From c3bf8400461f1d9076ef8e45f38d2c1f53fbe131 Mon Sep 17 00:00:00 2001
From: Jeremy Elbourn <jelbourn@google.com>
Date: Wed, 15 Jul 2015 14:59:04 -0700
Subject: [PATCH] feat(calendar): more fine-tuned a11y

---
 src/components/calendar/calendar.js           | 17 ++++++----
 src/components/calendar/calendar.spec.js      |  2 +-
 src/components/calendar/calendarMonth.js      | 22 ++++++++++---
 src/components/calendar/dateLocaleProvider.js | 16 ++++++++++
 src/components/calendar/datePicker.js         | 32 +++++++++++++------
 src/components/calendar/datePicker.spec.js    |  2 +-
 6 files changed, 68 insertions(+), 23 deletions(-)

diff --git a/src/components/calendar/calendar.js b/src/components/calendar/calendar.js
index 1e07e22b2ce..a63e05703a2 100644
--- a/src/components/calendar/calendar.js
+++ b/src/components/calendar/calendar.js
@@ -15,7 +15,6 @@
 
   // PRE RELEASE
   // TODO(mchen): Date "isComplete" logic
-  // TODO(jelbourn): Fix NVDA stealing key presses (IE) ???
 
   // POST RELEASE
   // TODO(jelbourn): Animated month transition on ng-model change (virtual-repeat)
@@ -41,7 +40,6 @@
   function calendarDirective() {
     return {
       template:
-          //'<input class="md-visually-hidden md-dummy" aria-label="Select a date">' +
           '<table aria-hidden="true" class="md-calendar-day-header"><thead></thead></table>' +
           '<div class="md-calendar-scroll-mask">' +
             '<md-virtual-repeat-container class="md-calendar-scroll-container">' +
@@ -52,8 +50,7 @@
                     'md-item-size="' + TBODY_HEIGHT + '"></tbody>' +
               '</table>' +
             '</md-virtual-repeat-container>' +
-          '</div>' +
-          '<div aria-live="assertive" aria-atomic="true" class="md-visually-hidden"></div>',
+          '</div>',
       scope: {},
       require: ['ngModel', 'mdCalendar'],
       controller: CalendarCtrl,
@@ -269,8 +266,13 @@
     this.$scope.$apply(function() {
       // Capture escape and emit back up so that a wrapping component
       // (such as a date-picker) can decide to close.
-      if (event.which == self.keyCode.ESCAPE) {
-        self.$scope.$emit('md-calendar-escape');
+      if (event.which == self.keyCode.ESCAPE || event.which == self.keyCode.TAB) {
+        self.$scope.$emit('md-calendar-close');
+
+        if (event.which == self.keyCode.TAB) {
+          event.preventDefault();
+        }
+
         return;
       }
 
@@ -285,7 +287,6 @@
       // Selection isn't occuring, so the key event is either navigation or nothing.
       var date = self.getFocusDateFromKeyEvent(event);
       if (date) {
-        console.log('key event');
         event.preventDefault();
         event.stopPropagation();
 
@@ -410,6 +411,7 @@
             self.calendarElement.querySelector('#' + self.getDateId(previousSelectedDate));
         if (prevDateCell) {
           prevDateCell.classList.remove(SELECTED_DATE_CLASS);
+          prevDateCell.setAttribute('aria-selected', 'false');
         }
       }
 
@@ -418,6 +420,7 @@
         var dateCell = self.calendarElement.querySelector('#' + self.getDateId(date));
         if (dateCell) {
           dateCell.classList.add(SELECTED_DATE_CLASS);
+          dateCell.setAttribute('aria-selected', 'true');
         }
       }
     });
diff --git a/src/components/calendar/calendar.spec.js b/src/components/calendar/calendar.spec.js
index 5405ab1f8c4..40c60b93fca 100644
--- a/src/components/calendar/calendar.spec.js
+++ b/src/components/calendar/calendar.spec.js
@@ -275,7 +275,7 @@ describe('md-calendar', function() {
 
     it('should fire an event when escape is pressed', function() {
       var escapeHandler = jasmine.createSpy('escapeHandler');
-      pageScope.$on('md-calendar-escape', escapeHandler);
+      pageScope.$on('md-calendar-close', escapeHandler);
 
       pageScope.myDate = new Date(2014, FEB, 11);
       applyDateChange();
diff --git a/src/components/calendar/calendarMonth.js b/src/components/calendar/calendarMonth.js
index 44aaf62fdaf..af7f5b5114b 100644
--- a/src/components/calendar/calendarMonth.js
+++ b/src/components/calendar/calendarMonth.js
@@ -127,6 +127,7 @@
       if (this.dateUtil.isValidDate(calendarCtrl.selectedDate) &&
           this.dateUtil.isSameDay(opt_date, calendarCtrl.selectedDate)) {
         cell.classList.add(SELECTED_DATE_CLASS);
+        cell.setAttribute('aria-selected', 'true');
       }
 
       if (calendarCtrl.focusDate && this.dateUtil.isSameDay(opt_date, calendarCtrl.focusDate)) {
@@ -136,10 +137,21 @@
 
     return cell;
   };
-  
-  CalendarMonthCtrl.prototype.buildDateRow = function() {
+
+  /**
+   * Builds a `tr` element for the calendar grid.
+   * @param rowNumber The week number within the month.
+   * @returns {HTMLElement}
+   */
+  CalendarMonthCtrl.prototype.buildDateRow = function(rowNumber) {
     var row = document.createElement('tr');
     row.setAttribute('role', 'row');
+
+    // Because of an NVDA bug (with Firefox), the row needs an aria-label in order
+    // to prevent the entire row being read aloud when the user moves between rows.
+    // See http://community.nvda-project.org/ticket/4643.
+    //row.setAttribute('aria-label', this.dateLocale.weekNumberFormatter(rowNumber));
+
     return row;
   };
 
@@ -158,7 +170,8 @@
     // Store rows for the month in a document fragment so that we can append them all at once.
     var monthBody = document.createDocumentFragment();
 
-    var row = this.buildDateRow();
+    var rowNumber = 1;
+    var row = this.buildDateRow(rowNumber);
     monthBody.appendChild(row);
 
     // Add a label for the month. If the month starts on a Sun/Mon/Tues, the month label
@@ -196,7 +209,8 @@
       // If we've reached the end of the week, start a new row.
       if (dayOfWeek === 7) {
         dayOfWeek = 0;
-        row = this.buildDateRow();
+        rowNumber++;
+        row = this.buildDateRow(rowNumber);
         monthBody.appendChild(row);
       }
 
diff --git a/src/components/calendar/dateLocaleProvider.js b/src/components/calendar/dateLocaleProvider.js
index 59f8e6565ec..1411d4738eb 100644
--- a/src/components/calendar/dateLocaleProvider.js
+++ b/src/components/calendar/dateLocaleProvider.js
@@ -43,6 +43,12 @@
        */
       this.monthHeaderFormatter = null;
 
+      /**
+       * Function that formats a week number into a label for the week.
+       * @type {function(number): string}
+       */
+      this.weekNumberFormatter = null;
+
       /**
        * Function that formats a date into a short aria-live announcement that is read when
        * the focused date changes within the same month.
@@ -104,6 +110,15 @@
         return service.shortMonths[date.getMonth()] + ' ' + date.getFullYear();
       }
 
+      /**
+       * Default week number formatter.
+       * @param number
+       * @returns {string}
+       */
+      function defaultWeekNumberFormatter(number) {
+        return 'Week ' + number;
+      }
+
       /**
        * Default formatter for short aria-live announcements.
        * @param {!Date} date
@@ -154,6 +169,7 @@
         formatDate: this.formatDate || defaultFormatDate,
         parseDate: this.parseDate || defaultParseDate,
         monthHeaderFormatter: this.monthHeaderFormatter || defaultMonthHeaderFormatter,
+        weekNumberFormatter: this.weekNumberFormatter || defaultWeekNumberFormatter,
         shortAnnounceFormatter: this.shortAnnounceFormatter || defaultShortAnnounceFormatter,
         longAnnounceFormatter: this.longAnnounceFormatter || defaultLongAnnounceFormatter,
         msgCalendar: this.msgCalendar || defaultMsgCalendar,
diff --git a/src/components/calendar/datePicker.js b/src/components/calendar/datePicker.js
index 7a15e4302d2..af1a3976a87 100644
--- a/src/components/calendar/datePicker.js
+++ b/src/components/calendar/datePicker.js
@@ -26,16 +26,16 @@
           // interaction on the text input, and multiple tab stops for one component (picker)
           // may be confusing.
           '<md-button class="md-datepicker-button md-icon-button" type="button" ' +
-              'tabindex="-1" aria-label="{{::ctrl.dateLocale.msgOpenCalendar}}" ' +
-              'ng-click="ctrl.openCalendarPane()">' +
+              'tabindex="-1" aria-hidden="true" ' +
+              'ng-click="ctrl.openCalendarPane($event)">' +
               '<md-icon class="md-datepicker-calendar-icon" md-svg-icon="md-calendar"></md-icon>' +
           '</md-button>' +
           '<div class="md-datepicker-input-container">' +
-            '<input class="md-datepicker-input" aria-haspopup="true" aria-describedby="xxx">' +
-            '<span id="xxx" class="md-visually-hidden">Press Alt + Down to open the calendar</span>' +
+            '<input class="md-datepicker-input" aria-haspopup="true">' +
+            //'<span id="xxx" class="md-visually-hidden">Press Alt + Down to open the calendar</span>' +
 
             '<md-button md-no-ink class="md-datepicker-triangle-button md-icon-button" ' +
-                'ng-click="ctrl.openCalendarPane()" tabindex="-1" ' +
+                'ng-click="ctrl.openCalendarPane($event)" ' +
                 'aria-label="{{::ctrl.dateLocale.msgOpenCalendar}}">' +
               '<div class="md-datepicker-expand-triangle"></div>' +
             '</md-button>' +
@@ -127,6 +127,13 @@
     /** @type {boolean} Whether the date-picker's calendar pane is open. */
     this.isCalendarOpen = false;
 
+    /**
+     * Element from which the calendar pane was opened. Keep track of this so that we can return
+     * focus to it when the pane is closed.
+     * @type {HTMLElement}
+     */
+    this.calendarPaneOpenedFrom = null;
+
     this.calendarPane.id = 'md-date-pane' + $mdUtil.nextUid();
 
     /** Pre-bound click handler is saved so that the event listener can be removed. */
@@ -204,12 +211,12 @@
     angular.element(self.inputElement).on('keydown', function(event) {
       $scope.$apply(function() {
         if (event.altKey && event.keyCode == keyCodes.DOWN_ARROW) {
-          self.openCalendarPane();
+          self.openCalendarPane(event);
         }
       });
     });
 
-    self.$scope.$on('md-calendar-escape', function() {
+    self.$scope.$on('md-calendar-close', function() {
       self.closeCalendarPane();
     });
   };
@@ -272,10 +279,14 @@
     this.calendarPane.parentNode.removeChild(this.calendarPane);
   };
 
-  /** Open the floating calendar pane. */
-  DatePickerCtrl.prototype.openCalendarPane = function() {
+  /**
+   * Open the floating calendar pane.
+   * @param {Event} event
+   */
+  DatePickerCtrl.prototype.openCalendarPane = function(event) {
     if (!this.isCalendarOpen && !this.isDisabled) {
       this.isCalendarOpen = true;
+      this.calendarPaneOpenedFrom = event.target;
       this.attachCalendarPane();
       this.focusCalendar();
 
@@ -292,7 +303,8 @@
   DatePickerCtrl.prototype.closeCalendarPane = function() {
     this.isCalendarOpen = false;
     this.detachCalendarPane();
-    this.inputElement.focus();
+    this.calendarPaneOpenedFrom.focus();
+    this.calendarPaneOpenedFrom = null;
     document.body.removeEventListener('click', this.bodyClickHandler);
   };
 
diff --git a/src/components/calendar/datePicker.spec.js b/src/components/calendar/datePicker.spec.js
index 8bcabe1746a..600313dc72d 100644
--- a/src/components/calendar/datePicker.spec.js
+++ b/src/components/calendar/datePicker.spec.js
@@ -62,7 +62,7 @@ describe('md-date-picker', function() {
     expect(controller.calendarPane.offsetHeight).toBeGreaterThan(0);
 
     // Fake an escape event coming the the calendar.
-    pageScope.$broadcast('md-calendar-escape');
+    pageScope.$broadcast('md-calendar-close');
 
   });