Add API for minimize/maximize on Window component (#4581)

Closes #4400

api/cpp/include/slint-platform.h

@@ -249,6 +249,18 @@ public:
             return cbindgen_private::slint_window_properties_get_fullscreen(inner());
         }
 
+        /// Returns true if the window should be minimized; false otherwise
+        bool minimized() const
+        {
+            return cbindgen_private::slint_window_properties_get_minimized(inner());
+        }
+
+        /// Returns true if the window should be maximized; false otherwise
+        bool maximized() const
+        {
+            return cbindgen_private::slint_window_properties_get_maximized(inner());
+        }
+
         /// This struct describes the layout constraints of a window.
         ///
         /// It is the return value of WindowProperties::layout_constraints().

api/cpp/platform.rs

@@ -113,7 +113,17 @@ pub extern "C" fn slint_window_properties_get_background(
 
 #[no_mangle]
 pub extern "C" fn slint_window_properties_get_fullscreen(wp: &WindowProperties) -> bool {
-    wp.fullscreen()
+    wp.is_fullscreen()
+}
+
+#[no_mangle]
+pub extern "C" fn slint_window_properties_get_minimized(wp: &WindowProperties) -> bool {
+    wp.is_minimized()
+}
+
+#[no_mangle]
+pub extern "C" fn slint_window_properties_get_maximized(wp: &WindowProperties) -> bool {
+    wp.is_maximized()
 }
 
 #[repr(C)]