Adding miracle

[melted] / mlt++ / HOWTO

diff --git a/mlt++/HOWTO b/mlt++/HOWTO
index b16dbef..cc9d31e 100644 (file)
--- a/mlt++/HOWTO
+++ b/mlt++/HOWTO
@@ -13,7 +13,6 @@ Hello World
 
        An example of use is as follows:
 
-       #include <time.h>
        #include <mlt++/Mlt.h>
        using namespace Mlt;
 
@@ -23,7 +22,7 @@ Hello World
                Producer p( "pango:" );
                p.set( "text", "Hello World" );
                Consumer c( "sdl" );
-               Event *e = Consumer.setup_wait_for( "consumer-stopped" );
+               Event *e = c.setup_wait_for( "consumer-stopped" );
                c.connect( p );
                c.start( );
                c.wait_for( e );
@@ -63,7 +62,6 @@ Playlists
        As a simple example of the Playlist in action, we'll convert the example
        above into an application which plays multiple video or audio files.
 
-       #include <time.h>
        #include <mlt++/Mlt.h>
        using namespace Mlt;
 
@@ -79,7 +77,7 @@ Playlists
                }
                Consumer c( "sdl" );
                c.connect( list );
-               Event *e = Consumer.setup_wait_for( "consumer-stopped" );
+               Event *e = c.setup_wait_for( "consumer-stopped" );
                c.start( );
                c.wait_for( e );
                delete e;
@@ -111,7 +109,6 @@ Filters
        logo of some sort. We'll just use some black text on a partially 
        transparent red background.
 
-       #include <time.h>
        #include <mlt++/Mlt.h>
        using namespace Mlt;
 
@@ -132,7 +129,7 @@ Filters
                list.attach( f );
                Consumer c( "sdl" );
                c.connect( list );
-               Event *e = Consumer.setup_wait_for( "consumer-stopped" );
+               Event *e = c.setup_wait_for( "consumer-stopped" );
                c.start( );
                c.wait_for( e );
                delete e;
@@ -197,6 +194,43 @@ Transition
        The tractor returned will now mix the audio from the original video and the audio.
 
 
+Events
+------
+
+       Typically, applications need to be informed when changes occur in an mlt++ object.
+       This facilitates application services such as undo/redo management, or project
+       rendering in a timeline type widget and many other types of operations which an
+       application needs.
+
+       As an example, consider the following:
+
+       class Westley
+       {
+               private:
+                       Consumer consumer;
+                       Tractor &tractor;
+               public:
+                       Westley( MltTractor &tractor ) :
+                               tractor( tractor ),
+                               consumer( "westley" )
+                       {
+                               consumer.connect( tractor );
+                               tractor.listen( tractor, "producer-changed", ( mlt_listener )Westley::listener );
+                       }
+                       
+                       static void listener( Properties *tractor, Westley *object )
+                       {
+                               object->activate( );
+                       }
+
+                       void activate( )
+                       {
+                               consumer.start( );
+                       }
+       };
+
+       
+
 That's All Folks...
 -------------------