feat(datepicker): opening animation and better shadow

src/components/calendar/calendar-theme.scss

@@ -32,6 +32,6 @@
 .md-calendar-date:focus.md-calendar-selected-date {
   .md-calendar-date-selection-indicator {
     background-color: '{{primary-500}}'; // blue-500
-    color: '{{primary-500-contrast}}'; // SHOULD BE WHITE (ish)
+    color: '{{primary-500-contrast}}'; // white
   }
 }

src/components/calendar/datePicker-theme.scss

@@ -21,11 +21,11 @@
 
 // Open state for all of the elements of the picker.
 .md-datepicker-open {
-  .md-datepicker-input-container {
-    border-color: '{{background-300}}';
-  }
-
   .md-datepicker-calendar-icon {
     fill: '{{primary-500}}';
   }
 }
+
+.md-datepicker-calendar {
+  background: white;
+}

src/components/calendar/datePicker.js

@@ -37,15 +37,13 @@
             '</md-button>' +
           '</div>' +
 
-          // This pane (and its shadow) will be detached from here and re-attached to the
-          // document body.
-          '<div class="md-datepicker-calendar-pane">' +
-            '<md-calendar ng-model="ctrl.date" ng-if="ctrl.isCalendarOpen"></md-calendar>' +
-          '</div>' +
-
-          // We have a separate shadow element in order to wrap both the floating pane and the
-          // inline input / trigger as one shadowed whole.
-          '<div class="md-datepicker-calendar-pane-shadow md-whiteframe-z1"></div>',
+          // This pane will be detached from here and re-attached to the document body.
+          '<div class="md-datepicker-calendar-pane md-whiteframe-z1">' +
+            '<div class="md-datepicker-input-mask"></div>' +
+            '<div class="md-datepicker-calendar">' +
+              '<md-calendar ng-model="ctrl.date" ng-if="ctrl.isCalendarOpen"></md-calendar>' +
+            '</div>' +
+          '</div>',
       require: ['ngModel', 'mdDatePicker'],
       scope: {
         placeholder: '@mdPlaceholder'
@@ -71,7 +69,7 @@
    * @ngInject @constructor
    */
   function DatePickerCtrl($scope, $element, $attrs, $compile, $timeout, $mdConstant, $mdUtil,
-      $$mdDateLocale, $$mdDateUtil) {
+      $$mdDateLocale, $$mdDateUtil, $mdMenu, $$rAF) {
     /** @final */
     this.$compile = $compile;
 
@@ -90,6 +88,11 @@
     /* @final */
     this.$mdUtil = $mdUtil;
 
+    /** @final */
+    this.$mdMenu = $mdMenu;
+
+    this.$$rAF = $$rAF;
+
     /** @type {!angular.NgModelController} */
     this.ngModelCtrl = null;
 
@@ -102,9 +105,6 @@
     /** @type {HTMLElement} Floating calendar pane. */
     this.calendarPane = $element[0].querySelector('.md-datepicker-calendar-pane');
 
-    /** @type {HTMLElement} Shadow for floating calendar pane and input trigger. */
-    this.calendarShadow = $element[0].querySelector('.md-datepicker-calendar-pane-shadow');
-
     /** @type {HTMLElement} Calendar icon button. */
     this.calendarButton = $element[0].querySelector('.md-datepicker-button');
 
@@ -240,26 +240,20 @@
 
   /** Position and attach the floating calendar to the document. */
   DatePickerCtrl.prototype.attachCalendarPane = function() {
+    var calendarPane = this.calendarPane;
     this.$element.addClass('md-datepicker-open');
 
     var elementRect = this.inputContainer.getBoundingClientRect();
     var bodyRect = document.body.getBoundingClientRect();
 
-    this.calendarPane.style.left = (elementRect.left - bodyRect.left) + 'px';
-    this.calendarPane.style.top = (elementRect.bottom - bodyRect.top) + 'px';
+    calendarPane.style.left = (elementRect.left - bodyRect.left) + 'px';
+    calendarPane.style.top = (elementRect.top - bodyRect.top) + 'px';
     document.body.appendChild(this.calendarPane);
 
-    // Add shadow to the calendar pane only after the UI thread has reached idle, allowing the
-    // content of the calender pane to be rendered.
-    this.$timeout(function() {
-      this.calendarPane.classList.add('md-pane-open');
-
-      this.calendarShadow.style.top = (elementRect.top - bodyRect.top) + 'px';
-      this.calendarShadow.style.left = this.calendarPane.style.left;
-      this.calendarShadow.style.height =
-          (this.calendarPane.getBoundingClientRect().bottom - elementRect.top) + 'px';
-      document.body.appendChild(this.calendarShadow);
-    }.bind(this), 0, false);
+    // Add CSS class after one frame to trigger animation.
+    this.$$rAF(function() {
+      calendarPane.classList.add('md-pane-open');
+    });
   };
 
   /** Detach the floating calendar pane from the document. */
@@ -270,7 +264,6 @@
     // Use native DOM removal because we do not want any of the angular state of this element
     // to be disposed.
     this.calendarPane.parentNode.removeChild(this.calendarPane);
-    this.calendarShadow.parentNode.removeChild(this.calendarShadow);
   };
 
   /** Open the floating calendar pane. */

src/components/calendar/datePicker.scss

@@ -36,11 +36,11 @@ $md-datepicker-button-gap: 12px;
 // Container for the datepicker input.
 .md-datepicker-input-container {
   position: relative;
-  z-index: $z-index-datepicker-trigger;
 
-  display: inline-block;
   border-bottom-width: 1px;
   border-bottom-style: solid;
+
+  display: inline-block;
   width: 120px;
   margin-left: $md-datepicker-button-gap;
 }
@@ -55,15 +55,35 @@ $md-datepicker-button-gap: 12px;
 
   border-width: 1px;
   border-style: solid;
-  border-top: none;
-  background: white;
+  background: transparent;
+
+  transform: scale(0);
+  transform-origin: 0 0;
+  transition: transform 0.2s $swift-ease-out-timing-function;
+
+  &.md-pane-open {
+    transform: scale(1);
+  }
 }
 
-// Shadow that wraps around both the floating calendar pane and the in-line input.
-.md-datepicker-calendar-pane-shadow {
-  position: absolute;
-  z-index: $z-index-datepicker-shadow;
+// Portion of the floating panel that sits, invisibly, on top of the input.
+.md-datepicker-input-mask {
+  height: 40px;
   width: $md-calendar-width;
+
+  background: transparent;
+  pointer-events: none;
+  cursor: text;
+}
+
+// The calendar portion of the floating pane (vs. the input mask).
+.md-datepicker-calendar {
+  opacity: 0;
+  transition: opacity 0.2s cubic-bezier(0.5, 0, 0.25, 1);
+
+  .md-pane-open & {
+    opacity: 1;
+  }
 }
 
 // Down triangle/arrow indicating that the datepicker can be opened.
@@ -97,17 +117,16 @@ $md-date-arrow-size: 6px;
 // Only apply this high specifiy to the property we need to override.
 .md-datepicker-triangle-button.md-button.md-icon-button {
   height: 100%;
+  position: absolute;
 }
 
 
 // Open state for all of the elements of the picker.
 .md-datepicker-open {
   .md-datepicker-input-container {
-    border-width: 1px;
-    border-style: solid;
-    border-bottom: none;
     min-width: $md-calendar-width;
     margin-left: -$md-datepicker-button-gap;
+    border: none;
   }
 
   .md-datepicker-input {

src/core/style/variables.scss

@@ -73,10 +73,6 @@ $z-index-sidenav: 60 !default;
 $z-index-backdrop: 50 !default;
 $z-index-fab: 20 !default;
 
-// It is important that datepicker shadow is underneath both the trigger and the floating pane.
-$z-index-datepicker-trigger: 5 !default;
-$z-index-datepicker-shadow:  4 !default;
-
 // Easing Curves
 //--------------------------------------------