/* * Copyright 2011-2014 Haiku, Inc. All rights reserved. * Distributed under the terms of the MIT License. * * Authors: * Gabe Yoder, gyoder@stny.rr.com * John Scipione, jscipione@gmail.com * * Corresponds to: * headers/os/app/Clipboard.h hrev47355 * src/kits/app/Clipboard.cpp hrev47355 */ /*! \file Clipboard.h \ingroup app \ingroup libbe \brief Provides the BClipboard class. */ /*! \var be_clipboard \brief Global system clipboard object. \since BeOS R3 */ /*! \class BClipboard \ingroup app \ingroup libbe \brief Used for short-term data storage between documents and applications via copy and paste operations. Clipboards are differentiated by their name. In order for two applications to share a clipboard they simply have to create a BClipboard object with the same name. However, it is rarely necessary to create your own clipboard, instead you can use the \c be_clipboard system clipboard object. \remark To access the system clipboard without a BApplication object, create a BClipboard object with the name "system". You should avoid creating a custom clipboard with the name "system" for your own use. To access the clipboard data call the Data() method. The BMessage object returned by the Data() method has the following properties: - The \c what value is unused. - The clipboard data is stored in a message field typed as \c B_MIME_TYPE. - The MIME type of the data is used as the name of the field that holds the data. - Each field in the data message contains the same data with a different format. To read and write to the clipboard you must first lock the BClipboard object. If you fail to lock the BClipboard object then the Data() method will return \c NULL instead of a pointer to a BMessage object. Below is an example of reading a string from the system clipboard. \code const char *string; int32 stringLen; if (be_clipboard->Lock()) { // Get the clipboard BMessage BMessage *clip = be_clipboard->Data(); // Read the string from the clipboard data message clip->FindData("text/plain", B_MIME_TYPE, (const void **)&string, &stringLen); be_clipboard->Unlock(); } else fprintf(stderr, "could not lock clipboard.\n"); \endcode Below is an example of writing a string to the system clipboard. \code const char* string = "Some clipboard data"; if (be_clipboard->Lock()) { // Clear the clipboard data be_clipboard->Clear(); // Get the clipboard data message BMessage *clip = be_clipboard->Data(); // Write string data to the clipboard data message clip->AddData("text/plain", B_MIME_TYPE, string, strlen(string)); // Commit the data to the clipboard status = be_clipboard->Commit(); if (status != B_OK) fprintf(stderr, "could not commit data to clipboard.\n"); be_clipboard->Unlock(); } else fprintf(stderr, "could not lock clipboard.\n"); \endcode \since BeOS R3 */ /*! \fn BClipboard::BClipboard(const char* name, bool transient = false) \brief Create a BClipboard object with the given \a name. If the \a name parameter is \c NULL then the "system" BClipboard object is constructed instead. \param name The \a name of the clipboard. \param transient If \c true, lose data after a reboot (currently unused). \since BeOS R3 */ /*! \fn BClipboard::~BClipboard() \brief Destroys the BClipboard object. The clipboard data is not destroyed. \since BeOS R3 */ /*! \fn const char* BClipboard::Name() const \brief Returns the name of the BClipboard object. \returns The name of the clipboard. \since BeOS R3 */ /*! \name Commit Count */ //! @{ /*! \fn uint32 BClipboard::LocalCount() const \brief Returns the (locally cached) number of commits to the clipboard. The returned value is the number of successful Commit() invocations for the clipboard represented by this object, either invoked on this object or another (even from another application). This method returns a locally cached value, which might already be obsolete. For an up-to-date value use SystemCount(). \return The number of commits to the clipboard. \sa SystemCount() \since BeOS R5 */ /*! \fn uint32 BClipboard::SystemCount() const \brief Returns the number of commits to the clipboard. The returned value is the number of successful Commit() invocations for the clipboard represented by this object, either invoked on this object or another (even from another application). This method retrieves the value directly from the system service managing the clipboards, so it is more expensive, but more up-to-date than LocalCount(), which returns a locally cached value. \return The number of commits to the clipboard. \sa LocalCount() \since BeOS R5 */ //! @} /*! \name Monitoring */ //! @{ /*! \fn status_t BClipboard::StartWatching(BMessenger target) \brief Start watching the BClipboard object for changes. When a change in the clipboard occurs, most like as the result of a cut or copy action, a \a B_CLIPBOARD_CHANGED message is sent to \a target. \retval B_OK Everything went fine. \retval B_BAD_VALUE \a target is invalid. \retval B_ERROR An error occured. \sa StopWatching() \since BeOS R5 */ /*! \fn status_t BClipboard::StopWatching(BMessenger target) \brief Stop watching the BClipboard object for changes. \retval B_OK Everything went fine. \retval B_BAD_VALUE \a target is invalid. \retval B_ERROR An error occurred. \sa StartWatching() \since BeOS R5 */ //! @} /*! \name Locking */ //! @{ /*! \fn bool BClipboard::Lock() \brief Locks the clipboard so that no other tread can read from it or write to it. You should call Lock() before reading or writing to the clipboard. \returns \c true if the clipboard was locked, \c false otherwise. \sa Unlock() \since BeOS R3 */ /*! \fn void BClipboard::Unlock() \brief Unlocks the clipboard. \sa Lock() \since BeOS R3 */ /*! \fn bool BClipboard::IsLocked() const \brief Returns whether or not the clipboard is locked. \returns \c true if the clipboard is locked, \c false if it is unlocked. \since BeOS R5 */ //! @} /*! \name Clipboard Data Transaction */ //! @{ /*! \fn status_t BClipboard::Clear() \brief Clears out all data from the clipboard. You should call Clear() before adding new data to the BClipboard object. \return A status code. \retval B_OK Everything went find. \retval B_NOT_ALLOWED The clipboard is not locked. \retval B_NO_MEMORY Ran out of memory initializing the data message. \retval B_ERROR Another error occurred. \since BeOS R3 */ /*! \fn status_t BClipboard::Commit() \brief Commits the clipboard data to the BClipboard object. \return A status code. \retval B_OK Everything went find. \retval B_NOT_ALLOWED The clipboard is not locked. \retval B_ERROR Another error occurred. \since BeOS R3 */ /*! \fn status_t BClipboard::Commit(bool failIfChanged) \brief Commits the clipboard data to the BClipboard object with the option to fail if there is a change to the clipboard data. \param failIfChanged Whether or not to fail to commit the changes if there is a change in the clipboard data. \return A status code. \retval B_OK Everything went find. \retval B_NOT_ALLOWED The clipboard is not locked. \retval B_ERROR Another error occurred. \since BeOS R5 */ /*! \fn status_t BClipboard::Revert() \brief Reverts the clipboard data. The method should be used in the case that you have made a change to the clipboard data message and then decide to revert the change instead of committing it. \return A status code. \retval B_OK Everything went find. \retval B_NOT_ALLOWED The clipboard is not locked. \retval B_NO_MEMORY Ran out of memory initializing the data message. \retval B_ERROR Another error occurred. \since BeOS R5 */ //! @} /*! \name Clipboard Data Message */ //! @{ /*! \fn BMessenger BClipboard::DataSource() const \brief Gets a BMessenger object targeting the application that last modified the clipboard. The clipboard object does not need to be locked to call this method. \returns A BMessenger object that targets the application that last modified the clipboard. \since BeOS R3 */ /*! \fn BMessage* BClipboard::Data() const \brief Gets a pointer to the BMessage object that holds the clipboard data. If the BClipboard object is not locked this method returns \c NULL. \returns A pointer to the BMessage object that holds the clipboard data or \c NULL if the clipboard is not locked. \since BeOS R3 */ //! @}