优化

app/src/main/java/io/legado/app/help/book/ContentProcessor.kt

@@ -1,5 +1,6 @@
 package io.legado.app.help.book
 
+import android.os.Build
 import io.legado.app.constant.AppLog
 import io.legado.app.constant.AppPattern.spaceRegex
 import io.legado.app.data.appDb
@@ -27,6 +28,7 @@ class ContentProcessor private constructor(
 
     companion object {
         private val processors = hashMapOf<String, WeakReference<ContentProcessor>>()
+        private val isAndroid8 = Build.VERSION.SDK_INT in 26..27
 
         fun get(book: Book) = get(book.name, book.origin)
 
@@ -182,6 +184,9 @@ class ContentProcessor private constructor(
                 useReplace = useReplace && book.getUseReplaceRule()
             ) + "\n" + mContent
         }
+        if (isAndroid8) {
+            mContent = mContent.replace('\u00A0', ' ')
+        }
         val contents = arrayListOf<String>()
         mContent.split("\n").forEach { str ->
             val paragraph = str.trim {

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

@@ -215,7 +215,9 @@ data class TextLine(
         if (exceed || !onlyTextColumn || textPage.isMsgPage) {
             return false
         }
-        if (!atLeastApi29 && wordSpacing != 0f) {
+        if (!atLeastApi26 && wordSpacing != 0f) {
+            return false
+        } else if (!wordSpacingWorking) {
             return false
         }
         return searchResultColumnCount == 0
@@ -234,9 +236,20 @@ data class TextLine(
         canvasRecorder.recycle()
     }
 
+    @SuppressLint("NewApi")
     companion object {
         val emptyTextLine = TextLine()
-        private val atLeastApi29 = Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q
+        private val atLeastApi26 = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O
+        private val wordSpacingWorking by lazy {
+            // issue 3785
+            val paint = PaintPool.obtain()
+            val text = "一二 三"
+            val width1 = paint.measureText(text)
+            paint.wordSpacing = 10f
+            val width2 = paint.measureText(text)
+            PaintPool.recycle(paint)
+            width2 - width1 == 10f
+        }
     }
 
 }

app/src/main/java/io/legado/app/ui/book/read/page/provider/ChapterProvider.kt

@@ -23,7 +23,6 @@ import io.legado.app.ui.book.read.page.entities.TextPage
 import io.legado.app.ui.book.read.page.entities.column.ImageColumn
 import io.legado.app.ui.book.read.page.entities.column.ReviewColumn
 import io.legado.app.ui.book.read.page.entities.column.TextColumn
-import io.legado.app.utils.LogUtils
 import io.legado.app.utils.RealPathUtil
 import io.legado.app.utils.dpToPx
 import io.legado.app.utils.fastSum
@@ -817,9 +816,6 @@ object ChapterProvider {
         titleBottomSpacing = ReadBookConfig.titleBottomSpacing.dpToPx()
         val bodyIndent = ReadBookConfig.paragraphIndent
         indentCharWidth = StaticLayout.getDesiredWidth(bodyIndent, contentPaint) / bodyIndent.length
-        LogUtils.d("ChapterProvider") {
-            "bodyIndentLength:${bodyIndent.length} indentCharWidth:$indentCharWidth"
-        }
         titlePaintTextHeight = titlePaint.textHeight
         contentPaintTextHeight = contentPaint.textHeight
         titlePaintFontMetrics = titlePaint.fontMetrics
@@ -889,17 +885,9 @@ object ChapterProvider {
         //正文
         val cPaint = TextPaint()
         cPaint.color = ReadBookConfig.textColor
-        cPaint.letterSpacing = ReadBookConfig.letterSpacing.also {
-            LogUtils.d("ChapterProvider") {
-                "ReadBookConfig.letterSpacing:$it"
-            }
-        }
+        cPaint.letterSpacing = ReadBookConfig.letterSpacing
         cPaint.typeface = textFont
-        cPaint.textSize = ReadBookConfig.textSize.toFloat().spToPx().also {
-            LogUtils.d("ChapterProvider") {
-                "ReadBookConfig.textSize:$it"
-            }
-        }
+        cPaint.textSize = ReadBookConfig.textSize.toFloat().spToPx()
         cPaint.isAntiAlias = true
         cPaint.isLinearText = true
         return Pair(tPaint, cPaint)

app/src/main/java/io/legado/app/ui/book/read/page/provider/TextChapterLayout.kt

@@ -21,7 +21,6 @@ import io.legado.app.ui.book.read.page.entities.TextPage
 import io.legado.app.ui.book.read.page.entities.column.ImageColumn
 import io.legado.app.ui.book.read.page.entities.column.ReviewColumn
 import io.legado.app.ui.book.read.page.entities.column.TextColumn
-import io.legado.app.utils.LogUtils
 import io.legado.app.utils.dpToPx
 import io.legado.app.utils.fastSum
 import io.legado.app.utils.splitNotBlank
@@ -30,8 +29,6 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.ensureActive
 import kotlinx.coroutines.launch
-import kotlinx.coroutines.sync.Mutex
-import kotlinx.coroutines.sync.withLock
 import java.util.LinkedList
 import java.util.Locale
 import kotlin.coroutines.coroutineContext
@@ -84,19 +81,13 @@ class TextChapterLayout(
 
     var channel = Channel<TextPage>(Int.MAX_VALUE)
 
-    companion object {
-        val lock = Mutex()
-    }
-
     init {
         job = Coroutine.async(scope) {
             launch {
                 val bookSource = book.getBookSource() ?: return@launch
                 BookHelp.saveImages(bookSource, book, bookChapter, bookContent.toString())
             }
-            lock.withLock {
-                getTextChapter(book, bookChapter, displayTitle, bookContent)
-            }
+            getTextChapter(book, bookChapter, displayTitle, bookContent)
         }.onError {
             exception = it
             onException(it)
@@ -659,20 +650,7 @@ class TextChapterLayout(
             val gapCount: Int = words.lastIndex
             val d = residualWidth / gapCount
             textLine.extraLetterSpacingOffsetX = -d / 2
-            val textSize = textPaint.textSize
-            textLine.extraLetterSpacing = d / textSize
-            LogUtils.d("TextChapterLayout") {
-                "words:${words.joinToString("")}"
-            }
-            LogUtils.d("TextChapterLayout") {
-                "textWidths(${textWidths.fastSum()}):$textWidths"
-            }
-            LogUtils.d("TextChapterLayout") {
-                "textSize:$textSize desiredWidth:$desiredWidth residualWidth:$residualWidth " +
-                        "gapCount:$gapCount d:$d " +
-                        "extraLetterSpacingOffsetX:${textLine.extraLetterSpacingOffsetX} " +
-                        "extraLetterSpacing:${textLine.extraLetterSpacing}"
-            }
+            textLine.extraLetterSpacing = d / textPaint.textSize
             var x = startX
             for (index in words.indices) {
                 val char = words[index]