3 files changed, 23 insertions, 9 deletions
diff --git a/include/cru/platform/GraphicsBase.h b/include/cru/platform/GraphicsBase.h
index b0f653ef..d5936476 100644
--- a/include/cru/platform/GraphicsBase.h
+++ b/include/cru/platform/GraphicsBase.h
@@ -206,10 +206,22 @@ struct Rect final {
                 height + thickness.GetVerticalTotal());
   }
 
-  constexpr Rect Shrink(const Thickness& thickness) const {
-    return Rect(left + thickness.left, top + thickness.top,
+  constexpr Rect Shrink(const Thickness& thickness,
+                        bool normalize = false) const {
+    Rect result(left + thickness.left, top + thickness.top,
                 width - thickness.GetHorizontalTotal(),
                 height - thickness.GetVerticalTotal());
+
+    if (normalize) {
+      if (result.width < 0) {
+        result.width = 0;
+      }
+      if (result.height < 0) {
+        result.height = 0;
+      }
+    }
+
+    return result;
   }
 
   constexpr bool IsPointInside(const Point& point) const {
diff --git a/include/cru/platform/gui/xcb/UiApplication.h b/include/cru/platform/gui/xcb/UiApplication.h
index 6063a8ab..591ac33f 100644
--- a/include/cru/platform/gui/xcb/UiApplication.h
+++ b/include/cru/platform/gui/xcb/UiApplication.h
@@ -41,6 +41,7 @@ class XcbUiApplication : public XcbResource, public virtual IUiApplication {
   CRU_XCB_UI_APPLICATION_DEFINE_XCB_ATOM(_NET_WM_WINDOW_TYPE)
   CRU_XCB_UI_APPLICATION_DEFINE_XCB_ATOM(_NET_WM_WINDOW_TYPE_NORMAL)
   CRU_XCB_UI_APPLICATION_DEFINE_XCB_ATOM(_NET_WM_WINDOW_TYPE_UTILITY)
+  CRU_XCB_UI_APPLICATION_DEFINE_XCB_ATOM(_NET_FRAME_EXTENTS)
 
 #undef CRU_XCB_UI_APPLICATION_DEFINE_XCB_ATOM
 
diff --git a/include/cru/platform/gui/xcb/Window.h b/include/cru/platform/gui/xcb/Window.h
index 927c3db9..ba4798a5 100644
--- a/include/cru/platform/gui/xcb/Window.h
+++ b/include/cru/platform/gui/xcb/Window.h
@@ -1,5 +1,6 @@
 
 #pragma once
+#include "../../GraphicsBase.h"
 #include "../Window.h"
 #include "Base.h"
 
@@ -38,13 +39,8 @@ class XcbWindow : public XcbResource, public virtual INativeWindow {
   Rect GetClientRect() override;
   void SetClientRect(const Rect& rect) override;
 
-  // Get the rect of the window containing frame.
-  // The lefttop of the rect is relative to screen lefttop.
-  virtual Rect GetWindowRect() = 0;
-
-  // Set the rect of the window containing frame.
-  // The lefttop of the rect is relative to screen lefttop.
-  virtual void SetWindowRect(const Rect& rect) = 0;
+  Rect GetWindowRect() override;
+  void SetWindowRect(const Rect& rect) override;
 
   virtual bool RequestFocus() = 0;
 
@@ -98,6 +94,11 @@ class XcbWindow : public XcbResource, public virtual INativeWindow {
                        std::uint32_t length,
                        std::uint32_t* out_length = nullptr);
 
+  // Relative to screen lefttop.
+  Point GetXcbWindowPosition(xcb_window_t window);
+
+  std::optional<Thickness> Get_NET_FRAME_EXTENTS(xcb_window_t window);
+
  private:
   XcbUiApplication* application_;
   std::optional<xcb_window_t> xcb_window_;