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livetrax/libs/canvas/text.cc

200 lines
4.3 KiB
C++

/*
Copyright (C) 2011-2013 Paul Davis
Author: Carl Hetherington <cth@carlh.net>
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 <gdk/gdk.h>
#include <cairomm/cairomm.h>
#include <gtkmm/label.h>
#include "pbd/stacktrace.h"
#include "canvas/text.h"
#include "canvas/canvas.h"
#include "canvas/utils.h"
using namespace std;
using namespace ArdourCanvas;
Text::Text (Group* parent)
: Item (parent)
, _color (0x000000ff)
, _font_description (0)
, _alignment (Pango::ALIGN_LEFT)
, _width (0)
, _height (0)
, _need_redraw (false)
, _clamped_width (COORD_MAX)
{
}
Text::~Text ()
{
delete _font_description;
}
void
Text::set (string const & text)
{
begin_change ();
_text = text;
_need_redraw = true;
_bounding_box_dirty = true;
end_change ();
}
void
Text::redraw (Cairo::RefPtr<Cairo::Context> context) const
{
Glib::RefPtr<Pango::Layout> layout = Pango::Layout::create (context);
layout->set_text (_text);
if (_font_description) {
layout->set_font_description (*_font_description);
}
layout->set_alignment (_alignment);
Pango::Rectangle ink_rect = layout->get_ink_extents();
_origin.x = ink_rect.get_x() / Pango::SCALE;
_origin.y = ink_rect.get_y() / Pango::SCALE;
_width = _origin.x + (ink_rect.get_width() / Pango::SCALE);
_height = _origin.y + (ink_rect.get_height() / Pango::SCALE);
_image = Cairo::ImageSurface::create (Cairo::FORMAT_ARGB32, _width, _height);
Cairo::RefPtr<Cairo::Context> img_context = Cairo::Context::create (_image);
/* and draw, in the appropriate color of course */
set_source_rgba (img_context, _color);
layout->show_in_cairo_context (img_context);
/* text has now been rendered in _image and is ready for blit in
* ::render
*/
_need_redraw = false;
}
void
Text::render (Rect const & /*area*/, Cairo::RefPtr<Cairo::Context> context) const
{
if (_text.empty()) {
return;
}
if (_need_redraw) {
redraw (context);
}
Rect self = item_to_window (Rect (0, 0, min (_clamped_width, _width), _height));
context->rectangle (self.x0, self.y0, self.width(), self.height());
context->set_source (_image, self.x0, self.y0);
context->fill ();
}
void
Text::clamp_width (double w)
{
_clamped_width = w;
}
void
Text::compute_bounding_box () const
{
if (!_canvas || _text.empty()) {
_bounding_box = boost::optional<Rect> ();
_bounding_box_dirty = false;
return;
}
PangoContext* _pc = gdk_pango_context_get ();
Glib::RefPtr<Pango::Context> context = Glib::wrap (_pc); // context now owns _pc and will free it
Glib::RefPtr<Pango::Layout> layout = Pango::Layout::create (context);
layout->set_text (_text);
if (_font_description) {
layout->set_font_description (*_font_description);
}
layout->set_alignment (_alignment);
Pango::Rectangle const r = layout->get_ink_extents ();
_bounding_box = Rect (
r.get_x() / Pango::SCALE,
r.get_y() / Pango::SCALE,
(r.get_x() + r.get_width()) / Pango::SCALE,
(r.get_y() + r.get_height()) / Pango::SCALE
);
_bounding_box_dirty = false;
}
void
Text::set_alignment (Pango::Alignment alignment)
{
begin_change ();
_alignment = alignment;
_need_redraw = true;
_bounding_box_dirty = true;
end_change ();
}
void
Text::set_font_description (Pango::FontDescription font_description)
{
begin_change ();
_font_description = new Pango::FontDescription (font_description);
_need_redraw = true;
_bounding_box_dirty = true;
end_change ();
}
void
Text::set_color (Color color)
{
begin_change ();
_color = color;
_need_redraw = true;
end_change ();
}
void
Text::dump (ostream& o) const
{
Item::dump (o);
o << _canvas->indent() << '\t' << " text = " << _text << endl
<< _canvas->indent() << " color = " << _color;
o << endl;
}