Add horizontal caret scrolling for single-line TextBox

ui/README.md

@@ -80,6 +80,7 @@
 - 调整了 `TreeView` 各层级节点背景框的左侧起点：子节点的圆角矩形现在会随缩进一起右移，更贴合本层内容的实际包裹范围
 - 为 `TreeView` 补充了竖向层级引导线：祖先层级列和展开节点的子树主干线现在都会显示，层级结构更直观
 - 微调了 `TreeView` 每个节点左侧的内部留白和引导线位置，让竖向层级线与下一层级节点边框之间留出更自然的间距
+- 单行 `TextBox` 现在支持基于光标位置的横向自动滚动：当文本向右溢出时，左右箭头、输入插入、删除和鼠标定位都会自动把当前 caret 滚动到可见区域
 
 ## 构建
 

ui/src/TextBox.cpp

@@ -113,6 +113,7 @@ void TextBox::Arrange(const RectF &finalRect)
     {
         RECT rc = ComputeEditorHostRect();
         editor_->SetHostRect(rc);
+        editor_->SetSingleLine(preferredHeight_ <= 100.0f ? TRUE : FALSE);
         editor_->SetContentPadding({});
         editor_->UpdateLayout();
         editor_->SetContentPadding(ComputeEditorContentPadding());

ui/src/tsf/TextEditor.cpp

@@ -24,6 +24,7 @@ void CTextEditor::MoveSelection(UINT nSelStart, UINT nSelEnd)
     _nSelStart = nSelStart;
     _nSelEnd = nSelEnd;
     _layout.ResetCaretBlink();
+    _layout.EnsureCaretVisible(_nSelEnd);
 
     _pTextStore->OnSelectionChange();
 }
@@ -149,6 +150,7 @@ BOOL CTextEditor::InsertAtSelection(LPCWSTR psz)
     _nSelEnd = _nSelStart;
     _layout.ResetCaretBlink();
     UpdateLayout();
+    _layout.EnsureCaretVisible(_nSelEnd);
 
     _pTextStore->OnTextChange(_nSelStart, lOldSelEnd, _nSelEnd);
     _pTextStore->OnSelectionChange();
@@ -177,6 +179,7 @@ BOOL CTextEditor::DeleteAtSelection(BOOL fBack)
 
         _layout.ResetCaretBlink();
         UpdateLayout();
+        _layout.EnsureCaretVisible(_nSelEnd);
         _pTextStore->OnTextChange(_nSelEnd, _nSelEnd + 1, _nSelEnd);
     }
 
@@ -189,6 +192,7 @@ BOOL CTextEditor::DeleteAtSelection(BOOL fBack)
         _nSelEnd = _nSelStart;
         _layout.ResetCaretBlink();
         UpdateLayout();
+        _layout.EnsureCaretVisible(_nSelEnd);
 
         _pTextStore->OnTextChange(_nSelStart, _nSelStart + 1, _nSelStart);
         _pTextStore->OnSelectionChange();
@@ -211,6 +215,7 @@ BOOL CTextEditor::DeleteSelection()
     _nSelEnd = _nSelStart;
     _layout.ResetCaretBlink();
     UpdateLayout();
+    _layout.EnsureCaretVisible(_nSelEnd);
 
     _pTextStore->OnTextChange(_nSelStart, nSelOldEnd, _nSelStart);
     _pTextStore->OnSelectionChange();
@@ -276,7 +281,8 @@ void CTextEditor::UpdateLayout()
     const LONG width = max(_rcHost.right - _rcHost.left, 1L);
     _layout.Layout(GetTextBuffer(), GetTextLength(), &_lfCurrentFont, static_cast<FLOAT>(width), dpi, dpi,
                    static_cast<FLOAT>(_rcContentPadding.left), static_cast<FLOAT>(_rcContentPadding.top),
-                   static_cast<FLOAT>(_rcContentPadding.right), static_cast<FLOAT>(_rcContentPadding.bottom));
+                   static_cast<FLOAT>(_rcContentPadding.right), static_cast<FLOAT>(_rcContentPadding.bottom), _singleLine);
+    _layout.EnsureCaretVisible(_nSelEnd);
 }
 
 void CTextEditor::NotifyLayoutChange()

ui/src/tsf/TextEditor.h

@@ -62,6 +62,10 @@ class CTextEditor : public CTextContainer
     {
         _rcContentPadding = rcPadding;
     }
+    void SetSingleLine(BOOL singleLine)
+    {
+        _singleLine = singleLine;
+    }
 
     UINT GetSelectionStart()
     {
@@ -134,6 +138,7 @@ class CTextEditor : public CTextContainer
     HWND _hwnd;
     RECT _rcHost = {};
     RECT _rcContentPadding = {};
+    BOOL _singleLine = FALSE;
 
     CTextLayout _layout;
     LOGFONT _lfCurrentFont;

ui/src/tsf/TextLayout.cpp

@@ -79,7 +79,7 @@ BOOL CTextLayout::EnsureTextFormat(const LOGFONT *plf, FLOAT dpiY)
 
 BOOL CTextLayout::Layout(const WCHAR *psz, UINT nCnt, const LOGFONT *plf, FLOAT layoutWidthPixels, FLOAT dpiX, FLOAT dpiY,
                          FLOAT paddingLeftPixels, FLOAT paddingTopPixels, FLOAT paddingRightPixels,
-                         FLOAT paddingBottomPixels)
+                         FLOAT paddingBottomPixels, BOOL singleLine)
 {
     Clear();
 
@@ -94,6 +94,7 @@ BOOL CTextLayout::Layout(const WCHAR *psz, UINT nCnt, const LOGFONT *plf, FLOAT
     _paddingTopDips = PixelsToDipsY(kEditorPaddingPixels + paddingTopPixels);
     _paddingRightDips = PixelsToDipsX(kEditorPaddingPixels + paddingRightPixels);
     _paddingBottomDips = PixelsToDipsY(kEditorPaddingPixels + paddingBottomPixels);
+    _singleLine = singleLine;
     _layoutWidth = max(PixelsToDipsX(layoutWidthPixels) - _paddingLeftDips - _paddingRightDips, 1.0f);
 
     const WCHAR *layoutText = psz ? psz : L"";
@@ -112,7 +113,7 @@ BOOL CTextLayout::Layout(const WCHAR *psz, UINT nCnt, const LOGFONT *plf, FLOAT
         return FALSE;
     }
 
-    _pTextLayout->SetWordWrapping(DWRITE_WORD_WRAPPING_WRAP);
+    _pTextLayout->SetWordWrapping(_singleLine ? DWRITE_WORD_WRAPPING_NO_WRAP : DWRITE_WORD_WRAPPING_WRAP);
 
     DWRITE_TEXT_METRICS textMetrics = {};
     if (FAILED(_pTextLayout->GetMetrics(&textMetrics)))
@@ -280,7 +281,9 @@ BOOL CTextLayout::Render(ID2D1HwndRenderTarget *pRenderTarget, const WCHAR *psz,
                 for (UINT j = nSelStartInLine; j < nSelEndInLine; j++)
                 {
                     const D2D1_RECT_F &rc = line.prgCharInfo[j].rc;
-                    pRenderTarget->FillRectangle(D2D1::RectF(rc.left, rc.top, rc.right, rc.bottom), pSelectionBrush);
+                    const FLOAT scrollX = _singleLine ? _horizontalScrollDips : 0.0f;
+                    pRenderTarget->FillRectangle(D2D1::RectF(rc.left - scrollX, rc.top, rc.right - scrollX, rc.bottom),
+                                                 pSelectionBrush);
                 }
             }
         }
@@ -288,7 +291,9 @@ BOOL CTextLayout::Render(ID2D1HwndRenderTarget *pRenderTarget, const WCHAR *psz,
 
     if (_pTextLayout && nCnt > 0)
     {
-        pRenderTarget->DrawTextLayout(D2D1::Point2F(_paddingLeftDips, _paddingTopDips), _pTextLayout, pTextBrush,
+        pRenderTarget->DrawTextLayout(D2D1::Point2F(_paddingLeftDips - (_singleLine ? _horizontalScrollDips : 0.0f),
+                                                    _paddingTopDips),
+                                      _pTextLayout, pTextBrush,
                                       D2D1_DRAW_TEXT_OPTIONS_ENABLE_COLOR_FONT);
     }
 
@@ -318,7 +323,9 @@ BOOL CTextLayout::Render(ID2D1HwndRenderTarget *pRenderTarget, const WCHAR *psz,
                     if (composition.da.crBk.type != TF_CT_NONE)
                     {
                         pCompositionBrush->SetColor(GetAttributeColor(&composition.da.crBk, GetSysColor(COLOR_WINDOW)));
-                        pRenderTarget->FillRectangle(D2D1::RectF(rc.left, rc.top, rc.right, rc.bottom), pCompositionBrush);
+                        const FLOAT scrollX = _singleLine ? _horizontalScrollDips : 0.0f;
+                        pRenderTarget->FillRectangle(D2D1::RectF(rc.left - scrollX, rc.top, rc.right - scrollX, rc.bottom),
+                                                     pCompositionBrush);
                     }
 
                     WCHAR ch = psz[line.nPos + k];
@@ -329,8 +336,9 @@ BOOL CTextLayout::Render(ID2D1HwndRenderTarget *pRenderTarget, const WCHAR *psz,
                     }
 
                     pCompositionBrush->SetColor(compositionTextColor);
+                    const FLOAT scrollX = _singleLine ? _horizontalScrollDips : 0.0f;
                     pRenderTarget->DrawTextW(&ch, 1, _pTextFormat,
-                                             D2D1::RectF(rc.left, rc.top, rc.right + PixelsToDipsX(2.0f), rc.bottom),
+                                             D2D1::RectF(rc.left - scrollX, rc.top, rc.right - scrollX + PixelsToDipsX(2.0f), rc.bottom),
                                              pCompositionBrush, D2D1_DRAW_TEXT_OPTIONS_ENABLE_COLOR_FONT,
                                              DWRITE_MEASURING_MODE_NATURAL);
 
@@ -433,6 +441,21 @@ BOOL CTextLayout::RectFromCharPos(UINT nPos, RECT *prc)
 }
 
 BOOL CTextLayout::RectFromCharPosDips(UINT nPos, D2D1_RECT_F *prc)
+{
+    if (!RectFromCharPosDipsRaw(nPos, prc))
+    {
+        return FALSE;
+    }
+
+    if (_singleLine)
+    {
+        prc->left -= _horizontalScrollDips;
+        prc->right -= _horizontalScrollDips;
+    }
+    return TRUE;
+}
+
+BOOL CTextLayout::RectFromCharPosDipsRaw(UINT nPos, D2D1_RECT_F *prc)
 {
     *prc = D2D1::RectF();
 
@@ -481,7 +504,7 @@ BOOL CTextLayout::RectFromCharPosDips(UINT nPos, D2D1_RECT_F *prc)
 
 UINT CTextLayout::CharPosFromPoint(POINT pt)
 {
-    const FLOAT dipX = PixelsToDipsX(static_cast<FLOAT>(pt.x));
+    const FLOAT dipX = PixelsToDipsX(static_cast<FLOAT>(pt.x)) + (_singleLine ? _horizontalScrollDips : 0.0f);
     const FLOAT dipY = PixelsToDipsY(static_cast<FLOAT>(pt.y));
     for (UINT i = 0; i < _nLineCnt; i++)
     {
@@ -515,7 +538,7 @@ UINT CTextLayout::InsertionIndexFromPoint(POINT pt)
         return 0;
     }
 
-    const FLOAT dipX = PixelsToDipsX(static_cast<FLOAT>(pt.x));
+    const FLOAT dipX = PixelsToDipsX(static_cast<FLOAT>(pt.x)) + (_singleLine ? _horizontalScrollDips : 0.0f);
     const FLOAT dipY = PixelsToDipsY(static_cast<FLOAT>(pt.y));
 
     for (UINT i = 0; i < _nLineCnt; i++)
@@ -576,7 +599,7 @@ UINT CTextLayout::InsertionIndexFromPoint(POINT pt)
 
 UINT CTextLayout::ExactCharPosFromPoint(POINT pt)
 {
-    const FLOAT dipX = PixelsToDipsX(static_cast<FLOAT>(pt.x));
+    const FLOAT dipX = PixelsToDipsX(static_cast<FLOAT>(pt.x)) + (_singleLine ? _horizontalScrollDips : 0.0f);
     const FLOAT dipY = PixelsToDipsY(static_cast<FLOAT>(pt.y));
     for (UINT i = 0; i < _nLineCnt; i++)
     {
@@ -609,6 +632,36 @@ UINT CTextLayout::FineFirstEndCharPosInLine(UINT uCurPos, BOOL bFirst)
     return static_cast<UINT>(-1);
 }
 
+void CTextLayout::EnsureCaretVisible(UINT nPos)
+{
+    if (!_singleLine)
+    {
+        _horizontalScrollDips = 0.0f;
+        return;
+    }
+
+    D2D1_RECT_F rawCaret = {};
+    if (!RectFromCharPosDipsRaw(nPos, &rawCaret))
+    {
+        return;
+    }
+
+    const FLOAT caretWidth = PixelsToDipsX(kCaretWidthPixels);
+    const FLOAT visibleLeft = _paddingLeftDips;
+    const FLOAT visibleRight = _paddingLeftDips + _layoutWidth;
+    const FLOAT displayLeft = rawCaret.left - _horizontalScrollDips;
+    const FLOAT displayRight = max(rawCaret.right, rawCaret.left + caretWidth) - _horizontalScrollDips;
+
+    if (displayLeft < visibleLeft)
+    {
+        _horizontalScrollDips = max(rawCaret.left - visibleLeft, 0.0f);
+    }
+    else if (displayRight > visibleRight)
+    {
+        _horizontalScrollDips = max(max(rawCaret.right, rawCaret.left + caretWidth) - visibleRight, 0.0f);
+    }
+}
+
 void CTextLayout::Clear()
 {
     if (_pTextLayout)

ui/src/tsf/TextLayout.h

@@ -67,6 +67,8 @@ class CTextLayout
         _paddingTopDips = 0.0f;
         _paddingRightDips = 0.0f;
         _paddingBottomDips = 0.0f;
+        _horizontalScrollDips = 0.0f;
+        _singleLine = FALSE;
         _rcCaret = D2D1::RectF();
     }
 
@@ -86,7 +88,7 @@ class CTextLayout
     BOOL Initialize(IDWriteFactory *pDWriteFactory);
     BOOL Layout(const WCHAR *psz, UINT nCnt, const LOGFONT *plf, FLOAT layoutWidthPixels, FLOAT dpiX, FLOAT dpiY,
                 FLOAT paddingLeftPixels = 0.0f, FLOAT paddingTopPixels = 0.0f, FLOAT paddingRightPixels = 0.0f,
-                FLOAT paddingBottomPixels = 0.0f);
+                FLOAT paddingBottomPixels = 0.0f, BOOL singleLine = FALSE);
     BOOL Render(ID2D1HwndRenderTarget *pRenderTarget, const WCHAR *psz, UINT nCnt, UINT nSelStart, UINT nSelEnd,
                 const COMPOSITIONRENDERINFO *pCompositionRenderInfo, UINT nCompositionRenderInfo);
     BOOL RectFromCharPos(UINT nPos, RECT *prc);
@@ -94,6 +96,7 @@ class CTextLayout
     UINT InsertionIndexFromPoint(POINT pt);
     UINT ExactCharPosFromPoint(POINT pt);
     UINT FineFirstEndCharPosInLine(UINT uCurPos, BOOL bFirst);
+    void EnsureCaretVisible(UINT nPos);
     void ToggleCaretBlink();
     void ResetCaretBlink();
     void SetCaretVisible(BOOL fVisible)
@@ -130,6 +133,7 @@ class CTextLayout
   private:
     BOOL EnsureTextFormat(const LOGFONT *plf, FLOAT dpiY);
     BOOL RectFromCharPosDips(UINT nPos, D2D1_RECT_F *prc);
+    BOOL RectFromCharPosDipsRaw(UINT nPos, D2D1_RECT_F *prc);
     FLOAT PixelsToDipsX(FLOAT value) const;
     FLOAT PixelsToDipsY(FLOAT value) const;
     LONG DipsToPixelsX(FLOAT value) const;
@@ -152,6 +156,8 @@ class CTextLayout
     FLOAT _paddingTopDips;
     FLOAT _paddingRightDips;
     FLOAT _paddingBottomDips;
+    FLOAT _horizontalScrollDips;
+    BOOL _singleLine;
 
     LINEINFO *_prgLines;
     UINT _nLineCnt;