private async void LoadNextChapter()
{
if (currentChapterIndex == null)
{
return;
}
ChapterNavigationItem nextChapter = null;
try
{
var currentMainChapter = chapterList[currentChapterIndex ?? 0];
nextChapter = currentMainChapter.SubChapters.ElementAtOrDefault((currentChapterIndex ?? 0) + 1);
if (nextChapter == null)
{
var nextMainChapter = chapterList.ElementAtOrDefault((currentChapterIndex ?? 0) + 1);
nextChapter = nextMainChapter?.SubChapters?.FirstOrDefault();
if (nextChapter == null)
{
nextChapter = nextMainChapter;
}
}
}
catch { }
if (nextChapter != null)
{
await LoadChapterAsync(nextChapter, true);
}
}
private static List <ChapterNavigationItem> FindChapterList(XElement root)
{
var elements = root.Elements().Where(d => d.Name.LocalName == "navPoint");
var chapterList = new List <ChapterNavigationItem>();
foreach (var element in elements)
{
var chapterElements = element.Elements();
var chapterElement = chapterElements.FirstOrDefault(d => d.Name.LocalName == "navLabel");
var chapterTitle = chapterElement.Elements().FirstOrDefault(d => d.Name.LocalName == "text")?.Value;
var chapterSrcElement = chapterElements.FirstOrDefault(d => d.Name.LocalName == "content");
var chapterSrc = chapterSrcElement.Attributes().FirstOrDefault(a => a.Name == "src")?.Value;
var chapter = new ChapterNavigationItem
{
Text = chapterTitle,
Src = chapterSrc,
SubChapters = FindChapterList(element)
};
chapterList.Add(chapter);
}
return(chapterList);
}
private async Task LoadChapterAsync(ChapterNavigationItem chapter, bool forceReload = false)
{
var link = chapter.Src.Split("#");
var src = link[0];
var anchor = link.Length > 1 ? link[1] : string.Empty;
if (loadedSrc != src || forceReload)
{
var url = book.GetChapterUrl(src);
webView.LoadUrl(url);
loadedSrc = src;
}
if (!string.IsNullOrEmpty(anchor))
{
webView.ScrollToAnchor(anchor);
}
else
{
webView.ScrollToTop();
}
var chapterIndex = chapterList.IndexOf(chapter);
if (chapterIndex >= 0)
{
currentChapterIndex = chapterIndex;
currentSubChapterIndex = null;
}
else
{
var mainChapter = chapterList.FirstOrDefault(c => c.SubChapters != null && c.SubChapters.Contains(chapter));
if (mainChapter == null)
{
return;
}
currentChapterIndex = chapterList.IndexOf(mainChapter);
currentSubChapterIndex = mainChapter.SubChapters.IndexOf(chapter);
}
}
