feat: 优化代码

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

@@ -119,12 +119,12 @@ object ChapterProvider {
             Layout.Alignment.ALIGN_NORMAL, 1f, lineSpacingExtra, true
         )
         for (lineIndex in 0 until layout.lineCount) {
+            textPages.last().height = durY
             durY = durY + layout.getLineBottom(lineIndex) - layout.getLineTop(lineIndex)
             val textLine = TextLine(isTitle = true)
             if (durY < visibleHeight) {
                 textPages.last().textLines.add(textLine)
             } else {
-                textPages.last().height = durY
                 textPages.last().text = stringBuilder.toString()
                 stringBuilder.clear()
                 pageLines.add(textPages.last().textLines.size)
@@ -202,12 +202,12 @@ object ChapterProvider {
             Layout.Alignment.ALIGN_NORMAL, 1f, lineSpacingExtra, true
         )
         for (lineIndex in 0 until layout.lineCount) {
-            val textLine = TextLine(isTitle = false)
+            textPages.last().height = durY
             durY = durY + layout.getLineBottom(lineIndex) - layout.getLineTop(lineIndex)
+            val textLine = TextLine()
             if (durY < visibleHeight) {
                 textPages.last().textLines.add(textLine)
             } else {
-                textPages.last().height = durY
                 textPages.last().text = stringBuilder.toString()
                 stringBuilder.clear()
                 pageLines.add(textPages.last().textLines.size)

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

@@ -77,7 +77,12 @@ class ContentTextView(context: Context, attrs: AttributeSet?) : View(context, at
                 ReadBookConfig.durConfig.textColor()
             }
             textLine.textChars.forEach {
-                canvas.drawText(it.charData, it.start, textLine.lineBase, textPaint)
+                canvas.drawText(
+                    it.charData,
+                    it.start,
+                    textLine.lineBase,
+                    textPaint
+                )
                 if (it.selected) {
                     canvas.drawRect(
                         it.start,
@@ -92,11 +97,101 @@ class ContentTextView(context: Context, attrs: AttributeSet?) : View(context, at
     }
 
     private fun drawScrollPage(canvas: Canvas) {
-
+        if (pageOffset <= 0) {
+            textPage.textLines.forEach { textLine ->
+                val textPaint = if (textLine.isTitle) {
+                    ChapterProvider.titlePaint
+                } else {
+                    ChapterProvider.contentPaint
+                }
+                textPaint.color = if (textLine.isReadAloud) {
+                    context.accentColor
+                } else {
+                    ReadBookConfig.durConfig.textColor()
+                }
+                textLine.textChars.forEach {
+                    canvas.drawText(
+                        it.charData,
+                        it.start,
+                        textLine.lineBase + pageOffset,
+                        textPaint
+                    )
+                    if (it.selected) {
+                        canvas.drawRect(
+                            it.start,
+                            textLine.lineTop + pageOffset,
+                            it.end,
+                            textLine.lineBottom + pageOffset,
+                            selectedPaint
+                        )
+                    }
+                }
+            }
+            pageFactory.nextPage?.textLines?.forEach { textLine ->
+                val textPaint = if (textLine.isTitle) {
+                    ChapterProvider.titlePaint
+                } else {
+                    ChapterProvider.contentPaint
+                }
+                textPaint.color = if (textLine.isReadAloud) {
+                    context.accentColor
+                } else {
+                    ReadBookConfig.durConfig.textColor()
+                }
+                textLine.textChars.forEach {
+                    canvas.drawText(
+                        it.charData,
+                        it.start,
+                        textLine.lineBase + pageOffset + textPage.height - ChapterProvider.paddingTop,
+                        textPaint
+                    )
+                    if (it.selected) {
+                        canvas.drawRect(
+                            it.start,
+                            textLine.lineTop + pageOffset + textPage.height - ChapterProvider.paddingTop,
+                            it.end,
+                            textLine.lineBottom + pageOffset + textPage.height - ChapterProvider.paddingTop,
+                            selectedPaint
+                        )
+                    }
+                }
+            }
+        } else {
+            textPage.textLines.forEach { textLine ->
+                val textPaint = if (textLine.isTitle) {
+                    ChapterProvider.titlePaint
+                } else {
+                    ChapterProvider.contentPaint
+                }
+                textPaint.color = if (textLine.isReadAloud) {
+                    context.accentColor
+                } else {
+                    ReadBookConfig.durConfig.textColor()
+                }
+                textLine.textChars.forEach {
+                    canvas.drawText(
+                        it.charData,
+                        it.start,
+                        textLine.lineBase + pageOffset,
+                        textPaint
+                    )
+                    if (it.selected) {
+                        canvas.drawRect(
+                            it.start,
+                            textLine.lineTop + pageOffset,
+                            it.end,
+                            textLine.lineBottom + pageOffset,
+                            selectedPaint
+                        )
+                    }
+                }
+            }
+        }
     }
 
     fun onScroll(mOffset: Float) {
-        var offset = mOffset
+        if (mOffset == 0f) return
+        var offset = -mOffset
         if (offset > maxScrollOffset) {
             offset = maxScrollOffset
         } else if (offset < -maxScrollOffset) {
@@ -104,6 +199,7 @@ class ContentTextView(context: Context, attrs: AttributeSet?) : View(context, at
         }
 
         pageOffset += offset
+        invalidate()
     }
 
     fun resetPageOffset() {

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

@@ -10,11 +10,11 @@ abstract class PageFactory<DATA>(protected val dataSource: DataSource) {
 
     abstract fun moveToPrevious(): Boolean
 
-    abstract fun nextPage(): DATA?
+    abstract val nextPage: DATA?
 
-    abstract fun previousPage(): DATA?
+    abstract val prevPage: DATA?
 
-    abstract fun currentPage(): DATA?
+    abstract val currentPage: DATA?
 
     abstract fun hasNext(): Boolean
 

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

@@ -100,15 +100,15 @@ class PageView(context: Context, attrs: AttributeSet) :
 
     fun upContent(position: Int = 0) {
         if (ReadBookConfig.isScroll) {
-            curPage.setContent(pageFactory.currentPage())
+            curPage.setContent(pageFactory.currentPage)
         } else {
             when (position) {
-                -1 -> prevPage.setContent(pageFactory.previousPage())
-                1 -> nextPage.setContent(pageFactory.nextPage())
+                -1 -> prevPage.setContent(pageFactory.prevPage)
+                1 -> nextPage.setContent(pageFactory.nextPage)
                 else -> {
-                    curPage.setContent(pageFactory.currentPage())
-                    nextPage.setContent(pageFactory.nextPage())
-                    prevPage.setContent(pageFactory.previousPage())
+                    curPage.setContent(pageFactory.currentPage)
+                    nextPage.setContent(pageFactory.nextPage)
+                    prevPage.setContent(pageFactory.prevPage)
                 }
             }
         }

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

@@ -52,11 +52,13 @@ class TextPageFactory(dataSource: DataSource) : PageFactory<TextPage>(dataSource
             false
     }
 
-    override fun currentPage(): TextPage? = with(dataSource) {
+    override val currentPage: TextPage?
+        get() = with(dataSource) {
         return getCurrentChapter()?.page(pageIndex)
     }
 
-    override fun nextPage(): TextPage? = with(dataSource) {
+    override val nextPage: TextPage?
+        get() = with(dataSource) {
         getCurrentChapter()?.let {
             if (pageIndex < it.pageSize() - 1) {
                 return getCurrentChapter()?.page(pageIndex + 1)?.removePageAloudSpan()
@@ -65,7 +67,8 @@ class TextPageFactory(dataSource: DataSource) : PageFactory<TextPage>(dataSource
         return getNextChapter()?.page(0)?.removePageAloudSpan()
     }
 
-    override fun previousPage(): TextPage? = with(dataSource) {
+    override val prevPage: TextPage?
+        get() = with(dataSource) {
         if (pageIndex > 0) {
             return getCurrentChapter()?.page(pageIndex - 1)?.removePageAloudSpan()
         }