// widget_jump.ysl2

widget_desc("Jump") {
    longdesc
    ||
    Jump widget brings focus to a different page. Mandatory single argument
    gives name of the page.

    Optional single path is used as new reference when jumping to a relative
    page, it must point to a HMI_NODE.

    "active"+"inactive" labeled elements can be provided and reflect current
    page being shown.

    "disabled" labeled element, if provided, is shown instead of "active" or
    "inactive" widget when pointed HMI_NODE is null.
    ||

    shortdesc > Jump to given page

    arg name="page" accepts="string" > name of page to jump to

    path name="reference" count="optional" accepts="HMI_NODE" > reference for relative jump
}

widget_class("Jump") {
||
        activable = false;
        active = false;
        disabled = false;
        frequency = 2;

        update_activity() {
            if(this.active) {
                 /* show active */ 
                 this.active_elt.style.display = "";
                 /* hide inactive */ 
                 this.inactive_elt.style.display = "none";
            } else {
                 /* show inactive */ 
                 this.inactive_elt.style.display = "";
                 /* hide active */ 
                 this.active_elt.style.display = "none";
            }
        }

        update_disability() {
            if(this.disabled) {
                /* show disabled */ 
                this.disabled_elt.style.display = "";
                /* hide inactive */ 
                this.inactive_elt.style.display = "none";
                /* hide active */ 
                this.active_elt.style.display = "none";
            } else {
                /* hide disabled */ 
                this.disabled_elt.style.display = "none";
                this.update_activity();
            }
        }

        make_on_click() {
            let that = this;
            const name = this.args[0];
            return function(evt){
                /* TODO: in order to allow jumps to page selected through for exemple a dropdown,
                   support path pointing to local variable whom value 
                   would be an HMI_TREE index and then jump to a relative page not hard-coded in advance */

                if(!that.disabled) {
                    const index = that.indexes.length > 0 ? that.indexes[0] + that.offset : undefined;
                    switch_page(name, index);
                }
            }
        }

        notify_page_change(page_name, index) {
            if(this.activable) {
                const ref_index = this.indexes.length > 0 ? this.indexes[0] + this.offset : undefined;
                const ref_name = this.args[0];
                this.active = ((ref_name == undefined || ref_name == page_name) && index == ref_index);
                this.update_state();
            }
        }

        dispatch(value) {
            this.disabled = !Number(value);
            this.update_state();
        }
||
}

widget_defs("Jump") {
    // TODO: ensure both active and inactive are provided
    const "activity" optional_labels("active inactive");
    const "have_activity","string-length($activity)>0";
    value "$activity";

    const "disability" optional_labels("disabled");
    const "have_disability","$have_activity and string-length($disability)>0";
    value "$disability";

    |     init: function() {
    |         this.element.onclick = this.make_on_click();
    if "$have_activity" {
    |         this.activable = true;
    }
    if "not($have_disability)" {
    |         this.unsubscribable = true;
    }
    >         this.update_state = 
    choose {
        when "$have_disability" {
            > this.update_disability
        }
        when "$have_activity" {
            > this.update_activity
        }
        otherwise > null
    }
    > ;\n
    |     },

}

widget_page("Jump"){
    param "page_desc";
    /* check that given path is compatible with page's reference path */
    if "path" {
        /* TODO: suport local variable containing an HMI_TREE index to jump to a relative page */
        /* when no page name provided, check for same page */
        const "target_page_name" choose {
            when "arg" value "arg[1]/@value";
            otherwise value "$page_desc/arg[1]/@value";
        }
        const "target_page_path" choose {
            when "arg" value "$hmi_pages_descs[arg[1]/@value = $target_page_name]/path[1]/@value";
            otherwise value "$page_desc/path[1]/@value";
        }

        if "not(func:same_class_paths($target_page_path, path[1]/@value))"
            error > Jump id="«@id»" to page "«$target_page_name»" with incompatible path "«path[1]/@value» (must be same class as "«$target_page_path»")
    }
}

emit "declarations:jump"
||
var jumps_need_update = false;
var jump_history = [[default_page, undefined]];

function update_jumps() {
    page_desc[current_visible_page].jumps.map(w=>w.notify_page_change(current_visible_page,current_page_index));
    jumps_need_update = false;
};

||