auto_spin.cc

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/*
    Copyright (C) 1999 Paul Barton-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.

    $Id$
*/

#include <cmath>
#include "gtkmm2ext/auto_spin.h"
#include "gtkmm2ext/keyboard.h"

using namespace Gtkmm2ext;
using namespace std;

#define upper          adjustment.get_upper()
#define lower          adjustment.get_lower()
#define step_increment adjustment.get_step_increment()
#define page_increment adjustment.get_page_increment()

const unsigned int AutoSpin::initial_timer_interval = 500;   /* msecs */
const unsigned int AutoSpin::timer_interval = 20;            /* msecs */
const unsigned int AutoSpin::climb_timer_calls = 5;    /* between climbing */

AutoSpin::AutoSpin (Gtk::Adjustment &adjr, gfloat cr, bool round_to_steps_yn) 
        : adjustment (adjr),
          climb_rate (cr)

{
        initial = adjustment.get_value();
        left_is_decrement = true;
        wrap = false;
        have_timer = false;
        need_timer = false;
        timer_calls = 0;
        round_to_steps = round_to_steps_yn;
}

void
AutoSpin::stop_timer ()
{
        if (have_timer) {
                g_source_remove (timeout_tag);
                have_timer = false;     
        }
}

gint
AutoSpin::stop_spinning (GdkEventButton */*ev*/)
{
        need_timer = false;
        stop_timer ();
        return FALSE;
}

gint
AutoSpin::button_press (GdkEventButton *ev)
{
        bool shifted = false;
        bool control = false;
        bool with_decrement = false;

        stop_spinning (0);

        if (ev->state & Keyboard::TertiaryModifier) {
                /* use page shift */

                shifted = true;
        }

        if (ev->state & Keyboard::PrimaryModifier) {
                /* go to upper/lower bound on button1/button2 */

                control = true;
        }

        /* XXX should figure out which button is left/right */

        switch (ev->button) {
        case 1:
                if (control) {
                        set_value (left_is_decrement ? lower : upper);
                        return TRUE;
                } else {
                        if (left_is_decrement) {
                                with_decrement = true;
                        } else {
                                with_decrement = false;
                        }
                }
                break;

        case 2:
                if (!control) {
                        set_value (initial);
                }
                return TRUE;
                break;

        case 3:
                if (control) {
                        set_value (left_is_decrement ? upper : lower);
                        return TRUE;
                }
                break;

        case 4:
                if (!control) {
                        adjust_value (shifted ? page_increment : step_increment);
                } else {
                        set_value (upper);
                }
                return TRUE;
                break;

        case 5:
                if (!control) {
                        adjust_value (shifted ? -page_increment : -step_increment);
                } else {
                        set_value (lower);
                }
                return TRUE;
                break;
        } 

        start_spinning (with_decrement, shifted);
        return TRUE;
}

void
AutoSpin::start_spinning (bool decrement, bool page)
{
        timer_increment = page ? page_increment : step_increment;

        if (decrement) { 
                timer_increment = -timer_increment;
        }

        adjust_value (timer_increment);
        
        have_timer = true;
        timer_calls = 0;
        timeout_tag = g_timeout_add (initial_timer_interval,
                                       AutoSpin::_timer,
                                       this);
}

gint
AutoSpin::_timer (void *arg)
{
        return ((AutoSpin *) arg)->timer ();
}

void
AutoSpin::set_value (gfloat value)
{
        if (round_to_steps)
                adjustment.set_value (floor((value / step_increment) + 0.5f) * step_increment);
        else
                adjustment.set_value (value);
}

bool
AutoSpin::adjust_value (gfloat increment)
{
        gfloat val;
        bool done = false;

        val = adjustment.get_value();

        val += increment;

        if (val > upper) {
                if (wrap) {
                        val = lower;
                } else {
                        val = upper;
                        done = true;
                }
        } else if (val < lower) {
                if (wrap) {
                        val = upper;
                } else {
                        val = lower;
                        done = true;
                }
        }

        set_value(val);
        return done;
}

gint
AutoSpin::timer ()
{
        bool done;
        int retval = FALSE;

        done = adjust_value (timer_increment);

        if (need_timer) {

                /* we're in the initial call, which happened
                   after initial_timer_interval msecs. Now
                   request a much more frequent update.
                */
                
                timeout_tag = g_timeout_add (timer_interval,
                                               _timer,
                                               this);
                have_timer = true;
                need_timer = false;

                /* cancel this initial timeout */
                
                retval = FALSE;

        } else { 
                /* this is the regular "fast" call after each
                   timer_interval msecs. 
                */

                if (timer_calls < climb_timer_calls) {
                        timer_calls++;
                } else {
                        if (climb_rate > 0.0) {
                                if (timer_increment > 0) {
                                        timer_increment += climb_rate;
                                } else {
                                        timer_increment -= climb_rate;
                                }
                        }
                        timer_calls = 0;
                }

                if (!done) {
                        retval = TRUE;
                }
        }

        return retval;
}       

void
AutoSpin::set_bounds (gfloat init, gfloat up, gfloat down, bool with_reset)
{
        adjustment.set_upper(up);
        adjustment.set_lower(down);

        initial = init;
        
        adjustment.changed ();
        
        if (with_reset) {
                adjustment.set_value (init);
        }
}