org.zkoss.zk.ui.sys
Interface DesktopCtrl

All Known Implementing Classes:

DesktopImpl

public interface DesktopCtrl

An addition interface to Desktop for implementation.

Note: applications shall never access this interface.

Author:

tomyeh

Method Summary

boolean	activateServerPush(long timeout) Activates the server push.
void	addComponent(Component comp) Adds a component to this page.
void	addPage(Page page) Adds a page to this desktop.
void	afterComponentAttached(Component comp, Page page) Invokes UiLifeCycle.afterComponentAttached(org.zkoss.zk.ui.Component, org.zkoss.zk.ui.Page).
void	afterComponentDetached(Component comp, Page prevpage) Invokes UiLifeCycle.afterComponentDetached(org.zkoss.zk.ui.Component, org.zkoss.zk.ui.Page).
void	afterComponentMoved(Component parent, Component child, Component prevparent) Invokes UiLifeCycle.afterComponentMoved(org.zkoss.zk.ui.Component, org.zkoss.zk.ui.Component, org.zkoss.zk.ui.Component).
void	afterProcessEvent(Event event) Invokes EventInterceptor.afterProcessEvent(org.zkoss.zk.ui.event.Event) registered by Desktop.addListener(java.lang.Object).
Event	beforePostEvent(Event event) Invokes EventInterceptor.beforePostEvent(org.zkoss.zk.ui.event.Event) registered by Desktop.addListener(java.lang.Object).
Event	beforeProcessEvent(Event event) Invokes EventInterceptor.beforeProcessEvent(org.zkoss.zk.ui.event.Event) registered by Desktop.addListener(java.lang.Object).
Event	beforeSendEvent(Event event) Invokes EventInterceptor.beforeSendEvent(org.zkoss.zk.ui.event.Event) registered by Desktop.addListener(java.lang.Object).
boolean	ceaseSuspendedThread(EventProcessingThread evtthd, java.lang.String cause) Ceases the specified event thread.
void	deactivateServerPush() Deactivates the server push.
void	destroy() Called when the desktop is about to be destroyed.
boolean	enableServerPush(ServerPush serverpush) Enables the server-push feature with the specified server-push controller.
Media	getDownloadMedia(java.lang.String medId, boolean reserved) Returns the media that is associated with Desktop.getDownloadMediaURI(org.zkoss.util.media.Media, java.lang.String), or null if not found.
java.lang.Object	getLastResponse(java.lang.String channel, java.lang.String reqId) Returns the information of response for the last request, or null if no response yet, or the specified request ID doesn't match the last one (passed to responseSent(java.lang.String, java.lang.String, java.lang.Object)).
int	getNextKey() Returns the next available key which is unique in the whole desktop.
java.lang.String	getNextUuid() Returns the next available UUID for a component.
RequestQueue	getRequestQueue() Returns the request queue.
int	getResponseId(boolean advance) Returns the sequence ID of the response.
ServerPush	getServerPush() Returns the server-push controller, or null if it is not enabled yet.
java.util.Collection	getSuspendedThreads() Returns a collection of suspended event processing threads, or empty if no suspended thread at all.
void	invokeDesktopCleanups() Invokes DesktopCleanup.cleanup(org.zkoss.zk.ui.Desktop) for each relevant listener registered by Desktop.addListener(java.lang.Object).
void	invokeExecutionCleanups(Execution exec, Execution parent, java.util.List errs) Invokes ExecutionCleanup.cleanup(org.zkoss.zk.ui.Execution, org.zkoss.zk.ui.Execution, java.util.List) for each relevant listener registered by Desktop.addListener(java.lang.Object).
void	invokeExecutionInits(Execution exec, Execution parent) Invokes ExecutionInit.init(org.zkoss.zk.ui.Execution, org.zkoss.zk.ui.Execution) for each relevant listener registered by Desktop.addListener(java.lang.Object).
void	onPiggyback() Called each time ZK Update Engine processes all events.
void	onPiggybackListened(Component comp, boolean listen) Called when a component added or removed a listener for Events.ON_PIGGYBACK.
void	recoverDidFail(java.lang.Throwable ex) Called when the recoving failed.
void	removeComponent(Component comp) Removes a component to this page.
void	removePage(Page page) Removes a page from this desktop.
void	responseSent(java.lang.String channel, java.lang.String reqId, java.lang.Object resInfo) Called when ZK Update Engine has sent a response to the client.
void	sessionDidActivate(Session sess) Notification that the session, which owns this desktop, has just been activated (aka., deserialized) by the Web container.
void	sessionWillPassivate(Session sess) Notification that the session, which owns this desktop, is about to be passivated (aka., serialized) by the Web container.
void	setBookmarkByClient(java.lang.String name) Sets the bookmark when receiving the onBookmarkChange command from the client.
void	setExecution(Execution exec) Sets the execution (used to represent a lock).
void	setId(java.lang.String id) Sets the desktop identifier.
void	setResponseId(int resId) Sets the sequence ID of the response.

Method Detail

getRequestQueue

RequestQueue getRequestQueue()

Returns the request queue.

getNextKey

int getNextKey()

Returns the next available key which is unique in the whole desktop.

getNextUuid

java.lang.String getNextUuid()

Returns the next available UUID for a component. The returned UUID is unique in the desktop. You can consider it as unique in the whole session, though it may not be true if RawId is used (developer's responsibility to avoid conflict), or integer overflow (too many UUID in one session, which can be considered as impossible).

addComponent

void addComponent(Component comp)

Adds a component to this page.

It is used internally and developers shall not invoke it explicityly.

removeComponent

void removeComponent(Component comp)

Removes a component to this page.

It is used internally and developers shall not invoke it explicityly.

addPage

void addPage(Page page)

Adds a page to this desktop. It must be called when a page is created.

This is one of the only few method you could access before activating an execution.

removePage

void removePage(Page page)

Removes a page from this desktop.

NOTE: once a page is removed, you can NOT add it back. You shall just GC it.

setExecution

void setExecution(Execution exec)

Sets the execution (used to represent a lock). Called only internally (by UIEngine's implementation to activate an execution).

setBookmarkByClient

void setBookmarkByClient(java.lang.String name)

Sets the bookmark when receiving the onBookmarkChange command from the client.

setId

void setId(java.lang.String id)

Sets the desktop identifier.

It is callable only if it is the recovering phase, i.e., ExecutionCtrl.isRecovering() is true. In other words, callable only in the invocation of FailoverManager.recover(org.zkoss.zk.ui.Session, org.zkoss.zk.ui.Execution, org.zkoss.zk.ui.Desktop).

Throws:

java.lang.IllegalStateException - if it is NOT in recovering.

recoverDidFail

void recoverDidFail(java.lang.Throwable ex)

Called when the recoving failed.

sessionWillPassivate

void sessionWillPassivate(Session sess)

Notification that the session, which owns this desktop, is about to be passivated (aka., serialized) by the Web container.

sessionDidActivate

void sessionDidActivate(Session sess)

Notification that the session, which owns this desktop, has just been activated (aka., deserialized) by the Web container.

destroy

void destroy()

Called when the desktop is about to be destroyed.

getSuspendedThreads

java.util.Collection getSuspendedThreads()

Returns a collection of suspended event processing threads, or empty if no suspended thread at all.

An event processing thread is an instance of EventProcessingThread

Note: if you access this method NOT in an event listener for the SAME desktop, you have to synchronize the iteration (though the returned collection is synchronized). Of course, it is always safe to test whether it is empty (Collection.isEmpty()).

//Use the following pathern IF it is not in the SAME desktop's listener
Collection c = otherDesktop.getSuspendedThreads();
if (c.isEmpty()) {
        //do something accordingly
} else {
  synchronized (c) {
    for (Iterator it = c.iterator(); it.hasNext();) {
      //...
    }
  }
}

ceaseSuspendedThread

boolean ceaseSuspendedThread(EventProcessingThread evtthd,
                             java.lang.String cause)

Ceases the specified event thread.

Parameters:

cause - an arbitrary text to describe the cause. It will be the message of the thrown InterruptedException.

Returns:

true if the event processing thread is ceased successfully; false if no such thread or it is not suspended.

getDownloadMedia

Media getDownloadMedia(java.lang.String medId,
                       boolean reserved)

Returns the media that is associated with Desktop.getDownloadMediaURI(org.zkoss.util.media.Media, java.lang.String), or null if not found.

This method is used internally. Developers rarely need to access this method.

Parameters:

reserved - reserved for future use.

Returns:

the media or null if not found.

onPiggybackListened

void onPiggybackListened(Component comp,
                         boolean listen)

Called when a component added or removed a listener for Events.ON_PIGGYBACK.

The implementation usualy uses it to optimize whether to call the listener when onPiggyback() is called.

Parameters:

comp - the component that adds an listener for Events.ON_PIGGYBACK. The component may or may not be a root component.

listen - whether the listener is added (or removed).

Since:

3.0.0

onPiggyback

void onPiggyback()

Called each time ZK Update Engine processes all events. It is used to implement the piggyback feature (see Events.ON_PIGGYBACK).

Used only internally. Application develepers shall not call it.

Since:

3.0.0

getServerPush

ServerPush getServerPush()

Returns the server-push controller, or null if it is not enabled yet.

enableServerPush

boolean enableServerPush(ServerPush serverpush)

Enables the server-push feature with the specified server-push controller.

Parameters:

serverpush - the server-push controller. If null, the server-push feature is disabled (for this desktop). Note: this method will invoke ServerPush.start(org.zkoss.zk.ui.Desktop), so the caller doesn't need to do it.

Since:

3.0.0

See Also:

Desktop.enableServerPush(boolean)

beforeSendEvent

Event beforeSendEvent(Event event)

Invokes EventInterceptor.beforeSendEvent(org.zkoss.zk.ui.event.Event) registered by Desktop.addListener(java.lang.Object).

Note: it invokes Configuration.beforeSendEvent(org.zkoss.zk.ui.event.Event) automatically.

Since:

3.0.0

beforePostEvent

Event beforePostEvent(Event event)

Invokes EventInterceptor.beforePostEvent(org.zkoss.zk.ui.event.Event) registered by Desktop.addListener(java.lang.Object).

Note: it invokes Configuration.beforePostEvent(org.zkoss.zk.ui.event.Event) automatically.

Since:

3.0.0

beforeProcessEvent

Event beforeProcessEvent(Event event)

Invokes EventInterceptor.beforeProcessEvent(org.zkoss.zk.ui.event.Event) registered by Desktop.addListener(java.lang.Object).

Note: it invokes Configuration.beforeProcessEvent(org.zkoss.zk.ui.event.Event) automatically.

Since:

3.0.0

afterProcessEvent

void afterProcessEvent(Event event)

Invokes EventInterceptor.afterProcessEvent(org.zkoss.zk.ui.event.Event) registered by Desktop.addListener(java.lang.Object).

Note: it invokes Configuration.afterProcessEvent(org.zkoss.zk.ui.event.Event) automatically.

Since:

3.0.0

invokeDesktopCleanups

void invokeDesktopCleanups()

Invokes DesktopCleanup.cleanup(org.zkoss.zk.ui.Desktop) for each relevant listener registered by Desktop.addListener(java.lang.Object).

Used only internally.

It never throws an exception.

Since:

3.0.6

invokeExecutionInits

void invokeExecutionInits(Execution exec,
                          Execution parent)
                          throws UiException

Invokes ExecutionInit.init(org.zkoss.zk.ui.Execution, org.zkoss.zk.ui.Execution) for each relevant listener registered by Desktop.addListener(java.lang.Object).

Used only internally.

Parameters:

exec - the execution that is created

parent - the previous execution, or null if no previous at all

Throws:

UiException - to prevent an execution from being created

Since:

3.0.6

invokeExecutionCleanups

void invokeExecutionCleanups(Execution exec,
                             Execution parent,
                             java.util.List errs)

Invokes ExecutionCleanup.cleanup(org.zkoss.zk.ui.Execution, org.zkoss.zk.ui.Execution, java.util.List) for each relevant listener registered by Desktop.addListener(java.lang.Object).

Used only internally.

It never throws an exception but logs and adds it to the errs argument, if not null.

Parameters:

exec - the execution that is being destroyed

parent - the previous execution, or null if no previous at all

errs - a list of exceptions (java.lang.Throwable) if any exception occured before this method is called, or null if no exeption at all. Note: you can manipulate the list directly to add or clean up exceptions. For example, if exceptions are fixed correctly, you can call errs.clear() such that no error message will be displayed at the client.

Since:

3.0.6

afterComponentAttached

void afterComponentAttached(Component comp,
                            Page page)

Invokes UiLifeCycle.afterComponentAttached(org.zkoss.zk.ui.Component, org.zkoss.zk.ui.Page).

Since:

3.0.6

afterComponentDetached

void afterComponentDetached(Component comp,
                            Page prevpage)

Invokes UiLifeCycle.afterComponentDetached(org.zkoss.zk.ui.Component, org.zkoss.zk.ui.Page).

Since:

3.0.6

afterComponentMoved

void afterComponentMoved(Component parent,
                         Component child,
                         Component prevparent)

Invokes UiLifeCycle.afterComponentMoved(org.zkoss.zk.ui.Component, org.zkoss.zk.ui.Component, org.zkoss.zk.ui.Component).

Parameters:

prevparent - the previous parent. If it is the same as comp's Component.getParent(), comp is moved in the same parent.

Since:

3.0.6

responseSent

void responseSent(java.lang.String channel,
                  java.lang.String reqId,
                  java.lang.Object resInfo)

Called when ZK Update Engine has sent a response to the client.

Note: the implementation has to maintain one last-sent response information for each channel, since a different channel has different set of request IDs and might resend in a different condition.

Parameters:

channel - the request channel. For example, "au" for AU requests and "cm" for Comet requests.

reqId - the request ID that the response is generated for. Ingore if null.

resInfo - the response infomation. Ignored if reqId is null. The real value depends on the caller.

Since:

3.5.0

getLastResponse

java.lang.Object getLastResponse(java.lang.String channel,
                                 java.lang.String reqId)

Returns the information of response for the last request, or null if no response yet, or the specified request ID doesn't match the last one (passed to responseSent(java.lang.String, java.lang.String, java.lang.Object)).

The return value is the value passed to resInfo when calling responseSent(java.lang.String, java.lang.String, java.lang.Object). The real value depends on the caller.

Since:

3.5.0

getResponseId

int getResponseId(boolean advance)

Returns the sequence ID of the response. The client and server uses the sequence ID to make sure the responses are processed in the correct order.

The range of the sequence IDs is 1~999.

Parameters:

advance - whether to advance the number before returning. If true, the ID is increased and then returned. If false, the previous value is returned

Since:

3.5.0

setResponseId

void setResponseId(int resId)

Sets the sequence ID of the response.

It is rarely called other than in the recovering mode, i.e., ExecutionCtrl.isRecovering() is true.

Parameters:

resId - a value between 1 and 999. You can reset the ID by passing a non-positive value.

Since:

3.5.0

activateServerPush

boolean activateServerPush(long timeout)
                           throws java.lang.InterruptedException

Activates the server push. It is called by Executions.activate(org.zkoss.zk.ui.Desktop).

Note: the server push must be enabled first (by use of Desktop.enableServerPush(boolean)).

Parameters:

timeout - the maximum time to wait in milliseconds. Ingored (i.e., never timeout) if non-positive.

Throws:

java.lang.InterruptedException

Since:

3.5.2

deactivateServerPush

void deactivateServerPush()

Deactivates the server push. It is called by Executions.deactivate(org.zkoss.zk.ui.Desktop).

Since:

3.5.2