[gtk/master.win32: 1/3] gdksurface-win32.c: Add function to handle queued moves/resizes

[Chun-wei Fan <fanchunwei src gnome org>]

commit 4475a94360df99d5a9cb80792c8cf257c88465a5
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed Aug 5 10:36:53 2020 +0800

    gdksurface-win32.c: Add function to handle queued moves/resizes
    
    Since we need to deal with queued moves and resizes in the Cairo, GL and Vulkan
    draw contexts, and the logic involved in all three of these are largely
    similar, add a function that will handle this, which will be shared between
    these three types of draw contexts.

 gdk/win32/gdksurface-win32.c | 41 +++++++++++++++++++++++++++++++++++++++++
 gdk/win32/gdksurface-win32.h |  3 +++
 2 files changed, 44 insertions(+)
---
diff --git a/gdk/win32/gdksurface-win32.c b/gdk/win32/gdksurface-win32.c
index 357bfd813e..307ff0df9e 100644
--- a/gdk/win32/gdksurface-win32.c
+++ b/gdk/win32/gdksurface-win32.c
@@ -45,6 +45,7 @@
 #include "gdkwin32cursor.h"
 #include "gdkglcontext-win32.h"
 #include "gdkdisplay-win32.h"
+#include "gdkcairocontext-win32.h"
 
 #include <cairo-win32.h>
 #include <dwmapi.h>
@@ -5102,6 +5103,46 @@ _gdk_win32_surface_get_egl_surface (GdkSurface *surface,
 }
 #endif
 
+RECT
+gdk_win32_surface_apply_move_resize (GdkDrawContext *draw_context)
+{
+  GdkWin32CairoContext *cairo_ctx = NULL;
+  GdkSurface *surface;
+  GdkWin32Surface *impl;
+  int scale;
+  cairo_t *cr;
+  int width, height;
+  RECT queued_window_rect;
+
+  surface = gdk_draw_context_get_surface (draw_context);
+  impl = GDK_WIN32_SURFACE (surface);
+  scale = gdk_surface_get_scale_factor (surface);
+
+  if (GDK_IS_WIN32_CAIRO_CONTEXT (draw_context))
+    {
+      cairo_ctx = GDK_WIN32_CAIRO_CONTEXT (draw_context);
+      cairo_ctx->layered = impl->layered;
+    }
+
+  gdk_win32_surface_get_queued_window_rect (surface, scale, &queued_window_rect);
+
+  /* Apply queued resizes for non-double-buffered and non-layered windows
+   * before painting them (we paint on the window DC directly,
+   * it must have the right size).
+   * Due to some poorly-undetstood issue delayed
+   * resizing of double-buffered windows can produce weird
+   * artefacts, so these are also resized before we paint.
+   */
+  if (impl->drag_move_resize_context.native_move_resize_pending &&
+      (cairo_ctx == NULL || !cairo_ctx->layered))
+    {
+      impl->drag_move_resize_context.native_move_resize_pending = FALSE;
+      gdk_win32_surface_apply_queued_move_resize (surface, queued_window_rect);
+    }
+
+  return queued_window_rect;
+}
+
 void
 gdk_win32_surface_get_queued_window_rect (GdkSurface *surface,
                                           int         scale,
diff --git a/gdk/win32/gdksurface-win32.h b/gdk/win32/gdksurface-win32.h
index e4f97d11be..f914b825bb 100644
--- a/gdk/win32/gdksurface-win32.h
+++ b/gdk/win32/gdksurface-win32.h
@@ -393,6 +393,9 @@ void gdk_win32_surface_move_resize (GdkSurface *window,
                                     int         width,
                                     int         height);
 
+RECT
+gdk_win32_surface_apply_move_resize (GdkDrawContext *draw_context);
+
 void
 gdk_win32_surface_get_queued_window_rect (GdkSurface *surface,
                                           int         scale,