refactor(new_editor/app): reorganize host structure and add smoke test

new_editor/app/Platform/Win32/BorderlessWindowChrome.cpp

@@ -0,0 +1,72 @@
+#include "BorderlessWindowChrome.h"
+
+#include <algorithm>
+
+namespace XCEngine::UI::Editor::Host {
+
+namespace {
+
+using ::XCEngine::UI::UIPoint;
+using ::XCEngine::UI::UIRect;
+
+bool IsPointInsideRect(const UIRect& rect, const UIPoint& point) {
+    return rect.width > 0.0f &&
+        rect.height > 0.0f &&
+        point.x >= rect.x &&
+        point.x <= rect.x + rect.width &&
+        point.y >= rect.y &&
+        point.y <= rect.y + rect.height;
+}
+
+} // namespace
+
+BorderlessWindowChromeLayout BuildBorderlessWindowChromeLayout(
+    const UIRect& titleBarRect,
+    float leadingOccupiedRight,
+    const BorderlessWindowChromeMetrics& metrics) {
+    BorderlessWindowChromeLayout layout = {};
+    layout.titleBarRect = titleBarRect;
+    if (titleBarRect.width <= 0.0f || titleBarRect.height <= 0.0f) {
+        return layout;
+    }
+
+    const float buttonWidth = (std::max)(metrics.buttonWidth, 0.0f);
+    const float buttonX3 = titleBarRect.x + titleBarRect.width - metrics.buttonInsetX - buttonWidth;
+    const float buttonX2 = buttonX3 - buttonWidth;
+    const float buttonX1 = buttonX2 - buttonWidth;
+
+    layout.minimizeButtonRect = UIRect(buttonX1, titleBarRect.y, buttonWidth, titleBarRect.height);
+    layout.maximizeRestoreButtonRect = UIRect(buttonX2, titleBarRect.y, buttonWidth, titleBarRect.height);
+    layout.closeButtonRect = UIRect(buttonX3, titleBarRect.y, buttonWidth, titleBarRect.height);
+
+    const float dragLeft =
+        (std::max)(titleBarRect.x, leadingOccupiedRight + metrics.dragPaddingLeft);
+    const float dragRight =
+        (std::max)(dragLeft, layout.minimizeButtonRect.x - metrics.dragPaddingRight);
+    layout.dragRect = UIRect(
+        dragLeft,
+        titleBarRect.y,
+        (std::max)(0.0f, dragRight - dragLeft),
+        titleBarRect.height);
+    return layout;
+}
+
+BorderlessWindowChromeHitTarget HitTestBorderlessWindowChrome(
+    const BorderlessWindowChromeLayout& layout,
+    const UIPoint& point) {
+    if (IsPointInsideRect(layout.closeButtonRect, point)) {
+        return BorderlessWindowChromeHitTarget::CloseButton;
+    }
+    if (IsPointInsideRect(layout.maximizeRestoreButtonRect, point)) {
+        return BorderlessWindowChromeHitTarget::MaximizeRestoreButton;
+    }
+    if (IsPointInsideRect(layout.minimizeButtonRect, point)) {
+        return BorderlessWindowChromeHitTarget::MinimizeButton;
+    }
+    if (IsPointInsideRect(layout.dragRect, point)) {
+        return BorderlessWindowChromeHitTarget::DragRegion;
+    }
+    return BorderlessWindowChromeHitTarget::None;
+}
+
+} // namespace XCEngine::UI::Editor::Host