Automatically scroll timeline when dragging a region.

Region.C

@@ -19,6 +19,7 @@
 
 #include "Track.H"
 #include "Region.H"
+#include "Timeline.H"
 
 #include <FL/fl_draw.H>
 #include <FL/Fl.H>
@@ -27,6 +28,8 @@
 
 #include <stdio.h>
 
+extern Timeline timeline;
+
 Region::Region ( int X, int Y, int W, int H, const char *L=0 ) : Waveform( X, Y, W, H, L )
 {
     align( FL_ALIGN_INSIDE | FL_ALIGN_LEFT | FL_ALIGN_BOTTOM | FL_ALIGN_CLIP );
@@ -147,6 +150,19 @@ Region::handle ( int m )
             parent()->redraw();
 
             fl_cursor( FL_CURSOR_MOVE );
+
+            if ( Fl::event_x() >= timeline.scroll->x() + timeline.scroll->w() ||
+                 Fl::event_x() <= timeline.scroll->x() )
+            {
+                int d;
+                if ( Fl::event_x() <= timeline.scroll->x() )
+                    d = -100;
+                else
+                    d = 100;
+                /* this drag needs to scroll */
+                timeline.scroll->position( timeline.scroll->xposition() + d, timeline.scroll->yposition() );
+            }
+
             return 1;
         default:
             return 0;

Timeline.H

@@ -0,0 +1,26 @@
+
+/*******************************************************************************/
+/* Copyright (C) 2008 Jonathan Moore Liles                                     */
+/*                                                                             */
+/* This program is free software; you can redistribute it and/or modify it     */
+/* under the terms of the GNU General Public License as published by the       */
+/* Free Software Foundation; either version 2 of the License, or (at your      */
+/* option) any later version.                                                  */
+/*                                                                             */
+/* This program is distributed in the hope that it will be useful, but WITHOUT */
+/* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or       */
+/* FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for   */
+/* more details.                                                               */
+/*                                                                             */
+/* You should have received a copy of the GNU General Public License along     */
+/* with This program; see the file COPYING.  If not,write to the Free Software */
+/* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+/*******************************************************************************/
+
+#pragma once
+
+#include <FL/Fl_Scroll.H>
+
+struct Timeline {
+    Fl_Scroll *scroll;
+};

main.C

@@ -37,6 +37,7 @@
 Fl_Color velocity_colors[128];
 
 #include "Track.H"
+#include "Timeline.H"
 
 void
 init_colors ( void )
@@ -45,6 +46,8 @@ init_colors ( void )
         velocity_colors[i] = fl_rgb_color( 23, 255 - i * 2, 32 );
 }
 
+Timeline timeline;
+
 int
 main ( int argc, char **argv )
 {
@@ -53,7 +56,7 @@ main ( int argc, char **argv )
 
     Fl_Double_Window *main_window = new Fl_Double_Window( 0, 0, 800, 600 );
 
-    Fl_Scroll *scroll = new Fl_Scroll( 0, 0, 800, 600 );
+    timeline.scroll = new Fl_Scroll( 0, 0, 800, 600 );
 
     Fl_Pack *tracks = new Fl_Pack( 0, 0, 5000, 5000 );
     tracks->type( Fl_Pack::VERTICAL );
@@ -117,7 +120,7 @@ main ( int argc, char **argv )
     track2->prev( track1 );
 
     tracks->end();
-    scroll->end();
+    timeline.scroll->end();
 
     main_window->end();
     main_window->show();