SVGHMI: Add inhibition to widget's apply_hmi_value() so that it does not change variable more frquently than given widget's frequency. This prevents flooding network with many update if browser is producing events at high rate, as for exemple when dragging ScrollBar's cursor.
// widget_scrollbar.ysl2
template "widget[@type='ScrollBar']", mode="widget_class"{
||
class ScrollBarWidget extends Widget{
frequency = 10;
position = undefined;
range = undefined;
size = undefined;
mincursize = 0.1;
dispatch(value,oldval, index) {
switch(index) {
case 0:
if (Math.round(this.position) != value)
this.position = value;
break;
case 1:
this.range = value;
break;
case 2:
this.size = value;
break;
}
this.request_animate();
}
get_ratios() {
let range = this.range;
let size = Math.max(this.range * this.mincursize, Math.min(this.size, range));
let maxh = this.range_elt.height.baseVal.value;
let pixels = (range - size) * maxh;
let units = range*range;
return [size, maxh, range, pixels, units];
}
animate(){
if(this.position == undefined || this.range == undefined || this.size == undefined)
return;
let [size, maxh, range, pixels, units] = this.get_ratios();
let new_y = this.range_elt.y.baseVal.value + Math.round(Math.min(this.position,range) * pixels / units);
let new_height = Math.round(maxh * size/range);
this.cursor_elt.y.baseVal.value = new_y;
this.cursor_elt.height.baseVal.value = new_height;
}
init_mandatory() {
this.cursor_elt.onpointerdown = () => this.on_cursor_down();
this.bound_drag = this.drag.bind(this);
this.bound_drop = this.drop.bind(this);
}
apply_position(position){
this.position = Math.max(Math.min(position, this.range), 0);
this.apply_hmi_value(0, Math.round(this.position));
}
on_page_click(is_up){
this.apply_position(is_up ? this.position-this.size
: this.position+this.size);
}
on_cursor_down(e){
// get scrollbar -> root transform
let ctm = this.range_elt.getCTM();
// relative motion -> discard translation
ctm.e = 0;
ctm.f = 0;
// root -> scrollbar transform
this.invctm = ctm.inverse();
svg_root.addEventListener("pointerup", this.bound_drop, true);
svg_root.addEventListener("pointermove", this.bound_drag, true);
}
drop(e) {
svg_root.removeEventListener("pointerup", this.bound_drop, true);
svg_root.removeEventListener("pointermove", this.bound_drag, true);
}
drag(e) {
let [size, maxh, range, pixels, units] = this.get_ratios();
if(pixels == 0) return;
let point = new DOMPoint(e.movementX, e.movementY);
let movement = point.matrixTransform(this.invctm).y;
this.apply_position(this.position + movement * units / pixels);
}
}
||
}
template "widget[@type='ScrollBar']", mode="widget_defs" {
param "hmi_element";
labels("cursor range");
const "pagebuttons" optional_labels("pageup pagedown");
const "have_pagebuttons","string-length($pagebuttons)>0";
value "$pagebuttons";
| init: function() {
| this.init_mandatory();
if "$have_pagebuttons" {
| this.pageup_elt.onclick = () => this.on_page_click(true);
| this.pagedown_elt.onclick = () => this.on_page_click(false);
}
| },
}