#pragma once #include namespace lsp { /** * The IProgressMonitor interface is implemented * by objects that monitor the progress of an activity; the methods * in this interface are invoked by code that performs the activity. *

* All activity is broken down into a linear sequence of tasks against * which progress is reported. When a task begins, a beginTask(const wstring&, int) * notification is reported, followed by any number and mixture of * progress reports (worked()) and subtask notifications * (subTask(const wstring&)). When the task is eventually completed, a * done() notification is reported. After the done() * notification, the progress monitor cannot be reused; i.e., * beginTask(const wstring&, int) cannot be called again after the call to * done(). *

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* A request to cancel an operation can be signaled using the * setCanceled method. Operations taking a progress * monitor are expected to poll the monitor (using isCanceled) * periodically and abort at their earliest convenience. Operation can however * choose to ignore cancelation requests. *

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* Since notification is synchronous with the activity itself, the listener should * provide a fast and robust implementation. If the handling of notifications would * involve blocking operations, or operations which might throw uncaught exceptions, * the notifications should be queued, and the actual processing deferred (or perhaps * delegated to a separate thread). *

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* Clients may implement this interface. *

*/ class IProgressMonitor { public: virtual ~IProgressMonitor() { } /** Constant indicating an unknown amount of work. */ const static int UNKNOWN = -1; /** * Notifies that the main task is beginning. This must only be called once * on a given progress monitor instance. * * @param name the name (or description) of the main task * @param totalWork the total number of work units into which * the main task is been subdivided. If the value is UNKNOWN * the implemenation is free to indicate progress in a way which * doesn't require the total number of work units in advance. */ virtual void beginTask(void* , int totalWork) { }; /** * Notifies that the work is done; that is, either the main task is completed * or the user canceled it. This method may be called more than once * (implementations should be prepared to handle this case). */ virtual void endTask(void*, int totalWork) { } virtual void done(void*) = 0; /** * Internal method to handle scaling correctly. This method * must not be called by a client. Clients should * always use the method worked(int). */ virtual void internalWorked(double work) { } /** * Returns whether cancelation of current operation has been requested. * Long-running operations should poll to see if cancelation * has been requested. * * @return true if cancellation has been requested, * and false otherwise * @see #setCanceled */ virtual bool isCanceled() = 0; /** * Sets the cancel state to the given value. * * @param value true indicates that cancelation has * been requested (but not necessarily acknowledged); * false clears this flag * * @see #isCanceled */ virtual void setCanceled(bool value) = 0; /** * Sets the task name to the given value. This method is used to * restore the task label after a nested operation was executed. * Normally there is no need for clients to call this method. * * @param name the name (or description) of the main task * @see #beginTask(java.lang.const wstring&, int) */ virtual void setTaskName(void*) { }; /** * Notifies that a subtask of the main task is beginning. * Subtasks are optional; the main task might not have subtasks. * * @param name the name (or description) of the subtask */ virtual void subTask(void* ) { } /** * Notifies that a given number of work unit of the main task * has been completed. Note that this amount represents an * installment, as opposed to a cumulative amount of work done * to date. * * @param work the number of work units just completed */ virtual void worked(int work) { }; virtual void catch_exception(void*) = 0; }; }