Rockbox open source high quality audio player as a Music Player Daemon
mpris
rockbox
mpd
libadwaita
audio
rust
zig
deno
touchscreen: Add gesture recognition API
Add a basic gesture API which can detect taps, long presses,
and dragging gestures.
Change-Id: Id10bf8d46b9195330ce951f9f108c81e87a8dad4
authored by
Aidan MacDonald
and committed by
Solomon Peachy
7aa82321
0f4cc33d
+247
+3
apps/SOURCES
+3
apps/SOURCES
+121
apps/gesture.c
+121
apps/gesture.c
···
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/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2022 by Aidan MacDonald
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "gesture.h"
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#include "button.h"
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#include "viewport.h"
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#include "system.h"
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/* could be a setting */
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#define TOUCH_LONG_PRESS_TIME (30 * HZ / 100)
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void gesture_reset(struct gesture *g)
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{
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g->flags = 0;
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}
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void gesture_process(struct gesture *g, const struct touchevent *ev)
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{
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/* wait for the first press if we haven't seen it */
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if (!gesture_is_pressed(g) && ev->type != TOUCHEVENT_PRESS)
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return;
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int dx, dy, dist_sqr;
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switch (ev->type)
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{
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case TOUCHEVENT_PRESS:
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g->flags |= GESTURE_F_PRESSED | GESTURE_F_VALID;
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g->id = GESTURE_NONE;
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g->ox = g->x = ev->x;
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g->oy = g->y = ev->y;
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g->start_tick = ev->tick;
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g->last_tick = ev->tick;
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break;
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case TOUCHEVENT_CONTACT:
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g->x = ev->x;
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g->y = ev->y;
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g->last_tick = ev->tick;
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if (g->id == GESTURE_LONG_PRESS)
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g->id = GESTURE_HOLD;
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else if (g->id == GESTURE_DRAGSTART)
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g->id = GESTURE_DRAG;
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else if (g->id != GESTURE_DRAG)
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{
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dx = ev->x - g->ox;
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dy = ev->y - g->oy;
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dist_sqr = dx*dx + dy*dy;
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/* if squared distance exceeds a threshold, report as a DRAG. */
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const int thresh = touchscreen_get_scroll_threshold();
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if (dist_sqr > thresh*thresh)
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g->id = GESTURE_DRAGSTART;
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/* report a LONG_PRESS if no motion occurs within a timeout */
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if (g->id == GESTURE_NONE &&
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TIME_AFTER(ev->tick, g->start_tick + TOUCH_LONG_PRESS_TIME))
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g->id = GESTURE_LONG_PRESS;
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}
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break;
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case TOUCHEVENT_RELEASE:
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/* report a RELEASE event after a continuous HOLD or DRAG */
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if (g->id == GESTURE_HOLD ||
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g->id == GESTURE_DRAGSTART ||
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g->id == GESTURE_DRAG)
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g->id = GESTURE_RELEASE;
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/* report a TAP event if we got a press & release without
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* triggering any other gestures */
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else if (g->id == GESTURE_NONE)
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g->id = GESTURE_TAP;
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g->flags &= ~GESTURE_F_PRESSED;
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g->last_tick = ev->tick;
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break;
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}
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}
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bool gesture_get_event_in_vp(struct gesture *g, struct gesture_event *gevt,
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const struct viewport *vp)
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{
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if (!gesture_is_valid(g))
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return false;
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gevt->id = g->id;
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gevt->x = g->x;
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gevt->y = g->y;
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gevt->ox = g->ox;
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gevt->oy = g->oy;
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gevt->start_tick = g->start_tick;
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gevt->last_tick = g->last_tick;
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if (vp) {
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gevt->x -= vp->x;
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gevt->y -= vp->y;
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gevt->ox -= vp->x;
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gevt->oy -= vp->y;
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}
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return !vp || viewport_point_within_vp(vp, g->ox, g->oy);
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}
+123
apps/gesture.h
+123
apps/gesture.h
···
1
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/***************************************************************************
2
+
* __________ __ ___.
3
+
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
4
+
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
5
+
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
6
+
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
7
+
* \/ \/ \/ \/ \/
8
+
* $Id$
9
+
*
10
+
* Copyright (C) 2022 Aidan MacDonald
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+
*
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+
* This program is free software; you can redistribute it and/or
13
+
* modify it under the terms of the GNU General Public License
14
+
* as published by the Free Software Foundation; either version 2
15
+
* of the License, or (at your option) any later version.
16
+
*
17
+
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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+
* KIND, either express or implied.
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+
*
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+
****************************************************************************/
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#ifndef _GESTURE_H_
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#define _GESTURE_H_
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#include <stddef.h>
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#include <stdbool.h>
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struct viewport;
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struct touchevent;
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/** Events which can be detected by the gesture API.
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*
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* The gesture state machine, informally, looks like this:
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*
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* NONE --+--> TAP ------------------------------------+
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* | |
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* +--> LONG_PRESS -----------------------------+
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* | | |
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* | +---> HOLD ---+ |
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* | | | |
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* +-------------+---> DRAG ---+--> RELEASE ----+--> NONE
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*
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* State transitions occur from gesture_process() in response to touch events.
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*
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* - The NONE "event" is returned prior to any other gesture being detected.
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* Although the graph above depicts a transition back to NONE at the end of
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* an event chain, that transition in fact happens on the TOUCHEVENT_PRESS
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* after the end of the last event.
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*
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* - TAP events are reported after getting a TOUCHEVENT_RELEASE event if no
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* other gestures were detected between the press and release.
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*
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* - LONG_PRESS events are reported on a TOUCHEVENT_CONTACT event if the long
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* press timeout has expired and the touch point hasn't moved too far from
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* its initial position.
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*
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* - HOLD events are reported on TOUCHEVENT_CONTACT events after a LONG_PRESS,
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* provided the touch point hasn't moved too far from its initial position.
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*
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* - DRAG events are reported on TOUCHEVENT_CONTACT events after the touch
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* point first moves a certain distance from its initial position. The first
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* time this happens, it is reported as DRAGSTART.
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*
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* - RELEASE events are reported on the TOUCHEVENT_RELEASE event following a
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* HOLD or DRAG gesture.
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*/
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enum gesture_id
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{
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GESTURE_NONE = 0, /** No gesture */
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GESTURE_TAP, /** Quick press & release */
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GESTURE_LONG_PRESS, /** Start of a long press */
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GESTURE_HOLD, /** Continuation of a long press */
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GESTURE_DRAGSTART, /** Start of a DRAG event */
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GESTURE_DRAG, /** Press and drag on the screen */
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GESTURE_RELEASE, /** End of a HOLD or DRAG event */
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};
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enum gesture_flags
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{
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GESTURE_F_VALID = 0x01,
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GESTURE_F_PRESSED = 0x02,
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};
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struct gesture
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{
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unsigned int flags;
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int id;
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short x, y;
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short ox, oy;
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long start_tick;
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long last_tick;
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};
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struct gesture_event
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{
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int id;
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short x, y;
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short ox, oy;
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long start_tick;
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long last_tick;
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};
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void gesture_reset(struct gesture *g);
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void gesture_process(struct gesture *g, const struct touchevent *ev);
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bool gesture_get_event_in_vp(struct gesture *g, struct gesture_event *gevt,
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const struct viewport *vp);
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static inline bool gesture_get_event(struct gesture *g,
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struct gesture_event *gevt)
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{
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return gesture_get_event_in_vp(g, gevt, NULL);
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}
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static inline bool gesture_is_valid(struct gesture *g)
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{
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return !!(g->flags & GESTURE_F_VALID);
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}
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static inline bool gesture_is_pressed(struct gesture *g)
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{
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return !!(g->flags & GESTURE_F_PRESSED);
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}
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#endif /* _GESTURE_H_ */