Create keyboard mode for ui-ace editor

src/core_plugins/kibana/public/management/sections/objects/_view.html

@@ -130,6 +130,7 @@ <h1 class="kuiTitle">
 
           <div
             ng-if="field.type === 'json' || field.type === 'array'"
+            kbn-ui-ace-keyboard-mode
             ui-ace="{ onLoad: aceLoaded, mode: 'json' }"
             id="{{field.name}}"
             ng-model="field.value"

src/core_plugins/kibana/public/management/sections/objects/_view.js

@@ -5,6 +5,7 @@ import { savedObjectManagementRegistry } from 'plugins/kibana/management/saved_o
 import objectViewHTML from 'plugins/kibana/management/sections/objects/_view.html';
 import uiRoutes from 'ui/routes';
 import { uiModules } from 'ui/modules';
+import 'ui/accessibility/kbn_ui_ace_keyboard_mode';
 import { castEsToKbnFieldTypeName } from '../../../../../../utils';
 import { SavedObjectsClientProvider } from 'ui/saved_objects';
 

src/ui/public/accessibility/__tests__/kbn_ui_ace_keyboard_mode.js

@@ -0,0 +1,57 @@
+import angular from 'angular';
+import sinon from 'sinon';
+import expect from 'expect.js';
+import ngMock from 'ng_mock';
+import '../kbn_ui_ace_keyboard_mode';
+import {
+  ENTER_KEY,
+  ESC_KEY_CODE,
+} from 'ui_framework/services';
+
+describe('kbnUiAceKeyboardMode directive', () => {
+  let element;
+
+  beforeEach(ngMock.module('kibana'));
+
+  beforeEach(ngMock.inject(($compile, $rootScope) => {
+    element = $compile(`<div ui-ace kbn-ui-ace-keyboard-mode></div>`)($rootScope.$new());
+  }));
+
+  it('should add the hint element', () => {
+    expect(element.find('.ui-ace-keyboard-hint').length).to.be(1);
+  });
+
+  describe('hint element', () => {
+    it('should be tabable', () => {
+      expect(element.find('.ui-ace-keyboard-hint').attr('tabindex')).to.be('0');
+    });
+
+    it('should move focus to textbox and be inactive if pressed enter on it', () => {
+      const textarea = element.find('textarea');
+      sinon.spy(textarea[0], 'focus');
+      const ev = angular.element.Event('keydown'); // eslint-disable-line new-cap
+      ev.keyCode = ENTER_KEY;
+      element.find('.ui-ace-keyboard-hint').trigger(ev);
+      expect(textarea[0].focus.called).to.be(true);
+      expect(element.find('.ui-ace-keyboard-hint').hasClass('ui-ace-keyboard-hint-inactive')).to.be(true);
+    });
+
+    it('should be shown again, when pressing Escape in ace editor', () => {
+      const textarea = element.find('textarea');
+      const hint = element.find('.ui-ace-keyboard-hint');
+      sinon.spy(hint[0], 'focus');
+      const ev = angular.element.Event('keydown'); // eslint-disable-line new-cap
+      ev.keyCode = ESC_KEY_CODE;
+      textarea.trigger(ev);
+      expect(hint[0].focus.called).to.be(true);
+      expect(hint.hasClass('ui-ace-keyboard-hint-inactive')).to.be(false);
+    });
+  });
+
+  describe('ui-ace textarea', () => {
+    it('should not be tabable anymore', () => {
+      expect(element.find('textarea').attr('tabindex')).to.be('-1');
+    });
+  });
+
+});

src/ui/public/accessibility/kbn_ui_ace_keyboard_mode.js

@@ -0,0 +1,80 @@
+/**
+ * The `kbn-ui-ace-keyboard-mode` directive should be used on any element, that
+ * `ui-ace` is used on. It will prevent the keyboard trap, that ui-ace usually
+ * has, i.e. tabbing into the box won't give you any possibilities to leave
+ * it via keyboard again, since tab inside the textbox works like a tab character.
+ *
+ * This directive won't change anything, if the user uses the mouse. But if she
+ * tabs to the ace editor, an overlay will be shown, that you have to press Enter
+ * to enter editing mode, and that it can be left by pressing Escape again.
+ *
+ * That way the ui-ace editor won't trap keyboard focus, and won't cause that
+ * accessibility issue anymore.
+ */
+
+import angular from 'angular';
+import { uiModules } from 'ui/modules';
+import './kbn_ui_ace_keyboard_mode.less';
+import { ESC_KEY_CODE, ENTER_KEY } from 'ui_framework/services';
+
+let aceKeyboardModeId = 0;
+
+uiModules.get('kibana').directive('kbnUiAceKeyboardMode', () => ({
+  restrict: 'A',
+  link(scope, element) {
+    const uniqueId = `uiAceKeyboardHint-${scope.$id}-${aceKeyboardModeId++}`;
+
+    const hint = angular.element(
+      `<div
+        class="uiAceKeyboardHint"
+        id="${uniqueId}"
+        tabindex="0"
+        role="application"
+      >
+        <p class="kuiText kuiVerticalRhythmSmall">
+          Press Enter to start editing.
+        </p>
+        <p class="kuiText kuiVerticalRhythmSmall">
+          When you&rsquo;re done, press Escape to stop editing.
+        </p>
+      </div>
+    `);
+
+    const uiAceTextbox = element.find('textarea');
+
+    function startEditing() {
+      // We are not using ng-class in the element, so that we won't need to $compile it
+      hint.addClass('uiAceKeyboardHint-isInactive');
+      uiAceTextbox.focus();
+    }
+
+    function enableOverlay() {
+      hint.removeClass('uiAceKeyboardHint-isInactive');
+    }
+
+    hint.keydown((ev) => {
+      if (ev.keyCode === ENTER_KEY) {
+        ev.preventDefault();
+        startEditing();
+      }
+    });
+
+    uiAceTextbox.blur(() => {
+      enableOverlay();
+    });
+
+    uiAceTextbox.keydown((ev) => {
+      if (ev.keyCode === ESC_KEY_CODE) {
+        ev.preventDefault();
+        ev.stopPropagation();
+        enableOverlay();
+        hint.focus();
+      }
+    });
+
+    hint.click(startEditing);
+    // Prevent tabbing into the ACE textarea, we now handle all focusing for it
+    uiAceTextbox.attr('tabindex', '-1');
+    element.prepend(hint);
+  }
+}));

src/ui/public/accessibility/kbn_ui_ace_keyboard_mode.less

@@ -0,0 +1,26 @@
+@import (reference) "~ui/styles/variables";
+
+.uiAceKeyboardHint {
+  position: absolute;
+  top: 0;
+  bottom: 0;
+  right: 0;
+  left: 0;
+  background: rgba(255, 255, 255, 0.7);
+  display: flex;
+  flex-direction: column;
+  justify-content: center;
+  align-items: center;
+  text-align: center;
+  opacity: 0;
+
+  &:focus {
+    opacity: 1;
+    border: 2px solid @globalColorBlue;
+    z-index: 1000;
+  }
+
+  &.uiAceKeyboardHint-isInactive {
+    display: none;
+  }
+}

src/ui/public/filter_editor/filter_query_dsl_editor.html

@@ -1,6 +1,7 @@
 <div
   json-input
   require-keys="true"
+  kbn-ui-ace-keyboard-mode
   ui-ace="{
     mode: 'json',
     onLoad: aceLoaded

src/ui/public/filter_editor/filter_query_dsl_editor.js

@@ -2,6 +2,7 @@ import 'ace';
 import _ from 'lodash';
 import { uiModules } from 'ui/modules';
 import template from './filter_query_dsl_editor.html';
+import 'ui/accessibility/kbn_ui_ace_keyboard_mode';
 
 const module = uiModules.get('kibana');
 module.directive('filterQueryDslEditor', function () {