drmr_ui.c

/* drmr.c
 * LV2 DrMr plugin
 * Copyright 2012 Nick Lanham <nick@afternight.org>
 *
 * Public License v3. source code is available at 
 * <http://github.com/nicklan/drmr>

 * THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <stdlib.h>

#include <gtk/gtk.h>

#include "drmr.h"
#include "drmr_hydrogen.h"
#include "nknob.h"
#include "lv2/lv2plug.in/ns/extensions/ui/ui.h"

#define DRMR_UI_URI "http://github.com/nicklan/drmr#ui"

typedef struct {
  LV2UI_Write_Function write;
  LV2UI_Controller     controller;

  GtkWidget *drmr_widget;
  GtkTable *sample_table;
  GtkComboBox *kit_combo;
  GtkWidget *no_kit_label;
  GtkSpinButton *base_spin;
  GtkLabel *base_label;
  GtkListStore *kit_store;
  GtkWidget** gain_sliders;
  GtkWidget** pan_sliders;
  GtkWidget *velocity_checkbox, *note_off_checkbox;
  float *gain_vals,*pan_vals;

  gchar *bundle_path;

  int cols;
  int startSamp;

  gboolean forceUpdate;

  int samples;

  GQuark gain_quark, pan_quark;

  int curKit;
  int kitReq;
  kits* kits;
} DrMrUi;

static gboolean gain_callback(GtkRange* range, GtkScrollType type, gdouble value, gpointer data) {
  DrMrUi* ui = (DrMrUi*)data;
  int gidx = GPOINTER_TO_INT(g_object_get_qdata(G_OBJECT(range),ui->gain_quark));
  float gain = (float)value;
  ui->gain_vals[gidx] = gain;
  ui->write(ui->controller,gidx+DRMR_GAIN_ONE,4,0,&gain);
  return FALSE;
}

static gboolean pan_callback(GtkRange* range, GtkScrollType type, gdouble value, gpointer data) {
  DrMrUi* ui = (DrMrUi*)data;
  int pidx = GPOINTER_TO_INT(g_object_get_qdata(G_OBJECT(range),ui->pan_quark));
  float pan = (float)value;
  ui->pan_vals[pidx] = pan;
  ui->write(ui->controller,pidx+DRMR_PAN_ONE,4,0,&pan);
  return FALSE;
}

static gboolean ignore_velocity_toggled(GtkToggleButton *button, gpointer data) {
  DrMrUi* ui = (DrMrUi*)data;
  float val =
    gtk_toggle_button_get_active(button)?1.0f:0.0f;
  ui->write(ui->controller,DRMR_IGNORE_VELOCITY,4,0,&val);
  return FALSE;
}

static gboolean ignore_note_off_toggled(GtkToggleButton *button, gpointer data) {
  DrMrUi* ui = (DrMrUi*)data;
  float val =
    gtk_toggle_button_get_active(button)?1.0f:0.0f;
  ui->write(ui->controller,DRMR_IGNORE_NOTE_OFF,4,0,&val);
  return FALSE;
}

static void fill_sample_table(DrMrUi* ui, int samples, char** names,GtkWidget** gain_sliders, GtkWidget** pan_sliders) {
  int row = 0;
  int col = 0;
  int si;
  gchar buf[64];
  int rows = (samples/ui->cols);
  if (samples % ui->cols != 0) rows++;
  gtk_table_resize(ui->sample_table,rows,ui->cols);

  switch (ui->startSamp) {
  case 1: // bottom left
    row = rows-1;
    break;
  case 2: // top right
    col = ui->cols-1;
    break;
  case 3: // bottom right
    row = rows-1;
    col = ui->cols-1;
    break;
  }

  for(si = 0;si<samples;si++) {
    GtkWidget *frame,*hbox,*gain_vbox,*pan_vbox;
    GtkWidget* gain_slider;
    GtkWidget* pan_slider;
    GtkWidget* gain_label;
    GtkWidget* pan_label;
    gboolean slide_expand;
    snprintf(buf,64,"<b>%s</b> (%i)",names[si],si);

    frame = gtk_frame_new(buf);
    gtk_label_set_use_markup(GTK_LABEL(gtk_frame_get_label_widget(GTK_FRAME(frame))),true);
    gtk_frame_set_shadow_type(GTK_FRAME(frame),GTK_SHADOW_OUT);
    hbox = gtk_hbox_new(false,0);

#ifdef NO_NKNOB
    gain_slider = gtk_vscale_new_with_range(GAIN_MIN,6.0,1.0);
    gtk_scale_set_value_pos(GTK_SCALE(gain_slider),GTK_POS_BOTTOM);
    gtk_scale_set_digits(GTK_SCALE(gain_slider),1);
    gtk_scale_add_mark(GTK_SCALE(gain_slider),0.0,GTK_POS_RIGHT,"0 dB");
    // Hrmm, -inf label is at top in ardour for some reason
    //gtk_scale_add_mark(GTK_SCALE(gain_slider),GAIN_MIN,GTK_POS_RIGHT,"-inf");
    gtk_range_set_inverted(GTK_RANGE(gain_slider),true);
    slide_expand = true;
#else
    gain_slider = n_knob_new_with_range(0.0,GAIN_MIN,6.0,1.0);
    n_knob_set_load_prefix(N_KNOB(gain_slider),ui->bundle_path);
    gtk_widget_set_has_tooltip(gain_slider,TRUE);
    slide_expand = false;
#endif
    g_object_set_qdata (G_OBJECT(gain_slider),ui->gain_quark,GINT_TO_POINTER(si));
    if (gain_sliders) gain_sliders[si] = gain_slider;
    if (si < 32)
      gtk_range_set_value(GTK_RANGE(gain_slider),ui->gain_vals[si]);
    else // things are gross if we have > 32 samples, what to do?
      gtk_range_set_value(GTK_RANGE(gain_slider),0.0);
    g_signal_connect(G_OBJECT(gain_slider),"change-value",G_CALLBACK(gain_callback),ui);
    gain_label = gtk_label_new("Gain");
    gain_vbox = gtk_vbox_new(false,0);

#ifdef NO_NKNOB
    pan_slider = gtk_hscale_new_with_range(-1.0,1.0,0.1);
    gtk_scale_add_mark(GTK_SCALE(pan_slider),0.0,GTK_POS_TOP,NULL);
#else
    pan_slider = n_knob_new_with_range(0.0,-1.0,1.0,0.1);
    n_knob_set_load_prefix(N_KNOB(pan_slider),ui->bundle_path);
    gtk_widget_set_has_tooltip(pan_slider,TRUE);
#endif
    if (pan_sliders) pan_sliders[si] = pan_slider;
    if (si < 32)
      gtk_range_set_value(GTK_RANGE(pan_slider),ui->pan_vals[si]);
    else
      gtk_range_set_value(GTK_RANGE(pan_slider),0);
    g_object_set_qdata (G_OBJECT(pan_slider),ui->pan_quark,GINT_TO_POINTER(si));
    g_signal_connect(G_OBJECT(pan_slider),"change-value",G_CALLBACK(pan_callback),ui);
    pan_label = gtk_label_new("Pan");
    pan_vbox = gtk_vbox_new(false,0);
    
    gtk_box_pack_start(GTK_BOX(gain_vbox),gain_slider,slide_expand,slide_expand,0);
    gtk_box_pack_start(GTK_BOX(gain_vbox),gain_label,false,false,0);

    gtk_box_pack_start(GTK_BOX(pan_vbox),pan_slider,slide_expand,slide_expand,0);
    gtk_box_pack_start(GTK_BOX(pan_vbox),pan_label,false,false,0);

    gtk_box_pack_start(GTK_BOX(hbox),gain_vbox,true,true,0);
    gtk_box_pack_start(GTK_BOX(hbox),pan_vbox,true,true,0);

    gtk_container_add(GTK_CONTAINER(frame),hbox);

    gtk_table_attach_defaults(ui->sample_table,frame,col,col+1,row,row+1);

    if (ui->startSamp > 1) {
      col--;
      if (col < 0) {
	if (ui->startSamp == 2)
	  row++;
	else
	  row--;
	col = ui->cols-1;
      }
    }
    else {
      col++;
      if (col >= ui->cols) {
	if (ui->startSamp == 0)
	  row++;
	else
	  row--;
	col = 0;
      }
    }
  }
  gtk_widget_queue_resize(GTK_WIDGET(ui->sample_table));
}

static const char* nstrs = "C C#D D#E F F#G G#A A#B ";
static char baseLabelBuf[32];
static void setBaseLabel(int noteIdx) {
  int oct = (noteIdx/12)-1;
  int nmt = (noteIdx%12)*2;
  snprintf(baseLabelBuf,32,"Midi Base Note <b>(%c%c%i)</b>:",
	   nstrs[nmt],nstrs[nmt+1],oct);
}

static void base_changed(GtkSpinButton *base_spin, gpointer data) {
  DrMrUi* ui = (DrMrUi*)data;
  float base = (float)gtk_spin_button_get_value(base_spin);

  if (base >= 21.0f && base <= 107.0f) {
    setBaseLabel((int)base);
    ui->write(ui->controller,DRMR_BASENOTE,4,0,&base);
    gtk_label_set_markup(ui->base_label,baseLabelBuf);
  }
  else
    fprintf(stderr,"Base spin got out of range: %f\n",base);
}

static void fill_kit_combo(GtkComboBox* combo, kits* kits) {
  int i;
  GtkTreeIter iter;
  GtkListStore *store = GTK_LIST_STORE(gtk_combo_box_get_model(combo));
  for (i=0;i<kits->num_kits;i++) {
    gtk_list_store_append (store, &iter);
    gtk_list_store_set(store, &iter, 0, kits->kits[i].name, -1);
  }
}

static gboolean idle = FALSE;
static gboolean kit_callback(gpointer data) {
  DrMrUi* ui = (DrMrUi*)data;
  if (ui->forceUpdate || (ui->kitReq != ui->curKit)) {
    ui->forceUpdate = false;
    int samples = (ui->kitReq<ui->kits->num_kits && ui->kitReq >= 0)?
      ui->kits->kits[ui->kitReq].samples:
      0;
    GtkWidget** gain_sliders;
    GtkWidget** pan_sliders;
    if (ui->sample_table) {
      gain_sliders = ui->gain_sliders;
      pan_sliders = ui->pan_sliders;
      ui->gain_sliders = NULL;
      ui->pan_sliders = NULL;
      if (gain_sliders) free(gain_sliders);
      if (pan_sliders) free(pan_sliders);
      gtk_widget_destroy(GTK_WIDGET(ui->sample_table));
      ui->sample_table = NULL;
    }
    if (samples > 0) {
      ui->sample_table = GTK_TABLE(gtk_table_new(1,1,true));
      gtk_table_set_col_spacings(ui->sample_table,5);
      gtk_table_set_row_spacings(ui->sample_table,5);

      gain_sliders = malloc(samples*sizeof(GtkWidget*));
      pan_sliders = malloc(samples*sizeof(GtkWidget*));
      fill_sample_table(ui,samples,ui->kits->kits[ui->kitReq].sample_names,gain_sliders,pan_sliders);
      gtk_box_pack_start(GTK_BOX(ui->drmr_widget),GTK_WIDGET(ui->sample_table),
			 true,true,5);
      gtk_box_reorder_child(GTK_BOX(ui->drmr_widget),GTK_WIDGET(ui->sample_table),0);
      gtk_widget_show_all(GTK_WIDGET(ui->sample_table));
      ui->samples = samples;
      ui->gain_sliders = gain_sliders;
      ui->pan_sliders = pan_sliders;

      ui->curKit = ui->kitReq;
      gtk_combo_box_set_active(ui->kit_combo,ui->curKit);
      gtk_widget_show(GTK_WIDGET(ui->kit_combo));
      gtk_widget_hide(ui->no_kit_label);
    } else {
      gtk_widget_show(ui->no_kit_label);
      gtk_widget_hide(GTK_WIDGET(ui->kit_combo));
    }
  }
  idle = FALSE;
  return FALSE; // don't keep calling
}

static void kit_combobox_changed(GtkComboBox* box, gpointer data) {
  DrMrUi* ui = (DrMrUi*)data;
  gint new_kit = gtk_combo_box_get_active (GTK_COMBO_BOX(box));
  float fkit = (float)new_kit;
  if (ui->curKit != new_kit)
    ui->write(ui->controller,DRMR_KITNUM,4,0,&fkit);

  /* Call our update func after 100 milliseconds.
   *
   * This is a hack to deal with hosts that don't send
   * back port_events properly after the write function.
   * In particular, qtractor doesn't, at the moment.
   */
  ui->kitReq = new_kit;
  g_timeout_add(100,kit_callback,ui);
}

static void position_combobox_changed(GtkComboBox* box, gpointer data) {
  DrMrUi* ui = (DrMrUi*)data;
  gint ss = gtk_combo_box_get_active (GTK_COMBO_BOX(box));
  if (ss != ui->startSamp) {
    ui->startSamp = ss;
    ui->forceUpdate = true;
    kit_callback(ui);
  }
}

static GtkWidget *create_position_combo(void)
{
  GtkWidget *combo;
  GtkListStore *list_store;
  GtkCellRenderer *cell;
  GtkTreeIter iter;

  list_store = gtk_list_store_new(1, G_TYPE_STRING);

  gtk_list_store_append(list_store, &iter);
  gtk_list_store_set (list_store, &iter, 0, "Top Left", -1);
  gtk_list_store_append(list_store, &iter);
  gtk_list_store_set (list_store, &iter, 0, "Bottom Left", -1);
  gtk_list_store_append(list_store, &iter);
  gtk_list_store_set (list_store, &iter, 0, "Top Right", -1);
  gtk_list_store_append(list_store, &iter);
  gtk_list_store_set (list_store, &iter, 0, "Bottom Right", -1);

  combo = gtk_combo_box_new_with_model(GTK_TREE_MODEL(list_store));

#ifdef DRMR_UI_ZERO_SAMP
  gtk_combo_box_set_active(GTK_COMBO_BOX(combo),DRMR_UI_ZERO_SAMP);
#else
  gtk_combo_box_set_active(GTK_COMBO_BOX(combo),0);
#endif


  g_object_unref(list_store);

  cell = gtk_cell_renderer_text_new();
  gtk_cell_layout_pack_start(GTK_CELL_LAYOUT(combo), cell, TRUE);
  gtk_cell_layout_set_attributes(GTK_CELL_LAYOUT(combo), cell, "text", 0, NULL);

  return combo;
}

static void build_drmr_ui(DrMrUi* ui) {
  GtkWidget *drmr_ui_widget;
  GtkWidget *opts_hbox1, *opts_hbox2, 
    *kit_combo_box, *kit_label, *no_kit_label,
    *base_label, *base_spin, *position_label, *position_combo_box;
  GtkCellRenderer *cell_rend;
  GtkAdjustment *base_adj;
  
  drmr_ui_widget = gtk_vbox_new(false,0);
  g_object_set(drmr_ui_widget,"border-width",6,NULL);

  ui->kit_store = gtk_list_store_new(1,G_TYPE_STRING);

  opts_hbox1 = gtk_hbox_new(false,0);
  opts_hbox2 = gtk_hbox_new(false,0);
  kit_combo_box = gtk_combo_box_new_with_model(GTK_TREE_MODEL(ui->kit_store));
  kit_label = gtk_label_new("Kit:");

  no_kit_label = gtk_label_new("<b>No/Invalid Kit Selected</b>");
  gtk_label_set_use_markup(GTK_LABEL(no_kit_label),true);

  cell_rend = gtk_cell_renderer_text_new();
  gtk_cell_layout_pack_start(GTK_CELL_LAYOUT(kit_combo_box), cell_rend, true);
  gtk_cell_layout_set_attributes(GTK_CELL_LAYOUT(kit_combo_box), cell_rend,"text",0,NULL);

  base_label = gtk_label_new("Midi Base Note <b>(C 2)</b>:");
  gtk_label_set_use_markup(GTK_LABEL(base_label),true);
  base_adj = GTK_ADJUSTMENT
    (gtk_adjustment_new(36.0, // val
			21.0,107.0, // min/max
			1.0, // step
			5.0,0.0)); // page adj/size
  base_spin = gtk_spin_button_new(base_adj, 1.0, 0);

  position_label = gtk_label_new("Sample Zero Position: ");
  position_combo_box = create_position_combo();

  ui->velocity_checkbox = gtk_check_button_new_with_label("Ignore Velocity");
  ui->note_off_checkbox = gtk_check_button_new_with_label("Ignore Note Off");

  gtk_box_pack_start(GTK_BOX(opts_hbox1),kit_label,
		     false,false,15);
  gtk_box_pack_start(GTK_BOX(opts_hbox1),no_kit_label,
		     true,true,0);
  gtk_box_pack_start(GTK_BOX(opts_hbox1),kit_combo_box,
		     true,true,0);
  gtk_box_pack_start(GTK_BOX(opts_hbox1),base_label,
		     false,false,15);
  gtk_box_pack_start(GTK_BOX(opts_hbox1),base_spin,
		     true,true,0);

  gtk_box_pack_start(GTK_BOX(opts_hbox2),position_label,
		     false,false,15);
  gtk_box_pack_start(GTK_BOX(opts_hbox2),position_combo_box,
		     false,false,0);
  gtk_box_pack_start(GTK_BOX(opts_hbox2),ui->velocity_checkbox,
		     true,true,15);
  gtk_box_pack_start(GTK_BOX(opts_hbox2),ui->note_off_checkbox,
		     true,true,15);

  gtk_box_pack_start(GTK_BOX(drmr_ui_widget),gtk_hseparator_new(),
		     false,false,5);
  gtk_box_pack_start(GTK_BOX(drmr_ui_widget),opts_hbox1,
		     false,false,5);
  gtk_box_pack_start(GTK_BOX(drmr_ui_widget),opts_hbox2,
		     false,false,5);



  ui->drmr_widget = drmr_ui_widget;
  ui->sample_table = NULL;
  ui->kit_combo = GTK_COMBO_BOX(kit_combo_box);
  ui->base_label = GTK_LABEL(base_label);
  ui->base_spin = GTK_SPIN_BUTTON(base_spin);
  ui->no_kit_label = no_kit_label;

  g_signal_connect(G_OBJECT(kit_combo_box),"changed",G_CALLBACK(kit_combobox_changed),ui);
  g_signal_connect(G_OBJECT(base_spin),"value-changed",G_CALLBACK(base_changed),ui);
  g_signal_connect(G_OBJECT(position_combo_box),"changed",G_CALLBACK(position_combobox_changed),ui);
  g_signal_connect(G_OBJECT(ui->velocity_checkbox),"toggled",G_CALLBACK(ignore_velocity_toggled),ui);
  g_signal_connect(G_OBJECT(ui->note_off_checkbox),"toggled",G_CALLBACK(ignore_note_off_toggled),ui);

  gtk_widget_show_all(drmr_ui_widget);
  gtk_widget_hide(no_kit_label);
}

static LV2UI_Handle
instantiate(const LV2UI_Descriptor*   descriptor,
            const char*               plugin_uri,
            const char*               bundle_path,
            LV2UI_Write_Function      write_function,
            LV2UI_Controller          controller,
            LV2UI_Widget*             widget,
            const LV2_Feature* const* features) {
  DrMrUi     *ui = (DrMrUi*)malloc(sizeof(DrMrUi));

  ui->write      = write_function;
  ui->controller = controller;
  ui->drmr_widget = NULL;
  ui->curKit = -1;
  ui->samples = 0;
  ui->bundle_path = g_strdup(bundle_path);
  *widget = NULL;

  build_drmr_ui(ui);

  ui->kits = scan_kits();
  ui->gain_quark = g_quark_from_string("drmr_gain_quark");
  ui->pan_quark = g_quark_from_string("drmr_pan_quark");
  ui->gain_sliders = NULL;
  ui->pan_sliders = NULL;

  // store previous gain/pan vals to re-apply to sliders when we
  // change kits
  ui->gain_vals = malloc(32*sizeof(float));
  memset(ui->gain_vals,0,32*sizeof(float));
  ui->pan_vals  = malloc(32*sizeof(float));
  memset(ui->pan_vals,0,32*sizeof(float));
  ui->cols = 4;
  ui->forceUpdate = false;
  fill_kit_combo(ui->kit_combo, ui->kits);

#ifdef DRMR_UI_ZERO_SAMP
  ui->startSamp = DRMR_UI_ZERO_SAMP;
#else
  ui->startSamp = 0;
#endif


  *widget = ui->drmr_widget;

  return ui;
}


static void cleanup(LV2UI_Handle handle) {
  DrMrUi* ui = (DrMrUi*)handle;
  // seems qtractor likes to destory us
  // before calling, avoid double-destroy
  if (GTK_IS_WIDGET(ui->drmr_widget))
    gtk_widget_destroy(ui->drmr_widget);
  if (ui->gain_sliders) free(ui->gain_sliders);
  if (ui->pan_sliders) free(ui->pan_sliders);
  g_free(ui->bundle_path);
  free_kits(ui->kits);
  free(ui);
}

struct slider_callback_data {
  GtkRange* range;
  float val;
};
static gboolean slider_callback(gpointer data) {
  struct slider_callback_data *cbd = (struct slider_callback_data*)data;
  if (GTK_IS_RANGE(cbd->range))
    gtk_range_set_value(cbd->range,cbd->val);
  free(cbd);
  return FALSE; // don't keep calling
}

static void
port_event(LV2UI_Handle handle,
           uint32_t     port_index,
           uint32_t     buffer_size,
           uint32_t     format,
           const void*  buffer) {
  DrMrPortIndex index = (DrMrPortIndex)port_index;
  DrMrUi* ui = (DrMrUi*)handle;

  if (index == DRMR_KITNUM) {
    if (format != 0) 
      fprintf(stderr,"Invalid format for kitnum: %i\n",format);
    else {
      int kit = (int)(*((float*)buffer));
      ui->kitReq = kit;
      if (!idle) {
	idle = TRUE;
	g_idle_add(kit_callback,ui);
      }
    }
  }
  else if (index == DRMR_BASENOTE) {
    int base = (int)(*((float*)buffer));
    if (base >= 21 && base <= 107) {
      setBaseLabel((int)base);
      gtk_spin_button_set_value(ui->base_spin,base);
      gtk_label_set_markup(ui->base_label,baseLabelBuf);
    }
  }
  else if (index == DRMR_IGNORE_VELOCITY) {
    int ig = (int)(*((float*)buffer));
    gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(ui->velocity_checkbox),
				 ig?TRUE:FALSE);
  }
  else if (index == DRMR_IGNORE_NOTE_OFF) {
    int ig = (int)(*((float*)buffer));
    gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(ui->note_off_checkbox),
				 ig?TRUE:FALSE);
  }
  else if (index >= DRMR_GAIN_ONE &&
	   index <= DRMR_GAIN_THIRTYTWO) {
    float gain = *(float*)buffer;
    int idx = index-DRMR_GAIN_ONE;
    ui->gain_vals[idx] = gain;
    if (idx < ui->samples && ui->gain_sliders) {
      struct slider_callback_data* data = malloc(sizeof(struct slider_callback_data));
      data->range = GTK_RANGE(ui->gain_sliders[idx]);
      data->val = gain;
      g_idle_add(slider_callback,data);
      //GtkRange* range = GTK_RANGE(ui->gain_sliders[idx]);
      //gtk_range_set_value(range,gain);
    }
  }
  else if (index >= DRMR_PAN_ONE &&
	   index <= DRMR_PAN_THIRTYTWO) {
    float pan = *(float*)buffer;
    int idx = index-DRMR_PAN_ONE;
    ui->pan_vals[idx] = pan;
    if (idx < ui->samples && ui->pan_sliders) {
      struct slider_callback_data* data = malloc(sizeof(struct slider_callback_data));
      data->range = GTK_RANGE(ui->pan_sliders[idx]);
      data->val = pan;
      g_idle_add(slider_callback,data);
    }
  }
}

static const void*
extension_data(const char* uri) {
  return NULL;
}

static const LV2UI_Descriptor descriptor = {
  DRMR_UI_URI,
  instantiate,
  cleanup,
  port_event,
  extension_data
};

LV2_SYMBOL_EXPORT
const LV2UI_Descriptor*
lv2ui_descriptor(uint32_t index) {
  switch (index) {
  case 0:
    return &descriptor;
  default:
    return NULL;
  }
}