From 537a27d09805d2acd1657d865b1c63180fa859f1 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 14 Dec 2019 11:15:33 +0530
Subject: [PATCH] macOS; Use transient scrollbars unless they are disabled in
 system preferences

---
 src/calibre/gui2/__init__.py                             | 8 +++++++-
 .../gui2/progress_indicator/QProgressIndicator.cpp       | 9 ++++++---
 src/calibre/gui2/progress_indicator/QProgressIndicator.h | 2 +-
 .../gui2/progress_indicator/QProgressIndicator.sip       | 4 ++--
 4 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 8b39593939..38dd4f707a 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -1104,7 +1104,13 @@ class Application(QApplication):
                 pcache[v] = p
             v = pcache[v]
             icon_map[getattr(QStyle, 'SP_'+k)] = v
-        self.pi.load_style(icon_map)
+        transient_scroller = 0
+        if isosx:
+            transient_scroller = plugins['cocoa'][0].transient_scroller()
+        try:
+            self.pi.load_style(icon_map, transient_scroller)
+        except TypeError:
+            self.pi.load_style(icon_map)
 
     def _send_file_open_events(self):
         with self._file_open_lock:
diff --git a/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp b/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
index 05cec87e57..7f5e6c5e7c 100644
--- a/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
+++ b/src/calibre/gui2/progress_indicator/QProgressIndicator.cpp
@@ -138,9 +138,10 @@ class CalibreStyle: public QProxyStyle {
         QHash<int, QString> icon_map;
         QByteArray desktop_environment;
         QDialogButtonBox::ButtonLayout button_layout;
+        int transient_scroller;
 
     public:
-        CalibreStyle(QStyle *base, QHash<int, QString> icmap) : QProxyStyle(base), icon_map(icmap) {
+        CalibreStyle(QStyle *base, QHash<int, QString> icmap, int transient_scroller) : QProxyStyle(base), icon_map(icmap), transient_scroller(transient_scroller) {
             setObjectName(QString("calibre"));
             desktop_environment = detectDesktopEnvironment();
             button_layout = static_cast<QDialogButtonBox::ButtonLayout>(QProxyStyle::styleHint(SH_DialogButtonLayout));
@@ -163,6 +164,8 @@ class CalibreStyle: public QProxyStyle {
                     return button_layout;
                 case SH_FormLayoutFieldGrowthPolicy:
                     return QFormLayout::FieldsStayAtSizeHint;  // Do not have fields expand to fill all available space in QFormLayout
+                case SH_ScrollBar_Transient:
+                    return transient_scroller;
 				default:
                     break;
             }
@@ -320,9 +323,9 @@ class CalibreStyle: public QProxyStyle {
 		}
 };
 
-int load_style(QHash<int,QString> icon_map) {
+int load_style(QHash<int,QString> icon_map, int transient_scroller) {
     QStyle *base_style = QStyleFactory::create(QString("Fusion"));
-    QApplication::setStyle(new CalibreStyle(base_style, icon_map));
+    QApplication::setStyle(new CalibreStyle(base_style, icon_map, transient_scroller));
     return 0;
 }
 
diff --git a/src/calibre/gui2/progress_indicator/QProgressIndicator.h b/src/calibre/gui2/progress_indicator/QProgressIndicator.h
index 657ec154e3..7e50086e92 100644
--- a/src/calibre/gui2/progress_indicator/QProgressIndicator.h
+++ b/src/calibre/gui2/progress_indicator/QProgressIndicator.h
@@ -77,6 +77,6 @@ private:
     QColor m_dark, m_light;
 };
 
-int load_style(QHash<int,QString> icon_map);
+int load_style(QHash<int,QString> icon_map, int transient_scroller=0);
 void set_no_activate_on_click(QWidget *widget);
 void draw_snake_spinner(QPainter &painter, QRect rect, int angle, const QColor & light, const QColor & dark);
diff --git a/src/calibre/gui2/progress_indicator/QProgressIndicator.sip b/src/calibre/gui2/progress_indicator/QProgressIndicator.sip
index 7d2f1bd9d3..559f2b19d1 100644
--- a/src/calibre/gui2/progress_indicator/QProgressIndicator.sip
+++ b/src/calibre/gui2/progress_indicator/QProgressIndicator.sip
@@ -7,7 +7,7 @@
 
 %ModuleHeaderCode
 #include <QPainter>
-int load_style(QHash<int,QString> icon_map);
+int load_style(QHash<int,QString> icon_map, int transient_scroller);
 void set_no_activate_on_click(QWidget *widget);
 void draw_snake_spinner(QPainter &painter, QRect rect, int angle, const QColor & light, const QColor & dark);
 %End
@@ -55,6 +55,6 @@ protected:
 
 };
 
-int load_style(QHash<int,QString> icon_map);
+int load_style(QHash<int,QString> icon_map, int transient_scroller);
 void set_no_activate_on_click(QWidget *widget);
 void draw_snake_spinner(QPainter &painter, QRect rect, int angle, const QColor & light, const QColor & dark);