From 4e988ac8f2668c36786e8922852cd9c9abc33152 Mon Sep 17 00:00:00 2001
From: David Rosca <nowrep@gmail.com>
Date: Mon, 8 Jan 2018 12:22:49 +0100
Subject: [PATCH] ComboTabBar: Fixes in drawing tabs with drag offset

m_dragInProgress is now only true when dragging tab, not during
the tab sliding to target position animation.
---
 src/lib/tabwidget/combotabbar.cpp | 33 ++++++++++++-------------------
 src/lib/tabwidget/combotabbar.h   |  2 --
 2 files changed, 13 insertions(+), 22 deletions(-)

diff --git a/src/lib/tabwidget/combotabbar.cpp b/src/lib/tabwidget/combotabbar.cpp
index dd8f27db7..d153c0105 100644
--- a/src/lib/tabwidget/combotabbar.cpp
+++ b/src/lib/tabwidget/combotabbar.cpp
@@ -985,7 +985,6 @@ TabBarHelper::TabBarHelper(bool isPinnedTabBar, ComboTabBar* comboTabBar)
     , m_comboTabBar(comboTabBar)
     , m_scrollArea(0)
     , m_pressedIndex(-1)
-    , m_pressedGlobalX(-1)
     , m_dragInProgress(false)
     , m_activeTabBar(false)
     , m_isPinnedTabBar(isPinnedTabBar)
@@ -1202,6 +1201,9 @@ void TabBarHelper::paintEvent(QPaintEvent *event)
     if (m_dragInProgress) {
         // Still needs to be called because it updates movingTab geometry
         QTabBar::paintEvent(event);
+
+        QPainter p(this);
+        p.fillRect(rect(), palette().color(QPalette::Background));
     }
 
     // Hack to get dragOffset from QTabBar internals
@@ -1233,7 +1235,7 @@ void TabBarHelper::paintEvent(QPaintEvent *event)
         optTabBase.selectedTabRect = tabRect(selected);
     }
 
-    if (!m_dragInProgress && drawBase()) {
+    if (drawBase()) {
         p.drawPrimitive(QStyle::PE_FrameTabBarBase, optTabBase);
     }
 
@@ -1281,6 +1283,11 @@ void TabBarHelper::paintEvent(QPaintEvent *event)
         QStyleOptionTab tab;
         initStyleOption(&tab, selected);
 
+        const int tabDragOffset = dragOffset(&tab, selected);
+        if (tabDragOffset != 0) {
+            tab.rect.moveLeft(tab.rect.x() + tabDragOffset);
+        }
+
         // Update mouseover state when scrolling
         if (selected == indexUnderMouse) {
             tab.state |= QStyle::State_MouseOver;
@@ -1337,7 +1344,6 @@ void TabBarHelper::mousePressEvent(QMouseEvent* event)
     if (event->buttons() == Qt::LeftButton) {
         m_pressedIndex = tabAt(event->pos());
         if (m_pressedIndex != -1) {
-            m_pressedGlobalX = event->globalX();
             m_dragInProgress = true;
             // virtualize selecting tab by click
             if (m_pressedIndex == currentIndex() && !m_activeTabBar) {
@@ -1352,18 +1358,13 @@ void TabBarHelper::mousePressEvent(QMouseEvent* event)
 void TabBarHelper::mouseReleaseEvent(QMouseEvent* event)
 {
     event->ignore();
-    if (event->button() != Qt::LeftButton) {
-        return;
-    }
+
+    m_pressedIndex = -1;
+    m_dragInProgress = false;
 
     QTabBar::mouseReleaseEvent(event);
 
-    if (m_pressedIndex >= 0 && m_pressedIndex < count()) {
-        QTimer::singleShot(ComboTabBar::slideAnimationDuration(), this, &TabBarHelper::resetDragState);
-
-        m_pressedIndex = -1;
-        m_pressedGlobalX = -1;
-    }
+    update();
 }
 
 void TabBarHelper::initStyleOption(QStyleOptionTab* option, int tabIndex) const
@@ -1401,14 +1402,6 @@ void TabBarHelper::initStyleOption(QStyleOptionTab* option, int tabIndex) const
     }
 }
 
-void TabBarHelper::resetDragState()
-{
-    if (m_pressedIndex == -1) {
-        m_dragInProgress = false;
-        update();
-    }
-}
-
 void TabBarHelper::tabWasMoved(int from, int to)
 {
     if (m_pressedIndex != -1) {
diff --git a/src/lib/tabwidget/combotabbar.h b/src/lib/tabwidget/combotabbar.h
index b07e2508c..ed42cdda3 100644
--- a/src/lib/tabwidget/combotabbar.h
+++ b/src/lib/tabwidget/combotabbar.h
@@ -261,7 +261,6 @@ public slots:
     void setCurrentIndex(int index);
 
 private slots:
-    void resetDragState();
     void tabWasMoved(int from, int to);
 
 private:
@@ -280,7 +279,6 @@ private:
 
     int m_tabPadding = -1;
     int m_pressedIndex;
-    int m_pressedGlobalX;
     bool m_dragInProgress;
     bool m_activeTabBar;
     bool m_isPinnedTabBar;