Initial TabPane readme (#236)

src/tabpane/README.md

@@ -1 +1,116 @@
-# TabPane widget
+# @dojo/widgets/tabpane/TabPane widget
+
+Dojo 2's `TabPane` widget provides a user interface capable of displaying tabbed content. The content shown at any given time is based on the currently-selected tab button.
+
+## Features
+
+- Tab buttons can be positioned above, below, before, or after tab content
+- Tabs can be closeable, disabled, and can fetch data asynchronously
+- Completely keyboard accessible
+
+![Image of basic tabpane](http://placekitten.com/450/300)
+
+### Keyboard Usage
+
+`TabPane` supports standard keyboard navigation for switching between and closing tabs.
+
+**Tab Button Events**
+
+- Escape key: closes a closeable tab
+- Left Arrow: If tab buttons are aligned above or below content, requests to select the previous tab 
+- Right Arrow: If tab buttons are aligned above or below content, requests to select the next tab
+- Up Arrow: If tab buttons are aligned before or after content, requests to select the previous tab 
+- Down Arrow: If tab buttons are aligned before or after content, requests to select the next tab
+- Home key: Requests to select the first tab
+- End key: Requests to select the last tab
+
+### Accessibility Features
+
+Beyond complete keyboard accessibility, `TabPane` ensures that all appropriate ARIA attributes are included.
+
+## Example Usage
+
+*Basic Example*
+```typescript
+import TabPane from '@dojo/widgets/tabpane/TabPane';
+import Tab from '@dojo/widgets/tabpane/Tab';
+import { w } from '@dojo/widget-core/d';
+
+w(TabPane, {
+	activeIndex: this.state.activeIndex,
+	onRequestTabChange: (index: number) => this.setState({ activeIndex: index })
+}, [
+	w(Tab, {
+		key: 'foo',
+		label: 'Foo'
+	}, [ 'Some content...' ]),
+	w(Tab, {
+		key: 'bar',
+		disabled: true,
+		label: 'Bar'
+	}, [ 'Some more content...' ])
+]);
+```
+
+*Closeable Tab*
+```typescript
+import TabPane from '@dojo/widgets/tabpane/TabPane';
+import Tab from '@dojo/widgets/tabpane/Tab';
+import { w } from '@dojo/widget-core/d';
+
+w(TabPane, {
+	activeIndex: this.state.activeIndex,
+	onRequestTabChange: (index: number) => this.setState({ activeIndex: index }),
+	onRequestTabClose: (index: number, key: string) => {
+		this.setState({ closedKeys: [...closedKeys, key] });
+	}
+}, [
+	w(Tab, {
+		key: 'foo',
+		label: 'Foo'
+	}, [ 'Some content...' ]),
+	!this.state.closedKeys.includes('bar') ? w(Tab, {
+		key: 'bar',
+		label: 'Bar',
+		closeable: true
+	}, [ 'Some more content...' ]) : null
+]);
+```
+
+*Align Buttons Under Content*
+```typescript
+import TabPane, { Align } from '@dojo/widgets/tabpane/TabPane';
+import Tab from '@dojo/widgets/tabpane/Tab';
+import { w } from '@dojo/widget-core/d';
+
+w(TabPane, {
+	activeIndex: this.state.activeIndex,
+	alignButtons: Align.bottom,
+	onRequestTabChange: (index: number) => this.setState({ activeIndex: index })
+}, [
+	w(Tab, {
+		key: 'foo',
+		label: 'Foo'
+	}, [ 'Some content...' ]),
+	w(Tab, {
+		key: 'bar',
+		label: 'Bar'
+	}, [ 'Some more content...' ])
+]);
+```
+
+## Theming
+
+The following CSS classes are used to style the `TabPane` widget and should be provided by custom themes:
+
+- `activeTabButton`: Applied to the button associated with the currently-active tab
+- `alignBottom`: Applied to the top-level wrapper node when buttons are positioned under content
+- `alignLeft`: Applied to the top-level wrapper node when buttons are positioned before content
+- `alignRight`: Applied to the top-level wrapper node when buttons are positioned after content 
+- `close`: Applied to a closeable tab button's close icon
+- `disabledTabButton`: Applied to the button associated with a disabled tab
+- `root`: Applied to the top-level wrapper node
+- `tab`: Applied to the currently-visible content
+- `tabButton`: Applied to the button associated with a given tab
+- `tabButtons`: Applied to the element containing all tab buttons
+- `tabs`: Applied to the element containing all tabs