2 Copyright (C) 2010 Paul Davis
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <pangomm/layout.h>
26 #include "pbd/compose.h"
27 #include "pbd/error.h"
28 #include "pbd/stacktrace.h"
30 #include "gtkmm2ext/utils.h"
31 #include "gtkmm2ext/rgb_macros.h"
32 #include "gtkmm2ext/gui_thread.h"
34 #include "ardour/rc_configuration.h" // for widget prelight preference
36 #include "canvas/utils.h"
38 #include "ardour_button.h"
39 #include "ardour_ui.h"
40 #include "global_signals.h"
44 #define REFLECTION_HEIGHT 2
54 ArdourButton::Element ArdourButton::default_elements = ArdourButton::Element (ArdourButton::Edge|ArdourButton::Body|ArdourButton::Text);
55 ArdourButton::Element ArdourButton::led_default_elements = ArdourButton::Element (ArdourButton::default_elements|ArdourButton::Indicator);
56 ArdourButton::Element ArdourButton::just_led_default_elements = ArdourButton::Element (ArdourButton::Edge|ArdourButton::Body|ArdourButton::Indicator);
58 ArdourButton::ArdourButton (Element e)
60 , _tweaks (Tweaks (0))
64 , _corner_radius (4.0)
69 , fill_inactive_color (0)
70 , fill_active_color (0)
71 , text_active_color(0)
72 , text_inactive_color(0)
74 , led_inactive_color(0)
77 , led_inset_pattern (0)
79 , _act_on_release (true)
81 , _fixed_diameter (true)
82 , _distinct_led_click (false)
85 , _fixed_colors_set (false)
86 , _fallthrough_to_parent (false)
88 ARDOUR_UI_UTILS::ColorsChanged.connect (sigc::mem_fun (*this, &ArdourButton::color_handler));
91 ArdourButton::ArdourButton (const std::string& str, Element e)
93 , _tweaks (Tweaks (0))
97 , _corner_radius (4.0)
102 , fill_inactive_color (0)
103 , fill_active_color (0)
104 , text_active_color(0)
105 , text_inactive_color(0)
106 , led_active_color(0)
107 , led_inactive_color(0)
109 , concave_pattern (0)
110 , led_inset_pattern (0)
112 , _act_on_release (true)
114 , _fixed_diameter (true)
115 , _distinct_led_click (false)
118 , _fixed_colors_set (false)
123 ArdourButton::~ArdourButton()
127 if (convex_pattern) {
128 cairo_pattern_destroy (convex_pattern);
131 if (concave_pattern) {
132 cairo_pattern_destroy (concave_pattern);
135 if (led_inset_pattern) {
136 cairo_pattern_destroy (led_inset_pattern);
142 ArdourButton::set_text (const std::string& str)
146 if (!_layout && !_text.empty()) {
147 _layout = Pango::Layout::create (get_pango_context());
151 _layout->set_text (str);
158 ArdourButton::set_markup (const std::string& str)
163 _layout = Pango::Layout::create (get_pango_context());
166 _layout->set_markup (str);
171 ArdourButton::set_angle (const double angle)
177 ArdourButton::set_alignment (const float xa, const float ya)
184 ArdourButton::render (cairo_t* cr, cairo_rectangle_t *)
188 if ( active_state() == Gtkmm2ext::ExplicitActive ) {
189 text_color = text_active_color;
190 led_color = led_active_color;
192 text_color = text_inactive_color;
193 led_color = led_inactive_color;
196 void (*rounded_function)(cairo_t*, double, double, double, double, double);
198 switch (_corner_mask) {
199 case 0x1: /* upper left only */
200 rounded_function = Gtkmm2ext::rounded_top_left_rectangle;
202 case 0x2: /* upper right only */
203 rounded_function = Gtkmm2ext::rounded_top_right_rectangle;
205 case 0x3: /* upper only */
206 rounded_function = Gtkmm2ext::rounded_top_rectangle;
208 /* should really have functions for lower right, lower left,
209 lower only, but for now, we don't
212 rounded_function = Gtkmm2ext::rounded_rectangle;
215 if (!_fixed_diameter) {
216 _diameter = std::min (get_width(), get_height());
219 #if 0 // clear background - "transparent" round corners
220 /* Alas, neither get_style()->get_bg nor get_parent()->get_style()->get_bg
221 * does work for all places in ardour where a button is used.
222 * gtk style are sadly inconsisent throughout ardour.
223 * -> disabled for now.
226 Gdk::Color c = get_parent ()->get_style ()->get_bg (get_parent ()->get_state ());
227 CairoWidget::set_source_rgb_a (cr, c);
228 cairo_rectangle (cr, 0, 0, get_width(), get_height());
234 if ((_elements & Body)==Body) {
235 rounded_function (cr, 1, 1, get_width() - 2, get_height() - 2, _corner_radius);
236 if (active_state() == Gtkmm2ext::ImplicitActive && !((_elements & Indicator)==Indicator)) {
237 ArdourCanvas::set_source_rgba (cr, fill_inactive_color);
239 } else if ( (active_state() == Gtkmm2ext::ExplicitActive) && !((_elements & Indicator)==Indicator) ) {
241 ArdourCanvas::set_source_rgba (cr, fill_active_color);
243 } else { //inactive, or it has an indicator
245 ArdourCanvas::set_source_rgba (cr, fill_inactive_color);
250 //show the "convex" or "concave" gradient
251 if (!_flat_buttons) {
252 if ( active_state() == Gtkmm2ext::ExplicitActive && !((_elements & Indicator)==Indicator) ) {
254 cairo_set_source (cr, concave_pattern);
255 Gtkmm2ext::rounded_rectangle (cr, 1, 1, get_width() - 2, get_height() - 2, _corner_radius);
258 cairo_set_source (cr, convex_pattern);
259 Gtkmm2ext::rounded_rectangle (cr, 1, 1, get_width() - 2, get_height() - 2, _corner_radius);
264 // indicator border on top of gradient
265 if ((_elements & Body)==Body) {
266 if (active_state() == Gtkmm2ext::ImplicitActive && !((_elements & Indicator)==Indicator)) {
267 cairo_set_line_width (cr, 3.0);
268 rounded_function (cr, 1.5, 1.5, get_width() - 3, get_height() - 3, _corner_radius);
269 ArdourCanvas::set_source_rgba (cr, fill_active_color);
275 if ((_elements & (Body|Edge)) == (Body|Edge)) {
276 rounded_function (cr, .5, .5, get_width() - 1, get_height() - 1, _corner_radius);
277 cairo_set_source_rgba (cr, 0, 0, 0, 1);
278 cairo_set_line_width (cr, 1.0);
286 x = (get_width() - _pixbuf->get_width())/2.0;
287 y = (get_height() - _pixbuf->get_height())/2.0;
289 //if this is a DropDown with an icon, then we need to
290 //move the icon left slightly to accomomodate the arrow
291 if (((_elements & Menu)==Menu)) {
293 cairo_translate (cr, -8,0 );
296 cairo_rectangle (cr, x, y, _pixbuf->get_width(), _pixbuf->get_height());
297 gdk_cairo_set_source_pixbuf (cr, _pixbuf->gobj(), x, y);
300 //..and then return to our previous drawing position
301 if (((_elements & Menu)==Menu)) {
307 if (get_width() < 75) {
314 if ( !_pixbuf && ((_elements & Text)==Text) && !_text.empty()) {
317 cairo_rectangle (cr, 2, 1, get_width()-4, get_height()-2);
321 ArdourCanvas::set_source_rgba (cr, text_color);
323 if ( (_elements & Menu) == Menu) {
324 cairo_move_to (cr, text_margin, get_height()/2.0 - _text_height/2.0);
325 pango_cairo_show_layout (cr, _layout->gobj());
326 } else if ( (_elements & Indicator) == Indicator) {
328 cairo_move_to (cr, text_margin + _diameter + 4, get_height()/2.0 - _text_height/2.0);
330 cairo_move_to (cr, text_margin, get_height()/2.0 - _text_height/2.0);
332 pango_cairo_show_layout (cr, _layout->gobj());
340 cairo_save (cr); // TODO retain rotataion.. adj. LED,...
341 cairo_rotate(cr, _angle * M_PI / 180.0);
342 cairo_device_to_user(cr, &ww, &wh);
343 xa = (ww - _text_width) * _xalign;
344 ya = (wh - _text_height) * _yalign;
346 /* quick hack for left/bottom alignment at -90deg
347 * TODO this should be generalized incl rotation.
348 * currently only 'user' of this API is meter_strip.cc
350 if (_xalign < 0) xa = (ww * fabs(_xalign) + text_margin);
352 // TODO honor left/right text_margin with min/max()
354 cairo_move_to (cr, xa, ya);
355 pango_cairo_update_layout(cr, _layout->gobj());
356 pango_cairo_show_layout (cr, _layout->gobj());
359 /* use old center'ed layout for follow up items - until rotation/aligment code is completed */
360 cairo_move_to (cr, (get_width() - _text_width)/2.0, get_height()/2.0 - _text_height/2.0);
366 if (((_elements & Menu)==Menu)) {
371 cairo_set_source_rgba (cr, 1, 1, 1, 0.4);
372 cairo_move_to(cr, get_width() - ((_diameter/2.0) + 6.0), get_height()/2.0 +_diameter/4);
373 cairo_rel_line_to(cr, -_diameter/2, -_diameter/2);
374 cairo_rel_line_to(cr, _diameter, 0);
375 cairo_close_path(cr);
376 cairo_set_source_rgba (cr, 1, 1, 1, 0.4);
377 cairo_fill_preserve(cr);
378 cairo_set_source_rgba (cr, 0, 0, 0, 0.8);
379 cairo_set_line_width(cr, 0.5);
386 if (((_elements & Indicator)==Indicator)) {
388 /* move to the center of the indicator/led */
392 if (_elements & Text) {
394 cairo_translate (cr, text_margin + (_diameter/2.0), get_height()/2.0);
396 cairo_translate (cr, get_width() - ((_diameter/2.0) + 4.0), get_height()/2.0);
399 cairo_translate (cr, get_width()/2.0, get_height()/2.0);
403 if (!_flat_buttons) {
404 cairo_arc (cr, 0, 0, _diameter/2, 0, 2 * M_PI);
405 cairo_set_source (cr, led_inset_pattern);
410 cairo_set_source_rgb (cr, 0, 0, 0);
411 cairo_arc (cr, 0, 0, _diameter/2-1, 0, 2 * M_PI);
415 ArdourCanvas::set_source_rgba (cr, led_color);
416 cairo_arc (cr, 0, 0, _diameter/2-3, 0, 2 * M_PI);
423 // a transparent gray layer to indicate insensitivity
424 if ((visual_state() & Gtkmm2ext::Insensitive)) {
425 rounded_function (cr, 1, 1, get_width() - 2, get_height() - 2, _corner_radius);
426 cairo_set_source_rgba (cr, 0.505, 0.517, 0.525, 0.6);
430 // if requested, show hovering
431 if (ARDOUR::Config->get_widget_prelight()
432 && !((visual_state() & Gtkmm2ext::Insensitive))) {
434 rounded_function (cr, 1, 1, get_width() - 2, get_height() - 2, _corner_radius);
435 cairo_set_source_rgba (cr, 0.905, 0.917, 0.925, 0.2);
440 //user is currently pressing the button. black outline helps to indicate this
441 if ( _grabbed && !(_elements & (Inactive|Menu))) {
442 rounded_function (cr, 1, 1, get_width() - 2, get_height() - 2, _corner_radius);
443 cairo_set_line_width(cr, 2);
444 cairo_set_source_rgba (cr, 0.1, 0.1, 0.1, .5); // XXX no longer 'black'
448 //some buttons (like processor boxes) can be selected (so they can be deleted). Draw a selection indicator
449 if (visual_state() & Gtkmm2ext::Selected) {
450 #if 0 // outline, edge + 1px outside
451 cairo_set_line_width(cr, 2);
452 cairo_set_source_rgba (cr, 1, 0, 0, 0.8);
453 #else // replace edge (if any)
454 cairo_set_line_width(cr, 1);
455 cairo_set_source_rgba (cr, 1, 0, 0, 0.8);
457 rounded_function (cr, 0.5, 0.5, get_width() - 1, get_height() - 1, _corner_radius);
461 //I guess this means we have keyboard focus. I don't think this works currently
463 //A: yes, it's keyboard focus and it does work when there's no editor window
464 // (the editor is always the first receiver for KeyDown).
465 // It's needed for eg. the engine-dialog at startup or after closing a sesion.
467 rounded_function (cr, 1.5, 1.5, get_width() - 3, get_height() - 3, _corner_radius);
468 cairo_set_source_rgba (cr, 0.905, 0.917, 0.925, 0.8);
470 cairo_set_dash (cr, &dashes, 1, 0);
471 cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
472 cairo_set_line_width (cr, 1.0);
474 cairo_set_dash (cr, 0, 0, 0);
479 ArdourButton::set_diameter (float d)
481 _diameter = (d*2) + 5.0;
483 if (_diameter != 0.0) {
484 _fixed_diameter = true;
492 ArdourButton::set_corner_radius (float r)
499 ArdourButton::on_size_request (Gtk::Requisition* req)
504 CairoWidget::on_size_request (req);
506 if ((_elements & Text) && !_text.empty()) {
508 //calc our real width for our string (but ignore the height, because that results in inconsistent button heights)
510 _layout->get_pixel_size (_text_width, ignored);
512 //calc the height using some text with both ascenders and descenders
513 std::string t = _layout->get_text();
514 _layout->set_text ("WjgO"); //what we put here probably doesn't matter, as long as its the same for everyone
515 _layout->get_pixel_size (ignored, _text_height);
516 _layout->set_text (t);
518 if (_text_width + _diameter < 75) {
532 if ((_elements & Indicator) && _fixed_diameter) {
534 req->width = _pixbuf->get_width() + lrint (_diameter) + xpad;
535 req->height = max (_pixbuf->get_height(), (int) lrint (_diameter)) + ypad;
537 req->width = _text_width + lrint (_diameter) + xpad * 2; // margin left+right * 2
538 req->height = max (_text_height, (int) lrint (_diameter)) + ypad;
542 req->width = _pixbuf->get_width() + xpad;
543 req->height = _pixbuf->get_height() + ypad;
545 req->width = _text_width + xpad;
546 req->height = _text_height + ypad;
549 req->width += _corner_radius;
553 * This sets the colors used for rendering based on the name of the button, and
554 * thus uses information from the GUI config data.
557 ArdourButton::set_colors ()
559 if (_fixed_colors_set) {
562 std::string name = get_name();
564 fill_active_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1: fill active", name));
565 fill_inactive_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1: fill", name));
567 text_active_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1: text active", name));
568 text_inactive_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1: text", name));
570 led_active_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1: led active", name));
571 led_inactive_color = ARDOUR_UI::config()->color_by_name (string_compose ("%1: led", name));
574 * This sets the colors used for rendering based on two fixed values, rather
575 * than basing them on the button name, and thus information in the GUI config
578 void ArdourButton::set_fixed_colors (const uint32_t color_active, const uint32_t color_inactive)
580 _fixed_colors_set = true;
582 fill_active_color = color_active;
583 fill_inactive_color = color_inactive;
585 unsigned char r, g, b, a;
586 UINT_TO_RGBA(color_active, &r, &g, &b, &a);
588 double white_contrast = (max (double(r), 255.) - min (double(r), 255.)) +
589 (max (double(g), 255.) - min (double(g), 255.)) +
590 (max (double(b), 255.) - min (double(b), 255.));
592 double black_contrast = (max (double(r), 0.) - min (double(r), 0.)) +
593 (max (double(g), 0.) - min (double(g), 0.)) +
594 (max (double(b), 0.) - min (double(b), 0.));
596 text_active_color = (white_contrast > black_contrast) ?
597 RGBA_TO_UINT(255, 255, 255, 255) : /* use white */
598 RGBA_TO_UINT( 0, 0, 0, 255); /* use black */
601 UINT_TO_RGBA(color_inactive, &r, &g, &b, &a);
603 white_contrast = (max (double(r), 255.) - min (double(r), 255.)) +
604 (max (double(g), 255.) - min (double(g), 255.)) +
605 (max (double(b), 255.) - min (double(b), 255.));
607 black_contrast = (max (double(r), 0.) - min (double(r), 0.)) +
608 (max (double(g), 0.) - min (double(g), 0.)) +
609 (max (double(b), 0.) - min (double(b), 0.));
611 text_inactive_color = (white_contrast > black_contrast) ?
612 RGBA_TO_UINT(255, 255, 255, 255) : /* use white */
613 RGBA_TO_UINT( 0, 0, 0, 255); /* use black */
615 /* XXX what about led colors ? */
618 set_name (""); /* this will trigger a "style-changed" message and then set_colors() */
622 ArdourButton::build_patterns ()
624 if (convex_pattern) {
625 cairo_pattern_destroy (convex_pattern);
629 if (concave_pattern) {
630 cairo_pattern_destroy (concave_pattern);
634 if (led_inset_pattern) {
635 cairo_pattern_destroy (led_inset_pattern);
638 float width = get_width(); float height = get_height();
641 convex_pattern = cairo_pattern_create_linear (0.0, 0, 0.0, height);
642 cairo_pattern_add_color_stop_rgba (convex_pattern, 0.0, 0,0,0, 0.0);
643 cairo_pattern_add_color_stop_rgba (convex_pattern, 1.0, 0,0,0, 0.35);
646 concave_pattern = cairo_pattern_create_linear (0.0, 0, 0.0, height);
647 cairo_pattern_add_color_stop_rgba (concave_pattern, 0.0, 0,0,0, 0.5);
648 cairo_pattern_add_color_stop_rgba (concave_pattern, 0.7, 0,0,0, 0.0);
650 if (_elements & Indicator) {
651 led_inset_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, _diameter);
652 cairo_pattern_add_color_stop_rgba (led_inset_pattern, 0, 0,0,0, 0.4);
653 cairo_pattern_add_color_stop_rgba (led_inset_pattern, 1, 1,1,1, 0.7);
660 ArdourButton::set_led_left (bool yn)
666 ArdourButton::on_button_press_event (GdkEventButton *ev)
668 if ((_elements & Indicator) && _led_rect && _distinct_led_click) {
669 if (ev->x >= _led_rect->x && ev->x < _led_rect->x + _led_rect->width &&
670 ev->y >= _led_rect->y && ev->y < _led_rect->y + _led_rect->height) {
675 if (binding_proxy.button_press_handler (ev)) {
682 if (!_act_on_release) {
684 _action->activate ();
689 if (_fallthrough_to_parent)
696 ArdourButton::on_button_release_event (GdkEventButton *ev)
698 if (_hovering && (_elements & Indicator) && _led_rect && _distinct_led_click) {
699 if (ev->x >= _led_rect->x && ev->x < _led_rect->x + _led_rect->width &&
700 ev->y >= _led_rect->y && ev->y < _led_rect->y + _led_rect->height) {
701 signal_led_clicked(); /* EMIT SIGNAL */
711 if (_act_on_release) {
713 _action->activate ();
719 if (_fallthrough_to_parent)
726 ArdourButton::set_distinct_led_click (bool yn)
728 _distinct_led_click = yn;
733 ArdourButton::color_handler ()
741 ArdourButton::on_size_allocate (Allocation& alloc)
743 CairoWidget::on_size_allocate (alloc);
749 ArdourButton::set_controllable (boost::shared_ptr<Controllable> c)
751 watch_connection.disconnect ();
752 binding_proxy.set_controllable (c);
756 ArdourButton::watch ()
758 boost::shared_ptr<Controllable> c (binding_proxy.get_controllable ());
761 warning << _("button cannot watch state of non-existing Controllable\n") << endmsg;
765 c->Changed.connect (watch_connection, invalidator(*this), boost::bind (&ArdourButton::controllable_changed, this), gui_context());
769 ArdourButton::controllable_changed ()
771 float val = binding_proxy.get_controllable()->get_value();
773 if (fabs (val) >= 0.5f) {
774 set_active_state (Gtkmm2ext::ExplicitActive);
776 unset_active_state ();
781 ArdourButton::set_related_action (RefPtr<Action> act)
783 Gtkmm2ext::Activatable::set_related_action (act);
787 action_tooltip_changed ();
789 Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic (_action);
792 tact->signal_toggled().connect (sigc::mem_fun (*this, &ArdourButton::action_toggled));
795 _action->connect_property_changed ("sensitive", sigc::mem_fun (*this, &ArdourButton::action_sensitivity_changed));
796 _action->connect_property_changed ("visible", sigc::mem_fun (*this, &ArdourButton::action_visibility_changed));
797 _action->connect_property_changed ("tooltip", sigc::mem_fun (*this, &ArdourButton::action_tooltip_changed));
802 ArdourButton::action_toggled ()
804 Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic (_action);
807 if (tact->get_active()) {
808 set_active_state (Gtkmm2ext::ExplicitActive);
810 unset_active_state ();
816 ArdourButton::on_style_changed (const RefPtr<Gtk::Style>&)
823 ArdourButton::on_name_changed ()
830 ArdourButton::setup_led_rect ()
834 if (get_width() < 75) {
840 if (_elements & Indicator) {
841 _led_rect = new cairo_rectangle_t;
843 if (_elements & Text) {
845 _led_rect->x = text_margin;
847 _led_rect->x = get_width() - text_margin - _diameter/2.0;
851 _led_rect->x = get_width()/2.0 - _diameter/2.0;
854 _led_rect->y = get_height()/2.0 - _diameter/2.0;
855 _led_rect->width = _diameter;
856 _led_rect->height = _diameter;
865 ArdourButton::set_image (const RefPtr<Gdk::Pixbuf>& img)
872 ArdourButton::set_active_state (Gtkmm2ext::ActiveState s)
874 bool changed = (_active_state != s);
875 CairoWidget::set_active_state (s);
883 ArdourButton::set_visual_state (Gtkmm2ext::VisualState s)
885 bool changed = (_visual_state != s);
886 CairoWidget::set_visual_state (s);
895 ArdourButton::on_focus_in_event (GdkEventFocus* ev)
899 return CairoWidget::on_focus_in_event (ev);
903 ArdourButton::on_focus_out_event (GdkEventFocus* ev)
907 return CairoWidget::on_focus_out_event (ev);
911 ArdourButton::on_key_release_event (GdkEventKey *ev) {
913 (ev->keyval == GDK_KEY_space || ev->keyval == GDK_Return))
917 _action->activate ();
921 return CairoWidget::on_key_release_event (ev);
925 ArdourButton::on_enter_notify_event (GdkEventCrossing* ev)
927 _hovering = (_elements & Inactive) ? false : true;
929 if (ARDOUR::Config->get_widget_prelight()) {
933 return CairoWidget::on_enter_notify_event (ev);
937 ArdourButton::on_leave_notify_event (GdkEventCrossing* ev)
941 if (ARDOUR::Config->get_widget_prelight()) {
945 return CairoWidget::on_leave_notify_event (ev);
949 ArdourButton::set_tweaks (Tweaks t)
958 ArdourButton::action_sensitivity_changed ()
960 if (_action->property_sensitive ()) {
961 set_visual_state (Gtkmm2ext::VisualState (visual_state() & ~Gtkmm2ext::Insensitive));
963 set_visual_state (Gtkmm2ext::VisualState (visual_state() | Gtkmm2ext::Insensitive));
970 ArdourButton::action_visibility_changed ()
972 if (_action->property_visible ()) {
980 ArdourButton::action_tooltip_changed ()
982 string str = _action->property_tooltip().get_value();
983 ARDOUR_UI::instance()->set_tip (*this, str);
987 ArdourButton::set_elements (Element e)
993 ArdourButton::add_elements (Element e)
995 _elements = (ArdourButton::Element) (_elements | e);