Merge pull request #5296

0ceab00 [Qt, OSX] move QProgressBarMac to guiutil.h (Jonas Schnelli)
6093aa1 [Qt, OSX] QProgressBar CPU-Issue workaround (Jonas Schnelli)

src/qt/bitcoingui.cpp

@@ -190,7 +190,7 @@ BitcoinGUI::BitcoinGUI(const NetworkStyle *networkStyle, QWidget *parent) :
     // Progress bar and label for blocks download
     progressBarLabel = new QLabel();
     progressBarLabel->setVisible(false);
-    progressBar = new QProgressBar();
+    progressBar = new GUIUtil::ProgressBar();
     progressBar->setAlignment(Qt::AlignCenter);
     progressBar->setVisible(false);
 

src/qt/guiutil.h

@@ -7,9 +7,11 @@
 
 #include "amount.h"
 
+#include <QEvent>
 #include <QHeaderView>
 #include <QMessageBox>
 #include <QObject>
+#include <QProgressBar>
 #include <QString>
 #include <QTableView>
 
@@ -186,6 +188,21 @@ namespace GUIUtil
 
     /* Format a CNodeCombinedStats.dPingTime into a user-readable string or display N/A, if 0*/
     QString formatPingTime(double dPingTime);
+    
+#ifdef Q_OS_MAC
+    // workaround for Qt OSX Bug:
+    // https://bugreports.qt-project.org/browse/QTBUG-15631
+    // QProgressBar uses around 10% CPU even when app is in background
+    class ProgressBar : public QProgressBar
+    {
+        bool event(QEvent *e) {
+            return (e->type() != QEvent::StyleAnimationUpdate) ? QProgressBar::event(e) : false;
+        }
+    };
+#else
+    typedef QProgressBar ProgressBar;
+#endif
+    
 } // namespace GUIUtil
 
 #endif // BITCOIN_QT_GUIUTIL_H