/* * Copyright (c) 1999-2000, Eric Moon. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions, and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions, and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ // ExportContext.h // * PURPOSE // Describe the state of a serialization ('save') operation. // The 'load' equivalent is ImportContext. // // * HISTORY // e.moon 28jun99 Begun #ifndef __ExportContext_H__ #define __ExportContext_H__ #include <Debug.h> #include <String.h> #include <iostream> #include <list> #include <utility> #include "cortex_defs.h" __BEGIN_CORTEX_NAMESPACE class BDataIO; class IPersistent; class ExportContext; // writeAttr() helper inline BString& _pad_with_spaces(BString& out, const char* text, ExportContext& context, uint16 column); class ExportContext { public: ExportContext(); ExportContext(BDataIO* stream); virtual ~ExportContext(); // the output stream BDataIO* stream; // the element stack struct element_entry { element_entry() : hasAttributes(false), hasContent(false) {} BString name; bool hasAttributes; bool hasContent; }; typedef std::list<element_entry> element_list; element_list m_elementStack; public: // *** XML formatting helpers // writes a start tag. should be called from // IPersistent::xmlExportBegin() // (or xmlExportContent(), if you're writing nested elements) void beginElement(const char* name); // writes an end tag corresponding to the current element. // should only be called from IPersistent::xmlExportEnd() or // xmlExportContent(). void endElement(); // indicates that content follows (writes the end of the // current element's start tag.) void beginContent(); // // writes an attribute. // // should only be called from IPersistent::xmlExportAttributes(). // template <class T> // void writeAttr( // const char* key, // T value) { // // if(!m_objectStack.size()) { // reportError("writeAttr(): no object being written.\n"); // return; // } // ASSERT(m_elementStack.size()); // if(m_state != WRITE_ATTRIBUTES && // m_state != WRITE_CONTENT) { // reportError("writeAttr(): not allowed (state mismatch).\n"); // return; // } // // m_elementStack.back().hasAttributes = true; // // BString out; // out << "\n" << indentString() << key; // _pad_with_spaces(out, key, *this, m_attrColumn) << " = '" << value << '\''; // // writeString(out); // } // [e.moon 22dec99] // non-template forms of writeAttr() void writeAttr( const char* key, int8 value); void writeAttr( const char* key, uint8 value); void writeAttr( const char* key, int16 value); void writeAttr( const char* key, uint16 value); void writeAttr( const char* key, int32 value); void writeAttr( const char* key, uint32 value); void writeAttr( const char* key, int64 value); void writeAttr( const char* key, uint64 value); void writeAttr( const char* key, const char* value); void writeAttr( const char* key, const BString& value); void writeAttr( const char* key, float value); // writes a child object. // should only be called from IPersistent::xmlExportContent(). // returns B_OK on success, or B_ERROR if an error occurred. status_t writeObject( IPersistent* object); // writes an arbitrary string to the stream (calls reportError() // on failure.) status_t writeString( const BString& string); status_t writeString( const char* data, ssize_t length); public: // *** indentation helpers // return a string padded with spaces to the current // indent level const char* indentString() const; // return the current indent level uint16 indentLevel() const; // decrease the indent level void indentLess(); // increase the indent level void indentMore(); // +++++ extra formatting controls needed [e.moon 1dec99] // * attrColumn access // * single vs. multi-line element formatting public: // *** error operations // register a fatal error; halts the write process // as soon as possible. void reportError( const char* text); // fetch error text const char* errorText() const { return m_error.String(); } private: // members // * Indentation/formatting uint16 m_indentLevel; uint16 m_indentIncrement; uint16 m_attrColumn; BString m_indentString; // * State enum state_t { INIT, WRITE_BEGIN, WRITE_ATTRIBUTES, WRITE_CONTENT, WRITE_END, ABORT }; state_t m_state; BString m_error; // object stack struct object_entry { object_entry() : element(0), object(0) {} const char* element; IPersistent* object; }; typedef std::list<object_entry> object_list; object_list m_objectStack; private: void _dumpElementStack( BString& out); }; // ExportContext::writeAttr() helper inline BString& _pad_with_spaces( BString& out, const char* text, ExportContext& context, uint16 column) { int16 spaces = column - (strlen(text) + context.indentLevel()); if(spaces < 0) spaces = 0; while(spaces--) out << ' '; return out; } __END_CORTEX_NAMESPACE #endif /*__ExportContext_H__*/
