finish up MdFormFieldControl implementation

Author: mmalerba

src/lib/select/_select-theme.scss

@@ -52,9 +52,14 @@
     &.mat-accent {
       @include _mat-select-inner-content-theme($accent);
     }
+
+    &.mat-warn,
+    &.mat-select-invalid {
+      @include _mat-select-inner-content-theme($warn);
+    }
   }
 
-  .mat-select:focus:not(.mat-select-disabled).mat-warn, .mat-select-invalid {
+  .mat-select.mat-select-invalid:not(.mat-select-disabled) {
     @include _mat-select-inner-content-theme($warn);
   }
 }

src/lib/select/select.ts

@@ -164,11 +164,13 @@ export class MdSelectTrigger {}
     '[attr.aria-invalid]': 'errorState',
     '[attr.aria-owns]': '_optionIds',
     '[attr.aria-multiselectable]': 'multiple',
+    '[attr.aria-describedby]': '_ariaDescribedby || null',
     '[class.mat-select-disabled]': 'disabled',
     '[class.mat-select-invalid]': 'errorState',
     '[class.mat-select-required]': 'required',
     'class': 'mat-select',
     '(keydown)': '_handleClosedKeydown($event)',
+    '(focus)': '_onFocus()',
     '(blur)': '_onBlur()',
   },
   animations: [
@@ -213,6 +215,9 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
   /** The cached height of the trigger element. */
   private _triggerHeight: number;
 
+  /** The aria-describedby attribute on the select for improved a11y. */
+  _ariaDescribedby: string;
+
   /** The cached font-size of the trigger element. */
   _triggerFontSize = 0;
 
@@ -281,12 +286,8 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
    */
   stateChanges = new Subject<void>();
 
-  /** Whether the select is focused. TODO(mmalerba): Implement for real. */
   focused = false;
 
-  /** TODO(mmalerba): Implement for real. */
-  setDescribedByIds(x: string[]) {return x}
-
   /** Trigger that opens the select. */
   @ViewChild('trigger') trigger: ElementRef;
 
@@ -313,6 +314,7 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
   get placeholder() { return this._placeholder; }
   set placeholder(value: string) {
     this._placeholder = value;
+    this.stateChanges.next();
 
     // Must wait to record the trigger width to ensure placeholder width is included.
     Promise.resolve(null).then(() => this._setTriggerWidth());
@@ -321,7 +323,10 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
   /** Whether the component is required. */
   @Input()
   get required() { return this._required; }
-  set required(value: any) { this._required = coerceBooleanProperty(value); }
+  set required(value: any) {
+    this._required = coerceBooleanProperty(value);
+    this.stateChanges.next();
+  }
 
   /** Whether the user should be allowed to select multiple options. */
   @Input()
@@ -349,6 +354,7 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
   set value(newValue: any) {
     this.writeValue(newValue);
     this._value = newValue;
+    this.stateChanges.next();
   }
   private _value: any;
 
@@ -370,7 +376,10 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
   /** Unique id of the element. */
   @Input()
   get id() { return this._id; }
-  set id(value: string) { this._id = value || this._uid; }
+  set id(value: string) {
+    this._id = value || this._uid;
+    this.stateChanges.next();
+  }
   private _id: string;
 
   /** Combined stream of all of the child options' change events. */
@@ -521,6 +530,7 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
   setDisabledState(isDisabled: boolean): void {
     this.disabled = isDisabled;
     this._changeDetectorRef.markForCheck();
+    this.stateChanges.next();
   }
 
   /** Whether or not the overlay panel is open. */
@@ -613,14 +623,23 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
     this._changeDetectorRef.markForCheck();
   }
 
+  _onFocus() {
+    if (!this.disabled) {
+      this.focused = true;
+      this.stateChanges.next();
+    }
+  }
+
   /**
    * Calls the touched callback only if the panel is closed. Otherwise, the trigger will
    * "blur" to the panel when it opens, causing a false positive.
    */
   _onBlur() {
     if (!this.disabled && !this.panelOpen) {
+      this.focused = false;
       this._onTouched();
       this._changeDetectorRef.markForCheck();
+      this.stateChanges.next();
     }
   }
 
@@ -1131,6 +1150,8 @@ export class MdSelect extends _MdSelectMixinBase implements AfterContentInit, On
     return 0;
   }
 
+  /** Sets the list of element IDs that currently describe this select. */
+  setDescribedByIds(ids: string[]) { this._ariaDescribedby = ids.join(' '); }
 }
 
 /** Clamps a value n between min and max values. */