Add support for Level Meter labels

src/window-levels.c

@@ -1,6 +1,7 @@
 // SPDX-FileCopyrightText: 2022-2024 Geoffrey D. Bennett <g@b4.vu>
 // SPDX-License-Identifier: GPL-3.0-or-later
 
+#include <ctype.h>
 #include <gtk/gtk.h>
 
 #include "gtkdial.h"
@@ -26,6 +27,8 @@ static const double level_colours[] = {
 struct levels {
   struct alsa_card *card;
   struct alsa_elem *level_meter_elem;
+  GtkWidget        *top;
+  GtkGrid          *grid;
   GtkWidget        *meters[MAX_METERS];
   guint             timer;
 };
@@ -67,21 +70,121 @@ static void on_destroy(struct levels *data, GtkWidget *widget) {
   g_free(data);
 }
 
+static GtkWidget *create_levels_controls_with_labels(
+  struct alsa_card *card,
+  struct levels    *data
+) {
+  struct alsa_elem *level_meter_elem = data->level_meter_elem;
+  int count = level_meter_elem->count;
+
+  int row = 1;
+  int max_count = 0;
+  char *current_type = NULL;
+
+  for (int meter_num = 0; meter_num < count; meter_num++) {
+    char *label = strdup(level_meter_elem->meter_labels[meter_num]);
+
+    if (!label) {
+      fprintf(stderr, "Couldn't strdup label\n");
+      exit(1);
+    }
+
+    if (strlen(label) < 3) {
+      fprintf(stderr, "Label too short: %s\n", label);
+      exit(1);
+    }
+
+    // Label is "Source Analogue 1" or "Source Mix A" or "Sink
+    // Analogue 1", etc.
+    // get the number part of the label looking from the end
+    int label_idx = strlen(label) - 1;
+    int label_num = 1;
+    if (isdigit(label[label_idx])) {
+      while (label_idx > 1 && isdigit(label[label_idx - 1]))
+        label_idx--;
+      label_num = atoi(&label[label_idx]);
+
+      if (label[label_idx - 1] != ' ') {
+        fprintf(stderr, "Label %s is not in the expected format\n", label);
+        exit(1);
+      }
+      label[label_idx - 1] = '\0';
+
+    } else if (label[label_idx] >= 'A' && label[label_idx] <= 'Z') {
+      label_num = label[label_idx] - 'A' + 1;
+
+      if (label[label_idx - 1] != ' ') {
+        fprintf(stderr, "Label %s is not in the expected format\n", label);
+        exit(1);
+      }
+
+      label[label_idx - 1] = '\0';
+    }
+
+    if (label_num > max_count)
+      max_count = label_num;
+
+    if (!current_type || strcmp(current_type, label)) {
+      row++;
+
+      free(current_type);
+      current_type = strdup(label);
+
+      GtkWidget *l = gtk_label_new(current_type);
+      gtk_widget_set_halign(l, GTK_ALIGN_END);
+
+      // add the type label
+      gtk_grid_attach(GTK_GRID(data->grid), l, 0, row, 1, 1);
+    }
+
+    GtkWidget *meter = gtk_dial_new_with_range(-80, 0, 0, 0);
+    gtk_dial_set_taper(GTK_DIAL(meter), GTK_DIAL_TAPER_LINEAR);
+    gtk_dial_set_can_control(GTK_DIAL(meter), FALSE);
+    gtk_dial_set_peak_hold(GTK_DIAL(meter), 1000);
+    gtk_dial_set_level_meter_colours(
+      GTK_DIAL(meter),
+      level_breakpoints_out,
+      level_colours,
+      sizeof(level_breakpoints_out) / sizeof(int)
+    );
+    gtk_widget_set_sensitive(meter, FALSE);
+    gtk_dial_set_off_db(GTK_DIAL(meter), -45);
+    gtk_grid_attach(GTK_GRID(data->grid), meter, label_num, row, 1, 1);
+    data->meters[meter_num] = meter;
+
+    free(label);
+  }
+
+  free(current_type);
+
+  for (int col = 1; col <= max_count; col++) {
+    char s[20];
+    sprintf(s, "%d", col);
+    GtkWidget *l = gtk_label_new(s);
+    gtk_grid_attach(GTK_GRID(data->grid), l, col, 0, 1, 1);
+  }
+
+  data->timer = g_timeout_add(50, update_levels_controls, data);
+  g_object_weak_ref(G_OBJECT(data->grid), (GWeakNotify)on_destroy, data);
+
+  return data->top;
+}
+
 GtkWidget *create_levels_controls(struct alsa_card *card) {
   struct levels *data = g_malloc0(sizeof(struct levels));
 
   data->card = card;
 
-  GtkWidget *top = gtk_frame_new(NULL);
+  GtkWidget *top = data->top = gtk_frame_new(NULL);
   gtk_widget_add_css_class(top, "window-frame");
 
-  GtkWidget *levels_top = gtk_grid_new();
-  gtk_widget_add_css_class(levels_top, "window-content");
-  gtk_widget_add_css_class(levels_top, "top-level-content");
-  gtk_widget_add_css_class(levels_top, "window-levels");
-  gtk_frame_set_child(GTK_FRAME(top), levels_top);
+  GtkWidget *grid_widget = gtk_grid_new();
+  gtk_widget_add_css_class(grid_widget, "window-content");
+  gtk_widget_add_css_class(grid_widget, "top-level-content");
+  gtk_widget_add_css_class(grid_widget, "window-levels");
+  gtk_frame_set_child(GTK_FRAME(top), grid_widget);
 
-  GtkGrid *grid = GTK_GRID(levels_top);
+  GtkGrid *grid = data->grid = GTK_GRID(grid_widget);
 
   GtkWidget *count_labels[MAX_MUX_IN] = { NULL };
 
@@ -93,6 +196,9 @@ GtkWidget *create_levels_controls(struct alsa_card *card) {
     return NULL;
   }
 
+  if (data->level_meter_elem->meter_labels)
+    return create_levels_controls_with_labels(card, data);
+
   // go through the port categories
   for (int i = 0, row = 1; i < PC_COUNT; i++) {
 
@@ -140,12 +246,11 @@ GtkWidget *create_levels_controls(struct alsa_card *card) {
   int elem_count = data->level_meter_elem->count;
   if (meter_num != elem_count) {
     printf("meter_num is %d but elem count is %d\n", meter_num, elem_count);
-    return NULL;
   }
   data->level_meter_elem->count = elem_count;
 
   data->timer = g_timeout_add(50, update_levels_controls, data);
-  g_object_weak_ref(G_OBJECT(levels_top), (GWeakNotify)on_destroy, data);
+  g_object_weak_ref(G_OBJECT(grid), (GWeakNotify)on_destroy, data);
 
   return top;
 }