FancyZones: allow windows with invisible or zero-sized owner to be zo…

…nable (#1216)

src/modules/fancyzones/lib/FancyZones.cpp

@@ -593,13 +593,33 @@ LRESULT CALLBACK FancyZones::s_WndProc(HWND window, UINT message, WPARAM wparam,
         DefWindowProc(window, message, wparam, lparam);
 }
 
+static bool HasVisibleOwner(HWND window) noexcept
+{
+    auto owner = GetWindow(window, GW_OWNER);
+    if (owner == nullptr)
+    {
+        return false; // There is no owner at all
+    }
+    if (!IsWindowVisible(owner))
+    {
+        return false; // Owner is invisible
+    }
+    RECT rect;
+    if (!GetWindowRect(owner, &rect))
+    {
+        return true; // Could not get the rect, return true (and filter out the window) just in case
+    }
+    // Return false (and allow the window to be zonable) if the owner window size is zero
+    return rect.top != rect.bottom || rect.left != rect.right;
+}
+
 bool FancyZones::IsInterestingWindow(HWND window) noexcept
 {
     auto style = GetWindowLongPtr(window, GWL_STYLE);
     auto exStyle = GetWindowLongPtr(window, GWL_EXSTYLE);
     // Ignore:
     if (GetAncestor(window, GA_ROOT) != window || // windows that are not top-level
-        GetWindow(window, GW_OWNER) != nullptr || // windows that have an owner - like Save As dialogs
+        HasVisibleOwner(window) || // windows that have an visible owner - like Save As dialogs
         (style & WS_CHILD) != 0 || // windows that are child elements of other windows - like buttons
         (style & WS_DISABLED) != 0 || // windows that are disabled
         (exStyle & WS_EX_TOOLWINDOW) != 0 || // toolbar windows