Merge pull request #2088 from 821938089/fix-textpage-layout-update

修复文字居中显示的页面在旋转屏幕时文字布局不更新的bug

app/src/main/java/io/legado/app/ui/book/read/page/entities/TextPage.kt

@@ -26,6 +26,7 @@ data class TextPage(
 
     val lineSize get() = textLines.size
     val charSize get() = text.length
+    var isMsgPage: Boolean = false
 
     fun getLine(index: Int): TextLine {
         return textLines.getOrElse(index) {
@@ -78,7 +79,9 @@ data class TextPage(
 
     @Suppress("DEPRECATION")
     fun format(): TextPage {
-        if (textLines.isEmpty() && ChapterProvider.viewWidth > 0) {
+        if (textLines.isEmpty()) isMsgPage = true
+        if (isMsgPage && ChapterProvider.viewWidth > 0) {
+            textLines.clear()
             val visibleWidth = ChapterProvider.visibleRight - ChapterProvider.paddingLeft
             val layout = StaticLayout(
                 text, ChapterProvider.contentPaint, visibleWidth,