first basic pass at a single widget stereo panner

git-svn-id: svn://localhost/ardour2/branches/3.0@8135 d708f5d6-7413-0410-9779-e7cbd77b26cf

1 files changed, 162 insertions, 0 deletions

diff --git a/gtk2_ardour/stereo_panner.cc b/gtk2_ardour/stereo_panner.cc
new file mode 100644
index 0000000000..9f3cad1290
--- /dev/null
+++ b/gtk2_ardour/stereo_panner.cc
@@ -0,0 +1,162 @@
+/*
+    Copyright (C) 2000-2007 Paul Davis
+
+    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; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <iostream>
+#include <iomanip>
+#include <cstring>
+
+#include "pbd/controllable.h"
+
+#include "gtkmm2ext/gui_thread.h"
+
+#include "ardour/panner.h"
+#include "stereo_panner.h"
+
+#include "i18n.h"
+
+using namespace std;
+using namespace Gtk;
+
+StereoPanner::StereoPanner (boost::shared_ptr<PBD::Controllable> position, boost::shared_ptr<PBD::Controllable> width)
+        : position_control (position)
+        , width_control (width)
+        , dragging (false)
+        , dragging_position (false)
+        , drag_start_x (0)
+        , last_drag_x (0)
+{
+        set_size_request (-1, 15);
+
+        position_control->Changed.connect (connections, invalidator(*this), boost::bind (&DrawingArea::queue_draw, this), gui_context());
+        width_control->Changed.connect (connections, invalidator(*this), boost::bind (&DrawingArea::queue_draw, this), gui_context());
+        
+        add_events (Gdk::BUTTON_PRESS_MASK|Gdk::BUTTON_RELEASE_MASK|Gdk::SCROLL_MASK|Gdk::POINTER_MOTION_MASK);
+}
+
+StereoPanner::~StereoPanner ()
+{
+}
+
+bool
+StereoPanner::on_expose_event (GdkEventExpose* ev)
+{
+	Glib::RefPtr<Gdk::Window> win (get_window());
+	Glib::RefPtr<Gdk::GC> gc (get_style()->get_base_gc (get_state()));
+
+        cairo_t* cr = gdk_cairo_create (win->gobj());
+        
+        int x1, x2, y1, y2;
+        int h, w;
+        int width, height;
+        double pos = position_control->get_value (); /* 0..1 */
+        double swidth = width_control->get_value (); /* -1..+1 */
+        const int pos_box_size = 5;
+
+        width = get_width();
+        height = get_height ();
+
+        /* compute where the central box is */
+
+        x1 = (int) floor (width * pos);
+        x1 -= pos_box_size/2;
+
+	cairo_set_source_rgb (cr, 255, 0, 0);
+	cairo_rectangle (cr, x1, 4, pos_box_size, pos_box_size);
+	cairo_fill (cr);
+
+        /* compute & draw the line through the box */
+
+        x2 = x1 - (int) floor ((fabs (swidth) * width)/2.0); // center, then back up half the swidth value
+
+	cairo_set_source_rgb (cr, 0, 255, 0);
+        cairo_move_to (cr, x2, 4+(pos_box_size/2));
+        cairo_line_to (cr, x2 + floor ((fabs (swidth * width))), 4+(pos_box_size/2));
+        cairo_stroke (cr);
+
+        cairo_destroy (cr);
+	return true;
+}
+
+bool
+StereoPanner::on_button_press_event (GdkEventButton* ev)
+{
+        drag_start_x = ev->x;
+        last_drag_x = ev->x;
+
+        /* center 8 pixels are for position drag */
+
+        int w = get_width();
+
+        if ((ev->x >= (w/2)-4) && (ev->x <= (w/2)+4)) {
+                dragging_position = true;
+        } else {
+                dragging_position = false;
+        }
+
+        dragging = true;
+        return true;
+}
+
+bool
+StereoPanner::on_button_release_event (GdkEventButton* ev)
+{
+        dragging = false;
+        dragging_position = false;
+        return true;
+}
+
+bool
+StereoPanner::on_motion_notify_event (GdkEventMotion* ev)
+{
+        if (!dragging) {
+                return false;
+        }
+
+        int w = get_width();
+        float delta = ((fabs) (ev->x - last_drag_x)) / (double) (w/2);
+
+        if (!dragging_position) {
+                double wv = width_control->get_value();        
+                
+                if (((drag_start_x < w/2) && ev->x > last_drag_x) || // start left of center, move towards it
+                    ((drag_start_x > w/2) && ev->x < last_drag_x)) { // start right of center, move towards it
+                        wv = wv  * (1.0 - delta);
+                } else {
+                        /* moving out, so increase the width */
+                        wv = wv * (1.0 + delta);
+                }
+                
+                width_control->set_value (wv);
+
+        } else {
+
+                double pv = position_control->get_value(); // 0..1.0 ; 0 = left
+                
+                if (ev->x > last_drag_x) { // increasing 
+                        pv = pv * (1.0 + delta);
+                } else {
+                        pv = pv * (1.0 - delta);
+                }
+
+                position_control->set_value (pv);
+        }
+
+        last_drag_x = ev->x;
+        return true;
+}