HGKeeper

// widget_touchdetect.ysl2 — global overlay; place the group as a direct child of the root

// svg alongside HMI:Page groups so it is not removed on page changes.

widget_desc("TouchDetect") {

longdesc

TouchDetect publishes whether any finger is on the screen via one HMI variable (first path).

Place the group under the document svg as a sibling of page groups (it is not tied to any page's

widget list). init() sets relativeness/offset so get_variable_index works without calling sub()

(sub() registers with subscribers and runs apply_cache; not needed for outbound-only touch writes).

Label example: HMI:TouchDetect@/YourBoolOrInt — while at least one touch pointer is active the

variable is 1, otherwise 0. Listeners are on document.body (pointerdown/pointerup/pointercancel).

shortdesc > Global touch active flag (body pointer events, touch pointers only)

path name="touch_active" count="1" accepts="HMI_BOOL,HMI_INT"

}

widget_class("TouchDetect") {

init() {

const n = this.indexes ? this.indexes.length : 0;

if (n > 0) {

this.offset = 0;

this.relativeness = Array(n).fill(false);

this.container_id = "";

}

this._touchPointerIds = new Set();

this._onPointerDown = (e) => {

if (this._touchPointerIds.size === 0) {

this.apply_hmi_value(0, 1);

}

this._touchPointerIds.add(e.pointerId);

};

this._onPointerUp = (e) => {

this._touchPointerIds.delete(e.pointerId);

if (this._touchPointerIds.size === 0) {

this.apply_hmi_value(0, 0);

}

};

document.body.addEventListener("pointerdown", this._onPointerDown, { passive: true });

document.body.addEventListener("pointerup", this._onPointerUp, { passive: true });

document.body.addEventListener("pointercancel", this._onPointerUp, { passive: true });

}

widget_defs("TouchDetect") {

if "count(path) != 1"

error > TouchDetect id="«@id»": exactly one HMI path is required (e.g. HMI:TouchDetect@/PLC_TOUCH_ACTIVE)

}