DiffLineSpan.java

package com.alorma.github.ui.view;

import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Rect;
import android.text.style.LineBackgroundSpan;

/**
 * Line span used to highlight a diff change
 */
public class DiffLineSpan implements LineBackgroundSpan {
  private static Rect mTmpRect = new Rect();
  private final int color;
  private final int padding;

  public DiffLineSpan(int color, int padding) {
    this.color = color;
    this.padding = padding;
  }

  @Override
  public void drawBackground(Canvas c, Paint p, int left, int right, int top, int baseline, int bottom, CharSequence text, int start,
      int end, int lnum) {
    // expand canvas bounds by padding
    Rect clipBounds = c.getClipBounds();
    clipBounds.inset(-padding, 0);
    //c.clipRect(clipBounds, Region.Op.REPLACE);

    final int paintColor = p.getColor();
    p.setColor(color);
    mTmpRect.set(left - padding, top, right + padding, bottom);
    c.drawRect(mTmpRect, p);
    p.setColor(paintColor);
  }
}