android.text.Layout#getLineAscent ( )源码实例Demo

/**
 * Prior to version 20, If the Layout specifies extra space between lines (either by spacingmult
 * or spacingadd) the StaticLayout would erroneously add this space after the last line as well.
 * This bug was fixed in version 20. This method calculates the extra space and reduces the height
 * by that amount.
 *
 * @param layout The layout.
 * @return The height of the layout.
 */
public static int getHeight(Layout layout) {
  if (layout == null) {
    return 0;
  }

  int extra = 0;
  if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT_WATCH
      && layout instanceof StaticLayout) {
    int line = Math.max(0, layout.getLineCount() - 1);
    int above = layout.getLineAscent(line);
    int below = layout.getLineDescent(line);
    float originalSize = (below - above - layout.getSpacingAdd()) / layout.getSpacingMultiplier();
    float ex = below - above - originalSize;
    if (ex >= 0) {
      extra = (int) (ex + 0.5);
    } else {
      extra = -(int) (-ex + 0.5);
    }
  }
  return layout.getHeight() - extra;
}
 

/**
 * @param line   - current line
 * @param column - column of line
 * @return Position (in pixels) for edittext at line and column
 */
public Point getDebugPosition(int line, int column, int gravity) {
    Layout layout = getLayout();
    if (layout != null) {
        int pos = layout.getLineStart(line) + column;

        int baseline = layout.getLineBaseline(line);
        int ascent = layout.getLineAscent(line);

        int offsetHorizontal = (int) layout.getPrimaryHorizontal(pos) + mLinePadding; //x

        float y;
        int offsetVertical = 0;

        if (gravity == Gravity.BOTTOM) {
            y = baseline + ascent;
            if (verticalScroll != null) {
                offsetVertical = (int) ((y + mCharHeight) - verticalScroll.getScrollY());
            } else {
                offsetVertical = (int) ((y + mCharHeight) - getScrollY());
            }
            return new Point(offsetHorizontal, offsetVertical);
        } else if (gravity == Gravity.TOP) {
            y = layout.getLineTop(line);
            if (verticalScroll != null) {
                offsetVertical = (int) (y - verticalScroll.getScrollY());
            } else {
                offsetVertical = (int) (y - getScrollY());
            }
            return new Point(offsetHorizontal, offsetVertical);
        }

        return new Point(offsetHorizontal, offsetVertical);
    }
    return new Point();
}
 

@Override
public void onPopupChangePosition() {
    try {
        Layout layout = getLayout();
        if (layout != null) {
            int pos = getSelectionStart();
            int line = layout.getLineForOffset(pos);
            int baseline = layout.getLineBaseline(line);
            int ascent = layout.getLineAscent(line);

            float x = layout.getPrimaryHorizontal(pos);
            float y = baseline + ascent;

            int offsetHorizontal = (int) x + mLinePadding;
            setDropDownHorizontalOffset(offsetHorizontal);

            int heightVisible = getHeightVisible();
            int offsetVertical = 0;
            if (verticalScroll != null) {
                offsetVertical = (int) ((y + mCharHeight) - verticalScroll.getScrollY());
            } else {
                offsetVertical = (int) ((y + mCharHeight) - getScrollY());
            }

            int tmp = offsetVertical + getDropDownHeight() + mCharHeight;
            if (tmp < heightVisible) {
                tmp = offsetVertical + mCharHeight / 2;
                setDropDownVerticalOffset(tmp);
            } else {
                tmp = offsetVertical - getDropDownHeight() - mCharHeight;
                setDropDownVerticalOffset(tmp);
            }
        }
    } catch (Exception ignored) {
    }
}
 

protected void onPopupChangePosition() {
        try {
            Layout layout = getLayout();
            if (layout != null) {

                int pos = getSelectionStart();
                int line = layout.getLineForOffset(pos);
                int baseline = layout.getLineBaseline(line);
                int ascent = layout.getLineAscent(line);

                Rect bounds = new Rect();
                Paint textPaint = getPaint();
                String sample="A";
                textPaint.getTextBounds(sample, 0, sample.length(), bounds);
                int width = bounds.width()/sample.length();


                float x = layout.getPrimaryHorizontal(pos);
                float y = baseline + ascent;

                int offsetHorizontal = (int) x + mGutterWidth;
                setDropDownHorizontalOffset(offsetHorizontal);

                int heightVisible = getHeightVisible();
                int offsetVertical = (int) ((y + mCharHeight) - getScrollY());

                int tmp = offsetVertical + getDropDownHeight() + mCharHeight;
                //if (tmp < heightVisible) {
                    tmp = -h + ((offsetVertical*2 / (mCharHeight)) * (mCharHeight / 2))+(mCharHeight/2);
                    setDropDownVerticalOffset(tmp);
                    //((Activity)(mContext)).setTitle("ov :"+offsetVertical +" ch "+mCharHeight+" tmp"+tmp +"h "+h+"p:"+pos);
//                } else {
//                    tmp = offsetVertical - getDropDownHeight() - mCharHeight;
//                    setDropDownVerticalOffset(tmp);
//                    ((Activity)(mContext)).setTitle(" 2 tmp :"+tmp);
//                }


//                int pos = getSelectionStart();
//                int line = layout.getLineForOffset(pos);
//                int baseline = layout.getLineBaseline(line);
//                int ascent = layout.getLineAscent(line);
//
//                float x = layout.getPrimaryHorizontal(pos);
//                float y = baseline + ascent;
//
//                int offsetHorizontal = (int) x + mGutterWidth;
//                setDropDownHorizontalOffset(offsetHorizontal);
//
//                //    int heightVisible = getHeightVisible();
//                int offsetVertical = (int) ((y + mCharHeight) - getScrollY());
//
//                int tmp = offsetVertical + getDropDownHeight() + mCharHeight;
////                if (tmp < heightVisible) {
//                tmp = -(offsetVertical + mCharHeight) + ((offsetVertical / mCharHeight) * (mCharHeight / 2));
//                setDropDownVerticalOffset(tmp);
////                } else {
////                    tmp = offsetVertical - getDropDownHeight() - mCharHeight;
////                    setDropDownVerticalOffset(tmp);
////                }

            }
        } catch (Exception e) {
            Logger.error(TAG, e);
        }
    }