From a8bb796f8c39cbca62ec93d262e006cbcd2671b4 Mon Sep 17 00:00:00 2001
From: Vadim Zeitlin <vadim@wxwidgets.org>
Date: Tue, 21 Jul 2020 17:13:41 +0200
Subject: [PATCH] Add OSXMakeDPIFromScaleFactor() helper

No real changes, just avoid repeating wxRound(scaleFactor*72) in several
places and do it in this single function instead.
---
 include/wx/osx/window.h      |  3 +++
 src/osx/cocoa/nonownedwnd.mm |  4 ++--
 src/osx/window_osx.cpp       | 10 +++++++++-
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/include/wx/osx/window.h b/include/wx/osx/window.h
index 479307975e..76ec9bdb1c 100644
--- a/include/wx/osx/window.h
+++ b/include/wx/osx/window.h
@@ -294,6 +294,9 @@ public:
     // internal response to size events
     virtual void MacOnInternalSize() {}
 
+    // Return the DPI corresponding to the given scale factor.
+    static wxSize       OSXMakeDPIFromScaleFactor(double scaleFactor);
+
 protected:
     // For controls like radio buttons which are genuinely composite
     wxList              m_subControls;
diff --git a/src/osx/cocoa/nonownedwnd.mm b/src/osx/cocoa/nonownedwnd.mm
index a0ad84b8d4..f118433a03 100644
--- a/src/osx/cocoa/nonownedwnd.mm
+++ b/src/osx/cocoa/nonownedwnd.mm
@@ -629,8 +629,8 @@ extern int wxOSXGetIdFromSelector(SEL action );
                                          doubleValue];
         if (newBackingScaleFactor != oldBackingScaleFactor)
         {
-            wxSize oldDPI((int)(oldBackingScaleFactor*72.0),(int)(oldBackingScaleFactor*72.0));
-            wxSize newDPI((int)(newBackingScaleFactor*72.0),(int)(newBackingScaleFactor*72.0));
+            const wxSize oldDPI = wxWindow::OSXMakeDPIFromScaleFactor(oldBackingScaleFactor);
+            const wxSize newDPI = wxWindow::OSXMakeDPIFromScaleFactor(newBackingScaleFactor);
 
             wxDPIChangedEvent event(oldDPI, newDPI);
             event.SetEventObject(wxpeer);
diff --git a/src/osx/window_osx.cpp b/src/osx/window_osx.cpp
index 61bf54cbea..4e5db615b2 100644
--- a/src/osx/window_osx.cpp
+++ b/src/osx/window_osx.cpp
@@ -2620,6 +2620,14 @@ bool wxWindowMac::OSXHandleKeyEvent( wxKeyEvent& event )
     return handled ;
 }
 
+/* static */
+wxSize wxWindowMac::OSXMakeDPIFromScaleFactor(double scaleFactor)
+{
+    const int dpi = wxRound(scaleFactor*72.0);
+
+    return wxSize(dpi, dpi);
+}
+
 wxSize wxWindowMac::GetDPI() const
 {
     double scaleFactor;
@@ -2628,7 +2636,7 @@ wxSize wxWindowMac::GetDPI() const
     else
         scaleFactor = wxOSXGetMainScreenContentScaleFactor();
 
-    return wxSize(wxRound(scaleFactor*72.0),wxRound(scaleFactor*72.0));
+    return OSXMakeDPIFromScaleFactor(scaleFactor);
 }
 
 //