Extensions: New capability "meta-listener". Push unique commands

PushCommand takes now a new parameter: b_unique. If set, do not push
this command twice in the command queue.

modules/misc/lua/extension.c

@@ -27,6 +27,7 @@
 #include "assert.h"
 
 #include <vlc_input.h>
+#include <vlc_events.h>
 
 /* Functions to register */
 static const luaL_Reg p_reg[] =
@@ -38,14 +39,16 @@ static const luaL_Reg p_reg[] =
  * Extensions capabilities
  * Note: #define and ppsz_capabilities must be in sync
  */
-#define EXT_HAS_MENU          (1 << 0)
-#define EXT_TRIGGER_ONLY      (1 << 1)
-#define EXT_INPUT_LISTENER    (1 << 2)
+#define EXT_HAS_MENU          (1 << 0)   ///< Hook: menu
+#define EXT_TRIGGER_ONLY      (1 << 1)   ///< Hook: trigger. Not activable
+#define EXT_INPUT_LISTENER    (1 << 2)   ///< Hook: input_changed
+#define EXT_META_LISTENER     (1 << 3)   ///< Hook: meta_changed
 
 const char* const ppsz_capabilities[] = {
     "menu",
     "trigger",
     "input-listener",
+    "meta-listener",
     NULL
 };
 
@@ -70,6 +73,10 @@ static int vlclua_extension_dialog_callback( vlc_object_t *p_this,
                                              vlc_value_t newval,
                                              void *p_data );
 
+/* Input item callback: vlc_InputItemMetaChanged */
+static void inputItemMetaChanged( const vlc_event_t *p_event,
+                                  void *data );
+
 
 /**
  * Module entry-point
@@ -476,22 +483,50 @@ static int Control( extensions_manager_t *p_mgr, int i_control, va_list args )
 
             // Change input
             input_thread_t *old = p_ext->p_sys->p_input;
+            input_item_t *p_item;
             if( old )
+            {
+                // Untrack meta fetched events
+                if( p_ext->p_sys->i_capabilities & EXT_META_LISTENER )
+                {
+                    p_item = input_GetItem( old );
+                    vlc_event_detach( &p_item->event_manager,
+                                      vlc_InputItemMetaChanged,
+                                      inputItemMetaChanged,
+                                      p_ext );
+                    vlc_gc_decref( p_item );
+                }
                 vlc_object_release( old );
+            }
+
             p_ext->p_sys->p_input = p_input ? vlc_object_hold( p_input )
                                             : p_input;
 
             // Tell the script the input changed
             if( p_ext->p_sys->i_capabilities & EXT_INPUT_LISTENER )
-                PushCommand( p_ext, CMD_SET_INPUT );
+            {
+                PushCommandUnique( p_ext, CMD_SET_INPUT );
+            }
+
+            // Track meta fetched events
+            if( p_ext->p_sys->p_input &&
+                p_ext->p_sys->i_capabilities & EXT_META_LISTENER )
+            {
+                p_item = input_GetItem( p_ext->p_sys->p_input );
+                vlc_gc_incref( p_item );
+                vlc_event_attach( &p_item->event_manager,
+                                  vlc_InputItemMetaChanged,
+                                  inputItemMetaChanged,
+                                  p_ext );
+            }
 
             UnlockExtension( p_ext );
             break;
         }
 
         default:
-            msg_Err( p_mgr, "Control '%d' not yet implemented in Extension",
-                     i_control );
+            msg_Warn( p_mgr, "Control '%d' not yet implemented in Extension",
+                      i_control );
             return VLC_EGENERIC;
     }
 
@@ -511,6 +546,18 @@ int lua_ExtensionDeactivate( extensions_manager_t *p_mgr, extension_t *p_ext )
     if( !p_ext->p_sys->L )
         return VLC_SUCCESS;
 
+    // Unset and release input objects
+    if( p_ext->p_sys->p_input )
+    {
+        if( p_ext->p_sys->i_capabilities & EXT_META_LISTENER )
+        {
+            // Release item
+            input_item_t *p_item = input_GetItem( p_ext->p_sys->p_input );
+            vlc_gc_decref( p_item );
+        }
+        vlc_object_release( p_ext->p_sys->p_input );
+    }
+
     int i_ret = lua_ExecuteFunction( p_mgr, p_ext, "deactivate" );
 
     /* Clear Lua State */
@@ -871,7 +918,7 @@ static int vlclua_extension_dialog_callback( vlc_object_t *p_this,
             PushCommand( p_ext, CMD_CLICK, p_widget );
             break;
         case EXTENSION_EVENT_CLOSE:
-            PushCommand( p_ext, CMD_CLOSE );
+            PushCommandUnique( p_ext, CMD_CLOSE );
             break;
         default:
             msg_Dbg( p_this, "Received unknown UI event %d, discarded",
@@ -882,6 +929,19 @@ static int vlclua_extension_dialog_callback( vlc_object_t *p_this,
     return VLC_SUCCESS;
 }
 
+/** Callback on vlc_InputItemMetaChanged event
+ **/
+static void inputItemMetaChanged( const vlc_event_t *p_event,
+                                  void *data )
+{
+    assert( p_event && p_event->type == vlc_InputItemMetaChanged );
+
+    extension_t *p_ext = ( extension_t* ) data;
+    assert( p_ext != NULL );
+
+    PushCommandUnique( p_ext, CMD_UPDATE_META );
+}
+
 /* Lock this extension. Can fail. */
 bool LockExtension( extension_t *p_ext )
 {

modules/misc/lua/extension.h

@@ -37,6 +37,8 @@ TYPEDEF_ARRAY( extension_t, array_extension_t );
 #define CMD_CLICK       4    /* Arg1 = extension_widget_t* */
 #define CMD_CLOSE       5
 #define CMD_SET_INPUT   6    /* No arg. Just signal current input changed */
+#define CMD_UPDATE_META 7    /* No arg. Just signal current input item meta
+                              * changed */
 
 struct extensions_manager_sys_t
 {
@@ -88,7 +90,12 @@ int Activate( extensions_manager_t *p_mgr, extension_t * );
 bool IsActivated( extensions_manager_t *p_mgr, extension_t * );
 int Deactivate( extensions_manager_t *p_mgr, extension_t * );
 void WaitForDeactivation( extension_t *p_ext );
-int PushCommand( extension_t *p_ext, int i_command, ... );
+int __PushCommand( extension_t *p_ext, bool b_unique,
+                   int i_command, ... );
+#define PushCommand( ext, cmd, ... ) \
+      __PushCommand( ext, false, cmd, ## __VA_ARGS__ )
+#define PushCommandUnique( ext, cmd, ... ) \
+      __PushCommand( ext, true, cmd, ## __VA_ARGS__ )
 bool LockExtension( extension_t *p_ext );
 void UnlockExtension( extension_t *p_ext );
 

modules/misc/lua/extension_thread.c

@@ -124,6 +124,9 @@ static void FreeCommands( struct command_t *command )
         case CMD_TRIGGERMENU:
             free( command->data[0] ); // Arg1 is int*, to free
             break;
+
+        default:
+            break;
     }
     free( command );
     FreeCommands( next );
@@ -201,9 +204,10 @@ void WaitForDeactivation( extension_t *p_ext )
 }
 
 /** Push a UI command */
-int PushCommand( extension_t *p_ext,
-                 int i_command,
-                 ... )
+int __PushCommand( extension_t *p_ext,
+                   bool b_unique,
+                   int i_command,
+                   ... )
 {
     vlc_mutex_lock( &p_ext->p_sys->command_lock );
 
@@ -218,9 +222,6 @@ int PushCommand( extension_t *p_ext,
         case CMD_CLICK:
             cmd->data[0] = va_arg( args, void* );
             break;
-        case CMD_CLOSE:
-            // Nothing to do here
-            break;
         case CMD_TRIGGERMENU:
             {
                 int *pi = malloc( sizeof( int ) );
@@ -234,6 +235,11 @@ int PushCommand( extension_t *p_ext,
                 cmd->data[0] = pi;
             }
             break;
+        case CMD_CLOSE:
+        case CMD_SET_INPUT:
+        case CMD_UPDATE_META:
+            // Nothing to do here
+            break;
         default:
             msg_Dbg( p_ext->p_sys->p_mgr,
                      "Unknown command send to extension: %d", i_command );
@@ -250,11 +256,22 @@ int PushCommand( extension_t *p_ext,
     }
     else
     {
+        bool b_skip = false;
         while( last->next != NULL )
         {
-            last = last->next;
+            if( b_unique && last->i_command == i_command )
+            {
+                // Do not push this 'unique' command a second time
+                b_skip = true;
+                break;
+            }
+            else
+            {
+                last = last->next;
+            }
         }
-        last->next = cmd;
+        if( !b_skip )
+            last->next = cmd;
     }
 
     vlc_cond_signal( &p_ext->p_sys->wait );
@@ -348,6 +365,12 @@ static void* Run( void *data )
                         break;
                     }
 
+                    case CMD_UPDATE_META:
+                    {
+                        lua_ExecuteFunction( p_mgr, p_ext, "meta_changed" );
+                        break;
+                    }
+
                     default:
                     {
                         msg_Dbg( p_mgr, "Unknown command in extension command queue: %d",