In this tutorial we will implement a custom search for your RCP. Therefore we will first create the search logic and add UI components in a second step.
I found few resources on search functionality, here are some from the Eclipse FAQs:
To have something to search for we will look for files on the local file system. So this is our target for today:
Source code for this tutorial is available on github as a
single zip archive, as a
Team Project Set or you can
browse the files online.
Step 1: Search Results
First create a new
Plug-in Project and create a class
FileSearchResult that implements
ISearchResult. Therefore you need a dependency to
org.eclipse.search.
package com.codeandme.searchprovider;
import java.io.File;
import java.util.Collection;
import java.util.HashSet;
import org.eclipse.core.runtime.ListenerList;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.search.ui.ISearchQuery;
import org.eclipse.search.ui.ISearchResult;
import org.eclipse.search.ui.ISearchResultListener;
import org.eclipse.search.ui.SearchResultEvent;
public class FileSearchResult implements ISearchResult {
private final ISearchQuery fQuery;
private final ListenerList fListeners = new ListenerList();
private final Collection<File> fResult = new HashSet<File>();
public FileSearchResult(ISearchQuery query) {
fQuery = query;
}
@Override
public String getLabel() {
return fResult.size() + " file(s) found";
}
@Override
public String getTooltip() {
return "Found files in the filesystem";
}
@Override
public ImageDescriptor getImageDescriptor() {
return null;
}
@Override
public ISearchQuery getQuery() {
return fQuery;
}
@Override
public void addListener(ISearchResultListener l) {
fListeners.add(l);
}
@Override
public void removeListener(ISearchResultListener l) {
fListeners.remove(l);
}
private void notifyListeners(File file) {
SearchResultEvent event = new FileSearchResultEvent(this, file);
for (Object listener : fListeners.getListeners())
((ISearchResultListener) listener).searchResultChanged(event);
}
public void addFile(File file) {
fResult.add(file);
notifyListeners(file);
}
}
Nothing special here, we will use
addFile() later in this tutorial to add more and more files to our result set. Whenever the result changes, we need to inform interested listeners. So lets see how
FileSearchResultEvent looks like:
package com.codeandme.searchprovider;
import java.io.File;
import org.eclipse.search.ui.ISearchResult;
import org.eclipse.search.ui.SearchResultEvent;
public class FileSearchResultEvent extends SearchResultEvent {
private final File fAddedFile;
protected FileSearchResultEvent(ISearchResult searchResult, File addedFile) {
super(searchResult);
fAddedFile = addedFile;
}
public File getAddedFile() {
return fAddedFile;
}
}
Even simpler! To update results incrementally we hold a reference to the added file.
Step 2: The search query
The main logic for a search is implemented as an
ISearchQuery. It has 2 jobs: do the actual search and populate the search result.
package com.codeandme.searchprovider;
import java.io.File;
import java.io.FileFilter;
import java.util.Collection;
import java.util.HashSet;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.core.runtime.Status;
import org.eclipse.search.ui.ISearchQuery;
import org.eclipse.search.ui.ISearchResult;
public class FileSearchQuery implements ISearchQuery {
private final File fRoot;
private final String fFilter;
private final boolean fRecursive;
private final FileSearchResult fSearchResult;
public FileSearchQuery(String root, String filter, boolean recursive) {
fRoot = (root.isEmpty()) ? File.listRoots()[0] : new File(root);
fFilter = filter;
fRecursive = recursive;
fSearchResult = new FileSearchResult(this);
}
@Override
public IStatus run(IProgressMonitor monitor) throws OperationCanceledException {
Collection<File> entries = new HashSet<File>();
entries.add(fRoot);
do {
File entry = entries.iterator().next();
entries.remove(entry);
entry.listFiles(new FileFilter() {
@Override
public boolean accept(File pathname) {
if ((pathname.isFile()) && (pathname.getName().contains(fFilter))) {
// accept file
fSearchResult.addFile(pathname);
return true;
}
if ((pathname.isDirectory()) && (fRecursive))
entries.add(pathname);
return false;
}
});
} while (!entries.isEmpty());
return Status.OK_STATUS;
}
@Override
public String getLabel() {
return "Filesystem search";
}
@Override
public boolean canRerun() {
return true;
}
@Override
public boolean canRunInBackground() {
return true;
}
@Override
public ISearchResult getSearchResult() {
return fSearchResult;
}
}
Our query needs 3 parameters:
- a root object
- a file name filter
- a recursive flag to scan subfolders
In the constructor we create the
FileSearchResult and link it to our query. Then we traverse folders and add file by file to our search result. We do not check our input parameters very thoroughly for the sake of simplicity.
The logic is implemented, now lets add some nice UI elements.
Step 3: Search Dialog
To add a new search page to the search dialog (
main menu/Search/Search...) we use the extension point
org.eclipse.search.searchPages.
Just provide
id,
label and a
class reference to:
package com.codeandme.searchprovider.ui;
import org.eclipse.jface.dialogs.DialogPage;
import org.eclipse.search.ui.ISearchPage;
import org.eclipse.search.ui.ISearchPageContainer;
import org.eclipse.search.ui.NewSearchUI;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import com.codeandme.searchprovider.FileSearchQuery;
public class FileSearchPage extends DialogPage implements ISearchPage {
private ISearchPageContainer fContainer;
@Override
public boolean performAction() {
FileSearchQuery searchQuery = new FileSearchQuery("/home", "txt", true);
NewSearchUI.runQueryInForeground(fContainer.getRunnableContext(), searchQuery);
return true;
}
@Override
public void setContainer(ISearchPageContainer container) {
fContainer = container;
}
@Override
public void createControl(Composite parent) {
Composite root = new Composite(parent, SWT.NULL);
[...]
// need to set the root element
setControl(root);
}
}
I have removed the UI code from
createControl() as it is not relevant here. If interested you can
find it on github. The only important thing here is to set the root control using
setControl().
performAction() starts the actual search. Therefore we create a query and run it either as foreground or as background job. By returning
true we indicate that the search dialog shall be closed.
Step 4: Display search results
To add a new page to the
Search View we need another extension point:
org.eclipse.search.searchResultViewPages.
Add a new
viewPage with an
id and
label. To link this page with search results of a certain kind we provide the class of search results this page can display. Set it to our
FileSearchResult type. Finally we provide a class implementation for the page:
package com.codeandme.searchprovider.ui;
import org.eclipse.search.ui.ISearchResult;
import org.eclipse.search.ui.ISearchResultListener;
import org.eclipse.search.ui.ISearchResultPage;
import org.eclipse.search.ui.ISearchResultViewPart;
import org.eclipse.search.ui.SearchResultEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.IActionBars;
import org.eclipse.ui.IMemento;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.part.IPageSite;
import com.codeandme.searchprovider.FileSearchResultEvent;
public class SearchResultPage implements ISearchResultPage, ISearchResultListener {
private String fId;
private Composite fRootControl;
private IPageSite fSite;
private Text ftext;
@Override
public Object getUIState() {
return null;
}
@Override
public void setInput(ISearchResult search, Object uiState) {
search.addListener(this);
}
@Override
public void setViewPart(ISearchResultViewPart part) {
}
@Override
public void setID(String id) {
fId = id;
}
@Override
public String getID() {
return fId;
}
@Override
public String getLabel() {
return "Filesystem Search Results";
}
@Override
public IPageSite getSite() {
return fSite;
}
@Override
public void init(IPageSite site) throws PartInitException {
fSite = site;
}
@Override
public void createControl(Composite parent) {
fRootControl = new Composite(parent, SWT.NULL);
fRootControl.setLayout(new FillLayout(SWT.HORIZONTAL));
ftext = new Text(fRootControl, SWT.BORDER | SWT.READ_ONLY | SWT.H_SCROLL | SWT.V_SCROLL | SWT.CANCEL | SWT.MULTI);
}
@Override
public void dispose() {
// nothing to do
}
@Override
public Control getControl() {
return fRootControl;
}
@Override
public void setActionBars(IActionBars actionBars) {
}
@Override
public void setFocus() {
fRootControl.setFocus();
}
@Override
public void restoreState(IMemento memento) {
// nothing to do
}
@Override
public void saveState(IMemento memento) {
// nothing to do
}
@Override
public void searchResultChanged(SearchResultEvent event) {
if (event instanceof FileSearchResultEvent) {
Display.getDefault().asyncExec(new Runnable() {
@Override
public void run() {
String newText = ftext.getText() + "\n" + ((FileSearchResultEvent) event).getAddedFile().getAbsolutePath();
ftext.setText(newText);
}
});
}
}
}
Lots of getters and setters, but nothing complicated. For this example we use a simple text control to add the names of found files.
setInput() will be called by the framework to link this view with a search result. Now we attach a listeners to get notified on changes on the result.
I found one caveat while implementing: when your query code (from there we trigger
searchResultChanged()) raises an exception, you do not get the output on the console as you might expect. Basically this means that your result page remains empty without any notification that something went wrong. Use the debugger to single step through your code in that case.
