pixfader.cc

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/*
    Copyright (C) 2006 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.

    $Id: fastmeter.h 570 2006-06-07 21:21:21Z sampo $
*/


#include <iostream>
#include <assert.h>

#include "pbd/stacktrace.h"

#include "gtkmm2ext/cairo_widget.h"
#include "gtkmm2ext/keyboard.h"
#include "gtkmm2ext/pixfader.h"
#include "gtkmm2ext/utils.h"

using namespace Gtkmm2ext;
using namespace Gtk;
using namespace std;

#define CORNER_RADIUS 2.5
#define CORNER_SIZE   2
#define CORNER_OFFSET 1
#define FADER_RESERVE 6

std::list<PixFader::FaderImage*> PixFader::_patterns;

PixFader::PixFader (Gtk::Adjustment& adj, int orientation, int fader_length, int fader_girth)
        : _layout (0)
        , _tweaks (Tweaks(0))
        , _adjustment (adj)
        , _text_width (0)
        , _text_height (0)
        , _span (fader_length)
        , _girth (fader_girth)
        , _min_span (fader_length)
        , _min_girth (fader_girth)
        , _orien (orientation)
        , _pattern (0)
        , _hovering (false)
        , _dragging (false)
        , _centered_text (true)
        , _current_parent (0)
{
        _default_value = _adjustment.get_value();
        update_unity_position ();

        add_events (
                          Gdk::BUTTON_PRESS_MASK
                        | Gdk::BUTTON_RELEASE_MASK
                        | Gdk::POINTER_MOTION_MASK
                        | Gdk::SCROLL_MASK
                        | Gdk::ENTER_NOTIFY_MASK
                        | Gdk::LEAVE_NOTIFY_MASK
                        );

        _adjustment.signal_value_changed().connect (mem_fun (*this, &PixFader::adjustment_changed));
        _adjustment.signal_changed().connect (mem_fun (*this, &PixFader::adjustment_changed));

        if (_orien == VERT) {
                CairoWidget::set_size_request(_girth, _span);
        } else {
                CairoWidget::set_size_request(_span, _girth);
        }
}

PixFader::~PixFader ()
{
        if (_parent_style_change) _parent_style_change.disconnect();
        if (_layout) _layout.clear (); // drop reference to existing layout
}

cairo_pattern_t*
PixFader::find_pattern (double afr, double afg, double afb,
                        double abr, double abg, double abb,
                        int w, int h)
{
        for (list<FaderImage*>::iterator f = _patterns.begin(); f != _patterns.end(); ++f) {
                if ((*f)->matches (afr, afg, afb, abr, abg, abb, w, h)) {
                        return (*f)->pattern;
                }
        }
        return 0;
}

void
PixFader::create_patterns ()
{
        Gdk::Color c = get_style()->get_fg (get_state());
        float fr, fg, fb;
        float br, bg, bb;

        fr = c.get_red_p ();
        fg = c.get_green_p ();
        fb = c.get_blue_p ();

        c = get_style()->get_bg (get_state());

        br = c.get_red_p ();
        bg = c.get_green_p ();
        bb = c.get_blue_p ();

        cairo_surface_t* surface;
        cairo_t* tc = 0;

        if (get_width() <= 1 || get_height() <= 1) {
                return;
        }

        if ((_pattern = find_pattern (fr, fg, fb, br, bg, bb, get_width(), get_height())) != 0) {
                /* found it - use it */
                return;
        }

        if (_orien == VERT) {

                surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, get_width(), get_height() * 2.0);
                tc = cairo_create (surface);

                /* paint background + border */

                cairo_pattern_t* shade_pattern = cairo_pattern_create_linear (0.0, 0.0, get_width(), 0);
                cairo_pattern_add_color_stop_rgba (shade_pattern, 0, br*0.4,bg*0.4,bb*0.4, 1.0);
                cairo_pattern_add_color_stop_rgba (shade_pattern, 0.25, br*0.6,bg*0.6,bb*0.6, 1.0);
                cairo_pattern_add_color_stop_rgba (shade_pattern, 1, br*0.8,bg*0.8,bb*0.8, 1.0);
                cairo_set_source (tc, shade_pattern);
                cairo_rectangle (tc, 0, 0, get_width(), get_height() * 2.0);
                cairo_fill (tc);

                cairo_pattern_destroy (shade_pattern);

                /* paint lower shade */

                shade_pattern = cairo_pattern_create_linear (0.0, 0.0, get_width() - 2 - CORNER_OFFSET , 0);
                cairo_pattern_add_color_stop_rgba (shade_pattern, 0, fr*0.8,fg*0.8,fb*0.8, 1.0);
                cairo_pattern_add_color_stop_rgba (shade_pattern, 1, fr*0.6,fg*0.6,fb*0.6, 1.0);
                cairo_set_source (tc, shade_pattern);
                Gtkmm2ext::rounded_top_half_rectangle (tc, CORNER_OFFSET, get_height() + CORNER_OFFSET,
                                get_width() - CORNER_SIZE, get_height(), CORNER_RADIUS);
                cairo_fill (tc);

                cairo_pattern_destroy (shade_pattern);

                _pattern = cairo_pattern_create_for_surface (surface);

        } else {

                surface = cairo_image_surface_create (CAIRO_FORMAT_ARGB32, get_width() * 2.0, get_height());
                tc = cairo_create (surface);

                /* paint right shade (background section)*/

                cairo_pattern_t* shade_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, get_height());
                cairo_pattern_add_color_stop_rgba (shade_pattern, 0, br*0.4,bg*0.4,bb*0.4, 1.0);
                cairo_pattern_add_color_stop_rgba (shade_pattern, 0.25, br*0.6,bg*0.6,bb*0.6, 1.0);
                cairo_pattern_add_color_stop_rgba (shade_pattern, 1, br*0.8,bg*0.8,bb*0.8, 1.0);
                cairo_set_source (tc, shade_pattern);
                cairo_rectangle (tc, 0, 0, get_width() * 2.0, get_height());
                cairo_fill (tc);

                /* paint left shade (active section/foreground) */

                shade_pattern = cairo_pattern_create_linear (0.0, 0.0, 0.0, get_height());
                cairo_pattern_add_color_stop_rgba (shade_pattern, 0, fr*0.8,fg*0.8,fb*0.8, 1.0);
                cairo_pattern_add_color_stop_rgba (shade_pattern, 1, fr*0.6,fg*0.6,fb*0.6, 1.0);
                cairo_set_source (tc, shade_pattern);
                Gtkmm2ext::rounded_right_half_rectangle (tc, CORNER_OFFSET, CORNER_OFFSET,
                                get_width() - CORNER_OFFSET, get_height() - CORNER_SIZE, CORNER_RADIUS);
                cairo_fill (tc);
                cairo_pattern_destroy (shade_pattern);

                _pattern = cairo_pattern_create_for_surface (surface);
        }

        /* cache it for others to use */

        _patterns.push_back (new FaderImage (_pattern, fr, fg, fb, br, bg, bb, get_width(), get_height()));

        cairo_destroy (tc);
        cairo_surface_destroy (surface);
}

void
PixFader::render (cairo_t *cr, cairo_rectangle_t* area)
{
        if (!_pattern) {
                create_patterns();
        }

        if (!_pattern) {
                /* this isn't supposed to be happen, but some wackiness whereby
                 * the pixfader ends up with a 1xN or Nx1 size allocation
                 * leads to it. the basic wackiness needs fixing but we
                 * shouldn't crash. just fill in the expose area with
                 * our bg color.
                 */

                CairoWidget::set_source_rgb_a (cr, get_style()->get_bg (get_state()), 1);
                cairo_rectangle (cr, area->x, area->y, area->width, area->height);
                cairo_fill (cr);
                return;
        }

        OnExpose();
        int ds = display_span ();
        const float w = get_width();
        const float h = get_height();

        CairoWidget::set_source_rgb_a (cr, get_parent_bg(), 1);
        cairo_rectangle (cr, 0, 0, w, h);
        cairo_fill(cr);

        cairo_set_line_width (cr, 2);
        cairo_set_source_rgba (cr, 0, 0, 0, 1.0);

        cairo_matrix_t matrix;
        Gtkmm2ext::rounded_rectangle (cr, CORNER_OFFSET, CORNER_OFFSET, w-CORNER_SIZE, h-CORNER_SIZE, CORNER_RADIUS);
        // we use a 'trick' here: The stoke is off by .5px but filling the interior area
        // after a stroke of 2px width results in an outline of 1px
        cairo_stroke_preserve(cr);

        if (_orien == VERT) {

                if (ds > h - FADER_RESERVE - CORNER_OFFSET) {
                        ds = h - FADER_RESERVE - CORNER_OFFSET;
                }

                if (!CairoWidget::flat_buttons() ) {
                        cairo_set_source (cr, _pattern);
                        cairo_matrix_init_translate (&matrix, 0, (h - ds));
                        cairo_pattern_set_matrix (_pattern, &matrix);
                } else {
                        CairoWidget::set_source_rgb_a (cr, get_style()->get_bg (get_state()), 1);
                        cairo_fill (cr);
                        CairoWidget::set_source_rgb_a (cr, get_style()->get_fg (get_state()), 1);
                        Gtkmm2ext::rounded_rectangle (cr, CORNER_OFFSET, ds + CORNER_OFFSET,
                                        w - CORNER_SIZE, h - ds - CORNER_SIZE, CORNER_RADIUS);
                }
                cairo_fill (cr);

        } else {

                if (ds < FADER_RESERVE) {
                        ds = FADER_RESERVE;
                }
                assert(ds <= w);

                /*
                 * if ds == w, the pattern does not need to be translated
                 * if ds == 0 (or FADER_RESERVE), the pattern needs to be moved
                 * w to the left, which is -w in pattern space, and w in user space
                 * if ds == 10, then the pattern needs to be moved w - 10
                 * to the left, which is -(w-10) in pattern space, which
                 * is (w - 10) in user space
                 * thus: translation = (w - ds)
                 */

                if (!CairoWidget::flat_buttons() ) {
                        cairo_set_source (cr, _pattern);
                        cairo_matrix_init_translate (&matrix, w - ds, 0);
                        cairo_pattern_set_matrix (_pattern, &matrix);
                } else {
                        CairoWidget::set_source_rgb_a (cr, get_style()->get_bg (get_state()), 1);
                        cairo_fill (cr);
                        CairoWidget::set_source_rgb_a (cr, get_style()->get_fg (get_state()), 1);
                        Gtkmm2ext::rounded_rectangle (cr, CORNER_OFFSET, CORNER_OFFSET,
                                        ds - CORNER_SIZE, h - CORNER_SIZE, CORNER_RADIUS);
                }
                cairo_fill (cr);
        }

        /* draw the unity-position line if it's not at either end*/
        if (!(_tweaks & NoShowUnityLine) && _unity_loc > CORNER_RADIUS) {
                cairo_set_line_width(cr, 1);
                cairo_set_line_cap(cr, CAIRO_LINE_CAP_ROUND);
                Gdk::Color c = get_style()->get_fg (Gtk::STATE_ACTIVE);
                cairo_set_source_rgba (cr, c.get_red_p() * 1.5, c.get_green_p() * 1.5, c.get_blue_p() * 1.5, 0.85);
                if (_orien == VERT) {
                        if (_unity_loc < h - CORNER_RADIUS) {
                                cairo_move_to (cr, 1.5, _unity_loc + CORNER_OFFSET + .5);
                                cairo_line_to (cr, _girth - 1.5, _unity_loc + CORNER_OFFSET + .5);
                                cairo_stroke (cr);
                        }
                } else {
                        if (_unity_loc < w - CORNER_RADIUS) {
                                cairo_move_to (cr, _unity_loc - CORNER_OFFSET + .5, 1.5);
                                cairo_line_to (cr, _unity_loc - CORNER_OFFSET + .5, _girth - 1.5);
                                cairo_stroke (cr);
                        }
                }
        }

        if (_layout && !_text.empty() && _orien == HORIZ) {
                cairo_save (cr);
                if (_centered_text) {
                        /* center text */
                        cairo_move_to (cr, (w - _text_width)/2.0, h/2.0 - _text_height/2.0);
                } else if (ds > .5 * w) {
                        cairo_move_to (cr, CORNER_OFFSET + 3, h/2.0 - _text_height/2.0);
                        cairo_set_operator(cr, CAIRO_OPERATOR_XOR);
                } else {
                        cairo_move_to (cr, w - _text_width - CORNER_OFFSET - 3, h/2.0 - _text_height/2.0);
                }
                CairoWidget::set_source_rgb_a (cr, get_style()->get_text (get_state()), 1);
                pango_cairo_show_layout (cr, _layout->gobj());
                cairo_restore (cr);
        }

        if (!get_sensitive()) {
                Gtkmm2ext::rounded_rectangle (cr, CORNER_OFFSET, CORNER_OFFSET, w-CORNER_SIZE, h-CORNER_SIZE, CORNER_RADIUS);
                cairo_set_source_rgba (cr, 0.505, 0.517, 0.525, 0.4);
                cairo_fill (cr);
        } else if (_hovering && CairoWidget::widget_prelight()) {
                Gtkmm2ext::rounded_rectangle (cr, CORNER_OFFSET, CORNER_OFFSET, w-CORNER_SIZE, h-CORNER_SIZE, CORNER_RADIUS);
                cairo_set_source_rgba (cr, 0.905, 0.917, 0.925, 0.1);
                cairo_fill (cr);
        }
}

void
PixFader::on_size_request (GtkRequisition* req)
{
        if (_orien == VERT) {
                req->width = (_min_girth ? _min_girth : -1);
                req->height = (_min_span ? _min_span : -1);
        } else {
                req->height = (_min_girth ? _min_girth : -1);
                req->width = (_min_span ? _min_span : -1);
        }
}

void
PixFader::on_size_allocate (Gtk::Allocation& alloc)
{
        CairoWidget::on_size_allocate(alloc);

        if (_orien == VERT) {
                _girth = alloc.get_width ();
                _span = alloc.get_height ();
        } else {
                _girth = alloc.get_height ();
                _span = alloc.get_width ();
        }

        if (is_realized()) {
                /* recreate patterns in case we've changed size */
                create_patterns ();
        }

        update_unity_position ();
}

bool
PixFader::on_button_press_event (GdkEventButton* ev)
{
        if (ev->type != GDK_BUTTON_PRESS) {
                if (_dragging) {
                        remove_modal_grab();
                        _dragging = false;
                        gdk_pointer_ungrab (GDK_CURRENT_TIME);
                        StopGesture ();
                }
                return (_tweaks & NoButtonForward) ? true : false;
        }

        if (ev->button != 1 && ev->button != 2) {
                return false;
        }

        add_modal_grab ();
        StartGesture ();
        _grab_loc = (_orien == VERT) ? ev->y : ev->x;
        _grab_start = (_orien == VERT) ? ev->y : ev->x;
        _grab_window = ev->window;
        _dragging = true;
        gdk_pointer_grab(ev->window,false,
                        GdkEventMask( Gdk::POINTER_MOTION_MASK | Gdk::BUTTON_PRESS_MASK |Gdk::BUTTON_RELEASE_MASK),
                        NULL,NULL,ev->time);

        if (ev->button == 2) {
                set_adjustment_from_event (ev);
        }

        return (_tweaks & NoButtonForward) ? true : false;
}

bool
PixFader::on_button_release_event (GdkEventButton* ev)
{
        double ev_pos = (_orien == VERT) ? ev->y : ev->x;

        switch (ev->button) {
        case 1:
                if (_dragging) {
                        remove_modal_grab();
                        _dragging = false;
                        gdk_pointer_ungrab (GDK_CURRENT_TIME);
                        StopGesture ();

                        if (!_hovering) {
                                if (!(_tweaks & NoVerticalScroll)) {
                                        Keyboard::magic_widget_drop_focus();
                                }
                                queue_draw ();
                        }

                        if (ev_pos == _grab_start) {
                                /* no motion - just a click */
                                ev_pos = rint(ev_pos);

                                if (ev->state & Keyboard::TertiaryModifier) {
                                        _adjustment.set_value (_default_value);
                                } else if (ev->state & Keyboard::GainFineScaleModifier) {
                                        _adjustment.set_value (_adjustment.get_lower());
#if 0 // ignore clicks
                                } else if (ev_pos == slider_pos) {
                                        ; // click on current position, no move.
                                } else if ((_orien == VERT && ev_pos < slider_pos) || (_orien == HORIZ && ev_pos > slider_pos)) {
                                        /* above the current display height, remember X Window coords */
                                        _adjustment.set_value (_adjustment.get_value() + _adjustment.get_step_increment());
                                } else {
                                        _adjustment.set_value (_adjustment.get_value() - _adjustment.get_step_increment());
#endif
                                }
                        }
                        return true;
                }
                break;

        case 2:
                if (_dragging) {
                        remove_modal_grab();
                        _dragging = false;
                        StopGesture ();
                        set_adjustment_from_event (ev);
                        gdk_pointer_ungrab (GDK_CURRENT_TIME);
                        return true;
                }
                break;

        default:
                break;
        }
        return false;
}

bool
PixFader::on_scroll_event (GdkEventScroll* ev)
{
        double scale;
        bool ret = false;

        if (ev->state & Keyboard::GainFineScaleModifier) {
                if (ev->state & Keyboard::GainExtraFineScaleModifier) {
                        scale = 0.005;
                } else {
                        scale = 0.1;
                }
        } else {
                scale = 1.0;
        }

        if (_orien == VERT) {
                switch (ev->direction) {
                        case GDK_SCROLL_UP:
                                _adjustment.set_value (_adjustment.get_value() + (_adjustment.get_page_increment() * scale));
                                ret = true;
                                break;
                        case GDK_SCROLL_DOWN:
                                _adjustment.set_value (_adjustment.get_value() - (_adjustment.get_page_increment() * scale));
                                ret = true;
                                break;
                        default:
                                break;
                }
        } else {
                int dir = ev->direction;

                if (ev->state & Keyboard::ScrollHorizontalModifier || !(_tweaks & NoVerticalScroll)) {
                        if (ev->direction == GDK_SCROLL_UP) dir = GDK_SCROLL_RIGHT;
                        if (ev->direction == GDK_SCROLL_DOWN) dir = GDK_SCROLL_LEFT;
                }

                switch (dir) {
                        case GDK_SCROLL_RIGHT:
                                _adjustment.set_value (_adjustment.get_value() + (_adjustment.get_page_increment() * scale));
                                ret = true;
                                break;
                        case GDK_SCROLL_LEFT:
                                _adjustment.set_value (_adjustment.get_value() - (_adjustment.get_page_increment() * scale));
                                ret = true;
                                break;
                        default:
                                break;
                }
        }
        return ret;
}

bool
PixFader::on_motion_notify_event (GdkEventMotion* ev)
{
        if (_dragging) {
                double scale = 1.0;
                double const ev_pos = (_orien == VERT) ? ev->y : ev->x;

                if (ev->window != _grab_window) {
                        _grab_loc = ev_pos;
                        _grab_window = ev->window;
                        return true;
                }

                if (ev->state & Keyboard::GainFineScaleModifier) {
                        if (ev->state & Keyboard::GainExtraFineScaleModifier) {
                                scale = 0.005;
                        } else {
                                scale = 0.1;
                        }
                }

                double const delta = ev_pos - _grab_loc;
                _grab_loc = ev_pos;

                const double off  = FADER_RESERVE + ((_orien == VERT) ? CORNER_OFFSET : 0);
                const double span = _span - off;
                double fract = (delta / span);

                fract = min (1.0, fract);
                fract = max (-1.0, fract);

                // X Window is top->bottom for 0..Y

                if (_orien == VERT) {
                        fract = -fract;
                }

                _adjustment.set_value (_adjustment.get_value() + scale * fract * (_adjustment.get_upper() - _adjustment.get_lower()));
        }

        return true;
}

void
PixFader::adjustment_changed ()
{
        queue_draw ();
}

int
PixFader::display_span ()
{
        float fract = (_adjustment.get_value () - _adjustment.get_lower()) / ((_adjustment.get_upper() - _adjustment.get_lower()));
        int ds;
        if (_orien == VERT) {
                const double off  = FADER_RESERVE + CORNER_OFFSET;
                const double span = _span - off;
                ds = (int)rint (span * (1.0 - fract));
        } else {
                const double off  = FADER_RESERVE;
                const double span = _span - off;
                ds = (int)rint (span * fract + off);
        }

        return ds;
}

void
PixFader::update_unity_position ()
{
        if (_orien == VERT) {
                const double span = _span - FADER_RESERVE - CORNER_OFFSET;
                _unity_loc = (int) rint (span * (1 - ((_default_value - _adjustment.get_lower()) / (_adjustment.get_upper() - _adjustment.get_lower())))) - 1;
        } else {
                const double span = _span - FADER_RESERVE;
                _unity_loc = (int) rint (FADER_RESERVE + (_default_value - _adjustment.get_lower()) * span / (_adjustment.get_upper() - _adjustment.get_lower()));
        }

        queue_draw ();
}

bool
PixFader::on_enter_notify_event (GdkEventCrossing*)
{
        _hovering = true;
        if (!(_tweaks & NoVerticalScroll)) {
                Keyboard::magic_widget_grab_focus ();
        }
        queue_draw ();
        return false;
}

bool
PixFader::on_leave_notify_event (GdkEventCrossing*)
{
        if (!_dragging) {
                _hovering = false;
                if (!(_tweaks & NoVerticalScroll)) {
                        Keyboard::magic_widget_drop_focus();
                }
                queue_draw ();
        }
        return false;
}

void
PixFader::set_adjustment_from_event (GdkEventButton* ev)
{
        const double off  = FADER_RESERVE + ((_orien == VERT) ? CORNER_OFFSET : 0);
        const double span = _span - off;
        double fract = (_orien == VERT) ? (1.0 - ((ev->y - off) / span)) : ((ev->x - off) / span);

        fract = min (1.0, fract);
        fract = max (0.0, fract);

        _adjustment.set_value (fract * (_adjustment.get_upper () - _adjustment.get_lower ()));
}

void
PixFader::set_default_value (float d)
{
        _default_value = d;
        update_unity_position ();
}

void
PixFader::set_tweaks (Tweaks t)
{
        bool need_redraw = false;
        if ((_tweaks & NoShowUnityLine) ^ (t & NoShowUnityLine)) {
                need_redraw = true;
        }
        _tweaks = t;
        if (need_redraw) {
                queue_draw();
        }
}

void
PixFader::set_text (const std::string& str, bool centered, bool expose)
{
        if (_layout && _text == str) {
                return;
        }
        if (!_layout && !str.empty()) {
                _layout = Pango::Layout::create (get_pango_context());
        }

        _text = str;
        _centered_text = centered;
        if (_layout) {
                _layout->set_text (str);
                _layout->get_pixel_size (_text_width, _text_height);
                // queue_resize ();
                if (expose) queue_draw ();
        }
}

void
PixFader::on_state_changed (Gtk::StateType old_state)
{
        Widget::on_state_changed (old_state);
        create_patterns ();
        queue_draw ();
}

void
PixFader::on_style_changed (const Glib::RefPtr<Gtk::Style>&)
{
        if (_layout) {
                std::string txt = _layout->get_text();
                _layout.clear (); // drop reference to existing layout
                _text = "";
                set_text (txt, _centered_text, false);
        }
        /* patterns are cached and re-created as needed 
         * during 'expose' in the GUI thread */
        _pattern = 0;
        queue_draw ();
}

Gdk::Color
PixFader::get_parent_bg ()
{
        Widget* parent = get_parent ();

        while (parent) {
                if (parent->get_has_window()) {
                        break;
                }
                parent = parent->get_parent();
        }

        if (parent && parent->get_has_window()) {
                if (_current_parent != parent) {
                        if (_parent_style_change) _parent_style_change.disconnect();
                        _current_parent = parent;
                        _parent_style_change = parent->signal_style_changed().connect (mem_fun (*this, &PixFader::on_style_changed));
                }
                return parent->get_style ()->get_bg (parent->get_state());
        }

        return get_style ()->get_bg (get_state());
}