Split CFDE_CSSTextBuf in two.

For the external buffer use case, use a CFDE_CSSExtTextBuf instead. With
the split, both text buffer implementations are simpler now. As a
result, it becomes obvious where it never fails. Adjust callers
accordingly.

Change-Id: I7b53d36593172487b8c939e6a55af2437ea4ee5a
Reviewed-on: https://pdfium-review.googlesource.com/6932
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>

1 files changed, 34 insertions, 0 deletions

diff --git a/xfa/fde/css/cfde_cssexttextbuf.h b/xfa/fde/css/cfde_cssexttextbuf.h
new file mode 100644
index 0000000000..0760182f25
--- /dev/null
+++ b/xfa/fde/css/cfde_cssexttextbuf.h
@@ -0,0 +1,34 @@
+// Copyright 2017 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef XFA_FDE_CSS_CFDE_CSSEXTTEXTBUF_H_
+#define XFA_FDE_CSS_CFDE_CSSEXTTEXTBUF_H_
+
+#include "core/fxcrt/fx_system.h"
+
+class CFDE_CSSExtTextBuf {
+ public:
+  CFDE_CSSExtTextBuf();
+  ~CFDE_CSSExtTextBuf();
+
+  void AttachBuffer(const wchar_t* pBuffer, int32_t iBufLen);
+
+  bool IsEOF() const { return m_iDatPos >= m_iDatLen; }
+
+  wchar_t GetChar() const { return m_pExtBuffer[m_iDatPos]; }
+  wchar_t GetNextChar() const {
+    return (m_iDatPos + 1 >= m_iDatLen) ? 0 : m_pExtBuffer[m_iDatPos + 1];
+  }
+
+  void MoveNext() { m_iDatPos++; }
+
+ protected:
+  const wchar_t* m_pExtBuffer;
+  int32_t m_iDatLen;
+  int32_t m_iDatPos;
+};
+
+#endif  // XFA_FDE_CSS_CFDE_CSSEXTTEXTBUF_H_