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package com.tvl.spi.editor.completion.support;
import com.tvl.spi.editor.completion.CompletionResultSet;
import com.tvl.spi.editor.completion.CompletionTask;
import javax.swing.SwingUtilities;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;
import org.netbeans.api.annotations.common.CheckForNull;
import org.netbeans.api.annotations.common.NonNull;
import org.netbeans.api.annotations.common.NullAllowed;
import org.openide.util.RequestProcessor;
/**
* Asynchronous completion task allowing asynchronous query execution
* through {@link AsyncCompletionQuery}.
* <br>
* This is a final class and all the logic must be defined
* in an implementation of {@link AsyncCompletionQuery} that must
* be passed to constructor of this task.
*
* @see AsyncCompletionQuery
* @author Miloslav Metelka, Dusan Balek
* @version 1.00
*/
public final class AsyncCompletionTask implements CompletionTask, Runnable {
private static final RequestProcessor RP = new RequestProcessor("Code Completion", 1, false, false); //NOI18N
private final AsyncCompletionQuery query;
private final JTextComponent component;
private Document doc;
private int queryCaretOffset;
private CompletionResultSet queryResultSet;
private CompletionResultSet refreshResultSet;
private RequestProcessor.Task rpTask;
/** Whether this task is canceled. */
private boolean cancelled;
/** Whether query was already invoked on this task. */
private boolean queryInvoked;
/**
* Construct asynchronous task for the given component.
*
* @param query non-null query implementation.
* @param component text component to operate with. The completion infrastructure
* will cancel the task if the component or its associated document would change.
* <br>
* It may be null to indicate that no component was provided.
*/
@SuppressWarnings({"LeakingThisInConstructor", "null"})
public AsyncCompletionTask(@NonNull AsyncCompletionQuery query, @NullAllowed JTextComponent component) {
assert (query != null) : "Query must be non-null";
this.query = query;
this.component = component;
query.initTask(this);
}
/**
* Constructor for the case when there is no valid component
* which can happen when creating task for documentation or tooltip computation.
*
* @param query non-null query implementation.
*/
public AsyncCompletionTask(@NonNull AsyncCompletionQuery query) {
this(query, null);
}
/**
* Gets the {@link AsyncCompletionQuery} wrapped by this task.
*
* @return The {@link AsyncCompletionQuery}.
*/
public @NonNull AsyncCompletionQuery getQuery() {
return query;
}
/**
* Gets the active component used by this task.
*
* @return The component.
*/
public @CheckForNull JTextComponent getComponent() {
return component;
}
/**
* Called by completion infrastructure in AWT thread to populate
* the given result set with data.
* @param resultSet
*/
@Override
public void query(CompletionResultSet resultSet) {
assert (resultSet != null);
assert (SwingUtilities.isEventDispatchThread());
if (component != null) {
doc = component.getDocument();
} else {
doc = null;
}
queryInvoked = true;
synchronized (this) {
performQuery(resultSet);
}
}
/**
* Called by completion infrastructure in AWT thread once there
* is a change in the component (caret position changes or document
* gets modified).
* <br>
* The results should be fired into the newly provided completion listener.
* @param resultSet
*/
@Override
public void refresh(CompletionResultSet resultSet) {
assert (SwingUtilities.isEventDispatchThread());
assert !cancelled : "refresh() called on canceled task"; // NOI18N
if (queryInvoked) {
assert (resultSet != null);
refreshResultSet = resultSet;
refreshImpl();
} else {
query.preQueryUpdate(component);
}
}
/**
* Called by completion infrastructure to cancel the running task.
*/
@Override
public void cancel() {
cancelled = true;
synchronized (this) {
if (rpTask != null) {
rpTask.cancel();
rpTask = null;
}
}
}
private void performQuery(CompletionResultSet resultSet) {
// Runs in AWT thread only
if (component != null) {
queryCaretOffset = component.getSelectionStart();
} else {
queryCaretOffset = -1;
}
query.prepareQuery(component);
synchronized (this) {
queryResultSet = resultSet;
rpTask = RP.post(this);
}
}
void refreshImpl() {
// Always called in AWT thread only
CompletionResultSet resultSet;
boolean rpTaskFinished;
synchronized (this) {
rpTaskFinished = (rpTask == null);
resultSet = refreshResultSet; // refreshResultSet checked in run()
}
if (resultSet != null) {
if (rpTaskFinished) { // query finished already
synchronized (this) {
refreshResultSet = null;
}
// Synchronously call the refresh()
if (query.canFilter(component)) {
query.filter(resultSet);
assert resultSet.isFinished()
: toString() + ": query.filter(): Result set not finished by resultSet.finish()"; // NOI18N
} else { // cannot filter and query stopped => another full query
performQuery(resultSet);
}
} else { // pending query not finished yet
if (!query.canFilter(component)) { // query should attempted to be stopped by canFilter()
// Leave the ongoing query to be finished and once that happens
// ask for another canFilter()
} // Let the query finish and schedule refreshing by (refreshResultSet != null)
}
}
}
/**
* This method will be run() from the RequestProcessor during
* performing of the query.
*/
@Override
public void run() {
// First check whether there was not request yet to stop the query: (queryResultSet == null)
CompletionResultSet resultSet = queryResultSet;
if (resultSet != null) {
// Perform the querying (outside of synchronized section)
query.query(resultSet, doc, queryCaretOffset);
assert resultSet.isFinished()
: toString() + ": query.query(): Result set not finished by resultSet.finish()"; // NOI18N
}
synchronized (this) {
rpTask = null;
queryResultSet = null;
// Check for pending refresh
if (refreshResultSet != null) {
// Post refresh computation into AWT thread
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
refreshImpl();
}
});
}
}
}
synchronized boolean isCancelled() {
return cancelled;
}
@Override
public String toString() {
return "AsyncCompletionTask: query=" + query; // NOI18N
}
}