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Diffstat (limited to 'kopete/libkopete/kopetetask.h')
| -rw-r--r-- | kopete/libkopete/kopetetask.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/kopete/libkopete/kopetetask.h b/kopete/libkopete/kopetetask.h new file mode 100644 index 00000000..115e1ebe --- /dev/null +++ b/kopete/libkopete/kopetetask.h @@ -0,0 +1,162 @@ +/* + kopetetask.h - Kopete Task + + Copyright (c) 2004 by Richard Smith <[email protected]> + Kopete (c) 2002-2004 by the Kopete developers <[email protected]> + + ************************************************************************* + * * + * This library is free software; you can redistribute it and/or * + * modify it under the terms of the GNU Lesser General Public * + * License as published by the Free Software Foundation; either * + * version 2 of the License, or (at your option) any later version. * + * * + ************************************************************************* +*/ + +#ifndef KOPETETASK_H +#define KOPETETASK_H + +#include <qobject.h> +#include <kdemacros.h> + +namespace Kopete +{ + +/** + * The base class for all tasks. + * For most tasks created in Kopete, the code looks like + * + * \code + * Kopete::Task *task = someobject->someoperation( some parameters ); + * connect( task, SIGNAL( result( Kopete::Task * ) ), + * this, SLOT( slotResult( Kopete::Task * ) ) ); + * \endcode + * (other connects, specific to the job) + * + * And slotResult is usually at least: + * + * \code + * if ( !task->succeeded() ) + * Kopete::UI::Global::showTaskError( task ); + * \endcode + * + * Much of the ideas (and some of the documentation and function names) for this + * class come from KIO::Job. + * @author Richard Smith <[email protected]> + */ +class Task : public QObject +{ + Q_OBJECT + +protected: + Task(); +public: + ~Task(); + + /** + * Returns whether the task completed successfully. + * Only call this method from the slot connected to result(). + * @return if the task succeeded, returns true, otherwise returns false. + */ + bool succeeded() const; + /** + * Converts an error code and a non-i18n error message into an + * error message in the current language. The low level (non-i18n) + * error message (usually a url) is put into the translated error + * message using %%1. + * + * Use this to display the error yourself, but for a dialog box + * use Kopete::UI::Global::showTaskError. Do not call it if succeeded() + * returns true. + * @return the error message and if there is no error, a message + * telling the user that the app is broken, so check with + * succeeded() whether there is an error. + */ + const QString &errorString() const; + + /** Flags for the abort() function */ + enum AbortFlags { AbortNormal = 0, AbortEmitResult = 1 }; +public slots: + /** + * Abort this task. + * This aborts all subtasks and deletes the task. + * + * @param flags a combination of flags from AbortFlags. If AbortEmitResult is + * set, Job will emit the result signal. AbortEmitResult is removed + * from the flags passed to the abort function of subtasks. + */ + virtual void abort( int flags = AbortNormal ); + +signals: + /** + * Emitted when the task is finished, in any case (completed, canceled, + * failed...). Use error() to find the result. + * @param task the task that emitted this signal + */ + void result( Kopete::Task *task ); + /** + * Emitted to display status information about this task. + * Examples of messages are: + * "Removing ICQ contact Joe from server-side list", + * "Loading account plugin", etc. + * @param task the task that emitted this signal + * @param message the info message + */ + void statusMessage( Kopete::Task *task, const QString &message ); + +protected: + /** + * Add a task that has to be completed before a result is emitted. This + * obviously should not be called after the finish signal is emitted by + * the subtask. + * + * @param task the subtask to add + */ + virtual void addSubtask( Task *task ); + + enum RemoveSubtaskIfLast { IfLastDoNothing, IfLastEmitResult }; + /** + * Mark a sub job as being done. If it's the last to + * wait on the job will emit a result - jobs with + * two steps might want to override slotResult + * in order to avoid calling this method. + * + * @param task the subjob to add + * @param actionIfLast the action to take if this is the last subtask. + * If set to IfLastEmitResult, the error information from @p task + * will be copied to this object, and emitResult() will be called. + */ + virtual void removeSubtask( Task *task, RemoveSubtaskIfLast actionIfLast = IfLastEmitResult ); + + enum Result { ResultFailed = 0, ResultSucceeded = 1 }; + /** + * Utility function to emit the result signal, and suicide this job. + * Sets the stored result and error message to @p result and @p errorMessage. + * You should call this instead of emitting the result() signal yourself. + */ + void emitResult( Result result = ResultSucceeded, const QString &errorMessage = QString::null ); + +protected slots: + /** + * Called whenever a subtask finishes. + * The default implementation checks for errors and propagates + * them to this task, then calls removeSubtask(). + * Override if you want to provide a different @p actionIfLast to + * removeSubtask, or want to perform some other processing in response + * to a subtask finishing + * @param task the subtask that finished + * @see result() + */ + virtual void slotResult( Kopete::Task *task ); + +private: + class Private; + Private *d; +}; + +} + +#endif + +// vim: set noet ts=4 sts=4 sw=4: |