// widget_foreach.ysl2

widget_desc("ForEach") {

longdesc

||

ForEach widget is used to span a small set of widget over a larger set of

repeated HMI_NODEs.

Idea is somewhat similar to relative page, but it all happens inside the

ForEach widget, no page involved.

Together with relative Jump widgets it can be used to build a menu to reach

relative pages covering many identical HMI_NODES siblings.

ForEach widget takes a HMI_CLASS name as argument and a HMI_NODE path as

variable.

Direct sub-elements can be either groups of widget to be spanned, labeled

"ClassName:offset", or buttons to control the spanning, labeled

"ClassName:+/-number".

In case of "ClassName:offset", offset for first element is 1.

||

shortdesc > span widgets over a set of repeated HMI_NODEs

arg name="class_name" accepts="string" > HMI_CLASS name

path name="root" accepts="HMI_NODE" > where to find HMI_NODEs whose HMI_CLASS is class_name

path name="position" accepts="HMI_INT" > position of HMI_NODE mapped to first item, among similar siblings

path name="range" accepts="HMI_INT" count="optional" > count of HMI_NODE siblings

path name="size" accepts="HMI_INT" count="optional" > count of visible items

}

widget_defs("ForEach") {

if "count(path) < 1" error > ForEach widget «$hmi_element/@id» must have one HMI path given.

if "count(arg) != 1" error > ForEach widget «$hmi_element/@id» must have one argument given : a class name.

const "class","arg[1]/@value";

const "base_path","path/@value";

const "hmi_index_base", "$indexed_hmitree/*[@hmipath = $base_path]";

const "hmi_tree_base", "$hmitree/descendant-or-self::*[@path = $hmi_index_base/@path]";

const "hmi_tree_items", "$hmi_tree_base/*[@class = $class]";

const "hmi_index_items", "$indexed_hmitree/*[@path = $hmi_tree_items/@path]";

const "items_paths", "$hmi_index_items/@hmipath";

| index_pool: [

foreach "$hmi_index_items" {

| «@index»`if "position()!=last()" > ,`

}

| ],

| init: function() {

const "prefix","concat($class,':')";

const "buttons_regex","concat('^',$prefix,'[+\-][0-9]+')";

const "buttons", "$hmi_element/*[regexp:test(@inkscape:label, $buttons_regex)]";

foreach "$buttons" {

const "op","substring-after(@inkscape:label, $prefix)";

| id("«@id»").setAttribute("onclick", "hmi_widgets['«$hmi_element/@id»'].on_click('«$op»', evt)");

}

|

| this.items = [

const "items_regex","concat('^',$prefix,'[0-9]+')";

const "unordered_items","$hmi_element//*[regexp:test(@inkscape:label, $items_regex)]";

foreach "$unordered_items" {

const "elt_label","concat($prefix, string(position()))";

const "elt","$unordered_items[@inkscape:label = $elt_label]";

const "pos","position()";

const "item_path", "$items_paths[$pos]";

| [ /* item="«$elt_label»" path="«$item_path»" */

if "count($elt)=0" error > Missing item labeled «$elt_label» in ForEach widget «$hmi_element/@id»

if "count($elt)>1" error > Duplicate item labeled «$elt_label» in ForEach widget «$hmi_element/@id»

foreach "func:refered_elements($elt)[@id = $hmi_elements/@id][not(@id = $elt/@id)]" {

if "not(func:is_descendant_path(func:widget(@id)/path/@value, $item_path))"

error > Widget id="«@id»" label="«@inkscape:label»" is having wrong path. Accroding to ForEach widget ancestor id="«$hmi_element/@id»", path should be descendant of "«$item_path»".

| hmi_widgets["«@id»"]`if "position()!=last()" > ,`

}

| ]`if "position()!=last()" > ,`

}

| ]

| },

| range: «count($hmi_index_items)»,

| size: «count($unordered_items)»,

| position: 0,

}

widget_class("ForEach")

||

items_subscribed = false;

unsub_items(){

if(this.items_subscribed){

for(let item of this.items){

for(let widget of item) {

widget.unsub();

}

}

this.items_subscribed = false;

}

}

unsub(){

super.unsub()

this.unsub_items();

}

sub_items(){

if(!this.items_subscribed){

for(let i = 0; i < this.size; i++) {

let item = this.items[i];

let orig_item_index = this.index_pool[i];

let item_index = this.index_pool[i+this.position];

let item_index_offset = item_index - orig_item_index;

if(this.relativeness[0])

item_index_offset += this.offset;

for(let widget of item) {

/* all variables of all widgets in a ForEach are all relative.

Really.

TODO: allow absolute variables in ForEach widgets

*/

widget.sub(item_index_offset, widget.indexes.map(_=>true));

}

}

}

}

sub(new_offset, relativeness, container_id){

let position_given = this.indexes.length > 1;

// sub() will call apply_cache() and then dispatch()

// undefining position forces dispatch() to call apply_position()

if(position_given)

this.position = undefined;

super.sub(new_offset, relativeness, container_id);

// if position isn't given as a variable

// dispatch() to call apply_position() aren't called

// and items must be subscibed now.

if(!position_given)

this.sub_items();

// as soon as subribed apply range and size once for all

if(this.indexes.length > 2)

this.apply_hmi_value(2, this.range);

if(this.indexes.length > 3)

this.apply_hmi_value(3, this.size);

}

apply_position(new_position){

let old_position = this.position;

let limited_position = Math.round(Math.max(Math.min(new_position, this.range - this.size), 0));

if(this.position == limited_position){

return false;

}

this.unsub_items();

this.position = limited_position;

this.sub_items();

request_subscriptions_update();

jumps_need_update = true;

this.request_animate();

return true;

}

on_click(opstr, evt) {

let new_position = eval(String(this.position)+opstr);

if(new_position + this.size > this.range) {

if(this.position + this.size == this.range)

new_position = 0;

else

new_position = this.range - this.size;

} else if(new_position < 0) {

if(this.position == 0)

new_position = this.range - this.size;

else

new_position = 0;

}

if(this.apply_position(new_position)){

this.apply_hmi_value(1, this.position);

}

}

dispatch(value, oldval, index) {

// Only care about position, others are constants

if(index == 1){

this.apply_position(value);

if(this.position != value){

// widget refused or apply different value, force it back

this.apply_hmi_value(1, this.position);

}

}

}

||