docs(DlDateTimePickerComponent): Add information about DlDateAdapter

Also fixed up comments in QuarterCenturyYearModelProvider

Author: dalelotts

src/lib/dl-date-time-picker/dl-date-time-picker.component.md

@@ -15,9 +15,20 @@ The following keyboard shortcuts are supported in in all views:
 | `PAGE_DOWN`          | Go to the same cell in the next time period     |
 | `ENTER` or `SPACE`   | Select current cell                             |
 
-## Model Providers
+## Date Adapter
 
-Model providers are used to create the `Model` for each of the `views` in the date/time picker.
+A `DateAdapter` is used to adapt the data type in the model to the `number` data type 
+used internally by the date/time picker.
+ 
+If you need a different data type than what is currently supported, you can extend 
+`DlDateAdapter<D>` to provide the data type you need then override the `DlDateAdapter` 
+provider in `app.module.ts` to use your new class. 
+
+`providers: [{provide: DlDateAdapter, useClass: MyCustomDateAdapter}],`
+
+## Model Provider
+
+`ModelProvider`s are used to create the `Model` for each of the `views` in the date/time picker.
 If your project has special requirements for one or more of the `views`, you may override 
 one or more of the model providers to meet your needs.
 
@@ -96,7 +107,7 @@ display `25 years`  by doing the following:
        *
        * The `year` model represents a quarter-century (25 years) as five rows with five columns.
        *
-       * The decade always starts on a year ending with zero.
+       * The quarter-century always starts on a year ending with zero or 5.
        *
        * Each cell represents midnight January 1 of the indicated year.
        *
@@ -170,9 +181,9 @@ display `25 years`  by doing the following:
        * The `active` year will be the January 1 `five (5) years after` the specified milliseconds.
        * This moves the `active` date one row `down` in the current `year` view.
        *
-       * Moving `down` can result in the `active` year being part of a different decade than
-       * the specified `fromMilliseconds`, in this case the decade represented by the model
-       * will change to show the correct decade.
+       * Moving `down` can result in the `active` year being part of a different quarter-century than
+       * the specified `fromMilliseconds`, in this case the quarter-century represented by the model
+       * will change to show the correct quarter-century.
        *
        * @param fromMilliseconds
        *  the moment in time from which the next `year` model `down` will be constructed.
@@ -191,9 +202,9 @@ display `25 years`  by doing the following:
        * The `active` year will be the January 1 `five (5) years before` the specified milliseconds.
        * This moves the `active` date one row `up` in the current `year` view.
        *
-       * Moving `up` can result in the `active` year being part of a different decade than
-       * the specified `fromMilliseconds`, in this case the decade represented by the model
-       * will change to show the correct decade.
+       * Moving `up` can result in the `active` year being part of a different quarter-century than
+       * the specified `fromMilliseconds`, in this case the quarter-century represented by the model
+       * will change to show the correct quarter-century.
        *
        * @param fromMilliseconds
        *  the moment in time from which the previous `year` model `up` will be constructed.
@@ -212,9 +223,9 @@ display `25 years`  by doing the following:
        * The `active` year will be the January 1 `one (1) year before` the specified milliseconds.
        * This moves the `active` date one year `left` in the current `year` view.
        *
-       * Moving `left` can result in the `active` year being part of a different decade than
-       * the specified `fromMilliseconds`, in this case the decade represented by the model
-       * will change to show the correct decade.
+       * Moving `left` can result in the `active` year being part of a different quarter-century than
+       * the specified `fromMilliseconds`, in this case the quarter-century represented by the model
+       * will change to show the correct quarter-century.
        *
        * @param fromMilliseconds
        *  the moment in time from which the `year` model to the `left` will be constructed.
@@ -233,9 +244,9 @@ display `25 years`  by doing the following:
        * The `active` year will be the January 1 `one (1) year after` the specified milliseconds.
        * This moves the `active` date one year `right` in the current `year` view.
        *
-       * Moving `right` can result in the `active` year being part of a different decade than
-       * the specified `fromMilliseconds`, in this case the decade represented by the model
-       * will change to show the correct decade.
+       * Moving `right` can result in the `active` year being part of a different quarter-century than
+       * the specified `fromMilliseconds`, in this case the quarter-century represented by the model
+       * will change to show the correct quarter-century.
        *
        * @param fromMilliseconds
        *  the moment in time from which the `year` model to the `right` will be constructed.
@@ -249,52 +260,52 @@ display `25 years`  by doing the following:
       }
 
       /**
-       * Move the active `year` one decade `down` from the specified moment in time.
+       * Move the active `year` one quarter-century `down` from the specified moment in time.
        *
        * The `active` year will be the January 1 `ten (10) years after` the specified milliseconds.
        * This moves the `active` date one `page` `down` from the current `year` view.
        *
-       * Paging `down` will result in the `active` year being part of a different decade than
-       * the specified `fromMilliseconds`. As a result, the decade represented by the model
-       * will change to show the correct decade.
+       * Paging `down` will result in the `active` year being part of a different quarter-century than
+       * the specified `fromMilliseconds`. As a result, the quarter-century represented by the model
+       * will change to show the correct quarter-century.
        *
        * @param fromMilliseconds
        *  the moment in time from which the next `year` model page `down` will be constructed.
        * @param selectedMilliseconds
        *  the current value of the date/time picker.
        * @returns
-       *  model containing an `active` `year` one decade `down` from the specified moment in time.
+       *  model containing an `active` `year` one quarter-century `down` from the specified moment in time.
        */
       pageDown(fromMilliseconds: number, selectedMilliseconds: number): DlDateTimePickerModel {
         return this.getModel(moment(fromMilliseconds).add(25, 'year').valueOf(), selectedMilliseconds);
       }
 
       /**
-       * Move the active `year` one decade `up` from the specified moment in time.
+       * Move the active `year` one quarter-century `up` from the specified moment in time.
        *
        * The `active` year will be the January 1 `ten (10) years before` the specified milliseconds.
        * This moves the `active` date one `page-up` from the current `year` view.
        *
-       * Paging `up` will result in the `active` year being part of a different decade than
-       * the specified `fromMilliseconds`. As a result, the decade represented by the model
-       * will change to show the correct decade.
+       * Paging `up` will result in the `active` year being part of a different quarter-century than
+       * the specified `fromMilliseconds`. As a result, the quarter-century represented by the model
+       * will change to show the correct quarter-century.
        *
        * @param fromMilliseconds
        *  the moment in time from which the next `year` model page `up` will be constructed.
        * @param selectedMilliseconds
        *  the current value of the date/time picker.
        * @returns
-       *  model containing an `active` `year` one decade `up` from the specified moment in time.
+       *  model containing an `active` `year` one quarter-century `up` from the specified moment in time.
        */
       pageUp(fromMilliseconds: number, selectedMilliseconds: number): DlDateTimePickerModel {
         return this.getModel(moment(fromMilliseconds).subtract(25, 'year').valueOf(), selectedMilliseconds);
       }
 
       /**
-       * Move the `active` `year` to the `last` year in the decade.
+       * Move the `active` `year` to the `last` year in the quarter-century.
        *
        * The view or time range will not change unless the `fromMilliseconds` value
-       * is in a different decade than the displayed decade.
+       * is in a different quarter-century than the displayed quarter-century.
        *
        * @param fromMilliseconds
        *  the moment in time from which the `last` active `year` will be calculated.
@@ -314,10 +325,10 @@ display `25 years`  by doing the following:
       }
 
       /**
-       * Move the `active` `year` to the `first` year in the decade.
+       * Move the `active` `year` to the `first` year in the quarter-century.
        *
        * The view or time range will not change unless the `fromMilliseconds` value
-       * is in a different decade than the displayed decade.
+       * is in a different quarter-century than the displayed quarter-century.
        *
        * @param fromMilliseconds
        *  the moment in time from which the `first` active `year` will be calculated.
@@ -348,3 +359,8 @@ display `25 years`  by doing the following:
     This will result in `QuarterCenturyYearModelProvider` being used in every instance of the date/time
     picker in your application. 
 
+This approach can be extended to any of the `ModelProvider`'s for a view.
+
+For example, imagine you need a time picker that only displays certain hours of the day. You can implement 
+an `HourModelProvider` that has the exact functionality you need without having the write the entire 
+component yourself.