source: mainline/uspace/lib/c/generic/clipboard.c@ d2bb25e7

/*
 * Copyright (c) 2009 Jiri Svoboda
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libc
 * @{
 */
/** @file
 * @brief System clipboard API.
 *
 * The clipboard data is managed by the clipboard service and it is shared by
 * the entire system.
 *
 */

#include <clipboard.h>
#include <ns.h>
#include <ipc/services.h>
#include <ipc/clipboard.h>
#include <fibril_synch.h>
#include <async.h>
#include <str.h>
#include <errno.h>
#include <malloc.h>

static FIBRIL_MUTEX_INITIALIZE(clip_mutex);
static async_sess_t *clip_sess = NULL;

/** Start an async exchange on the clipboard session.
 *
 * @return New exchange.
 *
 */
static async_exch_t *clip_exchange_begin(void)
{
        fibril_mutex_lock(&clip_mutex);
        
        while (clip_sess == NULL)
                clip_sess = service_connect_blocking(SERVICE_CLIPBOARD,
                    INTERFACE_CLIPBOARD, 0);
        
        fibril_mutex_unlock(&clip_mutex);
        
        return async_exchange_begin(clip_sess);
}

/** Finish an async exchange on the clipboard session.
 *
 * @param exch Exchange to be finished.
 *
 */
static void clip_exchange_end(async_exch_t *exch)
{
        async_exchange_end(exch);
}

/** Copy string to clipboard.
 *
 * Sets the clipboard contents to @a str. Passing an empty string or NULL
 * makes the clipboard empty.
 *
 * @param str String to put to clipboard or NULL.
 *
 * @return Zero on success or negative error code.
 *
 */
int clipboard_put_str(const char *str)
{
        size_t size = str_size(str);
        
        if (size == 0) {
                async_exch_t *exch = clip_exchange_begin();
                sysarg_t rc = async_req_1_0(exch, CLIPBOARD_PUT_DATA,
                    CLIPBOARD_TAG_NONE);
                clip_exchange_end(exch);
                
                return (int) rc;
        } else {
                async_exch_t *exch = clip_exchange_begin();
                aid_t req = async_send_1(exch, CLIPBOARD_PUT_DATA, CLIPBOARD_TAG_DATA,
                    NULL);
                sysarg_t rc = async_data_write_start(exch, (void *) str, size);
                clip_exchange_end(exch);
                
                if (rc != EOK) {
                        sysarg_t rc_orig;
                        async_wait_for(req, &rc_orig);
                        if (rc_orig == EOK)
                                return (int) rc;
                        else
                                return (int) rc_orig;
                }
                
                async_wait_for(req, &rc);
                
                return (int) rc;
        }
}

/** Get a copy of clipboard contents.
 *
 * Returns a new string that can be deallocated with free().
 *
 * @param str Here pointer to the newly allocated string is stored.
 *
 * @return Zero on success or negative error code.
 *
 */
int clipboard_get_str(char **str)
{
        /* Loop until clipboard read succesful */
        while (true) {
                async_exch_t *exch = clip_exchange_begin();
                
                sysarg_t size;
                sysarg_t tag;
                sysarg_t rc = async_req_0_2(exch, CLIPBOARD_CONTENT, &size, &tag);
                
                clip_exchange_end(exch);
                
                if (rc != EOK)
                        return (int) rc;
                
                char *sbuf;
                
                switch (tag) {
                case CLIPBOARD_TAG_NONE:
                        sbuf = malloc(1);
                        if (sbuf == NULL)
                                return ENOMEM;
                        
                        sbuf[0] = 0;
                        *str = sbuf;
                        return EOK;
                case CLIPBOARD_TAG_DATA:
                        sbuf = malloc(size + 1);
                        if (sbuf == NULL)
                                return ENOMEM;
                        
                        exch = clip_exchange_begin();
                        aid_t req = async_send_1(exch, CLIPBOARD_GET_DATA, tag, NULL);
                        rc = async_data_read_start(exch, (void *) sbuf, size);
                        clip_exchange_end(exch);
                        
                        if ((int) rc == EOVERFLOW) {
                                /*
                                 * The data in the clipboard has changed since
                                 * the last call of CLIPBOARD_CONTENT
                                 */
                                break;
                        }
                        
                        if (rc != EOK) {
                                sysarg_t rc_orig;
                                async_wait_for(req, &rc_orig);
                                if (rc_orig == EOK)
                                        return (int) rc;
                                else
                                        return (int) rc_orig;
                        }
                        
                        async_wait_for(req, &rc);
                        
                        if (rc == EOK) {
                                sbuf[size] = 0;
                                *str = sbuf;
                        }
                        
                        return rc;
                default:
                        return EINVAL;
                }
        }
}

/** @}
 */