{
           "manifest_version": 2.0,
           "id": "lesson_gauge_chart",
           "type": "widget",
           "name": "Gauge chart",
           "namespace": "LessonGaugeChart",
           "version": "1.0",
           "author": "Zabbix SIA"
       }

<?php
       
       /**
        * View віджета Gauge chart.
        *
       * @var CView $this
        * @var array $data
        */
       
       (new CWidgetView($data))
           ->additem(
               new CTag('h1', true, 'Hello, world!')
           )
           ->show();

<?php
       
       namespace Modules\LessonGaugeChart\Includes;
       
       use Zabbix\Widgets\CWidgetForm;
       
       class WidgetForm extends CWidgetForm {
       }

<?php
       
       namespace Modules\LessonGaugeChart\Includes;
       
       use Zabbix\Widgets\CWidgetForm;
       
       use Zabbix\Widgets\Fields\CWidgetFieldTextBox;
       
       class WidgetForm extends CWidgetForm {
       
           public function addFields(): self {
           return $this
           ->addField(
          new CWidgetFieldTextBox('description', _('Description'))
                   );
          }
       }

<?php
       
       /**
         * Gauge chart widget form view.
        *
        * @var CView $this
        * @var array $data
        */
       
       (new CWidgetFormView($data))
           ->addField(
          new CWidgetFieldTextBoxView($data['fields']['description'])
           )
           ->show();

<?php
       
       namespace Modules\LessonGaugeChart\Actions;
       
       use CControllerDashboardWidgetView,
           CControllerResponseData;
       
       class WidgetView extends CControllerDashboardWidgetView {
       
           protected function doAction(): void {
               $this->setResponse(new CControllerResponseData([
                   'name' => $this->getInput('name', $this->widget->getName()),
                   'description' => $this->fields_values['description'],
                   'user' => [
                       'debug_mode' => $this->getDebugMode()
                   ]
               ]));
           }
       }

{
           "manifest_version": 2.0,
           "id": "leson_gauge_chart",
           "type": "widget",
           "name": "Gauge chart",
           "namespace": "LessonGaugeChart",
           "version": "1.0",
           "author": "Zabbix SIA",
           "actions": {
               "widget.lesson_gauge_chart.view": {
                   "class": "WidgetView"
               }
           }
       }

<?php
       
       /**
        * Gauge chart widget view.
        *
       * @var CView $this
        * @var array $data
        */
       
       (new CWidgetView($data))
           ->additem(
           new CTag('h1', true, $data['description'])
           )
           ->show();

<?php
       
       amespace Modules\LessonGaugeChart\Includes;
       
       use Zabbix\Widgets\{
           CWidgetField,
           CWidgetForm
       };
       
       use Zabbix\Widgets\Fields\{
           CWidgetFieldMultiSelectItem,
           CWidgetFieldTextBox
       };
       
       /**
        * Gauge chart widget form.
        */
       class WidgetForm extends CWidgetForm {
       
           public function addFields(): self {
           return $this
           ->addField(
           (new CWidgetFieldMultiSelectItem('itemid', _('Item')))
           ->setFlags(CWidgetField::FLAG_NOT_EMPTY | CWidgetField::FLAG_LABEL_ASTERISK)
           ->setMultiple(false)
           )
          ->addField(
         new CWidgetFieldTextBox('description', _('Description'))
         );
           }
       }

<?php
       
       /**
        * Gauge chart widget form view.
        *
        * @var CView $this
        * @var array $data
        */
       
       (new CWidgetFormView($data))
           ->addField(new CWidgetFieldMultiSelectItemView($data['fields']['itemid'], $data['captions']['items']['itemid'])
           )
           ->addField(
           new CWidgetFieldTextBoxView($data['fields']['description'])
           )
           ->show();

<?php
       
       namespace Modules\LessonGaugeChart\Actions;
       
       use API,
           CControllerDashboardWidgetView,
           CControllerResponseData;
       
       class WidgetView extends CControllerDashboardWidgetView {
       
           protected function doAction(): void {
           $db_items = API::Item()->get([
           'output' => ['itemid', 'value_type', 'name', 'units'],
            'itemids' => $this->fields_values['itemid'],
            'webitems' => true,
            'filter' => [
            'value_type' => [ITEM_VALUE_TYPE_UINT64, ITEM_VALUE_TYPE_FLOAT]
            ]
            ]);
       
            $value = null;
       
             if ($db_items) {
             $item = $db_items[0];
       
             $history = API::History()->get([
             'output' => API_OUTPUT_EXTEND,
              'itemids' => $item['itemid'],
              'history' => $item['value_type'],
              'sortfield' => 'clock',
              'sortorder' => ZBX_SORT_DOWN,
              'limit' => 1
              ]);
       
              if ($history) {
              $value = convertUnitsRaw([
              'value' => $history[0]['value'],
              'units' => $item['units']
              ]);
              }
              }
       
               $this->setResponse(new CControllerResponseData([
               'name' => $this->getInput('name', $this->widget->getName()),
               'value' => $value,
               'description' => $this->fields_values['description'],
               'user' => [
                'debug_mode' => $this->getDebugMode()
                ]
               ]));
               }
       }

<?php
       
       /**
        * Gauge chart widget view.
        *
        * @var CView $this 
       * @var array $data
        */
       
       (new CWidgetView($data))
           ->addItem([
           new CTag('h1', true, $data['description']),
           new CDiv($data['value'] !== null ? $data['value']['value'] : _('No data'))
           ])
          ->show();

<?php
       
       use Modules\LessonGaugeChart\Widget;
       
       ?>
       
       window.widget_lesson_gauge_chart_form = new class {
       
       init({color_palette}) {
       this._form = document.getElementById('widget-dialogue-form');
       
       this._advanced_configuration = document.getElementById('adv_conf');
       this._unit_select = document.getElementById('value_units');
       this._unit_value = document.getElementById('value_static_units');
       
       this._advanced_configuration.addEventListener('change', () => this.updateForm());
       this._unit_select.addEventListener('change', () => this.updateForm());
       
       colorPalette.setThemeColors(color_palette);
       
       for (const colorpicker of jQuery('.<?= ZBX_STYLE_COLOR_PICKER ?> input')) {
       jQuery(colorpicker).colorpicker();
       }
       
       const overlay = overlays_stack.getById('widget_properties');
       
       for (const event of ['overlay.reload', 'overlay.close']) {
       overlay.$dialogue[0].addEventListener(event, () => { jQuery.colorpicker('hide'); });
       }
       
       this.updateForm();
       }
       
       updateForm() {
       const show_advanced_configuration = this._advanced_configuration.checked;
       
       for (const element of this._form.querySelectorAll('.js-advanced-configuration')) {
       element.style.display = show_advanced_configuration ? '' : 'none';
       }
       
       this._unit_value.disabled = this._unit_select.value == <?= Widget::UNIT_AUTO ?>;
       }
       };

<?php 
       
       namespace Modules\LessonGaugeChart;
       
       use Zabbix\Core\CWidget;
       
       class Widget extends CWidget {
       
       public const UNIT_AUTO = 0;
       public const UNIT_STATIC = 1;
       
       public function getTranslationStrings(): array {
       return [
       'class.widget.js' => [
       'No data' => _('No data')
       ]
       ];
       }
       }

<?php
       
       namespace Modules\LessonGaugeChart\Includes;
       
       use Modules\LessonGaugeChart\Widget;
       
       use Zabbix\Widgets\{
       CWidgetField,
       CWidgetForm
       };
       
       use Zabbix\Widgets\Fields\{
       CWidgetFieldCheckBox,
       CWidgetFieldColor,
       CWidgetFieldMultiSelectItem,
       CWidgetFieldNumericBox,
       CWidgetFieldSelect,
       CWidgetFieldTextBox
       };
       /** 
       * Gauge chart widget form. 
       */
       class WidgetForm extends CWidgetForm {
       
       public function addFields(): self {
       return $this
       ->addField(
       (new CWidgetFieldMultiSelectItem('itemid', _('Item')))
       ->setFlags(CWidgetField::FLAG_NOT_EMPTY | CWidgetField::FLAG_LABEL_ASTERISK)
       ->setMultiple(false)
       ->setFilterParameter('numeric', true)
       )
       ->addField(
       new CWidgetFieldCheckBox('adv_conf', _('Advanced configuration'))
       )
       ->addField(
       (new CWidgetFieldColor('chart_color', _('Color')))->setDefault('FF0000')
       )
       ->addField(
       (new CWidgetFieldNumericBox('value_min', _('Min')))
       ->setDefault(0)
       ->setFlags(CWidgetField::FLAG_NOT_EMPTY | CWidgetField::FLAG_LABEL_ASTERISK)
       )
       ->addField(
       (new CWidgetFieldNumericBox('value_max', _('Max')))
       ->setDefault(100)
       ->setFlags(CWidgetField::FLAG_NOT_EMPTY | CWidgetField::FLAG_LABEL_ASTERISK)
       )
       ->addField(
       (new CWidgetFieldSelect('value_units', _('Units'), [
       Widget::UNIT_AUTO => _x('Auto', 'history source selection method'),
       Widget::UNIT_STATIC => _x('Static', 'history source selection method')
       ]))->setDefault(Widget::UNIT_AUTO)
       )
       ->addField(
       (new CWidgetFieldTextBox('value_static_units'))
       )
       ->addField(
       new CWidgetFieldTextBox('description', _('Description'))
       );
       }
       }

<?php
       
       /** 
       * Gauge chart widget form view. 
       * 
       * @var CView $this 
       * @var array $data 
       */
       
       use Zabbix\Widgets\Fields\CWidgetFieldGraphDataSet;
       
       $lefty_units = new CWidgetFieldSelectView($data['fields']['value_units']);
       $lefty_static_units = (new CWidgetFieldTextBoxView($data['fields']['value_static_units']))
       ->setPlaceholder(_('value'))
       ->setWidth(ZBX_TEXTAREA_TINY_WIDTH);
       
       (new CWidgetFormView($data))
       ->addField(
       new CWidgetFieldMultiSelectItemView($data['fields']['itemid'], $data['captions']['items']['itemid'])
       )
       ->addField(
       new CWidgetFieldCheckBoxView($data['fields']['adv_conf'])
       )
       ->addField(
       new CWidgetFieldColorView($data['fields']['chart_color']),
       'js-advanced-configuration'
       )
       ->addField(
       new CWidgetFieldNumericBoxView($data['fields']['value_min']),
       'js-advanced-configuration'
       )
       ->addField(
       new CWidgetFieldNumericBoxView($data['fields']['value_max']),
       'js-advanced-configuration'
       )
       ->addItem([
       $lefty_units->getLabel()->addClass('js-advanced-configuration'),
       (new CFormField([
       $lefty_units->getView()->addClass(ZBX_STYLE_FORM_INPUT_MARGIN),
       $lefty_static_units->getView()
       ]))->addClass('js-advanced-configuration')
       ])
       ->addField(
       new CWidgetFieldTextBoxView($data['fields']['description']),
       'js-advanced-configuration'
       )
       ->includeJsFile('widget.edit.js.php')
       ->addJavaScript('widget_lesson_gauge_chart_form.init('.json_encode([
       'color_palette' => CWidgetFieldGraphDataSet::DEFAULT_COLOR_PALETTE
       ], JSON_THROW_ON_ERROR).');')
       ->show();

<?php
       
       namespace Modules\LessonGaugeChart\Actions;
       
       use API,
       CControllerDashboardWidgetView,
       CControllerResponseData;
       
       class WidgetView extends CControllerDashboardWidgetView {
       
       protected function doAction(): void {
       $db_items = API::Item()->get([
       'output' => ['itemid', 'value_type', 'name', 'units'],
       'itemids' => $this->fields_values['itemid'],
       'webitems' => true,
       'filter' => [
       'value_type' => [ITEM_VALUE_TYPE_UINT64, ITEM_VALUE_TYPE_FLOAT]
       ]
       ]);
       
       $history_value = null;
       
       if ($db_items) {
       $item = $db_items[0];
       
       $history = API::History()->get([
       'output' => API_OUTPUT_EXTEND,
       'itemids' => $item['itemid'],
       'history' => $item['value_type'],
       'sortfield' => 'clock',
       'sortorder' => ZBX_SORT_DOWN,
       'limit' => 1
       ]);
       
       if ($history) {
       $history_value = convertUnitsRaw([
       'value' => $history[0]['value'],
       'units' => $item['units']
       ]);
       }
       }
       
       $this->setResponse(new CControllerResponseData([
       'name' => $this->getInput('name', $this->widget->getName()),
       'history' => $history_value,
       'fields_values' => $this->fields_values,
       'user' => [
       'debug_mode' => $this->getDebugMode()
       ]
       ]));
       }
       }

<?php
       
       /** 
       * Gauge chart widget view. 
       * 
       * @var CView $this 
       * @var array $data 
       */
       
       (new CWidgetView($data))
       ->addItem([
       (new CDiv())->addClass('chart'),
       $data['fields_values']['description']
       ? (new CDiv($data['fields_values']['description']))->addClass('description')
       : null
       ])
       ->setVar('history', $data['history'])
       ->setVar('fields_values', $data['fields_values'])
       ->show();

class WidgetLessonGaugeChart extends CWidget {
       
       static UNIT_AUTO = 0;
       static UNIT_STATIC = 1;
       
       _init() {
       super._init();
       
       this._refresh_frame = null;
       this._chart_container = null;
       this._canvas = null;
       this._chart_color = null;
       this._min = null;
       this._max = null;
       this._value = null;
       this._last_value = null;
       this._units = '';
       }
       
       _processUpdateResponse(response) {
       if (response.history === null) {
       this._value = null;
       this._units = '';
       }
       else {
       this._value = Number(response.history.value);
       this._units = response.fields_values.value_units == WidgetLessonGaugeChart.UNIT_AUTO
       ? response.history.units
       : response.fields_values.value_static_units;
       }
       
       this._chart_color = response.fields_values.chart_color;
       this._min = Number(response.fields_values.value_min);
       this._max = Number(response.fields_values.value_max);
       
       if (this._canvas === null) {
       super._processUpdateResponse(response);
       
       this._chart_container = this._content_body.querySelector('.chart');
       this._canvas = document.createElement('canvas');
       
       this._chart_container.appendChild(this._canvas);
       
       this._resizeChart();
       
       }
       else {
       this._updatedChart();
       }
       }
       
       resize() {
       super.resize();
       
       if (this._state === WIDGET_STATE_ACTIVE) {
       this._resizeChart();
       }
       }
       
       _resizeChart() {
       const ctx = this._canvas.getContext('2d');
       const dpr = window.devicePixelRatio;
       
       this._canvas.style.display = 'none';
       const size = Math.min(this._chart_container.offsetWidth, this._chart_container.offsetHeight);
       this._canvas.style.display = '';
       
       this._canvas.width = size * dpr;
       this._canvas.height = size * dpr;
       
       ctx.scale(dpr, dpr);
       
       this._canvas.style.width = `${size}px`;
       this._canvas.style.height = `${size}px`;
       
       this._refresh_frame = null;
       
       this._updatedChart();
       }
       
       _updatedChart() {
       if (this._last_value === null) {
       this._last_value = this._min;
       }
       
       const start_time = Date.now();
       const end_time = start_time + 400;
       
       const animate = () => {
       const time = Date.now();
       
       if (time <= end_time) {
       const progress = (time - start_time) / (end_time - start_time);
       const smooth_progress = 0.5 + Math.sin(Math.PI * (progress - 0.5)) / 2;
       let value = this._value !== null ? this._value : this._min;
       value = (this._last_value + (value - this._last_value) * smooth_progress - this._min) / (this._max - this._min);
       
       const ctx = this._canvas.getContext('2d');
       const size = this._canvas.width;
       const char_weight = size / 12;
       const char_shadow = 3;
       const char_x = size / 2;
       const char_y = size / 2
       ;const char_radius = (size - char_weight) / 2 - char_shadow;
       
       const font_ratio = 32 / 100;
       
       ctx.clearRect(0, 0, size, size);
       
       ctx.beginPath();ctx.shadowBlur = char_shadow;
       ctx.shadowColor = '#bbb';
       ctx.strokeStyle = '#eee';
       ctx.lineWidth = char_weight;
       ctx.lineCap = 'round';
       ctx.arc(char_x, char_y, char_radius, Math.PI * 0.749, Math.PI * 2.251, false);
       ctx.stroke();
       
       ctx.beginPath();
       ctx.strokeStyle = `#${this._chart_color}`;
       ctx.lineWidth = char_weight - 2;
       ctx.lineCap = 'round';
       ctx.arc(char_x, char_y, char_radius, 
       Math.PI * 0.75,Math.PI * (0.75 + (1.5 * Math.min(1, Math.max(0, value)))), false
       );
       ctx.stroke();
       
       ctx.shadowBlur = 2;
       ctx.fillStyle = '#1f2c33';
       ctx.font = `${(char_radius * font_ratio)|0}px Arial`;
       ctx.textAlign = 'center';
       ctx.textBaseline = 'middle';
       ctx.fillText(`${this._value !== null ? this._value : t('No data')}${this._units}`,
       char_x, char_y, size - char_shadow * 4 - char_weight * 2
       );
       
       ctx.fillStyle = '#768d99';
       ctx.font = `${(char_radius * font_ratio * .5)|0}px Arial`;
       ctx.textBaseline = 'top';
       
       ctx.textAlign = 'left';
       ctx.fillText(`${this._min}${this._min != '' ? this._units : ''}`,
       char_weight * .75, size - char_weight * 1.25, size / 2 - char_weight
       );
       
       ctx.textAlign = 'right';
       ctx.fillText(`${this._max}${this._max != '' ? this._units : ''}`,
       size - char_weight * .75, size - char_weight * 1.25, size / 2 - char_weight
       );
       
       requestAnimationFrame(animate);
       }
       else {
       this._last_value = this._value;
       }
       };
       
       requestAnimationFrame(animate);
       }
       }

{
       "manifest_version": 2.0,
       "id": "lesson_gauge_chart",
       "type": "widget",
       "name": "Gauge chart",
       "namespace": "LessonGaugeChart",
       "version": "1.0",
       "author": "Zabbix SIA",
       "actions": {
       "widget.lesson_gauge_chart.view": {
       "class": "WidgetView"
       }
       },
       "widget": {
       "js_class": "WidgetLessonGaugeChart"
       },
       "assets": {
       "js": ["class.widget.js"]
       }
       }

div.dashboard-widget-lesson_gauge_chart {
           display: grid;
           grid-template-rows: 1fr;
           padding: 0; 
       }
       
       div.dashboard-widget-lesson_gauge_chart .chart {
           display: grid;
           align-items: center;
           justify-items: center; 
       }
       
       div.dashboard-widget-lesson_gauge_chart .chart canvas {
           background: white; 
       }
       
       div.dashboard-widget-lesson_gauge_chart .description {
           padding-bottom: 8px;
           font-size: 1.750em;
           line-height: 1.2;text-align: center; 
       }
       
       .dashboard-grid-widget-hidden-header div.dashboard-widget-lesson_gauge_chart .chart {
           margin-top: 8px; 
       }

{
           "manifest_version": 2.0,
           "id": "leson_gauge_chart",
          "type": "widget",
           "name": "Gauge chart",
           "namespace": "LessonGaugeChart",
           "version": "1.0",
           "author": "Zabbix SIA",
           "actions": {
            "widget.lesson_gauge_chart.view": {
            "class": "WidgetView"
               }
           },
           "widget": {
               "js_class": "WidgetLessonGaugeChart"
           },
           "assets": {
               "css": ["widget.css"],
               "js": ["class.widget.js"]
           }
       }