From 74bb9cd27242b9320f99ff4d2b50c3051576cc14 Mon Sep 17 00:00:00 2001
From: crupest <crupest@outlook.com>
Date: Tue, 8 Feb 2022 16:53:51 +0800
Subject: ...

---
 include/cru/ui/render/TextRenderObject.h | 121 +++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 include/cru/ui/render/TextRenderObject.h

(limited to 'include/cru/ui/render/TextRenderObject.h')

diff --git a/include/cru/ui/render/TextRenderObject.h b/include/cru/ui/render/TextRenderObject.h
new file mode 100644
index 00000000..3b5f581a
--- /dev/null
+++ b/include/cru/ui/render/TextRenderObject.h
@@ -0,0 +1,121 @@
+#pragma once
+#include "RenderObject.h"
+
+#include <string>
+
+namespace cru::ui::render {
+// Layout logic:
+// 1. If preferred width is set then it is taken to do a text measure. If not
+// set, then max width is taken to do that.
+// 2. If the actual width of text after measure exceeds the required width,
+// coerced value is returned and an error is reported. If preferred width is set
+// and actual width is smaller than that, then preferred width is used. If
+// preferred width is not set, then the same thing is applied to min width.
+// 3. If actual height of text is bigger than max height, an error is reported
+// and coerced value is returned. Or height is lifted up to be at least
+// preferred size if set or min height.
+//
+// If the result layout box is bigger than actual text box, then text is center
+// aligned.
+class CRU_UI_API TextRenderObject : public RenderObject {
+  CRU_DEFINE_CLASS_LOG_TAG(u"cru::ui::render::TextRenderObject")
+
+ public:
+  constexpr static float default_caret_width = 2;
+
+ public:
+  TextRenderObject(std::shared_ptr<platform::graphics::IBrush> brush,
+                   std::shared_ptr<platform::graphics::IFont> font,
+                   std::shared_ptr<platform::graphics::IBrush> selection_brush,
+                   std::shared_ptr<platform::graphics::IBrush> caret_brush);
+  TextRenderObject(const TextRenderObject& other) = delete;
+  TextRenderObject(TextRenderObject&& other) = delete;
+  TextRenderObject& operator=(const TextRenderObject& other) = delete;
+  TextRenderObject& operator=(TextRenderObject&& other) = delete;
+  ~TextRenderObject() override;
+
+  String GetText() const;
+  void SetText(String new_text);
+
+  void SetBrush(std::shared_ptr<platform::graphics::IBrush> new_brush);
+
+  std::shared_ptr<platform::graphics::IFont> GetFont() const;
+  void SetFont(std::shared_ptr<platform::graphics::IFont> font);
+
+  bool IsEditMode();
+  void SetEditMode(bool enable);
+
+  Index GetLineCount();
+  Index GetLineIndexFromCharIndex(Index char_index);
+  float GetLineHeight(Index line_index);
+  std::vector<Rect> TextRangeRect(const TextRange& text_range);
+  Rect TextSinglePoint(gsl::index position, bool trailing);
+  platform::graphics::TextHitTestResult TextHitTest(const Point& point);
+
+  std::optional<TextRange> GetSelectionRange() const {
+    return selection_range_;
+  }
+  void SetSelectionRange(std::optional<TextRange> new_range);
+
+  std::shared_ptr<platform::graphics::IBrush> GetSelectionBrush() const {
+    return selection_brush_;
+  }
+  void SetSelectionBrush(std::shared_ptr<platform::graphics::IBrush> new_brush);
+
+  bool IsDrawCaret() const { return draw_caret_; }
+  void SetDrawCaret(bool draw_caret);
+  void ToggleDrawCaret() { SetDrawCaret(!IsDrawCaret()); }
+
+  // Caret position can be any value. When it is negative, 0 is used. When it
+  // exceeds the size of the string, the size of the string is used.
+  gsl::index GetCaretPosition() const { return caret_position_; }
+  void SetCaretPosition(gsl::index position);
+
+  // Lefttop relative to content lefttop.
+  Rect GetCaretRectInContent();
+  // Lefttop relative to render object lefttop.
+  Rect GetCaretRect();
+
+  std::shared_ptr<platform::graphics::IBrush> GetCaretBrush() const {
+    return caret_brush_;
+  }
+  void GetCaretBrush(std::shared_ptr<platform::graphics::IBrush> brush);
+
+  float GetCaretWidth() const { return caret_width_; }
+  void SetCaretWidth(float width);
+
+  bool IsMeasureIncludingTrailingSpace() const {
+    return is_measure_including_trailing_space_;
+  }
+  void SetMeasureIncludingTrailingSpace(bool including);
+
+  RenderObject* HitTest(const Point& point) override;
+
+  std::u16string_view GetName() const override { return u"TextRenderObject"; }
+
+ protected:
+  void OnDrawContent(platform::graphics::IPainter* painter) override;
+
+  // See remarks of this class.
+  Size OnMeasureContent(const MeasureRequirement& requirement,
+                        const MeasureSize& preferred_size) override;
+  void OnLayoutContent(const Rect& content_rect) override;
+
+  void OnAfterLayout() override;
+
+ private:
+  std::shared_ptr<platform::graphics::IBrush> brush_;
+  std::shared_ptr<platform::graphics::IFont> font_;
+  std::unique_ptr<platform::graphics::ITextLayout> text_layout_;
+
+  std::optional<TextRange> selection_range_ = std::nullopt;
+  std::shared_ptr<platform::graphics::IBrush> selection_brush_;
+
+  bool draw_caret_ = false;
+  gsl::index caret_position_ = 0;
+  std::shared_ptr<platform::graphics::IBrush> caret_brush_;
+  float caret_width_ = default_caret_width;
+
+  bool is_measure_including_trailing_space_ = false;
+};
+}  // namespace cru::ui::render
-- 
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