Remove obj_c for macOS Dock icon setting

Qt `setWindowIcon()` does this work.

Author: hebasto

src/qt/bitcoingui.cpp

@@ -92,12 +92,8 @@ BitcoinGUI::BitcoinGUI(interfaces::Node& node, const PlatformStyle *_platformSty
         windowTitle += tr("Node");
     }
     windowTitle += " " + networkStyle->getTitleAddText();
-#ifndef Q_OS_MAC
     QApplication::setWindowIcon(networkStyle->getTrayAndWindowIcon());
     setWindowIcon(networkStyle->getTrayAndWindowIcon());
-#else
-    MacDockIconHandler::instance()->setIcon(networkStyle->getAppIcon());
-#endif
     setWindowTitle(windowTitle);
 
     rpcConsole = new RPCConsole(node, _platformStyle, 0);

src/qt/macdockiconhandler.h

@@ -9,7 +9,6 @@
 #include <QObject>
 
 QT_BEGIN_NAMESPACE
-class QIcon;
 class QMenu;
 class QWidget;
 QT_END_NAMESPACE
@@ -24,7 +23,6 @@ class MacDockIconHandler : public QObject
     ~MacDockIconHandler();
 
     QMenu *dockMenu();
-    void setIcon(const QIcon &icon);
     void setMainWindow(QMainWindow *window);
     static MacDockIconHandler *instance();
     static void cleanup();

src/qt/macdockiconhandler.mm

@@ -4,9 +4,7 @@
 
 #include "macdockiconhandler.h"
 
-#include <QImageWriter>
 #include <QMenu>
-#include <QBuffer>
 #include <QWidget>
 
 #undef slots
@@ -71,39 +69,6 @@ void setupDockClickHandler() {
     return this->m_dockMenu;
 }
 
-void MacDockIconHandler::setIcon(const QIcon &icon)
-{
-    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
-    NSImage *image = nil;
-    if (icon.isNull())
-        image = [[NSImage imageNamed:@"NSApplicationIcon"] retain];
-    else {
-        // generate NSImage from QIcon and use this as dock icon.
-        QSize size = icon.actualSize(QSize(128, 128));
-        QPixmap pixmap = icon.pixmap(size);
-
-        // Write image into a R/W buffer from raw pixmap, then save the image.
-        QBuffer notificationBuffer;
-        if (!pixmap.isNull() && notificationBuffer.open(QIODevice::ReadWrite)) {
-            QImageWriter writer(&notificationBuffer, "PNG");
-            if (writer.write(pixmap.toImage())) {
-                NSData* macImgData = [NSData dataWithBytes:notificationBuffer.buffer().data()
-                                             length:notificationBuffer.buffer().size()];
-                image =  [[NSImage alloc] initWithData:macImgData];
-            }
-        }
-
-        if(!image) {
-            // if testnet image could not be created, load std. app icon
-            image = [[NSImage imageNamed:@"NSApplicationIcon"] retain];
-        }
-    }
-
-    [NSApp setApplicationIconImage:image];
-    [image release];
-    [pool release];
-}
-
 MacDockIconHandler *MacDockIconHandler::instance()
 {
     if (!s_instance)