content: /*
   * Copyright (C) 2015-2023 Emanuel Moecklin
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.onegravity.rteditor.spans;
  
  import android.graphics.Canvas;
  import android.graphics.Paint;
  import android.text.Layout;
  import android.text.Spanned;
  import android.text.style.LeadingMarginSpan;
  
  /**
   * Paragraph numbering.
   * <p>
   * Android seems to add the leading margin for an empty paragraph to the previous paragraph
   * (]0, 4][4, 4] --> the leading margin of the second span is added to the ]0, 4] paragraph regardless of the Spanned.flags)
   * --> therefore we ignore the leading margin for the last, empty paragraph unless it's the only one
   */
  public class NumberSpan extends BaseListItemSpan implements LeadingMarginSpan, RTSpan<Boolean>, RTParagraphSpan<Boolean> {
  
      private final int mNr;
      private final int mGapWidth;
      private final boolean mIgnoreSpan;
  
      private float mWidth;
  
      public NumberSpan(int nr, int gapWidth, boolean isEmpty, boolean isFirst, boolean isLast) {
          mNr = nr;
          mGapWidth = gapWidth;
          mIgnoreSpan = isEmpty && isLast && !isFirst;
      }
  
      private NumberSpan(int nr, int gapWidth, boolean ignoreSpan) {
          mNr = nr;
          mGapWidth = gapWidth;
          mIgnoreSpan = ignoreSpan;
      }
  
      @Override
      public int getLeadingMargin(boolean first) {
          return mIgnoreSpan ? 0 : Math.max(Math.round(mWidth + 2), mGapWidth);
      }
  
      @Override
      public void drawLeadingMargin(Canvas c, Paint p, int x, int dir, int top, int baseline, int bottom,
                                    CharSequence text, int start, int end, boolean first, Layout l) {
  
          Spanned spanned = (Spanned) text;
          if (!mIgnoreSpan && spanned.getSpanStart(this) == start) {
              // set paint
              Paint.Style oldStyle = p.getStyle();
              float oldTextSize = p.getTextSize();
              p.setStyle(Paint.Style.FILL);
              float textSize = determineTextSize(spanned, start, end, oldTextSize);
              p.setTextSize(textSize);
              mWidth = p.measureText(mNr + ".");
  
              // draw the number
              c.drawText(mNr + ".", x, baseline, p);
  
              // restore paint
              p.setStyle(oldStyle);
              p.setTextSize(oldTextSize);
          }
      }
  
      @Override
      public Boolean getValue() {
          return Boolean.TRUE;
      }
  
      @Override
      public NumberSpan createClone() {
          return new NumberSpan(mNr, mGapWidth, mIgnoreSpan);
      }
  
  }
  