/* align_layers.c
 * Author: Shuji Narazaki <narazaki@InetQ.or.jp>
 * Version:  0.26
 *
 * Copyright (C) 1997-1998 Shuji Narazaki <narazaki@InetQ.or.jp>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <libgimp/gimp.h>
#include <libgimp/gimpui.h>

#include "libgimp/stdplugins-intl.h"

#define PLUG_IN_PROC   "plug-in-align-layers"
#define PLUG_IN_BINARY "align-layers"
#define PLUG_IN_ROLE   "gimp-align-layers"
#define SCALE_WIDTH    150

enum
{
  H_NONE,
  H_COLLECT,
  LEFT2RIGHT,
  RIGHT2LEFT,
  SNAP2HGRID
};

enum
{
  H_BASE_LEFT,
  H_BASE_CENTER,
  H_BASE_RIGHT
};

enum
{
  V_NONE,
  V_COLLECT,
  TOP2BOTTOM,
  BOTTOM2TOP,
  SNAP2VGRID
};

enum
{
  V_BASE_TOP,
  V_BASE_CENTER,
  V_BASE_BOTTOM
};

static void     query   (void);
static void     run     (const gchar      *name,
                         gint              nparams,
                         const GimpParam  *param,
                         gint             *nreturn_vals,
                         GimpParam       **return_vals);

static GimpPDBStatusType align_layers                   (gint32  image_id);
static void              align_layers_get_align_offsets (gint32  drawable_id,
                                                         gint   *x,
                                                         gint   *y);

static gint              align_layers_dialog             (void);


const GimpPlugInInfo PLUG_IN_INFO =
{
  NULL,  /* init_proc  */
  NULL,  /* quit_proc  */
  query, /* query_proc */
  run,   /* run_proc   */
};


/* dialog variables */
typedef struct
{
  gint     h_style;
  gint     h_base;
  gint     v_style;
  gint     v_base;
  gboolean ignore_bottom;
  gboolean base_is_bottom_layer;
  gint     grid_size;
} ValueType;

static ValueType VALS =
{
  H_NONE,
  H_BASE_LEFT,
  V_NONE,
  V_BASE_TOP,
  TRUE,
  FALSE,
  10
};


MAIN ()

static void
query (void)
{
  static const GimpParamDef args [] =
  {
    { GIMP_PDB_INT32,    "run-mode",             "The run mode { RUN-INTERACTIVE (0), RUN-NONINTERACTIVE (1) }"},
    { GIMP_PDB_IMAGE,    "image",                "Input image"},
    { GIMP_PDB_DRAWABLE, "drawable",             "Input drawable (not used)"},
    { GIMP_PDB_INT32,    "link-after-alignment", "Link the visible layers after alignment { TRUE, FALSE }"},
    { GIMP_PDB_INT32,    "use-bottom",           "use the bottom layer as the base of alignment { TRUE, FALSE }"}
  };

  gimp_install_procedure (PLUG_IN_PROC,
                          N_("Align all visible layers of the image"),
                          "Align visible layers",
                          "Shuji Narazaki <narazaki@InetQ.or.jp>",
                          "Shuji Narazaki",
                          "1997",
                          N_("Align Visi_ble Layers..."),
                          "RGB*,GRAY*,INDEXED*",
                          GIMP_PLUGIN,
                          G_N_ELEMENTS (args), 0,
                          args, NULL);

  gimp_plugin_menu_register (PLUG_IN_PROC, "<Image>/Image/Arrange");
}

static void
run (const gchar      *name,
     gint              nparams,
     const GimpParam  *param,
     gint             *nreturn_vals,
     GimpParam       **return_vals)
{
  static GimpParam  values[2];
  GimpPDBStatusType status = GIMP_PDB_EXECUTION_ERROR;
  GimpRunMode       run_mode;
  gint              image_id, layer_num;

  run_mode = param[0].data.d_int32;
  image_id = param[1].data.d_int32;

  INIT_I18N ();

  *nreturn_vals = 1;
  *return_vals  = values;

  values[0].type          = GIMP_PDB_STATUS;
  values[0].data.d_status = status;

  switch ( run_mode )
    {
    case GIMP_RUN_INTERACTIVE:
      gimp_image_get_layers (image_id, &layer_num);
      if (layer_num < 2)
        {
          *nreturn_vals = 2;
          values[1].type          = GIMP_PDB_STRING;
          values[1].data.d_string = _("There are not enough layers to align.");
          return;
        }
      gimp_get_data (PLUG_IN_PROC, &VALS);
      VALS.grid_size = MAX (VALS.grid_size, 1);
      if (! align_layers_dialog ())
        return;
      break;

    case GIMP_RUN_NONINTERACTIVE:
      break;

    case GIMP_RUN_WITH_LAST_VALS:
      gimp_get_data (PLUG_IN_PROC, &VALS);
      break;
    }

  status = align_layers (image_id);

  if (run_mode != GIMP_RUN_NONINTERACTIVE)
    gimp_displays_flush ();
  if (run_mode == GIMP_RUN_INTERACTIVE && status == GIMP_PDB_SUCCESS)
    gimp_set_data (PLUG_IN_PROC, &VALS, sizeof (ValueType));

  values[0].type = GIMP_PDB_STATUS;
  values[0].data.d_status = status;
}

static GimpPDBStatusType
align_layers (gint32 image_id)
{
  gint  layer_num = 0;
  gint  visible_layer_num = 0;
  gint *layers = NULL;
  gint  index;
  gint  vindex;
  gint  step_x   = 0;
  gint  step_y   = 0;
  gint  x        = 0;
  gint  y        = 0;
  gint  orig_x   = 0;
  gint  orig_y   = 0;
  gint  offset_x = 0;
  gint  offset_y = 0;
  gint  base_x   = 0;
  gint  base_y   = 0;
  gint  bg_index = 0;

  layers = gimp_image_get_layers (image_id, &layer_num);
  bg_index = layer_num - 1;

  for (index = 0; index < layer_num; index++)
    {
      if (gimp_item_get_visible (layers[index]))
        visible_layer_num++;
    }

  if (VALS.ignore_bottom)
    {
      layer_num--;
      if (gimp_item_get_visible (layers[bg_index]))
        visible_layer_num--;
    }

  if (0 < visible_layer_num)
    {
      gint      min_x = G_MAXINT;
      gint      min_y = G_MAXINT;
      gint      max_x = G_MININT;
      gint      max_y = G_MININT;

      /* 0 is the top layer */
      for (index = 0; index < layer_num; index++)
        {
          if (gimp_item_get_visible (layers[index]))
            {
              gimp_drawable_offsets (layers[index], &orig_x, &orig_y);
              align_layers_get_align_offsets (layers[index], &offset_x,
                                              &offset_y);
              orig_x += offset_x;
              orig_y += offset_y;

              if ( orig_x < min_x ) min_x = orig_x;
              if ( max_x < orig_x ) max_x = orig_x;
              if ( orig_y < min_y ) min_y = orig_y;
              if ( max_y < orig_y ) max_y = orig_y;
            }
        }

      if (VALS.base_is_bottom_layer)
        {
          gimp_drawable_offsets (layers[bg_index], &orig_x, &orig_y);
          align_layers_get_align_offsets (layers[bg_index], &offset_x,
                                          &offset_y);
          orig_x += offset_x;
          orig_y += offset_y;
          base_x = min_x = orig_x;
          base_y = min_y = orig_y;
        }

      if (visible_layer_num > 1)
        {
          step_x = (max_x - min_x) / (visible_layer_num - 1);
          step_y = (max_y - min_y) / (visible_layer_num - 1);
        }

      if ( (VALS.h_style == LEFT2RIGHT) || (VALS.h_style == RIGHT2LEFT))
        base_x = min_x;

      if ( (VALS.v_style == TOP2BOTTOM) || (VALS.v_style == BOTTOM2TOP))
        base_y = min_y;
    }

  gimp_image_undo_group_start (image_id);

  for (vindex = -1, index = 0; index < layer_num; index++)
    {
      if (gimp_item_get_visible (layers[index]))
        vindex++;
      else
        continue;

      gimp_drawable_offsets (layers[index], &orig_x, &orig_y);
      align_layers_get_align_offsets (layers[index], &offset_x, &offset_y);

      switch (VALS.h_style)
        {
        case H_NONE:
          x = orig_x;
          break;
        case H_COLLECT:
          x = base_x - offset_x;
          break;
        case LEFT2RIGHT:
          x = (base_x + vindex * step_x) - offset_x;
          break;
        case RIGHT2LEFT:
          x = (base_x + (visible_layer_num - vindex - 1) * step_x) - offset_x;
          break;
        case SNAP2HGRID:
          x = VALS.grid_size
            * (int) ((orig_x + offset_x + VALS.grid_size /2) / VALS.grid_size)
            - offset_x;
          break;
        }
      switch (VALS.v_style)
        {
        case V_NONE:
          y = orig_y;
          break;
        case V_COLLECT:
          y = base_y - offset_y;
          break;
        case TOP2BOTTOM:
          y = (base_y + vindex * step_y) - offset_y;
          break;
        case BOTTOM2TOP:
          y = (base_y + (visible_layer_num - vindex - 1) * step_y) - offset_y;
          break;
        case SNAP2VGRID:
          y = VALS.grid_size
            * (int) ((orig_y + offset_y + VALS.grid_size / 2) / VALS.grid_size)
            - offset_y;
          break;
        }
      gimp_layer_set_offsets (layers[index], x, y);
    }

  gimp_image_undo_group_end (image_id);

  return GIMP_PDB_SUCCESS;
}

static void
align_layers_get_align_offsets (gint32  drawable_id,
                                gint   *x,
                                gint   *y)
{
  GimpDrawable *layer = gimp_drawable_get (drawable_id);

  switch (VALS.h_base)
    {
    case H_BASE_LEFT:
      *x = 0;
      break;
    case H_BASE_CENTER:
      *x = layer->width / 2;
      break;
    case H_BASE_RIGHT:
      *x = layer->width;
      break;
    default:
      *x = 0;
      break;
    }

  switch (VALS.v_base)
    {
    case V_BASE_TOP:
      *y = 0;
      break;
    case V_BASE_CENTER:
      *y = layer->height / 2;
      break;
    case V_BASE_BOTTOM:
      *y = layer->height;
      break;
    default:
      *y = 0;
      break;
    }

  gimp_drawable_detach (layer);
}

static int
align_layers_dialog (void)
{
  GtkWidget *dialog;
  GtkWidget *table;
  GtkWidget *combo;
  GtkWidget *toggle;
  GtkObject *adj;
  gboolean   run;

  gimp_ui_init (PLUG_IN_BINARY, FALSE);

  dialog = gimp_dialog_new (_("Align Visible Layers"), PLUG_IN_ROLE,
                            NULL, 0,
                            gimp_standard_help_func, PLUG_IN_PROC,

                            GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,
                            GTK_STOCK_OK,     GTK_RESPONSE_OK,

                            NULL);

  gtk_dialog_set_alternative_button_order (GTK_DIALOG (dialog),
                                           GTK_RESPONSE_OK,
                                           GTK_RESPONSE_CANCEL,
                                           -1);

  gimp_window_set_transient (GTK_WINDOW (dialog));

  table = gtk_table_new (7, 3, FALSE);
  gtk_table_set_col_spacings (GTK_TABLE (table), 6);
  gtk_table_set_row_spacings (GTK_TABLE (table), 6);
  gtk_container_set_border_width (GTK_CONTAINER (table), 12);
  gtk_box_pack_start (GTK_BOX (gtk_dialog_get_content_area (GTK_DIALOG (dialog))),
                      table, FALSE, FALSE, 0);
  gtk_widget_show (table);

  combo = gimp_int_combo_box_new (C_("align-style", "None"), H_NONE,
                                  _("Collect"),              H_COLLECT,
                                  _("Fill (left to right)"), LEFT2RIGHT,
                                  _("Fill (right to left)"), RIGHT2LEFT,
                                  _("Snap to grid"),         SNAP2HGRID,
                                  NULL);
  gimp_int_combo_box_set_active (GIMP_INT_COMBO_BOX (combo), VALS.h_style);

  g_signal_connect (combo, "changed",
                    G_CALLBACK (gimp_int_combo_box_get_active),
                    &VALS.h_style);

  gimp_table_attach_aligned (GTK_TABLE (table), 0, 0,
                             _("_Horizontal style:"), 0.0, 0.5,
                             combo, 2, FALSE);


  combo = gimp_int_combo_box_new (_("Left edge"),  H_BASE_LEFT,
                                  _("Center"),     H_BASE_CENTER,
                                  _("Right edge"), H_BASE_RIGHT,
                                  NULL);
  gimp_int_combo_box_set_active (GIMP_INT_COMBO_BOX (combo), VALS.h_base);

  g_signal_connect (combo, "changed",
                    G_CALLBACK (gimp_int_combo_box_get_active),
                    &VALS.h_base);

  gimp_table_attach_aligned (GTK_TABLE (table), 0, 1,
                             _("Ho_rizontal base:"), 0.0, 0.5,
                             combo, 2, FALSE);

  combo = gimp_int_combo_box_new (C_("align-style", "None"), V_NONE,
                                  _("Collect"),              V_COLLECT,
                                  _("Fill (top to bottom)"), TOP2BOTTOM,
                                  _("Fill (bottom to top)"), BOTTOM2TOP,
                                  _("Snap to grid"),         SNAP2VGRID,
                                  NULL);
  gimp_int_combo_box_set_active (GIMP_INT_COMBO_BOX (combo), VALS.v_style);

  g_signal_connect (combo, "changed",
                    G_CALLBACK (gimp_int_combo_box_get_active),
                    &VALS.v_style);

  gimp_table_attach_aligned (GTK_TABLE (table), 0, 2,
                             _("_Vertical style:"), 0.0, 0.5,
                             combo, 2, FALSE);

  combo = gimp_int_combo_box_new (_("Top edge"),    V_BASE_TOP,
                                  _("Center"),      V_BASE_CENTER,
                                  _("Bottom edge"), V_BASE_BOTTOM,
                                  NULL);
  gimp_int_combo_box_set_active (GIMP_INT_COMBO_BOX (combo), VALS.v_base);

  g_signal_connect (combo, "changed",
                    G_CALLBACK (gimp_int_combo_box_get_active),
                    &VALS.v_base);

  gimp_table_attach_aligned (GTK_TABLE (table), 0, 3,
                             _("Ver_tical base:"), 0.0, 0.5,
                             combo, 2, FALSE);

  adj = gimp_scale_entry_new (GTK_TABLE (table), 0, 4,
                              _("_Grid size:"), SCALE_WIDTH, 0,
                              VALS.grid_size, 1, 200, 1, 10, 0,
                              TRUE, 0, 0,
                              NULL, NULL);
  g_signal_connect (adj, "value-changed",
                    G_CALLBACK (gimp_int_adjustment_update),
                    &VALS.grid_size);

  toggle = gtk_check_button_new_with_mnemonic
    (_("_Ignore the bottom layer even if visible"));
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (toggle), VALS.ignore_bottom);
  gtk_table_attach_defaults (GTK_TABLE (table), toggle, 0, 3, 5, 6);
  gtk_widget_show (toggle);

  g_signal_connect (toggle, "toggled",
                    G_CALLBACK (gimp_toggle_button_update),
                    &VALS.ignore_bottom);

  toggle = gtk_check_button_new_with_mnemonic
    (_("_Use the (invisible) bottom layer as the base"));
  gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (toggle),
                                VALS.base_is_bottom_layer);
  gtk_table_attach_defaults (GTK_TABLE (table), toggle, 0, 3, 6, 7);
  gtk_widget_show (toggle);

  g_signal_connect (toggle, "toggled",
                    G_CALLBACK (gimp_toggle_button_update),
                    &VALS.base_is_bottom_layer);

  gtk_widget_show (dialog);

  run = (gimp_dialog_run (GIMP_DIALOG (dialog)) == GTK_RESPONSE_OK);

  gtk_widget_destroy (dialog);

  return run;
}