From 6fb7183006cbca1808983bf386b9d86bc316edbe Mon Sep 17 00:00:00 2001
From: laserpants <johannes@isomorphic.co>
Date: Tue, 3 May 2016 08:48:43 +0300
Subject: [PATCH] implement drag behavior

---
 components/slider.cpp | 42 ++++++++++++++++++++++++++++++++----------
 components/slider.h   |  1 +
 components/slider_p.h |  4 +++-
 3 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/components/slider.cpp b/components/slider.cpp
index 58bfa11..98122e4 100644
--- a/components/slider.cpp
+++ b/components/slider.cpp
@@ -59,28 +59,50 @@ void Slider::mouseMoveEvent(QMouseEvent *event)
 {
     Q_D(Slider);
 
-    QRect track(d->trackGeometry().adjusted(-2, -2, 2, 2));
+    if (d->slide) {
+        setSliderPosition(d->valueFromPosition(event->pos()));
+    } else
+    {
+        QRect track(d->trackGeometry().adjusted(-2, -2, 2, 2));
 
-    if (track.contains(event->pos()) != d->hoverTrack) {
-        d->hoverTrack = !d->hoverTrack;
-        update();
-    }
+        if (track.contains(event->pos()) != d->hoverTrack) {
+            d->hoverTrack = !d->hoverTrack;
+            update();
+        }
 
-    QRectF thumb(0, 0, 16, 16);
-    thumb.moveCenter(d->thumbGeometry().center());
+        QRectF thumb(0, 0, 16, 16);
+        thumb.moveCenter(d->thumbGeometry().center());
 
-    if (thumb.contains(event->pos()) != d->hoverThumb) {
-        d->hoverThumb = !d->hoverThumb;
-        update();
+        if (thumb.contains(event->pos()) != d->hoverThumb) {
+            d->hoverThumb = !d->hoverThumb;
+            update();
+        }
     }
 
     QAbstractSlider::mouseMoveEvent(event);
 }
 
+void Slider::mousePressEvent(QMouseEvent *event)
+{
+    Q_D(Slider);
+
+    QRectF thumb(0, 0, 16, 16);
+    thumb.moveCenter(d->thumbGeometry().center());
+
+    if (thumb.contains(event->pos())) {
+        d->slide = true;
+    }
+}
+
 void Slider::mouseReleaseEvent(QMouseEvent *event)
 {
     Q_D(Slider);
 
+    if (d->slide) {
+        d->slide = false;
+        return QAbstractSlider::mouseReleaseEvent(event);
+    }
+
     QRect track(d->trackGeometry().adjusted(-2, -2, 2, 2));
 
     if (track.contains(event->pos())) {
diff --git a/components/slider.h b/components/slider.h
index 7868149..39b5a6d 100644
--- a/components/slider.h
+++ b/components/slider.h
@@ -20,6 +20,7 @@ public:
 protected:
     void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
     void mouseMoveEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
+    void mousePressEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
     void mouseReleaseEvent(QMouseEvent *event) Q_DECL_OVERRIDE;
 
     const QScopedPointer<SliderPrivate> d_ptr;
diff --git a/components/slider_p.h b/components/slider_p.h
index 1ba766b..b6943dc 100644
--- a/components/slider_p.h
+++ b/components/slider_p.h
@@ -17,7 +17,8 @@ public:
         : q_ptr(parent),
           orientation(Qt::Horizontal),
           hoverTrack(false),
-          hoverThumb(false)
+          hoverThumb(false),
+          slide(false)
     {
         parent->setMouseTracking(true);
     }
@@ -134,6 +135,7 @@ public:
     Qt::Orientation orientation;
     bool            hoverTrack;
     bool            hoverThumb;
+    bool            slide;
 };
 
 #endif // SLIDER_P_H