ADD: Align Items

src/engine/core/gui/uiComponent/layout/LayoutStyle.h

@@ -50,6 +50,7 @@ struct LayoutStyle {
 
     FlexDirection flexDirection = FlexDirection::Column;
     JustifyContent justifyContent = JustifyContent::Start;
+    AlignItems alignItems = AlignItems::Start;
 
     float flexGrow = 0.0f;
 };

src/engine/core/gui/uiComponent/layout/UiPositioner.cpp

@@ -61,6 +61,52 @@ void UiPositioner::compute(const Dimensions &parent) {
         }
     }
 
+    // AlignItems
+    for (auto& child : uiComponent.children) {
+        if (style.flexDirection == FlexDirection::Column) {
+            float marginLeft  = child->uiPositioner.resolve(child->uiPositioner.style.margin.left,screenSpace.width,screenWidth);
+            float remainingCrossSpace = screenSpace.width - child->uiPositioner.screenSpace.width ;
+            switch (style.alignItems) {
+                case AlignItems::Start:
+                    child->uiPositioner.screenSpace.x = screenSpace.x + marginLeft;
+                    break;
+
+                case AlignItems::Center:
+                    child->uiPositioner.screenSpace.x =
+                        screenSpace.x + remainingCrossSpace / 2.0f + marginLeft;
+                    break;
+
+                case AlignItems::End:
+                    child->uiPositioner.screenSpace.x = screenSpace.x + remainingCrossSpace + marginLeft;
+                    break;
+
+                default:
+                    break;
+            }
+        } else {
+            float remainingCrossSpace = screenSpace.height - child->uiPositioner.screenSpace.height;
+            float marginTop = child->uiPositioner.resolve(child->uiPositioner.style.margin.top,screenSpace.height,screenHeight);
+            switch (style.alignItems) {
+                case AlignItems::Start:
+                    child->uiPositioner.screenSpace.y = screenSpace.y + marginTop;
+                    break;
+
+                case AlignItems::Center:
+                    child->uiPositioner.screenSpace.y =
+                        screenSpace.y + remainingCrossSpace / 2.0f + marginTop;
+                    break;
+
+                case AlignItems::End:
+                    child->uiPositioner.screenSpace.y =
+                        screenSpace.y + remainingCrossSpace + marginTop;
+                    break;
+
+                default:
+                    break;
+            }
+        }
+    }
+
 }
 
 LayoutStyle & UiPositioner::getLayout() {