xmpnodeutils.java

flash xmp sdk,flash官方SDK

		}
		else if (stepKind == XMPPath.QUALIFIER_STEP)
		{
			nextNode = findQualifierNode(
				parentNode, nextStep.getName().substring(1), createNodes);
		}
		else
		{
			// This is an array indexing step. First get the index, then get the node.

			if (!parentNode.getOptions().isArray())
			{
				throw new XMPException("Indexing applied to non-array", XMPError.BADXPATH);
			}

			if (stepKind == XMPPath.ARRAY_INDEX_STEP)
			{
				index = findIndexedItem(parentNode, nextStep.getName(), createNodes);
			}
			else if (stepKind == XMPPath.ARRAY_LAST_STEP)
			{
				index = parentNode.getChildrenLength();
			}
			else if (stepKind == XMPPath.FIELD_SELECTOR_STEP)
			{
				String[] result = Utils.splitNameAndValue(nextStep.getName());
				String fieldName = result[0];
				String fieldValue = result[1];
				index = lookupFieldSelector(parentNode, fieldName, fieldValue);
			}
			else if (stepKind == XMPPath.QUAL_SELECTOR_STEP)
			{
				String[] result = Utils.splitNameAndValue(nextStep.getName());
				String qualName = result[0];
				String qualValue = result[1];
				index = lookupQualSelector(
					parentNode, qualName, qualValue, nextStep.getAliasForm());
			}
			else
			{
				throw new XMPException("Unknown array indexing step in FollowXPathStep",
						XMPError.INTERNALFAILURE);
			}

			if (1 <= index  &&  index <=  parentNode.getChildrenLength())
			{
				nextNode = parentNode.getChild(index);
			}
		}
	
		return nextNode;		
	}


	/**
	 * Find or create a qualifier node under a given parent node. Returns a pointer to the 
	 * qualifier node, and optionally an iterator for the node's position in 
	 * the parent's vector of qualifiers. The iterator is unchanged if no qualifier node (null) 
	 * is returned.
	 * <em>Note:</em> On entry, the qualName parameter must not have the leading '?' from the 
	 * XMPPath step.
	 * 
	 * @param parent the parent XMPNode 
	 * @param qualName the qualifier name
	 * @param createNodes flag if nodes shall be created
	 * @return Returns the qualifier node if found or created, <code>null</code> otherwise.
	 * @throws XMPException 
	 */
	private static XMPNode findQualifierNode(XMPNode parent, String qualName, boolean createNodes)
			throws XMPException
	{
		assert !qualName.startsWith("?");
		
		XMPNode qualNode = parent.findQualifierByName(qualName);
		
		if (qualNode == null  &&  createNodes)
		{
			qualNode = new XMPNode(qualName, null);
			qualNode.setImplicit(true);
	
			parent.addQualifier(qualNode);				
		}
		
		return qualNode;
	}
	
	
	/**
	 * @param arrayNode an array node
	 * @param segment the segment containing the array index
	 * @param createNodes flag if new nodes are allowed to be created.
	 * @return Returns the index or index = -1 if not found
	 * @throws XMPException Throws Exceptions
	 */
	private static int findIndexedItem(XMPNode arrayNode, String segment, boolean createNodes)
			throws XMPException
	{
		int index = 0;
	
		try
		{
			segment = segment.substring(1, segment.length() - 1);
			index = Integer.parseInt(segment);
			if (index < 1)
			{
				throw new XMPException("Array index must be larger than zero",
						XMPError.BADXPATH);
			}
		}
		catch (NumberFormatException e)
		{
			throw new XMPException("Array index not digits.", XMPError.BADXPATH);
		}
	
		if (index == arrayNode.getChildrenLength() + 1  &&  createNodes)
		{
			// Append a new last + 1 node.
			XMPNode newItem = new XMPNode(ARRAY_ITEM_NAME, null);
			newItem.setImplicit(true);
			arrayNode.addChild(newItem);
		}
	
		// Don't throw here for a too large index. setProperty() will throw,
		// getProperty() will not.
		if (index > arrayNode.getChildrenLength())
		{
			index = -1;
		}
		return index;
	}
	
	
	/**
	 * Searches for a field selector in a node:
	 * [fieldName="value] - an element in an array of structs, chosen by a field value.
	 * No implicit nodes are created by field selectors. 
	 * 
	 * @param arrayNode
	 * @param fieldName
	 * @param fieldValue
	 * @return Returns the index of the field if found, otherwise -1.
	 * @throws XMPException 
	 */
	private static int lookupFieldSelector(XMPNode arrayNode, String fieldName, String fieldValue)
		throws XMPException
	{
		int result = -1;
		
		for (int index = 1; index <= arrayNode.getChildrenLength()  &&  result < 0; index++)
		{
			XMPNode currItem = arrayNode.getChild(index);
	
			if (!currItem.getOptions().isStruct())
			{
				throw new XMPException("Field selector must be used on array of struct",
						XMPError.BADXPATH);
			}
	
			for (int f = 1; f <= currItem.getChildrenLength(); f++)
			{
				XMPNode currField = currItem.getChild(f);
				if (!fieldName.equals(currField.getName()))
				{
					continue;
				}
				if (fieldValue.equals(currField.getValue())) 
				{
					result = index;
					break;
				}
			}
		}
		
		return result;
	}
	
	
	/**
	 * Searches for a qualifier selector in a node:
	 * [?qualName="value"] - an element in an array, chosen by a qualifier value.
	 * No implicit nodes are created for qualifier selectors, 
	 * except for an alias to an x-default item.
	 * 
	 * @param arrayNode an array node 
	 * @param qualName the qualifier name
	 * @param qualValue the qualifier value
	 * @param aliasForm in case the qual selector results from an alias,
	 * 		  an x-default node is created if there has not been one. 
	 * @return Returns the index of th
	 * @throws XMPException 
	 */
	private static int lookupQualSelector(XMPNode arrayNode, String qualName, 
		String qualValue, int aliasForm) throws XMPException
	{
		if (XML_LANG.equals(qualName))
		{
			qualValue = Utils.normalizeLangValue(qualValue);
			int index = XMPNodeUtils.lookupLanguageItem(arrayNode, qualValue);
			if (index < 0  &&  (aliasForm & AliasOptions.PROP_ARRAY_ALT_TEXT) > 0)
			{	
				XMPNode langNode = new XMPNode(ARRAY_ITEM_NAME, null);
				XMPNode xdefault = new XMPNode(XML_LANG, X_DEFAULT, null);
				langNode.addQualifier(xdefault);
				arrayNode.addChild(1, langNode);
				return 1;
			}
			else
			{
				return index;
			}
		}
		else
		{
			for (int index = 1; index < arrayNode.getChildrenLength(); index++)
			{
				XMPNode currItem = arrayNode.getChild(index);
		
				for (Iterator it = currItem.iterateQualifier(); it.hasNext();)
				{
					XMPNode qualifier = (XMPNode) it.next();
					if (qualName.equals(qualifier.getName())  &&
						qualValue.equals(qualifier.getValue()))
					{
						return index;
					}
				}
			}
			return -1;
		}	
	}


	/**
	 * Make sure the x-default item is first. Touch up &quot;single value&quot;
	 * arrays that have a default plus one real language. This case should have
	 * the same value for both items. Older Adobe apps were hardwired to only
	 * use the &quot;x-default&quot; item, so we copy that value to the other
	 * item.
	 * 
	 * @param arrayNode
	 *            an alt text array node
	 */
	static void normalizeLangArray(XMPNode arrayNode)
	{
		if (!arrayNode.getOptions().isArrayAltText())
		{
			return;
		}
	
		// check if node with x-default qual is first place
		for (int i = 2; i <= arrayNode.getChildrenLength(); i++)
		{
			XMPNode child = arrayNode.getChild(i);
			if (child.hasQualifier() && X_DEFAULT.equals(child.getQualifier(1).getValue()))
			{
				// move node to first place
				try
				{
					arrayNode.removeChild(i);
					arrayNode.addChild(1, child);
				}
				catch (XMPException e)
				{
					// cannot occur, because same child is removed before
					assert false;
				}
				
				if (i == 2)
				{
					arrayNode.getChild(2).setValue(child.getValue());
				}
				break;
			}
		}
	}


	/**
	 * See if an array is an alt-text array. If so, make sure the x-default item
	 * is first.
	 * 
	 * @param arrayNode
	 *            the array node to check if its an alt-text array
	 */
	static void detectAltText(XMPNode arrayNode)
	{
		if (arrayNode.getOptions().isArrayAlternate() && arrayNode.hasChildren())
		{
			boolean isAltText = false;
			for (Iterator it = arrayNode.iterateChildren(); it.hasNext();)
			{
				XMPNode child = (XMPNode) it.next();
				if (child.getOptions().getHasLanguage())
				{
					isAltText = true;
					break;
				}
			}
	
			if (isAltText)
			{
				arrayNode.getOptions().setArrayAltText(true);
				normalizeLangArray(arrayNode);
			}
		}
	}


	/**
	 * Appends a language item to an alt text array.
	 * 
	 * @param arrayNode the language array
	 * @param itemLang the language of the item
	 * @param itemValue the content of the item
	 * @throws XMPException Thrown if a duplicate property is added
	 */
	static void appendLangItem(XMPNode arrayNode, String itemLang, String itemValue)
			throws XMPException
	{
		XMPNode newItem = new XMPNode(ARRAY_ITEM_NAME, itemValue, null);
		XMPNode langQual = new XMPNode(XML_LANG, itemLang, null);
		newItem.addQualifier(langQual);
	
		if (!X_DEFAULT.equals(langQual.getValue()))
		{
			arrayNode.addChild(newItem);
		}
		else
		{
			arrayNode.addChild(1, newItem);
		}
	}


	/**
	 * <ol>
	 * <li>Look for an exact match with the specific language.
	 * <li>If a generic language is given, look for partial matches.
	 * <li>Look for an "x-default"-item.
	 * <li>Choose the first item.
	 * </ol>
	 * 
	 * @param arrayNode
	 *            the alt text array node
	 * @param genericLang
	 *            the generic language
	 * @param specificLang
	 *            the specific language
	 * @return Returns the kind of match as an Integer and the found node in an
	 *         array.
	 * 
	 * @throws XMPException
	 */
	static Object[] chooseLocalizedText(XMPNode arrayNode, String genericLang, String specificLang)
			throws XMPException
	{
		// See if the array has the right form. Allow empty alt arrays,
		// that is what parsing returns.
		if (!arrayNode.getOptions().isArrayAltText())
		{
			throw new XMPException("Localized text array is not alt-text", XMPError.BADXPATH);
		}
		else if (!arrayNode.hasChildren())
		{
			return new Object[] { new Integer(XMPNodeUtils.CLT_NO_VALUES), null };
		}
	
		int foundGenericMatches = 0;
		XMPNode resultNode = null;
		XMPNode xDefault = null;
	
		// Look for the first partial match with the generic language.
		for (Iterator it = arrayNode.iterateChildren(); it.hasNext();)
		{
			XMPNode currItem = (XMPNode) it.next();
	
			// perform some checks on the current item
			if (currItem.getOptions().isCompositeProperty())
			{
				throw new XMPException("Alt-text array item is not simple", XMPError.BADXPATH);
			}
			else if (!currItem.hasQualifier()
					|| !XML_LANG.equals(currItem.getQualifier(1).getName()))
			{
				throw new XMPException("Alt-text array item has no language qualifier",
						XMPError.BADXPATH);
			}
	
			String currLang = currItem.getQualifier(1).getValue();
	
			// Look for an exact match with the specific language.
			if (specificLang.equals(currLang))
			{
				return new Object[] { new Integer(XMPNodeUtils.CLT_SPECIFIC_MATCH), currItem };
			}
			else if (genericLang != null && currLang.startsWith(genericLang))
			{
				if (resultNode == null)
				{
					resultNode = currItem;
				}
				// ! Don't return/break, need to look for other matches.
				foundGenericMatches++;
			}
			else if (X_DEFAULT.equals(currLang))
			{
				xDefault = currItem;
			}
		}
	
		// evaluate loop
		if (foundGenericMatches == 1)
		{
			return new Object[] { new Integer(XMPNodeUtils.CLT_SINGLE_GENERIC), resultNode };
		}
		else if (foundGenericMatches > 1)
		{
			return new Object[] { new Integer(XMPNodeUtils.CLT_MULTIPLE_GENERIC), resultNode };
		}
		else if (xDefault != null)
		{
			return new Object[] { new Integer(XMPNodeUtils.CLT_XDEFAULT), xDefault };
		}
		else
		{
			// Everything failed, choose the first item.
			return new Object[] { new Integer(XMPNodeUtils.CLT_FIRST_ITEM), arrayNode.getChild(1) };
		}
	}


	/**
	 * Looks for the appropriate language item in a text alternative array.item
	 * 
	 * @param arrayNode
	 *            an array node
	 * @param language
	 *            the requested language
	 * @return Returns the index if the language has been found, -1 otherwise.
	 * @throws XMPException
	 */
	static int lookupLanguageItem(XMPNode arrayNode, String language) throws XMPException
	{
		if (!arrayNode.getOptions().isArray())
		{
			throw new XMPException("Language item must be used on array", XMPError.BADXPATH);
		}
	
		for (int index = 1; index <= arrayNode.getChildrenLength(); index++)
		{
			XMPNode child = arrayNode.getChild(index);
			if (!child.hasQualifier() || !XML_LANG.equals(child.getQualifier(1).getName()))
			{
				continue;
			}
			else if (language.equals(child.getQualifier(1).getValue()))
			{
				return index;
			}
		}
	
		return -1;
	}
}