Clean up scalebar zoom extremes.

Scalebar.H

@@ -31,11 +31,16 @@ class Scalebar : public Fl_Scrollbar
 
     bool _zoom_changed;
 
+    double _zoom_min;
+    double _zoom_max;
+
 public:
 
     Scalebar ( int X, int Y, int W, int H ) : Fl_Scrollbar ( X, Y, W, H )
         {
             _zoom = 1.0f;
+            _zoom_min = 0;
+            _zoom_max = 256;
             _zoom_changed = true;
 
             step( 1 );
@@ -44,6 +49,7 @@ public:
     bool zoom_changed ( void ) const { return _zoom_changed; }
     double zoom ( void ) const { return _zoom; }
     double value ( void ) const { return Fl_Slider::value(); }
+    void zoom_range ( double zmin, double zmax ) { _zoom_min = zmin; _zoom_max = zmax; }
 
     int
     handle ( int m )
@@ -54,6 +60,8 @@ public:
                 {
                     int d = Fl::event_dy();
 
+                    double z = _zoom;
+
                     if ( d < 0 )
                         while ( d++ )
                             _zoom /= 2;
@@ -61,11 +69,20 @@ public:
                         while ( d-- )
                             _zoom *= 2;
 
-                    _zoom_changed = true;
-                    do_callback();
-                    _zoom_changed = false;
+                    if ( _zoom > _zoom_max )
+                        _zoom = _zoom_max;
+                    else
+                        if ( _zoom < _zoom_min )
+                            _zoom = _zoom_min;
+
+                    if ( z != _zoom )
+                    {
+                        _zoom_changed = true;
+                        do_callback();
+                        _zoom_changed = false;
 
-                    slider_size( w() / maximum() );
+                        slider_size( w() / maximum() );
+                    }
 
                     return 1;
                 }

Timeline.H

@@ -24,6 +24,8 @@
 #include <FL/Fl_Scrollbar.H>
 #include <FL/Fl_Widget.H>
 
+#include "Scalebar.H"
+
 #include "Audio_File.H" // just for nframes_t
 #include <math.h>
 
@@ -60,7 +62,7 @@ struct Timeline : public Fl_Group
     Fl_Scroll *scroll;
     Fl_Pack *tracks;
     Fl_Pack *rulers;
-    Fl_Scrollbar *scrollbar;
+    Scalebar *scrollbar;
 
     Tempo_Track *tempo_track;
     Time_Track *time_track;

main.C

@@ -58,8 +58,10 @@ cb_scroll ( Fl_Widget *w, void *v )
 
     if ( sb->zoom_changed() )
     {
-        timeline->fpp = sb->zoom() * 256;
-        timeline->fpp = max( min( timeline->fpp, 4096.0f ), (float)2 );
+//        timeline->fpp = sb->zoom() * 256;
+        timeline->fpp = sb->zoom() * 1;
+
+/*         timeline->fpp = max( min( timeline->fpp, 4096.0f ), (float)2 ); */
 
         int maxx = timeline->ts_to_x( timeline->length );
         sb->range( 0, maxx );
@@ -121,6 +123,7 @@ main ( int argc, char **argv )
 
     timeline->scrollbar = new Scalebar( 0, 600 - 24, 800, 24 );
     timeline->scrollbar->range( 0, 48000 * 2 );
+    timeline->scrollbar->zoom_range( 2, 8192 );
     timeline->scrollbar->type( 1 );
     timeline->scrollbar->callback( cb_scroll, 0 );