...

5 files changed, 20 insertions, 3 deletions

diff --git a/include/cru/platform/graph_base.hpp b/include/cru/platform/graph_base.hpp
index 0b997770..c880c7a2 100644
--- a/include/cru/platform/graph_base.hpp
+++ b/include/cru/platform/graph_base.hpp
@@ -229,6 +229,15 @@ struct TextRange final {
 
   gsl::index GetEnd() const { return position + count; }
 
+  TextRange Normalize() const {
+    auto result = *this;
+    if (result.count < 0) {
+      result.position += result.count;
+      result.count = -result.count;
+    }
+    return result;
+  }
+
   gsl::index position = 0;
   gsl::index count = 0;
 };
diff --git a/include/cru/ui/render/text_render_object.hpp b/include/cru/ui/render/text_render_object.hpp
index 1c472753..c062c9f0 100644
--- a/include/cru/ui/render/text_render_object.hpp
+++ b/include/cru/ui/render/text_render_object.hpp
@@ -27,7 +27,7 @@ class TextRenderObject : public RenderObject {
   void SetFont(std::shared_ptr<platform::graph::IFont> font);
 
   std::vector<Rect> TextRangeRect(const TextRange& text_range);
-  Point TextSingleRect(int position, bool trailing);
+  Point TextSingleRect(gsl::index position, bool trailing);
   platform::graph::TextHitTestResult TextHitTest(const Point& point);
 
   std::optional<TextRange> GetSelectionRange() const {
diff --git a/include/cru/win/graph/direct/text_layout.hpp b/include/cru/win/graph/direct/text_layout.hpp
index a9b89011..90faadf9 100644
--- a/include/cru/win/graph/direct/text_layout.hpp
+++ b/include/cru/win/graph/direct/text_layout.hpp
@@ -37,6 +37,8 @@ class DWriteTextLayout : public DirectGraphResource,
   void SetMaxHeight(float max_height) override;
 
   Rect GetTextBounds() override;
+  // Return empty vector if text_range.count is 0. Text range could be in
+  // reverse direction, it should be normalized first in implementation.
   std::vector<Rect> TextRangeRect(const TextRange& text_range) override;
   Point TextSingleRect(gsl::index position, bool trailing) override;
   TextHitTestResult HitTest(const Point& point) override;
diff --git a/src/ui/render/text_render_object.cpp b/src/ui/render/text_render_object.cpp
index be02f8fe..e8368480 100644
--- a/src/ui/render/text_render_object.cpp
+++ b/src/ui/render/text_render_object.cpp
@@ -50,7 +50,7 @@ std::vector<Rect> TextRenderObject::TextRangeRect(const TextRange& text_range) {
   return text_layout_->TextRangeRect(text_range);
 }
 
-Point TextRenderObject::TextSingleRect(int position, bool trailing) {
+Point TextRenderObject::TextSingleRect(gsl::index position, bool trailing) {
   return text_layout_->TextSingleRect(position, trailing);
 }
 
diff --git a/src/win/graph/direct/text_layout.cpp b/src/win/graph/direct/text_layout.cpp
index f582dd0a..4a742694 100644
--- a/src/win/graph/direct/text_layout.cpp
+++ b/src/win/graph/direct/text_layout.cpp
@@ -66,7 +66,13 @@ Rect DWriteTextLayout::GetTextBounds() {
   return Rect{metrics.left, metrics.top, metrics.width, metrics.height};
 }
 
-std::vector<Rect> DWriteTextLayout::TextRangeRect(const TextRange& text_range) {
+std::vector<Rect> DWriteTextLayout::TextRangeRect(
+    const TextRange& text_range_arg) {
+  if (text_range_arg.count == 0) {
+    return {};
+  }
+  const auto text_range = text_range_arg.Normalize();
+
   // TODO: This can be faster with one iteration.
   const int start_index =
       IndexUtf8ToUtf16(text_, static_cast<int>(text_range.position), w_text_);