wayland: Read GDK_SCALEgdk-scale-wayland

This is somewhat disappointing, because the
surface size stays the same, just the rendering
changes.

3 files changed, 34 insertions, 1 deletions

diff --git a/gdk/wayland/gdkprivate-wayland.h b/gdk/wayland/gdkprivate-wayland.h
index 8db2dd8f49..e9752f3696 100644
--- a/gdk/wayland/gdkprivate-wayland.h
+++ b/gdk/wayland/gdkprivate-wayland.h
@@ -58,6 +58,7 @@ struct _GdkFractionalScale
 
 #define GDK_FRACTIONAL_SCALE_INIT(fractional_scale) (GdkFractionalScale) { fractional_scale }
 #define GDK_FRACTIONAL_SCALE_INIT_INT(scale) GDK_FRACTIONAL_SCALE_INIT (scale * GDK_FRACTIONAL_SCALE_FACTOR)
+#define GDK_FRACTIONAL_SCALE_INIT_FLOAT(scale) GDK_FRACTIONAL_SCALE_INIT ((int) (scale * GDK_FRACTIONAL_SCALE_FACTOR))
 
 static inline int
 gdk_fractional_scale_to_int (const GdkFractionalScale *self)
diff --git a/gdk/wayland/gdksurface-wayland-private.h b/gdk/wayland/gdksurface-wayland-private.h
index 1d87cc4b09..bb6354839c 100644
--- a/gdk/wayland/gdksurface-wayland-private.h
+++ b/gdk/wayland/gdksurface-wayland-private.h
@@ -48,6 +48,7 @@ struct _GdkWaylandSurface
   unsigned int mapped : 1;
   unsigned int awaiting_frame : 1;
   unsigned int awaiting_frame_frozen : 1;
+  unsigned int scale_overridden : 1;
 
   int pending_buffer_offset_x;
   int pending_buffer_offset_y;
diff --git a/gdk/wayland/gdksurface-wayland.c b/gdk/wayland/gdksurface-wayland.c
index f51f081a43..62cfcac477 100644
--- a/gdk/wayland/gdksurface-wayland.c
+++ b/gdk/wayland/gdksurface-wayland.c
@@ -172,6 +172,31 @@ gdk_wayland_surface_init (GdkWaylandSurface *impl)
 {
   impl->scale = GDK_FRACTIONAL_SCALE_INIT_INT (1);
   impl->viewport_dirty = TRUE;
+
+  if (g_getenv ("GDK_SCALE"))
+    {
+      const char *scale_str;
+      char *endptr = NULL;
+      double scale;
+
+      scale_str = g_getenv ("GDK_SCALE");
+
+      scale = g_ascii_strtod (scale_str, &endptr);
+
+      if (endptr && *endptr != '\0')
+        {
+          if (strcmp (endptr, "%") == 0)
+            scale /= 100.;
+          else
+            {
+              g_warning ("Failed to parse GDK_SCALE");
+              return;
+            }
+        }
+
+      impl->scale = GDK_FRACTIONAL_SCALE_INIT_FLOAT (scale);
+      impl->scale_overridden = TRUE;
+    }
 }
 
 void
@@ -464,6 +489,9 @@ gdk_wayland_surface_update_scale (GdkSurface *surface)
       wl_surface_get_version (impl->display_server.wl_surface) < WL_SURFACE_SET_BUFFER_SCALE_SINCE_VERSION)
     return;
 
+  if (impl->scale_overridden)
+    return;
+
   /* scale is tracked by the fractional scale extension */
   if (impl->display_server.fractional_scale)
     return;
@@ -831,7 +859,10 @@ gdk_wayland_surface_fractional_scale_preferred_scale_cb (void *data,
 {
   GdkWaylandSurface *self = GDK_WAYLAND_SURFACE (data);
   GdkSurface *surface = GDK_SURFACE (self);
-  
+
+  if (self->scale_overridden)
+    return;
+
   /* Notify app that scale changed */
   gdk_wayland_surface_maybe_resize (surface,
                                     surface->width, surface->height,