cairo_widget.cc

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/*
    Copyright (C) 2009 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.

*/
#if !defined USE_CAIRO_IMAGE_SURFACE && !defined NDEBUG
#define OPTIONAL_CAIRO_IMAGE_SURFACE
#endif

#include "gtkmm2ext/cairo_widget.h"
#include "gtkmm2ext/gui_thread.h"

#include "i18n.h"

static const char* has_cairo_widget_background_info = "has_cairo_widget_background_info";

bool CairoWidget::_flat_buttons = false;
bool CairoWidget::_widget_prelight = true;

static void noop() { }
sigc::slot<void> CairoWidget::focus_handler (sigc::ptr_fun (noop));

void CairoWidget::set_source_rgb_a( cairo_t* cr, Gdk::Color col, float a)  //ToDo:  this one and the Canvas version should be in a shared file (?)
{
        float r = col.get_red_p ();
        float g = col.get_green_p ();
        float b = col.get_blue_p ();
        
        cairo_set_source_rgba(cr, r, g, b, a);
}

CairoWidget::CairoWidget ()
        : _active_state (Gtkmm2ext::Off)
        , _visual_state (Gtkmm2ext::NoVisualState)
        , _need_bg (true)
        , _grabbed (false)
        , _name_proxy (this, X_("name"))
        , _current_parent (0)
{
        _name_proxy.connect (sigc::mem_fun (*this, &CairoWidget::on_name_changed));
}

CairoWidget::~CairoWidget ()
{
        if (_parent_style_change) _parent_style_change.disconnect();
}

bool
CairoWidget::on_button_press_event (GdkEventButton*)
{
        focus_handler();
        return false;
}

bool
CairoWidget::on_expose_event (GdkEventExpose *ev)
{
#ifdef OPTIONAL_CAIRO_IMAGE_SURFACE
        Cairo::RefPtr<Cairo::Context> cr;
        if (getenv("ARDOUR_IMAGE_SURFACE")) {
                if (!image_surface) {
                        image_surface = Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, get_width(), get_height());
                }
                cr = Cairo::Context::create (image_surface);
        } else {
                cr = get_window()->create_cairo_context ();
        }
#elif defined USE_CAIRO_IMAGE_SURFACE

        if (!image_surface) {
                image_surface = Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, get_width(), get_height());
        }

        Cairo::RefPtr<Cairo::Context> cr = Cairo::Context::create (image_surface);
#else
        Cairo::RefPtr<Cairo::Context> cr = get_window()->create_cairo_context ();
#endif

        cr->rectangle (ev->area.x, ev->area.y, ev->area.width, ev->area.height);
        cr->clip_preserve ();

        /* paint expose area the color of the parent window bg
        */
        
        Gdk::Color bg (get_parent_bg());
        
        cr->set_source_rgb (bg.get_red_p(), bg.get_green_p(), bg.get_blue_p());
        cr->fill ();

        cairo_rectangle_t expose_area;
        expose_area.x = ev->area.x;
        expose_area.y = ev->area.y;
        expose_area.width = ev->area.width;
        expose_area.height = ev->area.height;

        render (cr->cobj(), &expose_area);

#ifdef OPTIONAL_CAIRO_IMAGE_SURFACE
        if (getenv("ARDOUR_IMAGE_SURFACE")) {
#endif
#if defined USE_CAIRO_IMAGE_SURFACE || defined OPTIONAL_CAIRO_IMAGE_SURFACE
        image_surface->flush();
        /* now blit our private surface back to the GDK one */

        Cairo::RefPtr<Cairo::Context> cairo_context = get_window()->create_cairo_context ();

        cairo_context->rectangle (ev->area.x, ev->area.y, ev->area.width, ev->area.height);
        cairo_context->clip ();
        cairo_context->set_source (image_surface, 0, 0);
        cairo_context->set_operator (Cairo::OPERATOR_SOURCE);
        cairo_context->paint ();
#endif
#ifdef OPTIONAL_CAIRO_IMAGE_SURFACE
        }
#endif

        return true;
}

void
CairoWidget::set_dirty ()
{
        ENSURE_GUI_THREAD (*this, &CairoWidget::set_dirty);
        queue_draw ();
}

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

#ifdef OPTIONAL_CAIRO_IMAGE_SURFACE
        if (getenv("ARDOUR_IMAGE_SURFACE")) {
#endif
#if defined USE_CAIRO_IMAGE_SURFACE || defined OPTIONAL_CAIRO_IMAGE_SURFACE
        image_surface = Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, alloc.get_width(), alloc.get_height());
#endif
#ifdef OPTIONAL_CAIRO_IMAGE_SURFACE
        }
#endif

        set_dirty ();
}

Gdk::Color
CairoWidget::get_parent_bg ()
{
        Widget* parent;

        parent = get_parent ();

        while (parent) {
                void* p = g_object_get_data (G_OBJECT(parent->gobj()), has_cairo_widget_background_info);

                if (p) {
                        Glib::RefPtr<Gtk::Style> style = parent->get_style();
                        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, &CairoWidget::on_style_changed));
                        }
                        return style->get_bg (get_state());
                }

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

        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, &CairoWidget::on_style_changed));
                }
                return parent->get_style ()->get_bg (parent->get_state());
        }

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

void
CairoWidget::set_active_state (Gtkmm2ext::ActiveState s)
{
        if (_active_state != s) {
                _active_state = s;
                StateChanged ();
        }
}

void
CairoWidget::set_visual_state (Gtkmm2ext::VisualState s)
{
        if (_visual_state != s) {
                _visual_state = s;
                StateChanged ();
        }
}

void
CairoWidget::set_active (bool yn)
{
        /* this is an API simplification for buttons
           that only use the Active and Normal states.
        */

        if (yn) {
                set_active_state (Gtkmm2ext::ExplicitActive);
        } else {
                unset_active_state ();
        }
}

void
CairoWidget::on_style_changed (const Glib::RefPtr<Gtk::Style>&)
{
        queue_draw();
}

void
CairoWidget::on_state_changed (Gtk::StateType)
{
        /* this will catch GTK-level state changes from calls like
           ::set_sensitive()
        */

        if (get_state() == Gtk::STATE_INSENSITIVE) {
                set_visual_state (Gtkmm2ext::VisualState (visual_state() | Gtkmm2ext::Insensitive));
        } else {
                set_visual_state (Gtkmm2ext::VisualState (visual_state() & ~Gtkmm2ext::Insensitive));
        }

        queue_draw ();
}

void
CairoWidget::set_draw_background (bool yn)
{
        _need_bg = yn;
}

void
CairoWidget::provide_background_for_cairo_widget (Gtk::Widget& w, const Gdk::Color& bg)
{
        /* set up @w to be able to provide bg information to
           any CairoWidgets that are packed inside it.
        */

        w.modify_bg (Gtk::STATE_NORMAL, bg);
        w.modify_bg (Gtk::STATE_INSENSITIVE, bg);
        w.modify_bg (Gtk::STATE_ACTIVE, bg);
        w.modify_bg (Gtk::STATE_SELECTED, bg);

        g_object_set_data (G_OBJECT(w.gobj()), has_cairo_widget_background_info, (void*) 0xfeedface);
}

void
CairoWidget::set_flat_buttons (bool yn)
{
        _flat_buttons = yn;
}

void
CairoWidget::set_widget_prelight (bool yn)
{
        _widget_prelight = yn;
}

void
CairoWidget::set_focus_handler (sigc::slot<void> s)
{
        focus_handler = s;
}