sgpemv2/src/cairo_widget.cc

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// src/cairo_widget.cc - Copyright 2005, 2006, University
// of Padova, dept. of Pure and Applied
// Mathematics
//
// This file is part of SGPEMv2.
//
// This 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.
//
// SGPEMv2 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 SGPEMv2; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#include "cairo_elements.hh"
#include "cairo_widget.hh"
#include "backend/history.hh"
#include "backend/simulation.hh"
#include <gdkmm/window.h>
#include <cassert>
#include <memory>
using namespace sgpem;
CairoWidget::CairoWidget()
: Glib::ObjectBase("sgpem_CairoWidget"),
Gtk::Widget(), _h(1), _buf(NULL)
{
set_flags(Gtk::NO_WINDOW);
// Register this observer:
Simulation::get_instance().get_history().attach(*this);
}
CairoWidget::~CairoWidget()
{
Simulation::get_instance().get_history().detach(*this);
}
void
CairoWidget::update(const History& history)
{
// get_window() returns a null pointer
// if the widget has not been realized
if(!is_realized())
return; // Nowhere to draw to.
// Determine the final height before to start drawing
unsigned int w = get_allocation().get_width();
_h = calc_height(history);
_buf = Gdk::Pixmap::create(get_window(), w, _h);
// Draw the widget background as the first thing.
// I've seen this is how it's done in the very Gtk+ toolkit
// for the GtkProgressBar widget.
GtkStyle* gStyle = get_style()->gobj();
gtk_paint_box(gStyle, _buf->gobj(),
GTK_STATE_NORMAL, GTK_SHADOW_ETCHED_IN,
NULL, this->gobj(), "through",
0, 0, w, _h);
cairo_t* ctx = gdk_cairo_create(_buf->gobj());
// do the drawing...
draw_widget(ctx);
cairo_scale(ctx, w, _h);
// manually force an expose_event?
cairo_destroy(ctx);
queue_draw();
}
void
CairoWidget::on_realize()
{
if(is_realized()) return;
Gtk::Widget::on_realize();
ensure_style();
GdkWindowAttr attributes;
memset(&attributes, 0, sizeof(attributes));
Gtk::Allocation alloc = get_allocation();
attributes.x = alloc.get_x();
attributes.y = alloc.get_y();
attributes.width = alloc.get_width();
attributes.height = alloc.get_height();
attributes.wclass = GDK_INPUT_OUTPUT;
attributes.event_mask = get_events() | GDK_EXPOSURE_MASK;
attributes.window_type = GDK_WINDOW_CHILD;
attributes.visual = get_visual()->gobj();
attributes.colormap = get_colormap()->gobj();
static const gint attributes_mask = Gdk::WA_X | Gdk::WA_Y | Gdk::WA_WMCLASS
| Gdk::WA_VISUAL | Gdk::WA_COLORMAP;
Glib::RefPtr<Gdk::Window> window = Gdk::Window::create(get_parent_window(),
&attributes,
attributes_mask);
unset_flags(Gtk::NO_WINDOW);
set_window(window);
window->set_user_data(gobj());
// Not sure if the following line is needed:
gtk_style_attach(get_style()->gobj(), window->gobj());
get_style()->set_background(window, Gtk::STATE_ACTIVE);
}
void
CairoWidget::on_size_request(Gtk::Requisition* requisition)
{
// FIXME: take correct measures, consider also using a viewport(?)
*requisition = Gtk::Requisition();
requisition->width = get_allocation().get_width();
requisition->height = _h;
}
void
CairoWidget::on_size_allocate(const Gtk::Allocation& allocation)
{
set_allocation(allocation);
if(is_realized())
get_window()->move_resize(allocation.get_x(), allocation.get_y(),
allocation.get_width(), allocation.get_height());
}
bool
CairoWidget::on_expose_event(GdkEventExpose* event)
{
if(event == NULL || event->count > 0)
return false;
// calculated dinamically:
int w = get_allocation().get_width();
set_size_request(w, _h);
// Clip to redraw only the smallest possible area
// Use double buffering or we're CPU-dead
// Copy from the buffer to the screen
if(_buf)
get_window()->draw_drawable(get_style()->get_black_gc(), _buf,
event->area.x, event->area.y,
event->area.x, event->area.y,
event->area.width, event->area.height);
return true;
}
bool
CairoWidget::on_button_press_event(GdkEventButton* event)
{
// Not here. Yet.
return false;
}