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

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

commit 6ebd9816fed53e5ac31095b49d194b1f2250ad36
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 gdk_win32_surface_handle_queued_move_resize() 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..a848d56304 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_handle_queued_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..7fb35ed764 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_handle_queued_move_resize (GdkDrawContext *draw_context);
+
 void
 gdk_win32_surface_get_queued_window_rect (GdkSurface *surface,
                                           int         scale,