RIGHT) {
            return mWidth;
        } else if (align == Alignment.ALIGN_OPPOSITE) {
            if (dir == DIR_RIGHT_TO_LEFT)
                return getLineMax(line);
            else
                return mWidth;
        } else { /* align == Alignment.ALIGN_CENTER */
            int left = getParagraphLeft(line);
            int right = getParagraphRight(line);
            int max = ((int) getLineMax(line)) & ~1;

            return right - ((right - left) - max) / 2;
        }
    }

而ViewRootImpl在呼出输入法需要findFocus对应的TextView,然后TextView在计算需要偏移的Rect的时候（getFocusedRect）失败。。(详见下述方法）

    @Override
    public void getFocusedRect(Rect r) {
        if (mLayout == null) {
            super.getFocusedRect(r);
            return;
        }

        int selEnd = getSelectionEnd();
        if (selEnd < 0) {
            super.getFocusedRect(r);
            return;
        }

        int selStart = getSelectionStart();
        if (selStart < 0 || selStart >= selEnd) {
            int line = mLayout.getLineForOffset(selEnd);
            r.top = mLayout.getLineTop(line);
            r.bottom = mLayout.getLineBottom(line);
            r.left = (int) mLayout.getPrimaryHorizontal(selEnd) - 2;
            r.right = r.left + 4;
        } else {
            int lineStart = mLayout.getLineForOffset(selStart);
            int lineEnd = mLayout.getLineForOffset(selEnd);
            r.top = mLayout.getLineTop(lineStart);
            r.bottom = mLayout.getLineBottom(lineEnd);
            if (lineStart == lineEnd) {
                r.left = (int) mLayout.getPrimaryHorizontal(selStart);
                r.right = (int) mLayout.getPrimaryHorizontal(selEnd);
            } else {
                // Selection extends across multiple lines -- make the focused
                // rect cover the entire width.
                if (mHighlightPathBogus) {
                    if (mHighlightPath == null) mHighlightPath = new Path();
                    mHighlightPath.reset();
                    mLayout.getSelectionPath(selStart, selEnd, mHighlightPath);
                    mHighlightPathBogus = false;
                }
                synchronized (TEMP_RECTF) {
                    mHighlightPath.computeBounds(TEMP_RECTF, true);
                    r.left = (int)TEMP_RECTF.left-1;
                    r.right = (int)TEMP_RECTF.right+1;
                }
            }
        }

        // Adjust for padding and gravity.
        int paddingLeft = getCompoundPaddingLeft();
        int paddingTop = getExtendedPaddingTop();
        if ((mGravity & Gravity.VERTICAL_GRAVITY_MASK) != Gravity.TOP) {
            paddingTop += getVerticalOffset(false);
        }
        r.offset(paddingLeft, paddingTop);
        int paddingBottom = getExtendedPaddingBottom();
        r.bottom += paddingBottom;
    }