patch 8.2.4486: MS-Windows GUI: slow scrolling with maximized window
Problem: MS-Windows GUI: slow scrolling with maximized window.
Solution: Use a better way to check the window is on screen. (Ken Takata,
closes #9865)
diff --git a/src/gui_w32.c b/src/gui_w32.c
index ec62671..584e4ef 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -3016,7 +3016,7 @@
}
/*
- * Check if the whole area of the specified window is on-screen.
+ * Check if the whole client area of the specified window is on-screen.
*
* Note about DirectX: Windows 10 1809 or above no longer maintains image of
* the window portion that is off-screen. Scrolling by DWriteContext_Scroll()
@@ -3026,16 +3026,23 @@
is_window_onscreen(HWND hwnd)
{
RECT rc;
+ POINT p1, p2;
- GetWindowRect(hwnd, &rc);
+ GetClientRect(hwnd, &rc);
+ p1.x = rc.left;
+ p1.y = rc.top;
+ p2.x = rc.right - 1;
+ p2.y = rc.bottom - 1;
+ ClientToScreen(hwnd, &p1);
+ ClientToScreen(hwnd, &p2);
- if (!is_point_onscreen(rc.left, rc.top))
+ if (!is_point_onscreen(p1.x, p1.y))
return FALSE;
- if (!is_point_onscreen(rc.left, rc.bottom))
+ if (!is_point_onscreen(p1.x, p2.y))
return FALSE;
- if (!is_point_onscreen(rc.right, rc.top))
+ if (!is_point_onscreen(p2.x, p1.y))
return FALSE;
- if (!is_point_onscreen(rc.right, rc.bottom))
+ if (!is_point_onscreen(p2.x, p2.y))
return FALSE;
return TRUE;
}