fix(datepicker): add max/min filter to multi year and year views (#9727)

* add max/min filter to multi year and year views

* address @mmalerba's comments

* fix and tighten up logic

* possibility to have a null filter in month view

Author: julianobrasil

src/lib/datepicker/calendar.html

@@ -26,7 +26,9 @@
       *ngSwitchCase="'month'"
       [activeDate]="_activeDate"
       [selected]="selected"
-      [dateFilter]="_dateFilterForViews"
+      [dateFilter]="dateFilter"
+      [maxDate]="maxDate"
+      [minDate]="minDate"
       (selectedChange)="_dateSelected($event)"
       (_userSelection)="_userSelected()">
   </mat-month-view>
@@ -35,15 +37,19 @@
       *ngSwitchCase="'year'"
       [activeDate]="_activeDate"
       [selected]="selected"
-      [dateFilter]="_dateFilterForViews"
+      [dateFilter]="dateFilter"
+      [maxDate]="maxDate"
+      [minDate]="minDate"
       (selectedChange)="_goToDateInView($event, 'month')">
   </mat-year-view>
 
   <mat-multi-year-view
       *ngSwitchCase="'multi-year'"
       [activeDate]="_activeDate"
       [selected]="selected"
-      [dateFilter]="_dateFilterForViews"
+      [dateFilter]="dateFilter"
+      [maxDate]="maxDate"
+      [minDate]="minDate"
       (selectedChange)="_goToDateInView($event, 'year')">
   </mat-multi-year-view>
 </div>

src/lib/datepicker/calendar.ts

@@ -119,14 +119,6 @@ export class MatCalendar<D> implements AfterContentInit, OnDestroy, OnChanges {
   /** Reference to the current multi-year view component. */
   @ViewChild(MatMultiYearView) multiYearView: MatMultiYearView<D>;
 
-  /** Date filter for the month, year, and multi-year views. */
-  _dateFilterForViews = (date: D) => {
-    return !!date &&
-        (!this.dateFilter || this.dateFilter(date)) &&
-        (!this.minDate || this._dateAdapter.compareDate(date, this.minDate) >= 0) &&
-        (!this.maxDate || this._dateAdapter.compareDate(date, this.maxDate) <= 0);
-  }
-
   /**
    * The current active date. This determines which time period is shown and which date is
    * highlighted when using keyboard navigation.
@@ -346,7 +338,7 @@ export class MatCalendar<D> implements AfterContentInit, OnDestroy, OnChanges {
             this._dateAdapter.addCalendarMonths(this._activeDate, 1);
         break;
       case ENTER:
-        if (this._dateFilterForViews(this._activeDate)) {
+        if (!this.dateFilter || this.dateFilter(this._activeDate)) {
           this._dateSelected(this._activeDate);
           this._userSelected();
           // Prevent unexpected default actions such as form submission.

src/lib/datepicker/month-view.ts

@@ -64,6 +64,22 @@ export class MatMonthView<D> implements AfterContentInit {
   }
   private _selected: D | null;
 
+  /** The minimum selectable date. */
+  @Input()
+  get minDate(): D | null { return this._minDate; }
+  set minDate(value: D | null) {
+    this._minDate = this._getValidDateOrNull(this._dateAdapter.deserialize(value));
+  }
+  private _minDate: D | null;
+
+  /** The maximum selectable date. */
+  @Input()
+  get maxDate(): D | null { return this._maxDate; }
+  set maxDate(value: D | null) {
+    this._maxDate = this._getValidDateOrNull(this._dateAdapter.deserialize(value));
+  }
+  private _maxDate: D | null;
+
   /** A function used to filter which dates are selectable. */
   @Input() dateFilter: (date: D) => boolean;
 
@@ -154,25 +170,32 @@ export class MatMonthView<D> implements AfterContentInit {
 
   /** Creates MatCalendarCells for the dates in this month. */
   private _createWeekCells() {
-    let daysInMonth = this._dateAdapter.getNumDaysInMonth(this.activeDate);
-    let dateNames = this._dateAdapter.getDateNames();
+    const daysInMonth = this._dateAdapter.getNumDaysInMonth(this.activeDate);
+    const dateNames = this._dateAdapter.getDateNames();
     this._weeks = [[]];
     for (let i = 0, cell = this._firstWeekOffset; i < daysInMonth; i++, cell++) {
       if (cell == DAYS_PER_WEEK) {
         this._weeks.push([]);
         cell = 0;
       }
-      let date = this._dateAdapter.createDate(
-          this._dateAdapter.getYear(this.activeDate),
-          this._dateAdapter.getMonth(this.activeDate), i + 1);
-      let enabled = !this.dateFilter ||
-          this.dateFilter(date);
-      let ariaLabel = this._dateAdapter.format(date, this._dateFormats.display.dateA11yLabel);
+      const date = this._dateAdapter.createDate(
+            this._dateAdapter.getYear(this.activeDate),
+            this._dateAdapter.getMonth(this.activeDate), i + 1);
+      const enabled = this._shouldEnableDate(date);
+      const ariaLabel = this._dateAdapter.format(date, this._dateFormats.display.dateA11yLabel);
       this._weeks[this._weeks.length - 1]
           .push(new MatCalendarCell(i + 1, dateNames[i], ariaLabel, enabled));
     }
   }
 
+  /** Date filter for the month */
+  private _shouldEnableDate(date: D): boolean {
+    return !!date &&
+        (!this.dateFilter || this.dateFilter(date)) &&
+        (!this.minDate || this._dateAdapter.compareDate(date, this.minDate) >= 0) &&
+        (!this.maxDate || this._dateAdapter.compareDate(date, this.maxDate) <= 0);
+  }
+
   /**
    * Gets the date in this month that the given Date falls on.
    * Returns null if the given Date is in another month.

src/lib/datepicker/multi-year-view.ts

@@ -64,6 +64,22 @@ export class MatMultiYearView<D> implements AfterContentInit {
   }
   private _selected: D | null;
 
+  /** The minimum selectable date. */
+  @Input()
+  get minDate(): D | null { return this._minDate; }
+  set minDate(value: D | null) {
+    this._minDate = this._getValidDateOrNull(this._dateAdapter.deserialize(value));
+  }
+  private _minDate: D | null;
+
+  /** The maximum selectable date. */
+  @Input()
+  get maxDate(): D | null { return this._maxDate; }
+  set maxDate(value: D | null) {
+    this._maxDate = this._getValidDateOrNull(this._dateAdapter.deserialize(value));
+  }
+  private _maxDate: D | null;
+
   /** A function used to filter which dates are selectable. */
   @Input() dateFilter: (date: D) => boolean;
 
@@ -124,11 +140,19 @@ export class MatMultiYearView<D> implements AfterContentInit {
   /** Creates an MatCalendarCell for the given year. */
   private _createCellForYear(year: number) {
     let yearName = this._dateAdapter.getYearName(this._dateAdapter.createDate(year, 0, 1));
-    return new MatCalendarCell(year, yearName, yearName, this._isYearEnabled(year));
+    return new MatCalendarCell(year, yearName, yearName, this._shouldEnableYear(year));
   }
 
   /** Whether the given year is enabled. */
-  private _isYearEnabled(year: number) {
+  private _shouldEnableYear(year: number) {
+    // disable if the year is greater than maxDate lower than minDate
+    if (year === undefined || year === null ||
+        (this.maxDate && year > this._dateAdapter.getYear(this.maxDate)) ||
+        (this.minDate && year < this._dateAdapter.getYear(this.minDate))) {
+      return false;
+    }
+
+    // enable if it reaches here and there's no filter defined
     if (!this.dateFilter) {
       return true;
     }

src/lib/datepicker/year-view.ts

@@ -59,6 +59,22 @@ export class MatYearView<D> implements AfterContentInit {
   }
   private _selected: D | null;
 
+  /** The minimum selectable date. */
+  @Input()
+  get minDate(): D | null { return this._minDate; }
+  set minDate(value: D | null) {
+    this._minDate = this._getValidDateOrNull(this._dateAdapter.deserialize(value));
+  }
+  private _minDate: D | null;
+
+  /** The maximum selectable date. */
+  @Input()
+  get maxDate(): D | null { return this._maxDate; }
+  set maxDate(value: D | null) {
+    this._maxDate = this._getValidDateOrNull(this._dateAdapter.deserialize(value));
+  }
+  private _maxDate: D | null;
+
   /** A function used to filter which dates are selectable. */
   @Input() dateFilter: (date: D) => boolean;
 
@@ -134,17 +150,25 @@ export class MatYearView<D> implements AfterContentInit {
         this._dateAdapter.createDate(this._dateAdapter.getYear(this.activeDate), month, 1),
         this._dateFormats.display.monthYearA11yLabel);
     return new MatCalendarCell(
-        month, monthName.toLocaleUpperCase(), ariaLabel, this._isMonthEnabled(month));
+        month, monthName.toLocaleUpperCase(), ariaLabel, this._shouldEnableMonth(month));
   }
 
   /** Whether the given month is enabled. */
-  private _isMonthEnabled(month: number) {
+  private _shouldEnableMonth(month: number) {
+
+    const activeYear = this._dateAdapter.getYear(this.activeDate);
+
+    if (month === undefined || month === null ||
+        this._isYearAndMonthAfterMaxDate(activeYear, month) ||
+        this._isYearAndMonthBeforeMinDate(activeYear, month)) {
+      return false;
+    }
+
     if (!this.dateFilter) {
       return true;
     }
 
-    let firstOfMonth = this._dateAdapter.createDate(
-        this._dateAdapter.getYear(this.activeDate), month, 1);
+    const firstOfMonth = this._dateAdapter.createDate(activeYear, month, 1);
 
     // If any date in the month is enabled count the month as enabled.
     for (let date = firstOfMonth; this._dateAdapter.getMonth(date) == month;
@@ -157,6 +181,36 @@ export class MatYearView<D> implements AfterContentInit {
     return false;
   }
 
+  /**
+   * Tests whether the combination month/year is after this.maxDate, considering
+   * just the month and year of this.maxDate
+   */
+  private _isYearAndMonthAfterMaxDate(year: number, month: number) {
+    if (this.maxDate) {
+      const maxYear = this._dateAdapter.getYear(this.maxDate);
+      const maxMonth = this._dateAdapter.getMonth(this.maxDate);
+
+      return year > maxYear || (year === maxYear && month > maxMonth);
+    }
+
+    return false;
+  }
+
+  /**
+   * Tests whether the combination month/year is before this.minDate, considering
+   * just the month and year of this.minDate
+   */
+  private _isYearAndMonthBeforeMinDate(year: number, month: number) {
+    if (this.minDate) {
+      const minYear = this._dateAdapter.getYear(this.minDate);
+      const minMonth = this._dateAdapter.getMonth(this.minDate);
+
+      return year < minYear || (year === minYear && month < minMonth);
+    }
+
+    return false;
+  }
+
   /**
    * @param obj The object to check.
    * @returns The given object if it is both a date instance and valid, otherwise null.