Runtime: work around 1s delay added when using twisted reactor's callLater.
Since wxPython4, using wxReactor from non-main thread was producing
exceptions in wxWidget's C++ code. Then reactor.run() was called from
main thread, and runtime's worker was delegating calls to reactor
with callLater(0, callable).
While this worked perfectly with wxReactor, it did introduce an unexplained
1 second delay to each worker call when using nomal linux reactors
(i.e. without wxPython). As a workaround reactor runs in a thread when using
twisted without wxPython
// 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();
}