[PATCH 0/2] MR10712: wineandroid: fix desktop sizing and repaint on resolution changes

[Twaik Yont (＠twaik)]

This series fixes two related issues in wineandroid affecting desktop
initialization and repaint behavior when using the virtual desktop mode.

First, launching explorer.exe with an empty desktop size
("/desktop=shell,,android") does not behave as intended on wineandroid.

When the size is omitted, explorer attempts to determine the desktop
resolution via get_default_desktop_size(). If no matching registry entry
is found, it falls back to a hardcoded default (typically 800x600).
Later, even if the wineandroid backend sets the correct display size
through pCreateDesktop, explorer overrides it again during
initialize_display_settings(), restoring the default resolution.

As a result, the desktop ends up stuck at 800x600 regardless of the
actual display size reported by the backend.

To address this, the desktop is now launched with a size of "-1x-1".
This value is accepted by parse_size(), but does not correspond to a
valid resolution. As a result, explorer does not fall back to the default
resolution, and also avoids overriding the backend-provided size during
initialization. This allows the desktop to retain the correct resolution
as configured by wineandroid.

Second, window repainting on resolution changes is fixed.

Previously, WM_ANDROID_REFRESH used NtUserExposeWindowSurface(), which
only exposes existing surface contents without invalidating the window.
This prevents WM_PAINT and WM_ERASEBKGND from being generated. When the
desktop or other windows are resized (e.g. after applying a new display
mode), they may retain stale contents instead of repainting.

This is resolved by replacing NtUserExposeWindowSurface() with
NtUserRedrawWindow(), ensuring proper invalidation and repaint of window
contents. This fixes cases where the desktop background is not redrawn
after a resolution change.

Together, these changes ensure that the desktop starts with the correct
resolution and that windows are properly repainted when display settings
change.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10712

[PATCH 1/2] wineandroid: force window invalidation on WM_ANDROID_REFRESH

[Twaik Yont]

From: Twaik Yont <[e-mail]>

Replace NtUserExposeWindowSurface() with NtUserRedrawWindow() when
handling WM_ANDROID_REFRESH for non-OpenGL windows.

NtUserExposeWindowSurface() only exposes the existing surface contents,
but does not invalidate the window or trigger WM_PAINT / WM_ERASEBKGND.
As a result, when the display resolution changes, windows (including the
desktop window managed by explorer.exe) may be resized without receiving
a repaint, leaving stale contents on screen.

Using NtUserRedrawWindow() ensures that the window is properly
invalidated and repainted, so background and client areas are refreshed
correctly after resolution changes.

This fixes cases where the desktop background is not redrawn after
applying a new display mode.

Signed-off-by: Twaik Yont <[e-mail]>
---
 dlls/wineandroid.drv/window.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/dlls/wineandroid.drv/window.c b/dlls/wineandroid.drv/window.c
index 97eb3004ba8..5ce4828e1a4 100644
--- a/dlls/wineandroid.drv/window.c
+++ b/dlls/wineandroid.drv/window.c
@@ -1197,9 +1197,7 @@ LRESULT ANDROID_WindowMessage( HWND hwnd, UINT msg, WPARAM wp, LPARAM lp )
             detach_client_surfaces( hwnd );
         }
         else
-        {
-            NtUserExposeWindowSurface( hwnd, 0, NULL, 0 );
-        }
+            NtUserRedrawWindow( hwnd, NULL, 0, RDW_INVALIDATE | RDW_ERASE | RDW_ALLCHILDREN | RDW_FRAME );
         return 0;
     default:
         FIXME( "got window msg %x hwnd %p wp %lx lp %lx\n", msg, hwnd, (long)wp, lp );
-- 
GitLab


https://gitlab.winehq.org/wine/wine/-/merge_requests/10712

[PATCH 2/2] wineandroid: request dynamic desktop size using -1x-1

[Twaik Yont]

From: Twaik Yont <[e-mail]>

Use “-1x-1” instead of an empty size in the /desktop option when
launching explorer.exe.

An empty size causes get_default_desktop_size() to be used, which falls
back to a fixed default (typically 800x600). This prevents the desktop
from matching the actual display size provided by the Android backend.

Passing “-1x-1” is accepted by parse_size() and results in large unsigned
values, which are then clamped by the driver to the current screen size.
This effectively requests a dynamically sized desktop matching the
Android display.

This ensures that the desktop resolution is derived from the backend
instead of being forced to the default fixed size.

Signed-off-by: Twaik Yont <[e-mail]>
---
 dlls/wineandroid.drv/WineActivity.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/dlls/wineandroid.drv/WineActivity.java b/dlls/wineandroid.drv/WineActivity.java
index 6488188b93a..f0bade27a28 100644
--- a/dlls/wineandroid.drv/WineActivity.java
+++ b/dlls/wineandroid.drv/WineActivity.java
@@ -169,7 +169,7 @@ private final void runWine( String loader, String cmdline )
     {
         String[] cmd = { loader,
                          "c:\\windows\\system32\\explorer.exe",
-                         "/desktop=shell,,android",
+                         "/desktop=shell,-1x-1,android",
                          cmdline };
 
         String err = wine_init( cmd );
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10712

[Twaik Yont (＠twaik)]

@julliard Hi, just a gentle ping on this PR — would appreciate a review when you have a moment.

-- 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10712#note_137712