[PATCH 3/4] shell32/autocomplete: Prevent the listbox from going off screen when dropped

[Gabriel Ivăncescu]

Signed-off-by: Gabriel Ivăncescu <gabrielopcode at gmail.com>
---
 dlls/shell32/autocomplete.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/dlls/shell32/autocomplete.c b/dlls/shell32/autocomplete.c
index 136d9e8..f18517f 100644
--- a/dlls/shell32/autocomplete.c
+++ b/dlls/shell32/autocomplete.c
@@ -357,7 +357,10 @@ static void hide_listbox(IAutoCompleteImpl *ac, HWND hwnd, BOOL reset)
 static void show_listbox(IAutoCompleteImpl *ac)
 {
     RECT r;
-    UINT cnt, width, height;
+    LONG top;
+    HMONITOR hmon;
+    MONITORINFO info;
+    UINT cnt, width, height, grip_sz;
 
     GetWindowRect(ac->hwndEdit, &r);
 
@@ -374,8 +377,24 @@ static void show_listbox(IAutoCompleteImpl *ac)
         height = SendMessageW(ac->hwndListBox, LB_GETITEMHEIGHT, 0, 0) * min(cnt + 1, 7);
         width  = r.right - r.left;
     }
+    top = r.bottom + 1;
 
-    SetWindowPos(ac->hwndListBoxOwner, HWND_TOP, r.left, r.bottom + 1, width, height,
+    /* Don't drop off-screen when showing the listbox */
+    info.cbSize = sizeof(info);
+    hmon = MonitorFromRect(&r, MONITOR_DEFAULTTONEAREST);
+    if (GetMonitorInfoW(hmon, &info))
+    {
+        /* Permit the width to go off-screen if the editbox also does, though */
+        LONG max_w = max(info.rcMonitor.right, r.right) - r.left;
+        LONG max_h = info.rcMonitor.bottom - top;
+        width = min(width, max_w);
+        height = min(height, max_h);
+    }
+    grip_sz = GetSystemMetrics(SM_CXVSCROLL);
+    width   = max(width,  grip_sz);
+    height  = max(height, grip_sz);
+
+    SetWindowPos(ac->hwndListBoxOwner, HWND_TOP, r.left, top, width, height,
                  SWP_SHOWWINDOW | SWP_NOACTIVATE | SWP_NOSENDCHANGING | SWP_DEFERERASE);
 
     /* Update the grip here (as we skip it during message processing), due
-- 
2.20.1