From c6ada2a329fdb748e03a9ddb4c15bce77f5c1c42 Mon Sep 17 00:00:00 2001
From: Chun-wei Fan <fanchunwei@src.gnome.org>
Date: Wed, 5 Aug 2020 10:36:53 +0800
Subject: [PATCH] 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 | 39 ++++++++++++++++++++++++++++++++++++
 gdk/win32/gdksurface-win32.h |  3 +++
 2 files changed, 42 insertions(+)

diff --git a/gdk/win32/gdksurface-win32.c b/gdk/win32/gdksurface-win32.c
index 357bfd813e..9aa33b96ac 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>
@@ -5147,3 +5148,41 @@ gdk_win32_surface_apply_queued_move_resize (GdkSurface *surface,
   /* Don't move iconic windows */
   /* TODO: use SetWindowPlacement() to change non-minimized window position */
 }
+
+RECT
+gdk_win32_surface_handle_queued_move_resize (GdkDrawContext *draw_context)
+{
+  GdkWin32CairoContext *cairo_ctx = NULL;
+  GdkSurface *surface;
+  GdkWin32Surface *impl;
+  int scale;
+  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;
+}
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,