qt: Introduce PlatformStyle

Introduce a PlatformStyle to handle platform-specific customization of
the UI.

This replaces 'scicon', as well as #ifdefs to determine whether to place
icons on buttons.

The selected PlatformStyle defaults to the platform that the application
was compiled on, but can be overridden from the command line with
`-uiplatform=<x>`.

Also fixes the warning from #6328.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/qt/overviewpage.h b/src/qt/overviewpage.h
index de5ac345da..4139eb35d3 100644
--- a/src/qt/overviewpage.h
+++ b/src/qt/overviewpage.h
@@ -12,6 +12,7 @@
 class ClientModel;
 class TransactionFilterProxy;
 class TxViewDelegate;
+class PlatformStyle;
 class WalletModel;
 
 namespace Ui {
@@ -28,7 +29,7 @@ class OverviewPage : public QWidget
     Q_OBJECT
 
 public:
-    explicit OverviewPage(QWidget *parent = 0);
+    explicit OverviewPage(const PlatformStyle *platformStyle, QWidget *parent = 0);
     ~OverviewPage();
 
     void setClientModel(ClientModel *clientModel);