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/**
* \brief widget adjustable by dragging it to rotate away from a zero-change axis
*
* Authors:
* buliabyak@gmail.com
*
* Copyright (C) 2007 authors
*
* Released under GNU GPL. Read the file 'COPYING' for more information.
*/
#include "event-context.h"
#include "rotateable.h"
#include "libnr/nr-point.h"
#include "libnr/nr-point-fns.h"
#include <gtkmm/box.h>
#include <gtkmm/eventbox.h>
#include <glibmm/i18n.h>
namespace Inkscape {
namespace UI {
namespace Widget {
Rotateable::Rotateable():
axis(-M_PI/4),
maxdecl(M_PI/4)
{
dragging = false;
working = false;
modifier = 0;
current_axis = axis;
signal_button_press_event().connect(sigc::mem_fun(*this, &Rotateable::on_click));
signal_motion_notify_event().connect(sigc::mem_fun(*this, &Rotateable::on_motion));
signal_button_release_event().connect(sigc::mem_fun(*this, &Rotateable::on_release));
}
bool Rotateable::on_click(GdkEventButton *event) {
if (event->button == 1) {
drag_started_x = event->x;
drag_started_y = event->y;
modifier = get_single_modifier(modifier, event->state);
dragging = true;
working = false;
current_axis = axis;
return true;
}
return false;
}
guint Rotateable::get_single_modifier(guint old, guint state) {
if (old == 0) {
if (state & GDK_CONTROL_MASK)
return 1; // ctrl
if (state & GDK_SHIFT_MASK)
return 2; // shift
return 0;
} else {
if (!(state & GDK_CONTROL_MASK) && !(state & GDK_SHIFT_MASK))
return 0; // none
if (old == 1)
if (state & GDK_SHIFT_MASK && !(state & GDK_CONTROL_MASK))
return 2; // shift
else
return 1;
if (old == 2)
if (state & GDK_CONTROL_MASK && !(state & GDK_SHIFT_MASK))
return 1; // ctrl
else
return 2;
return old;
}
}
bool Rotateable::on_motion(GdkEventMotion *event) {
if (dragging) {
double dist = NR::L2(NR::Point(event->x, event->y) - NR::Point(drag_started_x, drag_started_y));
double angle = atan2(event->y - drag_started_y, event->x - drag_started_x);
if (dist > 20) {
working = true;
double force = CLAMP (-(angle - current_axis)/maxdecl, -1, 1);
if (fabs(force) < 0.002)
force = 0; // snap to zero
if (modifier != get_single_modifier(modifier, event->state)) {
// user has switched modifiers in mid drag, close past drag and start a new
// one, redefining axis temporarily
do_release(force, modifier);
current_axis = angle;
modifier = get_single_modifier(modifier, event->state);
} else {
do_motion(force, modifier);
}
}
gobble_motion_events(GDK_BUTTON1_MASK);
return true;
}
return false;
}
bool Rotateable::on_release(GdkEventButton *event) {
if (dragging && working) {
double angle = atan2(event->y - drag_started_y, event->x - drag_started_x);
double force = CLAMP (-(angle - current_axis)/maxdecl, -1, 1);
if (fabs(force) < 0.002)
force = 0; // snap to zero
do_release(force, modifier);
dragging = false;
working = false;
current_axis = axis;
return true;
}
return false;
}
Rotateable::~Rotateable() {
}
} // namespace Widget
} // namespace UI
} // namespace Inkscape
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=c++:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
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