ardour_button.cc

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/*
    Copyright (C) 2010 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 <cmath>
#include <algorithm>

#include <pangomm/layout.h>

#include "pbd/compose.h"
#include "pbd/error.h"
#include "pbd/stacktrace.h"

#include "gtkmm2ext/utils.h"
#include "gtkmm2ext/rgb_macros.h"
#include "gtkmm2ext/gui_thread.h"

#include "ardour/rc_configuration.h" // for widget prelight preference

#include "canvas/utils.h"
#include "canvas/colors.h"

#include "ardour_button.h"
#include "ardour_ui.h"
#include "global_signals.h"

#include "i18n.h"

#define BASELINESTRETCH (1.25)
#define TRACKHEADERBTNW (3.10)

using namespace Gdk;
using namespace Gtk;
using namespace Glib;
using namespace PBD;
using std::max;
using std::min;
using namespace std;

ArdourButton::Element ArdourButton::default_elements = ArdourButton::Element (ArdourButton::Edge|ArdourButton::Body|ArdourButton::Text);
ArdourButton::Element ArdourButton::led_default_elements = ArdourButton::Element (ArdourButton::default_elements|ArdourButton::Indicator);
ArdourButton::Element ArdourButton::just_led_default_elements = ArdourButton::Element (ArdourButton::Edge|ArdourButton::Body|ArdourButton::Indicator);

ArdourButton::ArdourButton (Element e)
        : _elements (e)
        , _icon (ArdourButton::NoIcon)
        , _tweaks (Tweaks (0))
        , _char_pixel_width (0)
        , _char_pixel_height (0)
        , _char_avg_pixel_width (0)
        , _text_width (0)
        , _text_height (0)
        , _diameter (0)
        , _corner_radius (2.5)
        , _corner_mask (0xf)
        , _angle(0)
        , _xalign(.5)
        , _yalign(.5)
        , fill_inactive_color (0)
        , fill_active_color (0)
        , text_active_color(0)
        , text_inactive_color(0)
        , led_active_color(0)
        , led_inactive_color(0)
        , led_custom_color (0)
        , use_custom_led_color (false)
        , convex_pattern (0)
        , concave_pattern (0)
        , led_inset_pattern (0)
        , _led_rect (0)
        , _act_on_release (true)
        , _led_left (false)
        , _distinct_led_click (false)
        , _hovering (false)
        , _focused (false)
        , _fixed_colors_set (false)
        , _fallthrough_to_parent (false)
        , _layout_ellipsize_width (-1)
        , _ellipsis (Pango::ELLIPSIZE_NONE)
        , _update_colors (true)
        , _pattern_height (0)
{
        ARDOUR_UI_UTILS::ColorsChanged.connect (sigc::mem_fun (*this, &ArdourButton::color_handler));
}

ArdourButton::ArdourButton (const std::string& str, Element e)
        : _elements (e)
        , _tweaks (Tweaks (0))
        , _text_width (0)
        , _text_height (0)
        , _diameter (0)
        , _corner_radius (2.5)
        , _corner_mask (0xf)
        , _angle(0)
        , _xalign(.5)
        , _yalign(.5)
        , fill_inactive_color (0)
        , fill_active_color (0)
        , text_active_color(0)
        , text_inactive_color(0)
        , led_active_color(0)
        , led_inactive_color(0)
        , led_custom_color (0)
        , use_custom_led_color (false)
        , convex_pattern (0)
        , concave_pattern (0)
        , led_inset_pattern (0)
        , _led_rect (0)
        , _act_on_release (true)
        , _led_left (false)
        , _distinct_led_click (false)
        , _hovering (false)
        , _focused (false)
        , _fixed_colors_set (false)
        , _fallthrough_to_parent (false)
        , _layout_ellipsize_width (-1)
        , _ellipsis (Pango::ELLIPSIZE_NONE)
        , _update_colors (true)
        , _pattern_height (0)
{
        set_text (str);
        ARDOUR_UI_UTILS::ColorsChanged.connect (sigc::mem_fun (*this, &ArdourButton::color_handler));
        ARDOUR_UI_UTILS::DPIReset.connect (sigc::mem_fun (*this, &ArdourButton::on_name_changed));
}

ArdourButton::~ArdourButton()
{
        delete _led_rect;

        if (convex_pattern) {
                cairo_pattern_destroy (convex_pattern);
        }

        if (concave_pattern) {
                cairo_pattern_destroy (concave_pattern);
        }

        if (led_inset_pattern) {
                cairo_pattern_destroy (led_inset_pattern);
        }
}

void
ArdourButton::set_layout_font (const Pango::FontDescription& fd)
{
        ensure_layout ();
        if (_layout) {
                _layout->set_font_description (fd);
                queue_resize ();
        }
}

void
ArdourButton::set_text (const std::string& str)
{
        _text = str;
        if (!is_realized()) {
                return;
        }
        ensure_layout ();
        if (_layout && _layout->get_text() != _text) {
                _layout->set_text (_text);
                queue_resize ();
        }
}

void
ArdourButton::set_angle (const double angle)
{
        _angle = angle;
}

void
ArdourButton::set_alignment (const float xa, const float ya)
{
        _xalign = xa;
        _yalign = ya;
}

void
ArdourButton::render (cairo_t* cr, cairo_rectangle_t *)
{
        uint32_t text_color;
        uint32_t led_color;

        const float corner_radius = std::max(2.f, _corner_radius * ARDOUR_UI::ui_scale);

        if (_update_colors) {
                set_colors ();
        }
        if (get_height() != _pattern_height) {
                build_patterns ();
        }

        if ( active_state() == Gtkmm2ext::ExplicitActive ) {
                text_color = text_active_color;
                led_color = led_active_color;
        } else {
                text_color = text_inactive_color;
                led_color = led_inactive_color;
        }

        if (use_custom_led_color) {
                led_color = led_custom_color;
        }

        void (*rounded_function)(cairo_t*, double, double, double, double, double);

        switch (_corner_mask) {
        case 0x1: /* upper left only */
                rounded_function = Gtkmm2ext::rounded_top_left_rectangle;
                break;
        case 0x2: /* upper right only */
                rounded_function = Gtkmm2ext::rounded_top_right_rectangle;
                break;
        case 0x3: /* upper only */
                rounded_function = Gtkmm2ext::rounded_top_rectangle;
                break;
                /* should really have functions for lower right, lower left,
                   lower only, but for now, we don't
                */
        default:
                rounded_function = Gtkmm2ext::rounded_rectangle;
        }

        // draw edge (filling a rect underneath, rather than stroking a border on top, allows the corners to be lighter-weight.
        if ((_elements & (Body|Edge)) == (Body|Edge)) {
                rounded_function (cr, 0, 0, get_width(), get_height(), corner_radius + 1.5);
                cairo_set_source_rgba (cr, 0, 0, 0, 1);
                cairo_fill(cr);
        }

        // background fill
        if ((_elements & Body)==Body) {
                rounded_function (cr, 1, 1, get_width() - 2, get_height() - 2, corner_radius);
                if (active_state() == Gtkmm2ext::ImplicitActive && !((_elements & Indicator)==Indicator)) {
                        ArdourCanvas::set_source_rgba (cr, fill_inactive_color);
                        cairo_fill (cr);
                } else if ( (active_state() == Gtkmm2ext::ExplicitActive) && !((_elements & Indicator)==Indicator) ) {
                        //background color
                        ArdourCanvas::set_source_rgba (cr, fill_active_color);
                        cairo_fill (cr);
                } else {  //inactive, or it has an indicator
                        //background color
                        ArdourCanvas::set_source_rgba (cr, fill_inactive_color);
                }
                cairo_fill (cr);
        }

        // IMPLICIT ACTIVE: draw a border of the active color
        if ((_elements & Body)==Body) {
                if (active_state() == Gtkmm2ext::ImplicitActive && !((_elements & Indicator)==Indicator)) {
                        cairo_set_line_width (cr, 2.0);
                        rounded_function (cr, 2, 2, get_width() - 4, get_height() - 4, corner_radius-0.5);
                        ArdourCanvas::set_source_rgba (cr, fill_active_color);
                        cairo_stroke (cr);
                }
        }

        //show the "convex" or "concave" gradient
        if (!_flat_buttons) {
                if ( active_state() == Gtkmm2ext::ExplicitActive && ( !((_elements & Indicator)==Indicator) || use_custom_led_color) ) {
                        //concave
                        cairo_set_source (cr, concave_pattern);
                        Gtkmm2ext::rounded_rectangle (cr, 1, 1, get_width() - 2, get_height() - 2, corner_radius);
                        cairo_fill (cr);
                } else {
                        cairo_set_source (cr, convex_pattern);
                        Gtkmm2ext::rounded_rectangle (cr, 1, 1, get_width() - 2, get_height() - 2, corner_radius);
                        cairo_fill (cr);
                }
        }

#define VECTORICONSTROKEFILL(fillalpha) \
        cairo_set_line_width(cr, 1.5); \
        cairo_set_source_rgba (cr, 0, 0, 0, 1.0); \
        cairo_stroke_preserve(cr); \
        cairo_set_source_rgba (cr, 1, 1, 1, (fillalpha)); \
        cairo_fill(cr);

        //Pixbuf, if any
        if (_pixbuf) {
                double x = rint((get_width() - _pixbuf->get_width()) * .5);
                const double y = rint((get_height() - _pixbuf->get_height()) * .5);
#if 0 // DEBUG style (print on hover)
                if (_hovering || (_elements & Inactive)) {
                        printf("%s: p:%dx%d (%dx%d)\n",
                                        get_name().c_str(),
                                        _pixbuf->get_width(), _pixbuf->get_height(),
                                        get_width(), get_height());
                }
#endif
                if (_elements & Menu) {
                        //if this is a DropDown with an icon, then we need to
                        //move the icon left slightly to accomomodate the arrow
                        x -= _diameter - 2;
                }
                cairo_rectangle (cr, x, y, _pixbuf->get_width(), _pixbuf->get_height());
                gdk_cairo_set_source_pixbuf (cr, _pixbuf->gobj(), x, y);
                cairo_fill (cr);
        }
        else /* VectorIcons are exclusive to Pixbuf Icons */
        /* TODO separate these into dedicated class
         * it may also be efficient to render them only once for every size (image-surface) */
        if ((_elements & VectorIcon) && _icon == RecTapeMode) {
                const double x = get_width() * .5;
                const double y = get_height() * .5;
                const double r = std::min(x, y) * .6;
                const double slit = .11 * M_PI;
                cairo_save(cr);
                cairo_translate(cr, x, y);

                cairo_arc (cr, 0, 0, r, 0, 2 * M_PI);
                if (active_state() == Gtkmm2ext::ExplicitActive) {
                        cairo_set_source_rgba (cr, .95, .1, .1, 1.);
                } else {
                        cairo_set_source_rgba (cr, .95, .44, .44, 1.); // #f46f6f
                }
                cairo_fill_preserve(cr);
                cairo_set_source_rgba (cr, .0, .0, .0, .5);
                cairo_set_line_width(cr, 1);
                cairo_stroke(cr);

                cairo_save(cr);
                cairo_set_source_rgba (cr, .15, .07, .07, 1.0);

                cairo_rotate (cr, -.5 * M_PI);
                cairo_move_to(cr, 0, 0);
                cairo_arc (cr, 0, 0, r *.85, -slit, slit);
                cairo_line_to(cr, 0, 0);
                cairo_close_path(cr);

                cairo_fill(cr);
                cairo_rotate (cr, 2. * M_PI / 3.);

                cairo_move_to(cr, 0, 0);
                cairo_arc (cr, 0, 0, r *.85, -slit, slit);
                cairo_line_to(cr, 0, 0);
                cairo_close_path(cr);
                cairo_fill(cr);

                cairo_rotate (cr, 2. * M_PI / 3.);
                cairo_move_to(cr, 0, 0);
                cairo_arc (cr, 0, 0, r *.85, -slit, slit);
                cairo_line_to(cr, 0, 0);
                cairo_close_path(cr);
                cairo_fill(cr);

                cairo_restore(cr);

                cairo_arc (cr, 0, 0, r * .3, 0, 2 * M_PI);
                if (active_state() == Gtkmm2ext::ExplicitActive)
                        cairo_set_source_rgba (cr, .95, .1, .1, 1.);
                else
                        cairo_set_source_rgba (cr, .95, .44, .44, 1.); // #f46f6f
                cairo_fill(cr);
                cairo_set_source_rgba (cr, .0, .0, .0, 1.0);
                cairo_arc (cr, 0, 0, r *.15, 0, 2 * M_PI); // hole in the middle
                cairo_fill(cr);

                cairo_restore(cr);
        }
        else if ((_elements & VectorIcon) && _icon == RecButton) {
                const double x = get_width() * .5;
                const double y = get_height() * .5;
                const double r = std::min(x, y) * .55;
                cairo_arc (cr, x, y, r, 0, 2 * M_PI);
                if (active_state() == Gtkmm2ext::ExplicitActive)
                        cairo_set_source_rgba (cr, .95, .1, .1, 1.);
                else
                        cairo_set_source_rgba (cr, .95, .44, .44, 1.); // #f46f6f
                cairo_fill_preserve(cr);
                cairo_set_source_rgba (cr, .0, .0, .0, .8);
                cairo_set_line_width(cr, 1);
                cairo_stroke(cr);
        }
        else if ((_elements & VectorIcon) && _icon == CloseCross) {
                const double x = get_width() * .5;
                const double y = get_height() * .5;
                const double o = .5 + std::min(x, y) * .4;
                ArdourCanvas::set_source_rgba (cr, text_color);
                cairo_set_line_width(cr, 1);
                cairo_move_to(cr, x-o, y-o);
                cairo_line_to(cr, x+o, y+o);
                cairo_move_to(cr, x+o, y-o);
                cairo_line_to(cr, x-o, y+o);
                cairo_stroke(cr);
        }
        else if ((_elements & VectorIcon) && _icon == StripWidth) {
                const double x0 = get_width()  * .2;
                const double x1 = get_width()  * .8;

                const double y0 = get_height() * .25;
                const double y1= get_height()  * .75;

                const double ym= get_height()  * .5;

                // arrow
                const double xa0= get_height()  * .39;
                const double xa1= get_height()  * .61;
                const double ya0= get_height()  * .35;
                const double ya1= get_height()  * .65;

                ArdourCanvas::set_source_rgba (cr, text_color);
                cairo_set_line_width(cr, 1);

                // left + right
                cairo_move_to(cr, x0, y0);
                cairo_line_to(cr, x0, y1);
                cairo_move_to(cr, x1, y0);
                cairo_line_to(cr, x1, y1);

                // horiz center line
                cairo_move_to(cr, x0, ym);
                cairo_line_to(cr, x1, ym);

                // arrow left
                cairo_move_to(cr,  x0, ym);
                cairo_line_to(cr, xa0, ya0);
                cairo_move_to(cr,  x0, ym);
                cairo_line_to(cr, xa0, ya1);

                // arrow right
                cairo_move_to(cr,  x1,  ym);
                cairo_line_to(cr, xa1, ya0);
                cairo_move_to(cr,  x1,  ym);
                cairo_line_to(cr, xa1, ya1);
                cairo_stroke(cr);
        }
        else if ((_elements & VectorIcon) && _icon == DinMidi) {
                const double x = get_width() * .5;
                const double y = get_height() * .5;
                const double r = std::min(x, y) * .75;
                ArdourCanvas::set_source_rgba (cr, text_color);
                cairo_set_line_width(cr, 1);
                cairo_arc (cr, x, y, r, .57 * M_PI, 2.43 * M_PI);
                cairo_stroke(cr);

                // pins equally spaced 45deg
                cairo_arc (cr, x, y * 0.5, r * .15, 0, 2 * M_PI);
                cairo_fill(cr);
                cairo_arc (cr, x * 0.5, y, r * .15, 0, 2 * M_PI);
                cairo_fill(cr);
                cairo_arc (cr, x * 1.5, y, r * .15, 0, 2 * M_PI);
                cairo_fill(cr);
                //  .5 + .5 * .5 * sin(45deg),  1.5 - .5 * .5 * cos(45deg)
                cairo_arc (cr, x * 0.677, y * .677, r * .15, 0, 2 * M_PI);
                cairo_fill(cr);
                cairo_arc (cr, x * 1.323, y * .677, r * .15, 0, 2 * M_PI);
                cairo_fill(cr);

                // bottom notch
                cairo_arc (cr, x, y+r, r * .26, 1.05 * M_PI, 1.95 * M_PI);
                cairo_stroke(cr);
        }
        else if ((_elements & VectorIcon) && _icon == TransportStop) {
                const int wh = std::min (get_width(), get_height());
                cairo_rectangle (cr,
                                (get_width() - wh) * .5 + wh * .25,
                                (get_height() - wh) * .5 + wh * .25,
                                wh * .5, wh * .5);

                VECTORICONSTROKEFILL(0.8);
        }
        else if ((_elements & VectorIcon) && _icon == TransportPlay) {
                const int wh = std::min (get_width(), get_height()) * .5;
                const double y = get_height() * .5;
                const double x = get_width() - wh;

                const float tri = ceil(.577 * wh); // 1/sqrt(3)

                cairo_move_to (cr,  x + wh * .5, y);
                cairo_line_to (cr,  x - wh * .5, y - tri);
                cairo_line_to (cr,  x - wh * .5, y + tri);
                cairo_close_path (cr);

                VECTORICONSTROKEFILL(0.8);
        }
        else if ((_elements & VectorIcon) && _icon == TransportPanic) {
                const int wh = std::min (get_width(), get_height()) * .1;
                const double xc = get_width() * .5;
                const double yh = get_height();
                cairo_rectangle (cr,
                                xc - wh, yh *.19,
                                wh * 2,  yh *.41);
                VECTORICONSTROKEFILL(0.8);

                cairo_arc (cr, xc, yh *.75, wh, 0, 2 * M_PI);
                VECTORICONSTROKEFILL(0.8);
        }
        else if ((_elements & VectorIcon) && (_icon == TransportStart || _icon == TransportEnd || _icon == TransportRange)) {
                // small play triangle
                int wh = std::min (get_width(), get_height());
                const double y = get_height() * .5;
                const double x = get_width() - wh * .5;
                wh *= .18;
                const float tri = ceil(.577 * wh * 2); // 1/sqrt(3)

                const float ln = std::min (get_width(), get_height()) * .07;

                if (_icon == TransportStart || _icon == TransportRange) {
                        cairo_rectangle (cr,
                                         x - wh - ln, y  - tri * 1.7,
                                         ln * 2,  tri * 3.4);

                        VECTORICONSTROKEFILL(1.0);
                }

                if (_icon == TransportEnd || _icon == TransportRange) {
                        cairo_rectangle (cr,
                                         x + wh - ln, y  - tri * 1.7,
                                         ln * 2,  tri * 3.4);

                        VECTORICONSTROKEFILL(1.0);
                }

                if (_icon == TransportStart) {
                        cairo_move_to (cr,  x - wh, y);
                        cairo_line_to (cr,  x + wh, y - tri);
                        cairo_line_to (cr,  x + wh, y + tri);
                } else {
                        cairo_move_to (cr,  x + wh, y);
                        cairo_line_to (cr,  x - wh, y - tri);
                        cairo_line_to (cr,  x - wh, y + tri);
                }

                cairo_close_path (cr);
                VECTORICONSTROKEFILL(1.0);
        }
        else if ((_elements & VectorIcon) && _icon == TransportLoop) {
                const double x = get_width() * .5;
                const double y = get_height() * .5;
                const double r = std::min(x, y);

                cairo_arc          (cr, x, y, r * .62, 0, 2 * M_PI);
                cairo_arc_negative (cr, x, y, r * .35, 2 * M_PI, 0);

                VECTORICONSTROKEFILL(1.0);
#define ARCARROW(rad, ang) \
                x + (rad) * sin((ang) * 2.0 * M_PI), y + (rad) * cos((ang) * 2.0 * M_PI)

                cairo_move_to (cr, ARCARROW(r * .35, .72));
                cairo_line_to (cr, ARCARROW(r * .15, .72));
                cairo_line_to (cr, ARCARROW(r * .56, .60));
                cairo_line_to (cr, ARCARROW(r * .75, .72));
                cairo_line_to (cr, ARCARROW(r * .62, .72));

                cairo_set_source_rgba (cr, 0, 0, 0, 1.0);
                cairo_stroke_preserve(cr);
                cairo_close_path (cr);
                cairo_set_source_rgba (cr, 1, 1, 1, 1.0);
                cairo_fill(cr);
#undef ARCARROW
        }
        else if ((_elements & VectorIcon) && _icon == TransportMetronom) {
                const double x  = get_width() * .5;
                const double y  = get_height() * .5;
                const double wh = std::min(x, y);
                const double h  = wh * .85;
                const double w  = wh * .55;
                const double lw = w  * .34;

                cairo_rectangle (cr,
                                 x - w * .7, y + h * .25,
                                 w * 1.4, lw);

                VECTORICONSTROKEFILL(1.0);

                cairo_move_to (cr,  x - w,       y + h);
                cairo_line_to (cr,  x + w,       y + h);
                cairo_line_to (cr,  x + w * .35, y - h);
                cairo_line_to (cr,  x - w * .35, y - h);
                cairo_line_to (cr,  x - w,       y + h);

                cairo_move_to (cr,  x - w + lw,       y + h -lw);
                cairo_line_to (cr,  x - w * .35 + lw, y - h + lw);
                cairo_line_to (cr,  x + w * .35 - lw, y - h + lw);
                cairo_line_to (cr,  x + w - lw,       y + h -lw);
                cairo_line_to (cr,  x - w + lw,       y + h -lw);

                VECTORICONSTROKEFILL(1.0);

                // ddx = .70 w      = .75 * .5 wh              = .375 wh
                // ddy = .75 h - lw = .75 * .8 wh - wh .5 * .2 = .5 wh
                // ang = (ddx/ddy):
                // -> angle = atan (ang) = atan (375 / .5) ~= 36deg
                const double dx = lw * .2;  // 1 - cos(tan^-1(ang))
                const double dy = lw * .4;  // 1 - sin(tan^-1(ang))
                cairo_move_to (cr,  x - w * .3     , y + h * .25 + lw * .5);
                cairo_line_to (cr,  x - w + dx     , y - h + lw + dy);
                cairo_line_to (cr,  x - w + lw     , y - h + lw);
                cairo_line_to (cr,  x - w * .3 + lw, y + h * .25 + lw * .5);
                cairo_close_path (cr);

                VECTORICONSTROKEFILL(1.0);

                cairo_rectangle (cr,
                                 x - w * .7, y + h * .25,
                                 w * 1.4, lw);
                cairo_fill(cr);
        }
        else if (_elements & VectorIcon) {
                // missing icon
                assert(0);
        }
#undef VECTORICONSTROKEFILL

        const int text_margin = char_pixel_width();
        // Text, if any
        if (!_pixbuf && ((_elements & Text)==Text) && !_text.empty()) {
                assert(_layout);
#if 0 // DEBUG style (print on hover)
                if (_hovering || (_elements & Inactive)) {
                        bool layout_font = true;
                        Pango::FontDescription fd = _layout->get_font_description();
                        if (fd.gobj() == NULL) {
                                layout_font = false;
                                fd = get_pango_context()->get_font_description();
                        }
                        printf("%s: f:%dx%d aw:%.3f bh:%.0f t:%dx%d (%dx%d) %s\"%s\"\n",
                                        get_name().c_str(),
                                        char_pixel_width(), char_pixel_height(), char_avg_pixel_width(),
                                        ceil(char_pixel_height() * BASELINESTRETCH),
                                        _text_width, _text_height,
                                        get_width(), get_height(),
                                        layout_font ? "L:" : "W:",
                                        fd.to_string().c_str());
                }
#endif

                cairo_save (cr);
                cairo_rectangle (cr, 2, 1, get_width() - 4, get_height() - 2);
                cairo_clip(cr);

                cairo_new_path (cr);
                ArdourCanvas::set_source_rgba (cr, text_color);
                const double text_ypos = (get_height() - _text_height) * .5;

                if (_elements & Menu) {
                        // always left align (dropdown)
                        cairo_move_to (cr, text_margin, text_ypos);
                        pango_cairo_show_layout (cr, _layout->gobj());
                } else if ( (_elements & Indicator)  == Indicator) {
                        // left/right align depending on LED position
                        if (_led_left) {
                                cairo_move_to (cr, text_margin + _diameter + .5 * char_pixel_width(), text_ypos);
                        } else {
                                cairo_move_to (cr, text_margin, text_ypos);
                        }
                        pango_cairo_show_layout (cr, _layout->gobj());
                } else {
                        /* centered text otherwise */
                        double ww, wh;
                        double xa, ya;
                        ww = get_width();
                        wh = get_height();

                        cairo_save (cr);
                        cairo_rotate(cr, _angle * M_PI / 180.0);
                        cairo_device_to_user(cr, &ww, &wh);
                        xa = (ww - _text_width) * _xalign;
                        ya = (wh - _text_height) * _yalign;

                        /* quick hack for left/bottom alignment at -90deg
                         * TODO this should be generalized incl rotation.
                         * currently only 'user' of this API is meter_strip.cc
                         */
                        if (_xalign < 0) xa = ceil(.5 + (ww * fabs(_xalign) + text_margin));

                        cairo_move_to (cr, xa, ya);
                        pango_cairo_update_layout(cr, _layout->gobj());
                        pango_cairo_show_layout (cr, _layout->gobj());
                        cairo_restore (cr);
                }
                cairo_restore (cr);
        }

        //Menu "triangle"
        if (_elements & Menu) {
                const float trih = ceil(_diameter * .5);
                const float triw2 = ceil(.577 * _diameter * .5); // 1/sqrt(3) Equilateral triangle
                //menu arrow
                cairo_set_source_rgba (cr, 1, 1, 1, 0.4);
                cairo_move_to(cr, get_width() - triw2 - 3. , rint((get_height() + trih) * .5));
                cairo_rel_line_to(cr, -triw2, -trih);
                cairo_rel_line_to(cr, 2. * triw2, 0);
                cairo_close_path(cr);

                cairo_set_source_rgba (cr, 1, 1, 1, 0.4);
                cairo_fill(cr);

                cairo_move_to(cr, get_width() - triw2 - 3 , rint((get_height() + trih) * .5));
                cairo_rel_line_to(cr, .5 - triw2, .5 - trih);
                cairo_rel_line_to(cr, 2. * triw2 - 1, 0);
                cairo_close_path(cr);
                cairo_set_source_rgba (cr, 0, 0, 0, 0.8);
                cairo_set_line_width(cr, 1);
                cairo_stroke(cr);
        }

        //Indicator LED
        if (_elements & Indicator) {
                cairo_save (cr);

                /* move to the center of the indicator/led */
                if (_elements & Text) {
                        int led_xoff = ceil(char_pixel_width() + _diameter * .5);
                        if (_led_left) {
                                cairo_translate (cr, led_xoff, get_height() * .5);
                        } else {
                                cairo_translate (cr, get_width() - led_xoff, get_height() * .5);
                        }
                } else {
                        cairo_translate (cr, get_width() * .5, get_height() * .5);
                }

                //inset
                if (!_flat_buttons) {
                        cairo_arc (cr, 0, 0, _diameter * .5, 0, 2 * M_PI);
                        cairo_set_source (cr, led_inset_pattern);
                        cairo_fill (cr);
                }

                //black ring
                cairo_set_source_rgb (cr, 0, 0, 0);
                cairo_arc (cr, 0, 0, _diameter * .5 - 1 * ARDOUR_UI::ui_scale, 0, 2 * M_PI);
                cairo_fill(cr);

                //led color
                ArdourCanvas::set_source_rgba (cr, led_color);
                cairo_arc (cr, 0, 0, _diameter * .5 - 3 * ARDOUR_UI::ui_scale, 0, 2 * M_PI);
                cairo_fill(cr);

                cairo_restore (cr);
        }

        // a transparent overlay to indicate insensitivity
        if ((visual_state() & Gtkmm2ext::Insensitive)) {
                rounded_function (cr, 0, 0, get_width(), get_height(), corner_radius);
                uint32_t ins_color = ARDOUR_UI::config()->color ("gtk_background");
                ArdourCanvas::set_source_rgb_a (cr, ins_color, 0.6);
                cairo_fill (cr);
        }

        // if requested, show hovering
        if (ARDOUR_UI::config()->get_widget_prelight()
                        && !((visual_state() & Gtkmm2ext::Insensitive))) {
                if (_hovering) {
                        rounded_function (cr, 1, 1, get_width() - 2, get_height() - 2, corner_radius);
                        cairo_set_source_rgba (cr, 0.905, 0.917, 0.925, 0.2);
                        cairo_fill (cr);
                }
        }

        //user is currently pressing the button. dark outline helps to indicate this
        if (_grabbed && !(_elements & (Inactive|Menu))) {
                rounded_function (cr, 1, 1, get_width() - 2, get_height() - 2, corner_radius);
                cairo_set_line_width(cr, 2);
                cairo_set_source_rgba (cr, 0.1, 0.1, 0.1, .5);
                cairo_stroke (cr);
        }

        //some buttons (like processor boxes) can be selected  (so they can be deleted).  Draw a selection indicator
        if (visual_state() & Gtkmm2ext::Selected) {
                cairo_set_line_width(cr, 1);
                cairo_set_source_rgba (cr, 1, 0, 0, 0.8);
                rounded_function (cr, 0.5, 0.5, get_width() - 1, get_height() - 1, corner_radius);
                cairo_stroke (cr);
        }

        //I guess this means we have keyboard focus.  I don't think this works currently
        //
        //A: yes, it's keyboard focus and it does work when there's no editor window
        //   (the editor is always the first receiver for KeyDown).
        //   It's needed for eg. the engine-dialog at startup or after closing a sesion.
        if (_focused) {
                rounded_function (cr, 1.5, 1.5, get_width() - 3, get_height() - 3, corner_radius);
                cairo_set_source_rgba (cr, 0.905, 0.917, 0.925, 0.8);
                double dashes = 1;
                cairo_set_dash (cr, &dashes, 1, 0);
                cairo_set_line_cap (cr, CAIRO_LINE_CAP_BUTT);
                cairo_set_line_width (cr, 1.0);
                cairo_stroke (cr);
                cairo_set_dash (cr, 0, 0, 0);
        }
}

void
ArdourButton::set_corner_radius (float r)
{
        _corner_radius = r;
        CairoWidget::set_dirty ();
}

void
ArdourButton::on_realize()
{
        CairoWidget::on_realize ();
        ensure_layout ();
        if (_layout && _layout->get_text() != _text) {
                _layout->set_text (_text);
                queue_resize ();
        }
}

void
ArdourButton::on_size_request (Gtk::Requisition* req)
{
        req->width = req->height = 0;
        CairoWidget::on_size_request (req);

        if (_diameter == 0) {
                const float newdia = rintf (11.f * ARDOUR_UI::ui_scale);
                if (_diameter != newdia) {
                        _pattern_height = 0;
                        _diameter = newdia;
                }
        }

        if ((_elements & Text) && !_text.empty()) {
                // if _layout does not exist, char_pixel_height() creates it,
                req->height = std::max(req->height, (int) ceil(char_pixel_height() * BASELINESTRETCH + 1.0));
                _layout->get_pixel_size (_text_width, _text_height);
                req->width += rint(1.75 * char_pixel_width()); // padding
                req->width += _text_width;
        } else {
                _text_width = 0;
                _text_height = 0;
        }

        if (_pixbuf) {
                req->width += _pixbuf->get_width() + char_pixel_width();
                req->height = std::max(req->height, _pixbuf->get_height() + 4);
        }

        if (_elements & Indicator) {
                req->width += lrint (_diameter) + char_pixel_width();
                req->height = std::max (req->height, (int) lrint (_diameter) + 4);
        }

        if ((_elements & Menu)) {
                req->width += _diameter + 4;
        }

        if (_elements & VectorIcon) {
                assert(!(_elements & Text));
                const int wh = std::max (rint (TRACKHEADERBTNW * char_avg_pixel_width()), ceil (char_pixel_height() * BASELINESTRETCH + 1.));
                req->width += wh;
                req->height = std::max(req->height, wh);
        }

        /* Tweaks to mess the nice stuff above up again. */
        if (_tweaks & TrackHeader) {
                // forget everything above and just use a fixed square [em] size
                // "TrackHeader Buttons" are single letter (usually uppercase)
                // a SizeGroup is much less efficient (lots of gtk work under the hood for each track)
                const int wh = std::max (rint (TRACKHEADERBTNW * char_avg_pixel_width()), ceil (char_pixel_height() * BASELINESTRETCH + 1.));
                req->width  = wh;
                req->height = wh;
        }
        else if (_tweaks & Square) {
                // currerntly unused (again)
                if (req->width < req->height)
                        req->width = req->height;
                if (req->height < req->width)
                        req->height = req->width;
        } else if (_text_width > 0 && !(_elements & (Menu | Indicator))) {
                // properly centered text for those elements that are centered
                // (no sub-pixel offset)
                if ((req->width - _text_width) & 1) { ++req->width; }
                if ((req->height - _text_height) & 1) { ++req->height; }
        }
#if 0
                printf("REQ: %s: %dx%d\n", get_name().c_str(), req->width, req->height);
#endif
}

void
ArdourButton::set_colors ()
{
        _update_colors = false;
        if (_fixed_colors_set) {
                return;
        }
        std::string name = get_name();
        bool failed = false;

        fill_active_color = ARDOUR_UI::config()->color (string_compose ("%1: fill active", name), &failed);
        if (failed) {
                fill_active_color = ARDOUR_UI::config()->color ("generic button: fill active");
        }
        fill_inactive_color = ARDOUR_UI::config()->color (string_compose ("%1: fill", name), &failed);
        if (failed) {
                fill_inactive_color = ARDOUR_UI::config()->color ("generic button: fill");
        }

        text_active_color = ArdourCanvas::contrasting_text_color (fill_active_color);
        text_inactive_color = ArdourCanvas::contrasting_text_color (fill_inactive_color);

        led_active_color = ARDOUR_UI::config()->color (string_compose ("%1: led active", name), &failed);
        if (failed) {
                led_active_color = ARDOUR_UI::config()->color ("generic button: led active");
        }

        /* The inactive color for the LED is just a fairly dark version of the
         * active color.
         */
        
        ArdourCanvas::HSV inactive (led_active_color);
        inactive.v = 0.35;

        led_inactive_color = inactive.color ();
}

void ArdourButton::set_fixed_colors (const uint32_t color_active, const uint32_t color_inactive)
{
        _fixed_colors_set = true;

        fill_active_color = color_active;
        fill_inactive_color = color_inactive;

        unsigned char r, g, b, a;
        UINT_TO_RGBA(color_active, &r, &g, &b, &a);

        double white_contrast = (max (double(r), 255.) - min (double(r), 255.)) +
                (max (double(g), 255.) - min (double(g), 255.)) +
                (max (double(b), 255.) - min (double(b), 255.));

        double black_contrast = (max (double(r), 0.) - min (double(r), 0.)) +
                (max (double(g), 0.) - min (double(g), 0.)) +
                (max (double(b), 0.) - min (double(b), 0.));

        text_active_color = (white_contrast > black_contrast) ?
                RGBA_TO_UINT(255, 255, 255, 255) : /* use white */
                RGBA_TO_UINT(  0,   0,   0,   255);  /* use black */


        UINT_TO_RGBA(color_inactive, &r, &g, &b, &a);

        white_contrast = (max (double(r), 255.) - min (double(r), 255.)) +
                (max (double(g), 255.) - min (double(g), 255.)) +
                (max (double(b), 255.) - min (double(b), 255.));

        black_contrast = (max (double(r), 0.) - min (double(r), 0.)) +
                (max (double(g), 0.) - min (double(g), 0.)) +
                (max (double(b), 0.) - min (double(b), 0.));

        text_inactive_color = (white_contrast > black_contrast) ?
                RGBA_TO_UINT(255, 255, 255, 255) : /* use white */
                RGBA_TO_UINT(  0,   0,   0,   255);  /* use black */

        /* XXX what about led colors ? */
        CairoWidget::set_dirty ();
}

void
ArdourButton::build_patterns ()
{
        if (convex_pattern) {
                cairo_pattern_destroy (convex_pattern);
                convex_pattern = 0;
        }

        if (concave_pattern) {
                cairo_pattern_destroy (concave_pattern);
                concave_pattern = 0;
        }

        if (led_inset_pattern) {
                cairo_pattern_destroy (led_inset_pattern);
                led_inset_pattern = 0;
        }

        //convex gradient
        convex_pattern = cairo_pattern_create_linear (0.0, 0, 0.0,  get_height());
        cairo_pattern_add_color_stop_rgba (convex_pattern, 0.0, 0,0,0, 0.0);
        cairo_pattern_add_color_stop_rgba (convex_pattern, 1.0, 0,0,0, 0.35);

        //concave gradient
        concave_pattern = cairo_pattern_create_linear (0.0, 0, 0.0,  get_height());
        cairo_pattern_add_color_stop_rgba (concave_pattern, 0.0, 0,0,0, 0.5);
        cairo_pattern_add_color_stop_rgba (concave_pattern, 0.7, 0,0,0, 0.0);

        led_inset_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, _diameter);
        cairo_pattern_add_color_stop_rgba (led_inset_pattern, 0, 0,0,0, 0.4);
        cairo_pattern_add_color_stop_rgba (led_inset_pattern, 1, 1,1,1, 0.7);

        _pattern_height = get_height() ;
}

void
ArdourButton::set_led_left (bool yn)
{
        _led_left = yn;
}

bool
ArdourButton::on_button_press_event (GdkEventButton *ev)
{
        focus_handler ();

        if (ev->button == 1 && (_elements & Indicator) && _led_rect && _distinct_led_click) {
                if (ev->x >= _led_rect->x && ev->x < _led_rect->x + _led_rect->width &&
                    ev->y >= _led_rect->y && ev->y < _led_rect->y + _led_rect->height) {
                        return true;
                }
        }

        if (binding_proxy.button_press_handler (ev)) {
                return true;
        }

        _grabbed = true;
        CairoWidget::set_dirty ();

        if (ev->button == 1 && !_act_on_release) {
                if (_action) {
                        _action->activate ();
                        return true;
                }
        }

        if (_fallthrough_to_parent)
                return false;

        return true;
}

bool
ArdourButton::on_button_release_event (GdkEventButton *ev)
{
        if (ev->button == 1 && _hovering && (_elements & Indicator) && _led_rect && _distinct_led_click) {
                if (ev->x >= _led_rect->x && ev->x < _led_rect->x + _led_rect->width &&
                    ev->y >= _led_rect->y && ev->y < _led_rect->y + _led_rect->height) {
                        signal_led_clicked(); /* EMIT SIGNAL */
                        return true;
                }
        }

        _grabbed = false;
        CairoWidget::set_dirty ();

        if (ev->button == 1 && _hovering) {
                signal_clicked ();
                if (_act_on_release) {
                        if (_action) {
                                _action->activate ();
                                return true;
                        }
                }
        }

        if (_fallthrough_to_parent)
                return false;

        return true;
}

void
ArdourButton::set_distinct_led_click (bool yn)
{
        _distinct_led_click = yn;
        setup_led_rect ();
}

void
ArdourButton::color_handler ()
{
        _update_colors = true;
        CairoWidget::set_dirty ();
}

void
ArdourButton::on_size_allocate (Allocation& alloc)
{
        CairoWidget::on_size_allocate (alloc);
        setup_led_rect ();
}

void
ArdourButton::set_controllable (boost::shared_ptr<Controllable> c)
{
        watch_connection.disconnect ();
        binding_proxy.set_controllable (c);
}

void
ArdourButton::watch ()
{
        boost::shared_ptr<Controllable> c (binding_proxy.get_controllable ());

        if (!c) {
                warning << _("button cannot watch state of non-existing Controllable\n") << endmsg;
                return;
        }
        c->Changed.connect (watch_connection, invalidator(*this), boost::bind (&ArdourButton::controllable_changed, this), gui_context());
}

void
ArdourButton::controllable_changed ()
{
        float val = binding_proxy.get_controllable()->get_value();

        if (fabs (val) >= 0.5f) {
                set_active_state (Gtkmm2ext::ExplicitActive);
        } else {
                unset_active_state ();
        }
        CairoWidget::set_dirty ();
}

void
ArdourButton::set_related_action (RefPtr<Action> act)
{
        Gtkmm2ext::Activatable::set_related_action (act);

        if (_action) {

                action_tooltip_changed ();

                Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic (_action);
                if (tact) {
                        action_toggled ();
                        tact->signal_toggled().connect (sigc::mem_fun (*this, &ArdourButton::action_toggled));
                }

                _action->connect_property_changed ("sensitive", sigc::mem_fun (*this, &ArdourButton::action_sensitivity_changed));
                _action->connect_property_changed ("visible", sigc::mem_fun (*this, &ArdourButton::action_visibility_changed));
                _action->connect_property_changed ("tooltip", sigc::mem_fun (*this, &ArdourButton::action_tooltip_changed));
        }
}

void
ArdourButton::action_toggled ()
{
        Glib::RefPtr<ToggleAction> tact = Glib::RefPtr<ToggleAction>::cast_dynamic (_action);

        if (tact) {
                if (tact->get_active()) {
                        set_active_state (Gtkmm2ext::ExplicitActive);
                } else {
                        unset_active_state ();
                }
        }
}

void
ArdourButton::on_style_changed (const RefPtr<Gtk::Style>&)
{
        _update_colors = true;
        CairoWidget::set_dirty ();
}

void
ArdourButton::on_name_changed ()
{
        _char_pixel_width = 0;
        _char_pixel_height = 0;
        _diameter = 0;
        _update_colors = true;
        if (is_realized()) {
                queue_resize ();
        }
}

void
ArdourButton::setup_led_rect ()
{
        if (!(_elements & Indicator)) {
                delete _led_rect;
                _led_rect = 0;
                return;
        }

        if (!_led_rect) {
                _led_rect = new cairo_rectangle_t;
        }

        if (_elements & Text) {
                if (_led_left) {
                        _led_rect->x = char_pixel_width();
                } else {
                        _led_rect->x = get_width() - char_pixel_width() + _diameter;
                }
        } else {
                /* centered */
                _led_rect->x = .5 * get_width() - _diameter;
        }

        _led_rect->y = .5 * (get_height() - _diameter);
        _led_rect->width = _diameter;
        _led_rect->height = _diameter;
}

void
ArdourButton::set_image (const RefPtr<Gdk::Pixbuf>& img)
{
        _pixbuf = img;
        if (is_realized()) {
                queue_resize ();
        }
}

void
ArdourButton::set_active_state (Gtkmm2ext::ActiveState s)
{
        bool changed = (_active_state != s);
        CairoWidget::set_active_state (s);
        if (changed) {
                _update_colors = true;
                CairoWidget::set_dirty ();
        }
}

void
ArdourButton::set_visual_state (Gtkmm2ext::VisualState s)
{
        bool changed = (_visual_state != s);
        CairoWidget::set_visual_state (s);
        if (changed) {
                _update_colors = true;
                CairoWidget::set_dirty ();
        }
}

bool
ArdourButton::on_focus_in_event (GdkEventFocus* ev)
{
        _focused = true;
        CairoWidget::set_dirty ();
        return CairoWidget::on_focus_in_event (ev);
}

bool
ArdourButton::on_focus_out_event (GdkEventFocus* ev)
{
        _focused = false;
        CairoWidget::set_dirty ();
        return CairoWidget::on_focus_out_event (ev);
}

bool
ArdourButton::on_key_release_event (GdkEventKey *ev) {
        if (_focused &&
                        (ev->keyval == GDK_space || ev->keyval == GDK_Return))
        {
                signal_clicked();
                if (_action) {
                        _action->activate ();
                }
                return true;
        }
        return CairoWidget::on_key_release_event (ev);
}

bool
ArdourButton::on_enter_notify_event (GdkEventCrossing* ev)
{
        _hovering = (_elements & Inactive) ? false : true;

        if (ARDOUR_UI::config()->get_widget_prelight()) {
                CairoWidget::set_dirty ();
        }

        return CairoWidget::on_enter_notify_event (ev);
}

bool
ArdourButton::on_leave_notify_event (GdkEventCrossing* ev)
{
        _hovering = false;

        if (ARDOUR_UI::config()->get_widget_prelight()) {
                CairoWidget::set_dirty ();
        }

        return CairoWidget::on_leave_notify_event (ev);
}

void
ArdourButton::set_tweaks (Tweaks t)
{
        if (_tweaks != t) {
                _tweaks = t;
                if (is_realized()) {
                        queue_resize ();
                }
        }
}

void
ArdourButton::action_sensitivity_changed ()
{
        if (_action->property_sensitive ()) {
                set_visual_state (Gtkmm2ext::VisualState (visual_state() & ~Gtkmm2ext::Insensitive));
        } else {
                set_visual_state (Gtkmm2ext::VisualState (visual_state() | Gtkmm2ext::Insensitive));
        }
}

void
ArdourButton::set_layout_ellipsize_width (int w)
{
        if (_layout_ellipsize_width == w) {
                return;
        }
        _layout_ellipsize_width = w;
        if (!_layout) {
                return;
        }
        if (_layout_ellipsize_width > 3 * PANGO_SCALE) {
                _layout->set_width (_layout_ellipsize_width - 3 * PANGO_SCALE);
        }
        if (is_realized ()) {
                queue_resize ();
        }
}

void
ArdourButton::set_text_ellipsize (Pango::EllipsizeMode e)
{
        if (_ellipsis == e) {
                return;
        }
        _ellipsis = e;
        if (!_layout) {
                return;
        }
        _layout->set_ellipsize(_ellipsis);
        if (_layout_ellipsize_width > 3 * PANGO_SCALE) {
                _layout->set_width (_layout_ellipsize_width - 3 * PANGO_SCALE);
        }
        if (is_realized ()) {
                queue_resize ();
        }
}

void
ArdourButton::ensure_layout ()
{
        if (!_layout) {
                ensure_style ();
                _layout = Pango::Layout::create (get_pango_context());
                _layout->set_ellipsize(_ellipsis);
                if (_layout_ellipsize_width > 3 * PANGO_SCALE) {
                        _layout->set_width (_layout_ellipsize_width - 3* PANGO_SCALE);
                }
        }
}

void
ArdourButton::recalc_char_pixel_geometry ()
{
        if (_char_pixel_height > 0 && _char_pixel_width > 0) {
                return;
        }
        ensure_layout();
        // NB. this is not static, since the geometry is different
        // depending on the font used.
        int w, h;
        std::string x = _("ABCDEFGHIJLKMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
        _layout->set_text (x);
        _layout->get_pixel_size (w, h);
        _char_pixel_height = std::max(4, h);
        // number of actual chars in the string (not bytes)
        // Glib to the rescue.
        Glib::ustring gx(x);
        _char_avg_pixel_width = w / (float)gx.size();
        _char_pixel_width = std::max(4, (int) ceil (_char_avg_pixel_width));
        _layout->set_text (_text);
}

void
ArdourButton::action_visibility_changed ()
{
        if (_action->property_visible ()) {
                show ();
        } else {
                hide ();
        }
}

void
ArdourButton::action_tooltip_changed ()
{
        string str = _action->property_tooltip().get_value();
        ARDOUR_UI::instance()->set_tip (*this, str);
}

void
ArdourButton::set_elements (Element e)
{
        _elements = e;
        CairoWidget::set_dirty ();
}

void
ArdourButton::add_elements (Element e)
{
        _elements = (ArdourButton::Element) (_elements | e);
        CairoWidget::set_dirty ();
}

void
ArdourButton::set_icon (Icon i)
{
        _icon = i;
        CairoWidget::set_dirty ();
}

void
ArdourButton::set_custom_led_color (uint32_t c, bool useit)
{
        if (led_custom_color == c && use_custom_led_color == useit) {
                return;
        }

        led_custom_color = c;
        use_custom_led_color = useit;
        CairoWidget::set_dirty ();
}