// widget_button.ysl2

widget_desc("Button") {

longdesc

||

Button widget takes one boolean variable path, and reflect current true

or false value by showing "active" or "inactive" labeled element

respectively. Pressing and releasing button changes variable to true and

false respectively. Potential inconsistency caused by quick consecutive

presses on the button is mitigated by using a state machine that wait for

previous state change to be reflected on variable before applying next one.

||

shortdesc > Push button reflecting consistently given boolean variable

path name="value" accepts="HMI_BOOL" > Boolean variable

}

// Finite state machine

decl fsm(name);

decl state(name);

decl on_mouse(position);

decl on_dispatch(value);

decl jump(state);

decl show(eltname);

decl hmi_value(value);

gen_index_xhtml {

const "_push_button_fsm" fsm {

state "init" {

on_dispatch "false" jump "reflect_off";

on_dispatch "true" jump "reflect_on";

}

state "reflect_on" {

show "active";

on_mouse "down" jump "on";

on_mouse "up" jump "off";

on_dispatch "false" jump "reflect_off";

}

state "on" {

hmi_value "true";

show "active";

on_mouse "up" jump "off";

on_dispatch "false" jump "reflect_off";

}

state "reflect_off" {

show "inactive";

on_mouse "down" jump "on";

on_mouse "up" jump "off";

on_dispatch "true" jump "reflect_on";

}

state "off" {

hmi_value "false";

show "inactive";

on_mouse "down" jump "on";

on_dispatch "true" jump "reflect_on";

}

}

// State machine to drive HMI_BOOL on a potentially laggy connection

const "_button_fsm" fsm {

state "init" {

on_dispatch "false" jump "released";

on_dispatch "true" jump "pressed";

}

state "pressing" {

// show "waitactive";

hmi_value "true";

on_dispatch "true" jump "pressed";

on_mouse "up" jump "shortpress";

}

state "pressed" {

show "active";

on_mouse "up" jump "releasing";

on_dispatch "false" jump "released";

}

state "shortpress" {

on_dispatch "true" jump "releasing";

on_mouse "down" jump "pressing";

}

state "releasing" {

// show "waitinactive";

hmi_value "false";

on_dispatch "false" jump "released";

on_mouse "down" jump "shortrelease";

}

state "released" {

show "inactive";

on_mouse "down" jump "pressing";

on_dispatch "true" jump "pressed";

}

state "shortrelease" {

on_dispatch "false" jump "pressing";

on_mouse "up" jump "releasing";

}

}

template "fsm", mode="dispatch_transition" {

| switch (this.state) {

apply "state", mode="dispatch_transition";

| }

}

template "state", mode="dispatch_transition" {

| case "«@name»":

apply "on-dispatch";

| break;

}

template "on-dispatch" {

| if(value == «@value») {

apply "jump", mode="transition";

| }

}

template "fsm", mode="mouse_transition" {

param "position";

| switch (this.state) {

apply "state", mode="mouse_transition" with "position", "$position";

| }

}

template "state", mode="mouse_transition" {

param "position";

| case "«@name»":

apply "on-mouse[@position = $position]";

| break;

}

template "on-mouse" {

// up or down state is already assumed because apply statement filters it

apply "jump", mode="transition";

}

template "jump", mode="transition" {

| this.state = "«@state»";

| this.«@state»_action();

}

template "fsm", mode="actions" {

apply "state", mode="actions";

}

template "state", mode="actions" {

| «@name»_action(){

// | console.log("Entering state «@name»", this.frequency);

apply "*", mode="actions";

| }

}

template "show", mode="actions" {

| this.activity_state = «@eltname = 'active'»;

| this.request_animate();

}

template "hmi-value", mode="actions" {

| this.apply_hmi_value(0, «@value»);

}

}

function "generated_button_class" {

param "fsm";

| state = "init";

| dispatch(value) {

apply "$fsm", mode="dispatch_transition";

| }

| onmouseup(evt) {

| svg_root.removeEventListener("pointerup", this.bound_onmouseup, true);

apply "$fsm", mode="mouse_transition" with "position", "'up'";

| }

| onmousedown(evt) {

| svg_root.addEventListener("pointerup", this.bound_onmouseup, true);

apply "$fsm", mode="mouse_transition" with "position", "'down'";

| }

apply "$fsm", mode="actions";

| init() {

| this.bound_onmouseup = this.onmouseup.bind(this);

| this.element.addEventListener("pointerdown", this.onmousedown.bind(this));

| this.activity_state = undefined;

| }

}

widget_class("Button"){

| frequency = 5;

const "fsm","exsl:node-set($_button_fsm)";

call "generated_button_class" with "fsm", "$fsm";

}

widget_defs("Button") {

activable();

}

widget_class("PushButton"){

| frequency = 20;

const "fsm","exsl:node-set($_push_button_fsm)";

call "generated_button_class" with "fsm", "$fsm";

}

widget_defs("PushButton") {

activable();

}