/**
* Returns a structure compare viewer based on an old viewer and an input object. If the old
* viewer is suitable for showing the input, the old viewer is returned. Otherwise, the input's
* type is used to find a viewer descriptor in the registry which in turn is used to create a
* structure compare viewer under the given parent composite. If no viewer descriptor can be found
* <code>null</code> is returned.
*
* @param oldViewer a new viewer is only created if this old viewer cannot show the given input
* @param input the input object for which to find a structure viewer
* @param parent the SWT parent composite under which the new viewer is created
* @param configuration a configuration which is passed to a newly created viewer
* @return the compare viewer which is suitable for the given input object or <code>null</code>
*/
public Viewer findStructureViewer(
Viewer oldViewer, ICompareInput input, Composite parent, CompareConfiguration configuration) {
ViewerDescriptor[] descriptors = findStructureViewerDescriptor(oldViewer, input, configuration);
if (descriptors == null || descriptors.length == 0) {
// we didn't found any viewer so far.
// now we try to find a structure creator for the generic StructureDiffViewer
IContentType ctype = getCommonType(input);
String[] types = getTypes(input);
String type = null;
if (isHomogenous(types)) {
type = normalizeCase(types[0]);
}
StructureCreatorDescriptor scc = null;
initializeRegistries();
Object desc = fStructureCreators.search(ctype); // search for content type
if (desc instanceof StructureCreatorDescriptor) scc = (StructureCreatorDescriptor) desc;
if (scc == null && type != null)
scc = getStructureCreator(type); // search for old-style type scheme
if (scc != null) {
IStructureCreator sc = scc.createStructureCreator();
if (sc != null) {
StructureDiffViewer sdv = new StructureDiffViewer(parent, configuration);
sdv.setStructureCreator(sc);
return sdv;
}
}
return null;
}
return getViewer(descriptors[0], oldViewer, parent, configuration);
}
public ViewerDescriptor[] findContentViewerDescriptor(
Viewer oldViewer, Object in, CompareConfiguration cc) {
Set result = new LinkedHashSet();
if (in instanceof IStreamContentAccessor) {
String type = ITypedElement.TEXT_TYPE;
if (in instanceof ITypedElement) {
ITypedElement tin = (ITypedElement) in;
IContentType ct = getContentType(tin);
if (ct != null) {
initializeRegistries();
List list = fContentViewers.searchAll(ct);
if (list != null) result.addAll(list);
}
String ty = tin.getType();
if (ty != null) type = ty;
}
initializeRegistries();
List list = fContentViewers.searchAll(type);
if (list != null) result.addAll(list);
// fallback
result.add(
fContentViewers.search(
Platform.getContentTypeManager().getContentType(IContentTypeManager.CT_TEXT)));
return (ViewerDescriptor[]) result.toArray(new ViewerDescriptor[0]);
}
if (!(in instanceof ICompareInput)) return null;
ICompareInput input = (ICompareInput) in;
IContentType ctype = getCommonType(input);
if (ctype != null) {
initializeRegistries();
List list = fContentMergeViewers.searchAll(ctype);
if (list != null) result.addAll(list);
}
String[] types = getTypes(input);
String type = null;
if (isHomogenous(types)) type = types[0];
if (ITypedElement.FOLDER_TYPE.equals(type)) return null;
if (type == null) {
int n = 0;
for (int i = 0; i < types.length; i++)
if (!ITypedElement.UNKNOWN_TYPE.equals(types[i])) {
n++;
if (type == null) type = types[i]; // remember the first known type
}
if (n > 1) // don't use the type if there were more than one
type = null;
}
if (type != null) {
initializeRegistries();
List list = fContentMergeViewers.searchAll(type);
if (list != null) result.addAll(list);
}
// fallback
String leftType = guessType(input.getLeft());
String rightType = guessType(input.getRight());
if (leftType != null || rightType != null) {
boolean right_text = rightType != null && ITypedElement.TEXT_TYPE.equals(rightType);
boolean left_text = leftType != null && ITypedElement.TEXT_TYPE.equals(leftType);
initializeRegistries();
if ((rightType != null && !right_text) || (leftType != null && !left_text)) {
List list = fContentMergeViewers.searchAll(BINARY_TYPE);
if (list != null) result.addAll(list);
}
List list = fContentMergeViewers.searchAll(ITypedElement.TEXT_TYPE);
if (list != null) result.addAll(list);
return (ViewerDescriptor[]) result.toArray(new ViewerDescriptor[0]);
}
return null;
}
/**
* Returns a stream merger for the given content type.
*
* @param type the type for which to find a stream merger
* @return a stream merger for the given type, or <code>null</code> if no stream merger has been
* registered
*/
public IStreamMerger createStreamMerger(IContentType type) {
initializeRegistries();
StreamMergerDescriptor descriptor = (StreamMergerDescriptor) fStreamMergers.search(type);
if (descriptor != null) return descriptor.createStreamMerger();
return null;
}
/**
* Returns an structure creator descriptor for the given type.
*
* @param type the type for which to find a descriptor
* @return a descriptor for the given type, or <code>null</code> if no descriptor has been
* registered
*/
public StructureCreatorDescriptor getStructureCreator(String type) {
initializeRegistries();
return (StructureCreatorDescriptor) fStructureCreators.search(type);
}