/* GStreamer Color Balance

 * Copyright (C) 2003 Ronald Bultje <rbultje@ronald.bitfreak.net>

 *

 * colorbalance.c: image color balance interface design

 *                 virtual class function wrappers

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "colorbalance.h"

/**

 * SECTION:gstcolorbalance

 * @title: GstColorBalance

 * @short_description: Interface for adjusting color balance settings

 *

 * This interface is implemented by elements which can perform some color

 * balance operation on video frames they process. For example, modifying

 * the brightness, contrast, hue or saturation.

 *

 * Example elements are 'xvimagesink' and 'colorbalance'

 *

 */

/* FIXME 0.11: check if we need to add API for sometimes-supportedness

 * (aka making up for GstImplementsInterface removal) */

/* FIXME 0.11: replace signals with messages (+ make API thread-safe) */

enum

{

  VALUE_CHANGED,

  LAST_SIGNAL

};

static void gst_color_balance_base_init (GstColorBalanceInterface * iface);

static guint gst_color_balance_signals[LAST_SIGNAL] = { 0 };

GType

gst_color_balance_get_type (void)

{

  static GType gst_color_balance_type = 0;

  if (!gst_color_balance_type) {

    static const GTypeInfo gst_color_balance_info = {

      sizeof (GstColorBalanceInterface),

      (GBaseInitFunc) gst_color_balance_base_init,

      NULL,

      NULL,

      NULL,

      NULL,

      0,

      0,

      NULL,

    };

    gst_color_balance_type = g_type_register_static (G_TYPE_INTERFACE,

        "GstColorBalance", &gst_color_balance_info, 0);

  }

  return gst_color_balance_type;

}

static void

gst_color_balance_base_init (GstColorBalanceInterface * iface)

{

  static gboolean initialized = FALSE;

  if (!initialized) {

    /**

     * GstColorBalance::value-changed:

     * @colorbalance: The GstColorBalance instance

     * @channel: The #GstColorBalanceChannel

     * @value: The new value

     *

     * Fired when the value of the indicated channel has changed.

     */

    gst_color_balance_signals[VALUE_CHANGED] =

        g_signal_new ("value-changed",

        GST_TYPE_COLOR_BALANCE, G_SIGNAL_RUN_LAST,

        G_STRUCT_OFFSET (GstColorBalanceInterface, value_changed),

        NULL, NULL, NULL,

        G_TYPE_NONE, 2, GST_TYPE_COLOR_BALANCE_CHANNEL, G_TYPE_INT);

    initialized = TRUE;

  }

  /* default virtual functions */

  iface->list_channels = NULL;

  iface->set_value = NULL;

  iface->get_value = NULL;

  iface->get_balance_type = NULL;

}

/**

 * gst_color_balance_list_channels:

 * @balance: A #GstColorBalance instance

 *

 * Retrieve a list of the available channels.

 *

 * Returns: (element-type GstColorBalanceChannel) (transfer none): A

 *          GList containing pointers to #GstColorBalanceChannel

 *          objects. The list is owned by the #GstColorBalance

 *          instance and must not be freed.

 */

const GList *

gst_color_balance_list_channels (GstColorBalance * balance)

{

  GstColorBalanceInterface *iface;

  g_return_val_if_fail (GST_IS_COLOR_BALANCE (balance), NULL);

  iface = GST_COLOR_BALANCE_GET_INTERFACE (balance);

  if (iface->list_channels) {

    return iface->list_channels (balance);

  }

  return NULL;

}

/**

 * gst_color_balance_set_value:

 * @balance: A #GstColorBalance instance

 * @channel: A #GstColorBalanceChannel instance

 * @value: The new value for the channel.

 *

 * Sets the current value of the channel to the passed value, which must

 * be between min_value and max_value.

 *

 * See Also: The #GstColorBalanceChannel.min_value and

 *         #GstColorBalanceChannel.max_value members of the

 *         #GstColorBalanceChannel object.

 */

void

gst_color_balance_set_value (GstColorBalance * balance,

    GstColorBalanceChannel * channel, gint value)

{

  GstColorBalanceInterface *iface = GST_COLOR_BALANCE_GET_INTERFACE (balance);

  if (iface->set_value) {

    iface->set_value (balance, channel, value);

  }

}

/**

 * gst_color_balance_get_value:

 * @balance: A #GstColorBalance instance

 * @channel: A #GstColorBalanceChannel instance

 *

 * Retrieve the current value of the indicated channel, between min_value

 * and max_value.

 *

 * See Also: The #GstColorBalanceChannel.min_value and

 *         #GstColorBalanceChannel.max_value members of the

 *         #GstColorBalanceChannel object.

 *

 * Returns: The current value of the channel.

 */

gint

gst_color_balance_get_value (GstColorBalance * balance,

    GstColorBalanceChannel * channel)

{

  GstColorBalanceInterface *iface;

  g_return_val_if_fail (GST_IS_COLOR_BALANCE (balance), 0);

  iface = GST_COLOR_BALANCE_GET_INTERFACE (balance);

  if (iface->get_value) {

    return iface->get_value (balance, channel);

  }

  return channel->min_value;

}

/**

 * gst_color_balance_get_balance_type:

 * @balance: The #GstColorBalance implementation

 *

 * Get the #GstColorBalanceType of this implementation.

 *

 * Returns: A the #GstColorBalanceType.

 */

GstColorBalanceType

gst_color_balance_get_balance_type (GstColorBalance * balance)

{

  GstColorBalanceInterface *iface;

  g_return_val_if_fail (GST_IS_COLOR_BALANCE (balance),

      GST_COLOR_BALANCE_SOFTWARE);

  iface = GST_COLOR_BALANCE_GET_INTERFACE (balance);

  g_return_val_if_fail (iface->get_balance_type != NULL,

      GST_COLOR_BALANCE_SOFTWARE);

  return iface->get_balance_type (balance);

}

/**

 * gst_color_balance_value_changed:

 * @balance: A #GstColorBalance instance

 * @channel: A #GstColorBalanceChannel whose value has changed

 * @value: The new value of the channel

 *

 * A helper function called by implementations of the GstColorBalance

 * interface. It fires the #GstColorBalance::value-changed signal on the

 * instance, and the #GstColorBalanceChannel::value-changed signal on the

 * channel object.

 */

void

gst_color_balance_value_changed (GstColorBalance * balance,

    GstColorBalanceChannel * channel, gint value)

{

  g_return_if_fail (GST_IS_COLOR_BALANCE (balance));

  g_signal_emit (G_OBJECT (balance),

      gst_color_balance_signals[VALUE_CHANGED], 0, channel, value);

  g_signal_emit_by_name (G_OBJECT (channel), "value_changed", value);

}