lighttable: quick buttons for per-day filter

src/db/db.c

@@ -78,14 +78,13 @@ compare_labels(const void *a, const void *b, void *arg)
   return db->image[ia[0]].labels - db->image[ib[0]].labels;
 }
 
-static inline void
-read_createdate(const dt_db_t *db, uint32_t imgid, char createdate[20])
+void
+dt_db_read_createdate(const dt_db_t *db, uint32_t imgid, char createdate[20])
 {
   char fn[1024], f[1024];
   dt_db_image_path(db, imgid, fn, sizeof(fn));
-  size_t off;
   fs_realpath(fn, f);
-  off = strnlen(f, sizeof(f));
+  size_t off = strnlen(f, sizeof(f));
   if(off > 4) f[off - 4] = 0;
   else f[off] = 0;
 
@@ -102,8 +101,8 @@ compare_createdate(const void *a, const void *b, void *arg)
   dt_db_t *db = arg;
   const uint32_t *ia = a, *ib = b;
   char cda[20] = {0}, cdb[20] = {0};
-  read_createdate(db, ia[0], cda);
-  read_createdate(db, ib[0], cdb);
+  dt_db_read_createdate(db, ia[0], cda);
+  dt_db_read_createdate(db, ib[0], cdb);
   return strcmp(cda, cdb);
 }
 
@@ -149,7 +148,7 @@ dt_db_update_collection(dt_db_t *db)
       if(!(db->image[k].labels & db->collection_filter_val)) continue;
       break;
     case s_prop_createdate:
-      read_createdate(db, k, createdate);
+      dt_db_read_createdate(db, k, createdate);
       char val[10]; snprintf(val, sizeof(val), "%" PRItkn, dt_token_str(db->collection_filter_val));
       if(!strstr(createdate, val)) continue;
       break;

src/db/db.h

@@ -192,3 +192,5 @@ void dt_db_current_set(dt_db_t *db, uint32_t colid);
 // internal storage anyways. this is all done at once by calling dt_gui_switch_collection,
 // which by separation of concerns also cares about the thumbnail creation (the db doesn't).
 void dt_db_duplicate_selected_images(dt_db_t *db);
+// convenience function to read create date of an image
+void dt_db_read_createdate(const dt_db_t *db, uint32_t imgid, char createdate[20]);

src/gui/render_lighttable.c

@@ -632,6 +632,49 @@ void render_lighttable_right_panel()
         vkdt.db.collection_filter_val = typed_filter_val;
         update_collection = 1;
       }
+      static int cached_hash = 0;
+      static int day_cnt = 0;
+      static dt_token_t day[31]; // okay if you have more than a month you should split it some other way first
+      if(sort_prop == s_prop_createdate)
+      {
+        int hash = nk_murmur_hash(vkdt.db.dirname, (int)nk_strlen(vkdt.db.dirname), 0);
+        if(hash != cached_hash)
+        {
+          dt_tooltip("create list of quick buttons for every day in current collection");
+          if(nk_button_label(ctx, "by day"))
+          {
+            day_cnt = 0;
+            for(int i=0;i<vkdt.db.collection_cnt;i++)
+            {
+              if(day_cnt >= NK_LEN(day)) break;
+              char createdate[20];
+              dt_db_read_createdate(&vkdt.db, vkdt.db.collection[i], createdate);
+              if(!day_cnt || strncmp(createdate+4, dt_token_str(day[day_cnt-1]), 6))
+              {
+                day[day_cnt] = 0;
+                strncpy(dt_token_str(day[day_cnt]), createdate+4, 6);
+                day_cnt++;
+              }
+            }
+            cached_hash = hash;
+          }
+        }
+        else
+        {
+          nk_label(ctx, "", 0);
+          nk_layout_row_dynamic(ctx, row_height, 7);
+          for(int i=0;i<day_cnt;i++)
+          {
+            dt_tooltip(dt_token_str(day[i])); // careful htis only works because we copy a max of 6<8 chars (so there'll always be 0 in the end)
+            if(nk_button_text(ctx, dt_token_str(day[i])+4, 2))
+            {
+              typed_filter_val = day[i];
+              vkdt.db.collection_filter_val = typed_filter_val;
+              update_collection = 1;
+            }
+          }
+        }
+      }
     }
     else if(filter_prop == s_prop_rating)
     {