From b717d0c8d50cca18325ab9f2e2cba49e34d02323 Mon Sep 17 00:00:00 2001
From: Paul Cornett <paulcor@users.noreply.github.com>
Date: Thu, 25 Jul 2019 10:35:12 -0700
Subject: [PATCH] Add GTK-specific implementation of wxDisplay::GetFromWindow()

The generic implementation indirectly uses ClientToScreen(), which won't work
with Wayland, and causes debug warnings when used before window is realized.
---
 src/gtk/display.cpp | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/src/gtk/display.cpp b/src/gtk/display.cpp
index 7ab2c8d36b..b1bdacb196 100644
--- a/src/gtk/display.cpp
+++ b/src/gtk/display.cpp
@@ -9,6 +9,9 @@
 #include "wx/wxprec.h"
 
 #include "wx/private/display.h"
+#if wxUSE_DISPLAY
+    #include "wx/window.h"
+#endif
 
 #include "wx/gtk/private/wrapgtk.h"
 #ifdef GDK_WINDOWING_X11
@@ -67,6 +70,7 @@ public:
     virtual wxDisplayImpl* CreateDisplay(unsigned n) wxOVERRIDE;
     virtual unsigned GetCount() wxOVERRIDE;
     virtual int GetFromPoint(const wxPoint& pt) wxOVERRIDE;
+    virtual int GetFromWindow(const wxWindow* win) wxOVERRIDE;
 };
 
 wxDisplayImpl* wxDisplayFactoryGTK::CreateDisplay(unsigned n)
@@ -95,6 +99,26 @@ int wxDisplayFactoryGTK::GetFromPoint(const wxPoint& pt)
     }
     return wxNOT_FOUND;
 }
+
+int wxDisplayFactoryGTK::GetFromWindow(const wxWindow* win)
+{
+    if (win && win->m_widget)
+    {
+        GdkDisplay* display = gtk_widget_get_display(win->m_widget);
+        GdkMonitor* monitor;
+        if (GdkWindow* window = gtk_widget_get_window(win->m_widget))
+            monitor = gdk_display_get_monitor_at_window(display, window);
+        else
+            monitor = gdk_display_get_primary_monitor(display);
+
+        for (unsigned i = gdk_display_get_n_monitors(display); i--;)
+        {
+            if (gdk_display_get_monitor(display, i) == monitor)
+                return i;
+        }
+    }
+    return wxNOT_FOUND;
+}
 #endif // wxUSE_DISPLAY
 
 wxDisplayImplGTK::wxDisplayImplGTK(unsigned i)
@@ -251,6 +275,7 @@ public:
     virtual wxDisplayImpl* CreateDisplay(unsigned n) wxOVERRIDE;
     virtual unsigned GetCount() wxOVERRIDE;
     virtual int GetFromPoint(const wxPoint& pt) wxOVERRIDE;
+    virtual int GetFromWindow(const wxWindow* win) wxOVERRIDE;
 };
 
 wxGCC_WARNING_SUPPRESS(deprecated-declarations)
@@ -275,6 +300,20 @@ int wxDisplayFactoryGTK::GetFromPoint(const wxPoint& pt)
         monitor = wxNOT_FOUND;
     return monitor;
 }
+
+int wxDisplayFactoryGTK::GetFromWindow(const wxWindow* win)
+{
+    int monitor = wxNOT_FOUND;
+    if (win && win->m_widget)
+    {
+        GdkScreen* screen = gtk_widget_get_screen(win->m_widget);
+        if (GdkWindow* window = gtk_widget_get_window(win->m_widget))
+            monitor = gdk_screen_get_monitor_at_window(screen, window);
+        else
+            monitor = gdk_screen_get_primary_monitor(screen);
+    }
+    return monitor;
+}
 #endif // wxUSE_DISPLAY
 
 wxDisplayImplGTK::wxDisplayImplGTK(unsigned i)