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.effects;
  
  import android.text.Layout;
  import android.text.Layout.Alignment;
  import android.text.Spannable;
  
  import com.onegravity.rteditor.RTEditText;
  import com.onegravity.rteditor.spans.AlignmentSpan;
  import com.onegravity.rteditor.spans.RTSpan;
  import com.onegravity.rteditor.utils.Helper;
  import com.onegravity.rteditor.utils.Paragraph;
  import com.onegravity.rteditor.utils.Selection;
  
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Left, Center, Right alignment.
   * <p>
   * AlignmentSpans are always applied to whole paragraphs and each paragraphs gets its "own" AlignmentSpan (1:1).
   * Editing might violate this rule (deleting a line feed merges two paragraphs).
   * Each call to applyToSelection will again make sure that each paragraph has again its own AlignmentSpan
   * (call applyToSelection(RTEditText, null, null) and all will be good again).
   */
  public class AlignmentEffect extends ParagraphEffect<Layout.Alignment, AlignmentSpan> {
  
      private ParagraphSpanProcessor<Layout.Alignment> mSpans2Process = new ParagraphSpanProcessor();
  
      @Override
      public void applyToSelection(RTEditText editor, Selection selectedParagraphs, Layout.Alignment alignment) {
          final Spannable str = editor.getText();
  
          mSpans2Process.clear();
  
          // a manual for loop is faster than the for-each loop for an ArrayList:
          // see https://developer.android.com/training/articles/perf-tips.html#Loops
          ArrayList<Paragraph> paragraphs = editor.getParagraphs();
          for (int i = 0, size = paragraphs.size(); i < size; i++) {
              Paragraph paragraph = paragraphs.get(i);
  
              // find existing AlignmentSpan and add them to mSpans2Process to be removed
              List<RTSpan<Layout.Alignment>> existingSpans = getSpans(str, paragraph, SpanCollectMode.SPAN_FLAGS);
              mSpans2Process.removeSpans(existingSpans, paragraph);
  
              // if the paragraph is selected then we sure have an alignment
              boolean hasExistingSpans = !existingSpans.isEmpty();
              Alignment newAlignment = paragraph.isSelected(selectedParagraphs) ? alignment :
                                       hasExistingSpans ? existingSpans.get(0).getValue() : null;
  
              if (newAlignment != null) {
                  boolean isRTL = Helper.isRTL(str, paragraph.start(), paragraph.end());
                  AlignmentSpan alignmentSpan = new AlignmentSpan(newAlignment, isRTL);
                  mSpans2Process.addSpan(alignmentSpan, paragraph);
              }
          }
  
          // add or remove spans
          mSpans2Process.process(str);
      }
  
  }
  