yahoosearchmodel.cpp

使用yahoo图片搜索功能在手机上的以应用

#include "YahooSearchModel.h"
#include <e32debug.h>

// XML tags
_LIT8(kResultSetTag, "ResultSet");
_LIT8(kResultTag, "Result");
_LIT8(kTitleTag, "Title");
_LIT8(kSummaryTag, "Summary");
_LIT8(kUrlTag, "Url");
_LIT8(kFileSizeTag, "FileSize");
_LIT8(kFileFormatTag, "FileFormat");
_LIT8(kHeightTag, "Height");
_LIT8(kWidthTag, "Width");
_LIT8(kThumbnailTag, "Thumbnail");

CYahooSearchModel::CYahooSearchModel()
{
	iParser = NULL;
	iInEntry = false;
	iCurrContent = NULL;
	iImages = NULL;
	iTagStack = NULL;
}

CYahooSearchModel::~CYahooSearchModel()
{
	iFeedText.Close();	
	delete iImages;
	delete iTagStack;
	delete iParser;
}

void CYahooSearchModel::ConstructL() 
{
	iImages = new(ELeave) CArrayFixFlat<TYahooImageInfo>(4);	
	iTagStack = new(ELeave) CArrayFixFlat<TTagBuf>(4);
}
		
void CYahooSearchModel::AppendL(const TDesC8& text)
{
	int newLength = iFeedText.Length() + text.Length();
	if (iFeedText.MaxLength() < newLength)
	{
		iFeedText.ReAllocL(newLength);
	}
	iFeedText.Append(text);
}
		
void CYahooSearchModel::ParseL()
{
	iImages->Reset();
	int len = iFeedText.Length();
	
	_LIT8(mimeType, "text/xml");
	iParser = Xml::CParser::NewL(mimeType, *this);

	iTagStack->Reset();
	
	Xml::ParseL(*iParser, iFeedText);
	iFeedText.SetLength(0);
	iFeedText.ReAlloc(0);
	delete iParser;
	iParser = NULL;
}
		
void CYahooSearchModel::OnStartDocumentL(const Xml::RDocumentParameters& aDocParam, TInt aErrorCode)
{
}

void CYahooSearchModel::OnEndDocumentL(TInt aErrorCode)
{
}

void CYahooSearchModel::OnStartElementL(const Xml::RTagInfo& aElement, const Xml::RAttributeArray& aAttributes, 
								 TInt aErrorCode)
{
	const TDesC8& tag = aElement.LocalName().DesC();
	iCurrContent = NULL;
	if (tag == kResultTag)
	{
		iInEntry = true;
		iPendingImage.title.SetLength(0);
		iPendingImage.summary.SetLength(0);
		iPendingImage.url.SetLength(0);
		iPendingImage.fileSize = 0;
		iPendingImage.width = 0;
		iPendingImage.height = 0;
		iPendingImage.thumbnailUrl.SetLength(0);
		iPendingImage.thumbnailWidth = 0;
		iPendingImage.thumbnailHeight = 0;
		iPendingImage.invalid = false;
	} else if (tag == kTitleTag) 
	{
		iCurrContent = &iPendingImage.title;
	} else if (tag == kSummaryTag) 
	{
		iCurrContent = &iPendingImage.summary;
	} else if (tag == kUrlTag) 
	{
		TTagBuf currTag = PeekTag();
		if (currTag == kThumbnailTag)
		{
			iCurrContent = &iPendingImage.thumbnailUrl;
		} else
		{
			iCurrContent = &iPendingImage.url;
		}
	} else if (tag == kFileFormatTag) 
	{
		iCurrContent = &iPendingImage.fileFormat;
	} else if (tag == kHeightTag || tag == kWidthTag || tag == kFileSizeTag) {
		iCurrContent = &iNumberText;	
	}
	PushTagL(tag);
}

void CYahooSearchModel::OnEndElementL(const Xml::RTagInfo& aElement, TInt aErrorCode)
{
	TTagBuf poppedTag = PopTag();
	TTagBuf currTag = PeekTag();
	if (poppedTag == kResultTag)
	{
		iImages->AppendL(iPendingImage);
		iInEntry = false;
	} else if (poppedTag == kFileSizeTag || poppedTag == kWidthTag || poppedTag == kHeightTag) 
	{
		TLex lex(iNumberText);
		TInt val;
		if (lex.Val(val) == KErrNone)
		{
			if (poppedTag == kFileSizeTag) {
				iPendingImage.fileSize = val;
			} else 
			{ 
				if (currTag == kThumbnailTag)
				{
					if (poppedTag == kWidthTag)
						iPendingImage.thumbnailWidth = val;
					else if (poppedTag == kHeightTag)
						iPendingImage.thumbnailHeight = val;
					else
						iPendingImage.invalid = true;
					
				} else if (currTag == kResultTag) 
				{
					if (poppedTag == kWidthTag)
						iPendingImage.width = val;
					else if (poppedTag == kHeightTag)
						iPendingImage.height = val;
					else
						iPendingImage.invalid = true;					
				} else
				{
					iPendingImage.invalid = true;
				}
			}
		}
	}
	iCurrContent = NULL;
}

void CYahooSearchModel::OnContentL(const TDesC8& aBytes, TInt aErrorCode)
{
	if (iCurrContent)
	{
		AppendDesCL(aBytes, *iCurrContent);
	}
}

void CYahooSearchModel::OnStartPrefixMappingL(const RString& aPrefix, const RString& aUri, 
												TInt aErrorCode)
{
	
}

void CYahooSearchModel::OnEndPrefixMappingL(const RString& aPrefix, TInt aErrorCode)
{
	
}

void CYahooSearchModel::OnIgnorableWhiteSpaceL(const TDesC8& aBytes, TInt aErrorCode)
{
	
}

void CYahooSearchModel::OnSkippedEntityL(const RString& aName, TInt aErrorCode)
{
	
}

void CYahooSearchModel::OnProcessingInstructionL(const TDesC8& aTarget, const TDesC8& aData, 
													TInt aErrorCode)
{
	
}

void CYahooSearchModel::OnError(TInt aErrorCode)
{
	
}

TAny* CYahooSearchModel::GetExtendedInterface(const TInt32 aUid)
{
	return NULL;
}

void CYahooSearchModel::PushTagL(TTagBuf tag)
{
	iTagStack->AppendL(tag);
}

CYahooSearchModel::TTagBuf CYahooSearchModel::PeekTag()
{
	TTagBuf result;
	if (iTagStack->Count() > 0)
		result = (*iTagStack)[iTagStack->Count()-1];
	return result;
}

CYahooSearchModel::TTagBuf CYahooSearchModel::PopTag()
{
	TTagBuf result;
	if (iTagStack->Count() > 0) 
	{
		result = (*iTagStack)[iTagStack->Count()-1];
		// since we're making the array smaller it ResizeL will not leave
		TRAPD(err, iTagStack->ResizeL(iTagStack->Count()-1));
	}
	return result;
}

void CYahooSearchModel::AppendDesCL(const TDesC8& src, TDes& dest)
{
	int length = src.Length();
	RBuf buf;
	buf.CreateL(length);
	buf.Copy(src);

	if (length + dest.Length() > dest.MaxLength())
	{
		length = dest.MaxLength() - dest.Length();
		buf.SetLength(length);
	}
	dest.Append(buf);
	buf.Close();
}