From e57a981406d744e825f093fa5a41c690df24a3aa Mon Sep 17 00:00:00 2001
From: kunfei <gekunfei@live.com>
Date: Wed, 19 Feb 2020 15:18:00 +0800
Subject: [PATCH] =?UTF-8?q?feat:=20=E4=BC=98=E5=8C=96=E4=BB=A3=E7=A0=81?=
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---
 .../page/delegate/SimulationPageDelegate.kt   | 50 +++++++++++--------
 1 file changed, 30 insertions(+), 20 deletions(-)

diff --git a/app/src/main/java/io/legado/app/ui/book/read/page/delegate/SimulationPageDelegate.kt b/app/src/main/java/io/legado/app/ui/book/read/page/delegate/SimulationPageDelegate.kt
index 6e9050b07..a0702a6c9 100644
--- a/app/src/main/java/io/legado/app/ui/book/read/page/delegate/SimulationPageDelegate.kt
+++ b/app/src/main/java/io/legado/app/ui/book/read/page/delegate/SimulationPageDelegate.kt
@@ -138,27 +138,37 @@ class SimulationPageDelegate(pageView: PageView) : HorizontalPageDelegate(pageVi
     }
 
     override fun onScrollStart() {
-        val distanceX: Float
-        when (mDirection) {
-            Direction.NEXT -> distanceX =
-                if (isCancel) {
-                    var dis = viewWidth - startX + touchX
-                    if (dis > viewWidth) {
-                        dis = viewWidth.toFloat()
-                    }
-                    viewWidth - dis
-                } else {
-                    -(touchX + (viewWidth - startX))
-                }
-            else -> distanceX =
-                if (isCancel) {
-                    -(touchX - startX)
-                } else {
-                    viewWidth - (touchX - startX)
-                }
+        var dx: Float
+        val dy: Float
+        // dx 水平方向滑动的距离，负值会使滚动向左滚动
+        // dy 垂直方向滑动的距离，负值会使滚动向上滚动
+        if (isCancel) {
+            dx = if (mCornerX > 0 && mDirection == Direction.NEXT) {
+                (viewWidth - touchX)
+            } else {
+                -touchX
+            }
+            if (mDirection != Direction.NEXT) {
+                dx = -(viewWidth + touchX)
+            }
+            dy = if (mCornerY > 0) {
+                (viewHeight - touchY)
+            } else {
+                -touchY // 防止mTouchY最终变为0
+            }
+        } else {
+            dx = if (mCornerX > 0 && mDirection == Direction.NEXT) {
+                -(viewWidth + touchX)
+            } else {
+                (viewWidth - touchX + viewWidth)
+            }
+            dy = if (mCornerY > 0) {
+                (viewHeight - touchY)
+            } else {
+                (1 - touchY) // 防止mTouchY最终变为0
+            }
         }
-
-        startScroll(touchX.toInt(), 0, distanceX.toInt(), 0)
+        startScroll(touchX.toInt(), touchY.toInt(), dx.toInt(), dy.toInt())
     }
 
     override fun onScrollStop() {