Add wxIconEx

This simplifies loading DPI-aware icons.

Signed-off-by: Simon Rozman <simon@rozman.si>

src/icon.cpp

@@ -0,0 +1,39 @@
+/*
+    ​​​SPDX-License-Identifier: GPL-3.0-or-later
+    Copyright © 2025 Amebis
+*/
+
+#include "pch.h"
+
+static wxSize GetDPIHelper(const wxWindowBase* w)
+{
+    wxSize dpi;
+
+    if ( w )
+        dpi = w->GetDPI();
+    if ( !dpi.x || !dpi.y )
+        dpi = wxDisplay().GetPPI();
+    if ( !dpi.x || !dpi.y )
+        dpi = wxDisplay::GetStdPPI();
+
+    return dpi;
+}
+
+
+wxIconEx::wxIconEx(const wxString& name,
+                     wxBitmapType type,
+                     int desiredWidth, int desiredHeight,
+                     wxWindowBase *window)
+{
+    wxSize dpi = GetDPIHelper(window);
+    wxSize baseline = wxDisplay::GetStdPPI();
+
+    if (desiredWidth != wxDefaultCoord)
+        desiredWidth = wxMulDivInt32(desiredWidth, dpi.x, baseline.x);
+
+    if (desiredHeight != wxDefaultCoord)
+        desiredHeight = wxMulDivInt32(desiredHeight, dpi.y, baseline.y);
+
+    LoadFile(name, type, desiredWidth, desiredHeight);
+	SetScaleFactor((double)dpi.y / (double)baseline.y);
+}