From 370e6dc61b456e5da29a564947941d709c2ee8d2 Mon Sep 17 00:00:00 2001
From: fourtf <tf.four@gmail.com>
Date: Tue, 21 Apr 2020 20:57:16 +0200
Subject: [PATCH] fixed scrollbar thumb not moving

---
 src/widgets/Scrollbar.cpp | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/src/widgets/Scrollbar.cpp b/src/widgets/Scrollbar.cpp
index 6f4288fd5..1bc3c19cf 100644
--- a/src/widgets/Scrollbar.cpp
+++ b/src/widgets/Scrollbar.cpp
@@ -276,8 +276,7 @@ void Scrollbar::paintEvent(QPaintEvent *)
 
     int w = this->width();
     float y = 0;
-    float dY =
-        float(this->height()) / std::max<float>(1.0f, float(snapshotLength));
+    float dY = float(this->height()) / float(snapshotLength);
     int highlightHeight =
         int(std::ceil(std::max<float>(this->scale() * 2, dY)));
 
@@ -357,10 +356,10 @@ void Scrollbar::mouseMoveEvent(QMouseEvent *event)
     {
         int delta = event->pos().y() - this->lastMousePosition_.y();
 
-        setDesiredValue(
-            this->desiredValue_ +
-            qreal(delta) /
-                std::max<qreal>(0.02, this->trackHeight_ * this->maximum_));
+        setDesiredValue(this->desiredValue_ +
+                        qreal(delta) /
+                            std::max<qreal>(0.00000002, this->trackHeight_ *
+                                                            this->maximum_));
     }
 
     this->lastMousePosition_ = event->pos();
@@ -445,11 +444,14 @@ void Scrollbar::updateScroll()
     this->trackHeight_ = this->height() - this->buttonHeight_ -
                          this->buttonHeight_ - MIN_THUMB_HEIGHT - 1;
 
-    auto div = std::max<qreal>(0.01, this->maximum_ * this->trackHeight_);
+    auto div = std::max<qreal>(0.0000001, this->maximum_);
 
-    this->thumbRect_ =
-        QRect(0, int(this->currentValue_ / div) + 1 + this->buttonHeight_,
-              this->width(), int(this->largeChange_ / div) + MIN_THUMB_HEIGHT);
+    this->thumbRect_ = QRect(
+        0,
+        int(this->currentValue_ / div * this->trackHeight_) + 1 +
+            this->buttonHeight_,
+        this->width(),
+        int(this->largeChange_ / div * this->trackHeight_) + MIN_THUMB_HEIGHT);
 
     this->update();
 }