summaryrefslogtreecommitdiffstats
path: root/apps/gui/bitmap/list.c
blob: 49479c1cb32e03813269f06ea47e522fa0340392 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
/***************************************************************************
 *             __________               __   ___.
 *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
 *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
 *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
 *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
 *                     \/            \/     \/    \/            \/
 * $Id$
 *
 * Copyright (C) 2007 by Jonathan Gordon
 *
 * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ****************************************************************************/

/* This file contains the code to draw the list widget on BITMAP LCDs. */

#include "config.h"
#include "system.h"
#include "lcd.h"
#include "font.h"
#include "button.h"
#include "string.h"
#include "settings.h"
#include "kernel.h"
#include "file.h"

#include "action.h"
#include "screen_access.h"
#include "list.h"
#include "scrollbar.h"
#include "lang.h"
#include "sound.h"
#include "misc.h"
#include "viewport.h"
#include "statusbar-skinned.h"
#include "debug.h"

#define ICON_PADDING 1

/* these are static to make scrolling work */
static struct viewport list_text[NB_SCREENS], title_text[NB_SCREENS];

#ifdef HAVE_TOUCHSCREEN
static int y_offset;
static bool hide_selection = true;
#endif

int gui_list_get_item_offset(struct gui_synclist * gui_list, int item_width,
                             int text_pos, struct screen * display,
                             struct viewport *vp);
bool list_display_title(struct gui_synclist *list, enum screen_type screen);

void gui_synclist_scroll_stop(struct gui_synclist *lists)
{
    FOR_NB_SCREENS(i)
    {
        screens[i].scroll_stop(&list_text[i]);
        screens[i].scroll_stop(&title_text[i]);
        screens[i].scroll_stop(lists->parent[i]);
    }
}

/* Draw the list...
    internal screen layout:
        -----------------
        |TI|  title     |   TI is title icon
        -----------------
        | | |            |
        |S|I|            |   S - scrollbar
        | | | items      |   I - icons
        | | |            |
        ------------------

        Note: This image is flipped horizontally when the language is a
        right-to-left one (Hebrew, Arabic)
*/

static int list_icon_width(enum screen_type screen)
{
    return get_icon_width(screen) + ICON_PADDING * 2;
}

static int list_icon_height(enum screen_type screen)
{
    return get_icon_height(screen);
}

static bool draw_title(struct screen *display, struct gui_synclist *list)
{
    const int screen = display->screen_type;
    int style = STYLE_DEFAULT;
    struct viewport *title_text_vp = &title_text[screen];

    if (sb_set_title_text(list->title, list->title_icon, screen))
        return false; /* the sbs is handling the title */
    display->scroll_stop(title_text_vp);
    if (!list_display_title(list, screen))
        return false;
    *title_text_vp = *(list->parent[screen]);
    title_text_vp->height = title_text_vp->line_height;

    if (list->title_icon != Icon_NOICON && global_settings.show_icons)
    {
        struct viewport title_icon = *title_text_vp;

        title_icon.width = list_icon_width(screen);
        title_icon.y += (title_icon.height - list_icon_height(screen)) / 2;
        title_icon.height = list_icon_height(screen);
        if (VP_IS_RTL(&title_icon))
        {
            title_icon.x += title_text_vp->width - title_icon.width;
        }
        else
        {
            title_text_vp->x += title_icon.width;
        }
        title_text_vp->width -= title_icon.width;

        display->set_viewport(&title_icon);
        screen_put_iconxy(display, 0, 0, list->title_icon);
    }
#ifdef HAVE_LCD_COLOR
    if (list->title_color >= 0)
    {
        style |= (STYLE_COLORED|list->title_color);
    }
#endif
    display->set_viewport(title_text_vp);
    display->puts_scroll_style(0, 0, list->title, style);
    return true;
}

void list_draw(struct screen *display, struct gui_synclist *list)
{
    struct viewport list_icons;
    int start, end, line_height, style, item_offset, i;
    const int screen = display->screen_type;
    const int list_start_item = list->start_item[screen];
    const int icon_width = list_icon_width(screen);
    const bool scrollbar_in_left = (global_settings.scrollbar == SCROLLBAR_LEFT);
    const bool show_cursor = !global_settings.cursor_style &&
                        list->show_selection_marker;
    struct viewport *parent = (list->parent[screen]);
#ifdef HAVE_LCD_COLOR
    unsigned char cur_line = 0;
#endif
    int icon_yoffset = 0; /* to center the icon */
    bool show_title;
    struct viewport *list_text_vp = &list_text[screen];

    line_height = parent->line_height;
    display->set_viewport(parent);
    display->clear_viewport();
    display->scroll_stop(list_text_vp);
    *list_text_vp = *parent;
    list_text_vp->line_height = line_height;
    if ((show_title = draw_title(display, list)))
    {
        int title_height = title_text[screen].height;
        list_text_vp->y += title_height;
        list_text_vp->height -= title_height;
    }

    const int nb_lines = viewport_get_nb_lines(list_text_vp);

    start = list_start_item;
    end = start + nb_lines;

#ifdef HAVE_TOUCHSCREEN
    if (list->selected_item == 0 || (list->nb_items < nb_lines))
        y_offset = 0; /* reset in case it's a new list */

    int draw_offset = y_offset;
    /* draw some extra items to not have empty lines at the top and bottom */
    if (y_offset > 0)
    {
        /* make it negative for more consistent apparence when switching
         * directions */
        draw_offset -= line_height;
        if (start > 0)
            start--;
    }
    else if (y_offset < 0)
        end++;
#else
    #define draw_offset 0
#endif

    /* draw the scrollbar if its needed */
    if (global_settings.scrollbar && nb_lines < list->nb_items)
    {
        struct viewport vp = *list_text_vp;
        vp.width = SCROLLBAR_WIDTH;
        vp.height = line_height * nb_lines;
        vp.x = parent->x;
        list_text_vp->width -= SCROLLBAR_WIDTH;
        if (scrollbar_in_left)
            list_text_vp->x += SCROLLBAR_WIDTH;
        else
            vp.x += list_text_vp->width;
        display->set_viewport(&vp);
        gui_scrollbar_draw(display,
                (scrollbar_in_left? 0: 1), 0, SCROLLBAR_WIDTH-1, vp.height,
                list->nb_items, list_start_item, list_start_item + nb_lines,
                VERTICAL);
    }
    else if (show_title)
    {
        /* shift everything a bit in relation to the title... */
        if (!VP_IS_RTL(list_text_vp) && scrollbar_in_left)
        {
            list_text_vp->width -= SCROLLBAR_WIDTH;
            list_text_vp->x += SCROLLBAR_WIDTH;
        }
        else if (VP_IS_RTL(list_text_vp) && !scrollbar_in_left)
        {
            list_text_vp->width -= SCROLLBAR_WIDTH;
        }
    }

    /* setup icon placement */
    list_icons = *list_text_vp;
    int icon_count = (list->callback_get_item_icon != NULL) ? 1 : 0;
    if (show_cursor)
        icon_count++;
    if (icon_count)
    {
        list_icons.width = icon_width * icon_count;
        list_text_vp->width -= list_icons.width + ICON_PADDING;
        if (VP_IS_RTL(&list_icons))
            list_icons.x += list_text_vp->width + ICON_PADDING;
        else
            list_text_vp->x += list_icons.width + ICON_PADDING;
        icon_yoffset = (line_height - list_icon_height(screen)) / 2;
    }

    for (i=start; i<end && i<list->nb_items; i++)
    {
        /* do the text */
        unsigned const char *s;
        char entry_buffer[MAX_PATH];
        unsigned char *entry_name;
        int text_pos = 0;
        int line = i - start;
        s = list->callback_get_item_name(i, list->data, entry_buffer,
                                         sizeof(entry_buffer));
        entry_name = P2STR(s);
        display->set_viewport(list_text_vp);
        style = STYLE_DEFAULT;
        /* position the string at the correct offset place */
        int item_width,h;
        display->getstringsize(entry_name, &item_width, &h);
        item_offset = gui_list_get_item_offset(list, item_width, text_pos,
                display, list_text_vp);

#ifdef HAVE_LCD_COLOR
        /* if the list has a color callback */
        if (list->callback_get_item_color)
        {
            int color = list->callback_get_item_color(i, list->data);
            /* if color selected */
            if (color >= 0)
            {
                style |= STYLE_COLORED|color;
            }
        }
#endif
        /* draw the selected line */
        if(
#ifdef HAVE_TOUCHSCREEN
            /* don't draw it during scrolling */
            !hide_selection &&
#endif
                i >= list->selected_item
                && i <  list->selected_item + list->selected_size
                && list->show_selection_marker)
        {/* The selected item must be displayed scrolling */
            if (global_settings.cursor_style == 1
#ifdef HAVE_REMOTE_LCD
                    /* the global_settings.cursor_style check is here to make
                    * sure if they want the cursor instead of bar it will work
                    */
                    || (display->depth < 16 && global_settings.cursor_style)
#endif
            )
            {
                /* Display inverted-line-style */
                style = STYLE_INVERT;
            }
#ifdef HAVE_LCD_COLOR
            else if (global_settings.cursor_style == 2)
            {
                /* Display colour line selector */
                style = STYLE_COLORBAR;
            }
            else if (global_settings.cursor_style == 3)
            {
                /* Display gradient line selector */
                style = STYLE_GRADIENT;

                /* Make the lcd driver know how many lines the gradient should
                   cover and current line number */
                /* number of selected lines */
                style |= NUMLN_PACK(list->selected_size);
                /* current line number, zero based */
                style |= CURLN_PACK(cur_line);
                cur_line++;
            }
#endif
            /* if the text is smaller than the viewport size */
            if (item_offset> item_width - (list_text_vp->width - text_pos))
            {
                /* don't scroll */
                display->puts_style_xyoffset(0, line, entry_name,
                        style, item_offset, draw_offset);
            }
            else
            {
                display->puts_scroll_style_xyoffset(0, line, entry_name,
                        style, item_offset, draw_offset);
            }
        }
        else
        {
            if (list->scroll_all)
                display->puts_scroll_style_xyoffset(0, line, entry_name,
                        style, item_offset, draw_offset);
            else
                display->puts_style_xyoffset(0, line, entry_name,
                        style, item_offset, draw_offset);
        }
        /* do the icon */
        display->set_viewport(&list_icons);
        if (list->callback_get_item_icon != NULL)
        {
            int xoff = show_cursor ? list_icon_width(screen) : 0;
            screen_put_iconxy(display, xoff,
                            line*line_height + draw_offset + icon_yoffset,
                            list->callback_get_item_icon(i, list->data));
        }
        /* do the cursor */
        if (show_cursor && i >= list->selected_item &&
                i <  list->selected_item + list->selected_size)
        {
            screen_put_iconxy(display, 0,
                            line*line_height + draw_offset + icon_yoffset,
                            Icon_Cursor);
        }
    }
    display->set_viewport(parent);
    display->update_viewport();
    display->set_viewport(NULL);
}

#if defined(HAVE_TOUCHSCREEN)
/* This needs to be fixed if we ever get more than 1 touchscreen on a target. */

/* difference in pixels between draws, above it means enough to start scrolling */
#define SCROLL_BEGIN_THRESHOLD 3 

static enum {
    SCROLL_NONE,            /* no scrolling */
    SCROLL_BAR,             /* scroll by using the scrollbar */
    SCROLL_SWIPE,           /* scroll by wiping over the screen */
    SCROLL_KINETIC,         /* state after releasing swipe */
} scroll_mode;

static int scrollbar_scroll(struct gui_synclist * gui_list,
                                              int y)
{
    const int screen = screens[SCREEN_MAIN].screen_type;
    const int nb_lines = viewport_get_nb_lines(&list_text[screen]);

    if (nb_lines <  gui_list->nb_items)
    {
        /* scrollbar scrolling is still line based */
        y_offset = 0;
        int scrollbar_size = nb_lines*gui_list->parent[screen]->line_height;
        int actual_y = y - list_text[screen].y;

        int new_selection = (actual_y * gui_list->nb_items)
                / scrollbar_size;

        int start_item = new_selection - nb_lines/2;
        if(start_item < 0)
            start_item = 0;
        else if(start_item > gui_list->nb_items - nb_lines)
            start_item = gui_list->nb_items - nb_lines;

        gui_list->start_item[screen] = start_item;

        return ACTION_REDRAW;
    }

    return ACTION_NONE;
}

/* kinetic scrolling, based on
 *
 * v = a*t + v0 and ds = v*dt
 *
 * In each (fixed interval) timeout, the list is advanced by ds, then
 * the v is reduced by a.
 * This way we get a linear and smooth deceleration of the scrolling
 *
 * As v is the difference of distance per time unit, v is passed (as
 * pixels moved since the last call) to the scrolling function which takes
 * care of the pixel accurate drawing
 *
 * v0 is dertermined by averaging the last 4 movements of the list
 * (the pixel and time difference is used to compute each v)
 *
 * influenced by http://stechz.com/tag/kinetic/
 * We take the easy and smooth first approach (until section "Drawbacks"),
 * since its drawbacks don't apply for us since our timers seem to be
 * relatively accurate
 */


#define SIGN(a) ((a) < 0 ? -1 : 1)
/* these could possibly be configurable */
/* the lower the smoother */
#define RELOAD_INTERVAL (HZ/25)
/* the higher the earler the list stops */
#define DECELERATION (1000*RELOAD_INTERVAL/HZ)

/* this array holds data to compute the initial velocity v0 */
static struct kinetic_info {
    int difference;
    long ticks;
} kinetic_data[4];
static size_t cur_idx;

static struct cb_data {
    struct gui_synclist *list;  /* current list */
    int velocity;               /* in pixel/s */
} cb_data;

/* data member points to the above struct */
static struct timeout kinetic_tmo;

static bool is_kinetic_over(void)
{
    return !cb_data.velocity && (scroll_mode == SCROLL_KINETIC);
}

/*
 * collect data about how fast the list is moved in order to compute
 * the initial velocity from it later */
static void kinetic_stats_collect(const int difference)
{
    static long last_tick;
    /* collect velocity statistics */
    kinetic_data[cur_idx].difference = difference;
    kinetic_data[cur_idx].ticks = current_tick - last_tick;

    last_tick = current_tick;
    cur_idx += 1;
    if (cur_idx >= ARRAYLEN(kinetic_data))
        cur_idx = 0; /* rewind the index */
}

/*
 * resets the statistic */
static void kinetic_stats_reset(void)
{
    memset(kinetic_data, 0, sizeof(kinetic_data));
    cur_idx = 0;
}

/* cancels all currently active kinetic scrolling */
static void kinetic_force_stop(void)
{
    timeout_cancel(&kinetic_tmo);
    kinetic_stats_reset();
}

/* helper for gui/list.c to cancel scrolling if a normal button event comes
 * through dpad or keyboard or whatever */
void _gui_synclist_stop_kinetic_scrolling(void)
{
    y_offset = 0;
    if (scroll_mode == SCROLL_KINETIC)
        kinetic_force_stop();
    scroll_mode = SCROLL_NONE;
    hide_selection = false;
}
/*
 * returns false if scrolling should be stopped entirely
 *
 * otherwise it returns true even if it didn't actually scroll,
 * but scrolling mode shouldn't be changed
 **/

 
static int scroll_begin_threshold;
static int threshold_accumulation;
static bool swipe_scroll(struct gui_synclist * gui_list, int difference)
{
    /* fixme */
    const enum screen_type screen = screens[SCREEN_MAIN].screen_type;
    const int nb_lines = viewport_get_nb_lines(&list_text[screen]);
    const int line_height = gui_list->parent[0]->line_height;

    if (UNLIKELY(scroll_begin_threshold == 0))
        scroll_begin_threshold = touchscreen_get_scroll_threshold();

    /* make selecting items easier */
    threshold_accumulation += abs(difference);
    if (threshold_accumulation < scroll_begin_threshold && scroll_mode == SCROLL_NONE)
        return false;

    threshold_accumulation = 0;

    /* does the list even scroll? if no, return but still show
     * the caller that we would scroll */
    if (nb_lines >= gui_list->nb_items)
        return true;

    const int old_start = gui_list->start_item[screen];
    int new_start_item = -1;
    int line_diff = 0;

    /* don't scroll at the edges of the list */
    if ((old_start == 0 && difference > 0)
     || (old_start == (gui_list->nb_items - nb_lines) && difference < 0))
    {
        y_offset = 0;
        gui_list->start_item[screen] = old_start;
        return scroll_mode != SCROLL_KINETIC; /* stop kinetic at the edges */
    }

    /* add up y_offset over time and translate to lines
     * if scrolled enough */
    y_offset += difference;
    if (abs(y_offset) > line_height)
    {
        line_diff = y_offset/line_height;
        y_offset -= line_diff * line_height;
    }

    if(line_diff != 0)
    {
        int selection_offset = gui_list->selected_item - old_start;
        new_start_item = old_start - line_diff;
        /* check if new_start_item is bigger than list item count */
        if(new_start_item > gui_list->nb_items - nb_lines)
            new_start_item = gui_list->nb_items - nb_lines;
        /* set new_start_item to 0 if it's negative */
        if(new_start_item < 0)
            new_start_item = 0;

        gui_list->start_item[screen] = new_start_item;
        /* keep selected item in sync */
        gui_list->selected_item = new_start_item + selection_offset;
    }

    return true;
}

static int kinetic_callback(struct timeout *tmo)
{
    /* cancel if screen was pressed */
    if (scroll_mode != SCROLL_KINETIC)
        return 0;

    struct cb_data *data = (struct cb_data*)tmo->data;
    /* ds = v*dt */
    int pixel_diff = data->velocity * RELOAD_INTERVAL / HZ;
    /* remember signedness to detect stopping */
    int old_sign = SIGN(data->velocity);
    /* advance the list */
    if (!swipe_scroll(data->list, pixel_diff))
    {
        /* nothing to scroll? */
        data->velocity = 0;
    }
    else
    {
        /* decelerate by a fixed amount
         * decrementing v0 over time by the deceleration is
         * equivalent to computing v = a*t + v0 */
        data->velocity -= SIGN(data->velocity)*DECELERATION;
        if (SIGN(data->velocity) != old_sign)
            data->velocity = 0;
    }

    /* let get_action() timeout, which loads to a
     * gui_synclist_draw() call from the main thread */
    queue_post(&button_queue, BUTTON_REDRAW, 0);
    /* stop if the velocity hit or crossed zero */
    if (!data->velocity)
    {
        kinetic_stats_reset();
        return 0;
    }
    return RELOAD_INTERVAL; /* cancel or reload */
}

/*
 * computes the initial velocity v0 and sets up the timer */
static bool kinetic_setup_scroll(struct gui_synclist *list)
{
    /* compute initial velocity */
    int i, _i, v0, len = ARRAYLEN(kinetic_data);
    for(i = 0, _i = 0, v0 = 0; i < len; i++)
    {   /* in pixel/s */
        if (kinetic_data[i].ticks > 0)
        {
            v0 += kinetic_data[i].difference*HZ/kinetic_data[i].ticks;
            _i++;
        }
    }
    if (_i > 0)
        v0 /= _i;
    else
        v0 = 0;

    if (v0 != 0)
    {
        cb_data.list = list;
        cb_data.velocity = v0;
        timeout_register(&kinetic_tmo, kinetic_callback, RELOAD_INTERVAL, (intptr_t)&cb_data);
        return true;
    }
    return false;
}

#define OUTSIDE    0
#define TITLE_TEXT (1<<0)
#define TITLE_ICON (1<<1)
#define SCROLLBAR  (1<<2)
#define LIST_TEXT  (1<<3)
#define LIST_ICON  (1<<4)

#define TITLE      (TITLE_TEXT|TITLE_ICON)
#define LIST       (LIST_TEXT|LIST_ICON)

static int get_click_location(struct gui_synclist *list, int x, int y)
{
    int screen = SCREEN_MAIN;
    struct viewport *parent, *title, *text;
    int retval = OUTSIDE;

    parent = list->parent[screen];
    if (viewport_point_within_vp(parent, x, y))
    {
        /* see if the title was clicked */
        title = &title_text[screen];
        if (viewport_point_within_vp(title, x, y))
            retval = TITLE_TEXT;
        /* check the icon too */
        if (list->title_icon != Icon_NOICON && global_settings.show_icons)
        {
            int width = list_icon_width(screen);
            struct viewport vp = *title;
            if (VP_IS_RTL(&vp))
                vp.x += vp.width;
            else
                vp.x -= width;
            vp.width = width;
            if (viewport_point_within_vp(&vp, x, y))
                retval = TITLE_ICON;
        }
        /* check scrollbar. assume it's shown, if it isn't it will be handled
         * later */
        if (retval == OUTSIDE)
        {
            bool on_scrollbar_clicked;
            int adj_x = x - parent->x;
            switch (global_settings.scrollbar)
            {
                case SCROLLBAR_LEFT:
                    on_scrollbar_clicked = adj_x <= SCROLLBAR_WIDTH; break;
                case SCROLLBAR_RIGHT:
                    on_scrollbar_clicked = adj_x > (title->x + title->width - SCROLLBAR_WIDTH); break;
                default:
                    on_scrollbar_clicked = false; break;
            }
            if (on_scrollbar_clicked)
                retval = SCROLLBAR;
        }
        if (retval == OUTSIDE)
        {
            text = &list_text[screen];
            if (viewport_point_within_vp(text, x, y))
                retval = LIST_TEXT;
            else /* if all fails, it must be on the list icons */
                retval = LIST_ICON;
        }
    }
    return retval;
}

unsigned gui_synclist_do_touchscreen(struct gui_synclist * list)
{
    enum screen_type screen;
    struct viewport *parent;
    short x, y;
    int action, adj_y, line, line_height, list_start_item;
    bool recurse;
    static int last_y = -1;
    
    screen = SCREEN_MAIN;
    parent = list->parent[screen];
    line_height = list->parent[screen]->line_height;
    list_start_item = list->start_item[screen];
    /* start with getting the action code and finding the click location */
    action = action_get_touchscreen_press(&x, &y);
    adj_y = y - parent->y;


    /* some defaults before running the state machine */
    recurse = false;
    hide_selection = true;

    switch (scroll_mode)
    {
        case SCROLL_NONE:
        {
            if (last_y == -1)
            {   /* first run. register adj_y and re-run (will then take the else case) */
                last_y = adj_y;
                recurse = true;
            }
            else
            {
                int click_loc = get_click_location(list, x, y);
                line = 0; /* silence gcc 'used uninitialized' warning */
                if (click_loc & LIST)
                {
                    /* selection needs to be corrected if items are only partially visible */
                    line = (adj_y - y_offset) / line_height;
                    if (list_display_title(list, screen))
                        line -= 1; /* adjust for the list title */
                    list->selected_item = list_start_item+line;
                    gui_synclist_speak_item(list);
                }
                if (action == BUTTON_TOUCHSCREEN)
                {
                    /* if not scrolling, the user is trying to select */
                    int diff = adj_y - last_y;
                    if ((click_loc & LIST) && swipe_scroll(list, diff))
                        scroll_mode = SCROLL_SWIPE;
                    else if (click_loc & SCROLLBAR)
                        scroll_mode = SCROLL_BAR;

                    /* only show selection bar if clicking the list */
                    hide_selection = click_loc & (SCROLLBAR|TITLE);
                }
                else if (action == BUTTON_REPEAT)
                {
                    if (click_loc & LIST)
                    {
                        /* held a single line for a while, bring up the context menu */
                        gui_synclist_select_item(list, list_start_item + line);
                        /* don't sent context repeatedly */
                        action_wait_for_release();
                        last_y = -1;
                        return ACTION_STD_CONTEXT;
                    }
                }
                else if (action & BUTTON_REL)
                {
                    last_y = -1;
                    if (click_loc & LIST)
                    {   /* release on list item enters it */
                        gui_synclist_select_item(list, list_start_item + line);
                        return ACTION_STD_OK;
                    }
                    else if (click_loc & TITLE_TEXT)
                    {   /* clicking the title goes one level up (cancel) */
                        return ACTION_STD_CANCEL;
                    }
                    else if (click_loc & TITLE_ICON)
                    {   /* clicking the title icon goes back to the root */
                        return ACTION_STD_MENU;
                    }
                }
            }
            break;
        }
        case SCROLL_SWIPE:
        {
            /* when swipe scrolling, we accept outside presses as well and
             * grab the entire screen (i.e. click_loc does not matter) */
            int diff = adj_y - last_y;
            kinetic_stats_collect(diff);
            if (swipe_scroll(list, diff))
            {
                /* letting the pen go enters kinetic scrolling */
                if ((action & BUTTON_REL))
                {
                    if (kinetic_setup_scroll(list))
                        scroll_mode = SCROLL_KINETIC;
                    else
                        scroll_mode = SCROLL_NONE;
                }
            }
            else if (action & BUTTON_REL)
                scroll_mode = SCROLL_NONE;

            if (scroll_mode == SCROLL_NONE)
                last_y = -1;
            break;
        }
        case SCROLL_KINETIC:
        {
            /* during kinetic scrolling we need to handle cancellation.
             * This state is actually only entered upon end of it as this
             * function is not called during the animation. */
            if (!is_kinetic_over())
            {   /* a) the user touched the screen (manual cancellation) */
                kinetic_force_stop();
                if (get_click_location(list, x, y) & SCROLLBAR)
                    scroll_mode = SCROLL_BAR;
                else
                    scroll_mode = SCROLL_SWIPE;
            }
            else
            {   /* b) kinetic scrolling stopped on its own */
                /* need to re-run this with SCROLL_NONE since otherwise
                 * the next touch is not detected correctly */
                scroll_mode = SCROLL_NONE;
                recurse = true;
            }
            break;
        }
        case SCROLL_BAR:
        {
            /* similarly to swipe scroll, using the scrollbar grabs
             * focus so the click location is irrelevant */
            scrollbar_scroll(list, adj_y);
            if (action & BUTTON_REL)
                scroll_mode = SCROLL_NONE;
            break;
        }
    }

    /* register y position unless forcefully reset to 1- */
    if (last_y >= 0)
        last_y = adj_y;

    return recurse ? gui_synclist_do_touchscreen(list) : ACTION_REDRAW;
}

#endif