/*
* ApplicationVisibility.java
*
* Copyright (C) 2009-12 by RStudio, Inc.
*
* Unless you have received this program directly from RStudio pursuant
* to the terms of a commercial license agreement with RStudio, then
* this program is licensed to you under the terms of version 3 of the
* GNU Affero General Public License. This program is distributed WITHOUT
* ANY EXPRESS OR IMPLIED WARRANTY, INCLUDING THOSE OF NON-INFRINGEMENT,
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Please refer to the
* AGPL (http://www.gnu.org/licenses/agpl-3.0.txt) for more details.
*
*/
package org.rstudio.studio.client.application;
import org.rstudio.core.client.Debug;
import org.rstudio.studio.client.application.events.ApplicationVisibilityChangedEvent;
import org.rstudio.studio.client.application.events.EventBus;
import org.rstudio.studio.client.application.model.ApplicationServerOperations;
import org.rstudio.studio.client.common.satellite.SatelliteManager;
import org.rstudio.studio.client.workbench.events.SessionInitEvent;
import org.rstudio.studio.client.workbench.events.SessionInitHandler;
import org.rstudio.studio.client.workbench.model.Session;
import com.google.gwt.user.client.Timer;
import com.google.inject.Inject;
import com.google.inject.Singleton;
@Singleton
public class ApplicationVisibility
{
@Inject
public ApplicationVisibility(ApplicationServerOperations server,
EventBus eventBus,
SatelliteManager satelliteManager,
final Session session)
{
server_ = server;
eventBus_ = eventBus;
satelliteManager_ = satelliteManager;
// don't register for visibility changed events in desktop mode
if (Desktop.isDesktop())
return;
// initialize after we have session info
eventBus_.addHandler(SessionInitEvent.TYPE, new SessionInitHandler() {
@Override
public void onSessionInit(SessionInitEvent sie)
{
// check for multi session
isMultiSession_ = session.getSessionInfo().getMultiSession();
// don't allow exceptions to escape (this code is being added
// late in the release cycle and will run at workbench startup
// so we need to make sure that unexpected errors don't bring
// the entire ide down with them
try
{
// register for page visibility changed events
registerPageVisibilityChangedHandler();
// check for being hidden 5 seconds after startup
// and stop the event listener if we are (handles
// cases where we never get visibility events because
// a browser tab was "restored" or opened as part of
// an "open all sessions" command
new Timer() {
@Override
public void run()
{
if (isHidden())
handleApplicationVisibilityChanged();
}
}.schedule(5000);;
}
catch(Exception e)
{
Debug.logException(e);
}
}
});
}
private native final boolean isHidden() /*-{
if (typeof $wnd.document.hidden !== "undefined")
return $wnd.document.hidden;
else if (typeof $wnd.document.mozHidden !== "undefined")
return $wnd.document.mozHidden;
else if (typeof $wnd.document.msHidden !== "undefined")
return $wnd.document.msHidden;
else if (typeof $wnd.document.webkitHidden !== "undefined")
return $wnd.document.webkitHidden;
else
return false;
}-*/;
private native final void registerPageVisibilityChangedHandler() /*-{
// determine name of visibilityChange event
var visibilityChange;
if (typeof $wnd.document.hidden !== "undefined")
visibilityChange = "visibilitychange";
else if (typeof $wnd.document.mozHidden !== "undefined")
visibilityChange = "mozvisibilitychange";
else if (typeof $wnd.document.msHidden !== "undefined")
visibilityChange = "msvisibilitychange";
else if (typeof $wnd.document.webkitHidden !== "undefined")
visibilityChange = "webkitvisibilitychange";
else
visibilityChange = null;
// add the event listener if we can
if (typeof $wnd.document.addEventListener !== "undefined" ||
visibilityChange !== null)
{
var thiz = this;
$wnd.document.addEventListener(
visibilityChange,
$entry(function(e) {
thiz.@org.rstudio.studio.client.application.ApplicationVisibility::handleApplicationVisibilityChanged()();
}),
false);
}
}-*/;
private void handleApplicationVisibilityChanged()
{
// if we are multi session then manage the event listener
// (to prevent an overload of long-polling connections being
// opened to the server)
if (isMultiSession_)
manageEventListener();
// fire visibility changed event
eventBus_.fireEvent(new ApplicationVisibilityChangedEvent(isHidden()));
}
private void manageEventListener()
{
try
{
if (shouldStopEventListener())
{
// Stop the event listener but do it on a delay to provide the
// system the time to confirm receipt of existing events.
// This is necessary because some events (like browseURL) can
// actually cause the de-activation of the window. If we stop
// the event listener right away then the next get_events call
// which acknowledges receipt of the event (e.g. browseURL) is
// actually aborted before it can acknowledge receipt. The
// subsequent call to start() then resets the lastEventId to -1
// causing a re-delivery of the original event.
//
// Note that the specified delay (5 seconds) is somewhat arbitrary
// The reason that we stop in the first place is to avoid
// saturation of per-domain request limits so the stop needs to
// occur reasonably soon but not right away.
if (stopTimer_.isRunning())
stopTimer_.cancel();
stopTimer_.schedule(5000);
}
else
{
server_.ensureEventListener();
}
}
catch(Exception e)
{
Debug.logException(e);
}
}
private boolean shouldStopEventListener()
{
return isHidden() && !satelliteManager_.getSatellitesOpen();
}
private final Timer stopTimer_ = new Timer() {
@Override
public void run()
{
if (shouldStopEventListener())
server_.stopEventListener();
}
};
private final ApplicationServerOperations server_;
private final EventBus eventBus_;
private final SatelliteManager satelliteManager_;
private boolean isMultiSession_ = false;
}