com.google.gwt.cell.client

## Class IconCellDecorator<C>

- java.lang.Object
- - com.google.gwt.cell.client.IconCellDecorator<C>

Type Parameters:
  `C` - the type that this Cell represents

All Implemented Interfaces:
  Cell<C>

    public class IconCellDecorator<C>
    extends java.lang.Object
    implements Cell<C>

A `Cell` decorator that adds an icon to another `Cell`.

### Nested Class Summary

Nested Classes
`(package private) static interface` `IconCellDecorator.Template`

### Nested classes/interfaces inherited from interface com.google.gwt.cell.client.Cell

`Cell.Context`

### Constructor Summary

Constructors
Constructor and Description
`IconCellDecorator(ImageResource icon, Cell<C> cell)` Construct a new `IconCellDecorator`.
`IconCellDecorator(ImageResource icon, Cell<C> cell, HasVerticalAlignment.VerticalAlignmentConstant valign, int spacing)` Construct a new `IconCellDecorator`.

### Method Summary

All Methods Instance Methods Concrete Methods
`boolean` `dependsOnSelection()` Check if this cell depends on the selection state.
`java.util.Set<java.lang.String>` `getConsumedEvents()` Get the set of events that this cell consumes (see `BrowserEvents` for useful constants).
`protected SafeHtml` `getIconHtml(C value)` Get the safe HTML string that represents the icon.
`(package private) SafeHtml` `getImageHtml(ImageResource res, HasVerticalAlignment.VerticalAlignmentConstant valign, boolean isPlaceholder)` Get the HTML representation of an image.
`boolean` `handlesSelection()` Check if this cell handles selection.
`boolean` `isEditing(Cell.Context context, Element parent, C value)` Returns true if the cell is currently editing the data identified by the given element and key.
`protected boolean` `isIconUsed(C value)` Check if the icon should be used for the value.
`void` `onBrowserEvent(Cell.Context context, Element parent, C value, NativeEvent event, ValueUpdater<C> valueUpdater)` Handle a browser event that took place within the cell.
`void` `render(Cell.Context context, C value, SafeHtmlBuilder sb)` Render a cell as HTML into a `SafeHtmlBuilder`, suitable for passing to `Element.setInnerHTML(String)` on a container element.
`boolean` `resetFocus(Cell.Context context, Element parent, C value)` Reset focus on the Cell.
`void` `setValue(Cell.Context context, Element parent, C value)` This method may be used by cell containers to set the value on a single cell directly, rather than using `Element.setInnerHTML(String)`.

### Methods inherited from class java.lang.Object

`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

### Constructor Detail

#### IconCellDecorator

    public IconCellDecorator(ImageResource icon,
                             Cell<C> cell)

Construct a new `IconCellDecorator`. The icon and the content will be middle aligned by default.

Parameters:
  `icon` - the icon to use
  `cell` - the cell to decorate

#### IconCellDecorator

    public IconCellDecorator(ImageResource icon,
                             Cell<C> cell,
                             HasVerticalAlignment.VerticalAlignmentConstant valign,
                             int spacing)

Construct a new `IconCellDecorator`.

Parameters:
  `icon` - the icon to use
  `cell` - the cell to decorate
  `valign` - the vertical alignment attribute of the contents
  `spacing` - the pixel space between the icon and the cell

### Method Detail

#### dependsOnSelection

    public boolean dependsOnSelection()

Description copied from interface: `Cell`
Check if this cell depends on the selection state.

Specified by:
  `dependsOnSelection` in interface `Cell<C>`
Returns:
  true if dependent on selection, false if not

#### getConsumedEvents

    public java.util.Set<java.lang.String> getConsumedEvents()

Description copied from interface: `Cell`
Get the set of events that this cell consumes (see `BrowserEvents` for useful constants). The container that uses this cell should only pass these events to `Cell.onBrowserEvent(Context, Element, Object, NativeEvent, ValueUpdater)` when the event occurs.

The returned value should not be modified, and may be an unmodifiable set. Changes to the return value may not be reflected in the cell.

Specified by:
  `getConsumedEvents` in interface `Cell<C>`
Returns:
  the consumed events, or null if no events are consumed
See Also:
  `BrowserEvents`

#### handlesSelection

    public boolean handlesSelection()

Description copied from interface: `Cell`
Check if this cell handles selection. If the cell handles selection, then its container should not automatically handle selection.

Specified by:
  `handlesSelection` in interface `Cell<C>`
Returns:
  true if the cell handles selection, false if not

#### isEditing

    public boolean isEditing(Cell.Context context,
                             Element parent,
                             C value)

Description copied from interface: `Cell`
Returns true if the cell is currently editing the data identified by the given element and key. While a cell is editing, widgets containing the cell may choose to pass keystrokes directly to the cell rather than using them for navigation purposes.

Specified by:
  `isEditing` in interface `Cell<C>`
Parameters:
  `context` - the `Cell.Context` of the cell
  `parent` - the parent Element
  `value` - the value associated with the cell
Returns:
  true if the cell is in edit mode

#### onBrowserEvent

    public void onBrowserEvent(Cell.Context context,
                               Element parent,
                               C value,
                               NativeEvent event,
                               ValueUpdater<C> valueUpdater)

Description copied from interface: `Cell`
Handle a browser event that took place within the cell. The default implementation returns null.

Specified by:
  `onBrowserEvent` in interface `Cell<C>`
Parameters:
  `context` - the `Cell.Context` of the cell
  `parent` - the parent Element
  `value` - the value associated with the cell
  `event` - the native browser event
  `valueUpdater` - a `ValueUpdater`, or null if not specified

#### render

    public void render(Cell.Context context,
                       C value,
                       SafeHtmlBuilder sb)

Description copied from interface: `Cell`
Render a cell as HTML into a `SafeHtmlBuilder`, suitable for passing to `Element.setInnerHTML(String)` on a container element.

Note: If your cell contains natively focusable elements, such as buttons or input elements, be sure to set the tabIndex to -1 so that they do not steal focus away from the containing widget.

Specified by:
  `render` in interface `Cell<C>`
Parameters:
  `context` - the `Cell.Context` of the cell
  `value` - the cell value to be rendered
  `sb` - the `SafeHtmlBuilder` to be written to

#### resetFocus

    public boolean resetFocus(Cell.Context context,
                              Element parent,
                              C value)

Description copied from interface: `Cell`
Reset focus on the Cell. This method is called if the cell has focus when it is refreshed.

Specified by:
  `resetFocus` in interface `Cell<C>`
Parameters:
  `context` - the `Cell.Context` of the cell
  `parent` - the parent Element
  `value` - the value associated with the cell
Returns:
  true if focus is taken, false if not

#### setValue

    public void setValue(Cell.Context context,
                         Element parent,
                         C value)

Description copied from interface: `Cell`
This method may be used by cell containers to set the value on a single cell directly, rather than using `Element.setInnerHTML(String)`. See `Cell.setValue(Context, Element, Object)` for a default implementation that uses `Cell.render(Context, Object, SafeHtmlBuilder)`.

Specified by:
  `setValue` in interface `Cell<C>`
Parameters:
  `context` - the `Cell.Context` of the cell
  `parent` - the parent Element
  `value` - the value associated with the cell

#### getIconHtml

    protected SafeHtml getIconHtml(C value)

Get the safe HTML string that represents the icon. Override this method to change the icon based on the value.

Parameters:
  `value` - the value being rendered
Returns:
  the HTML string that represents the icon

#### isIconUsed

    protected boolean isIconUsed(C value)

Check if the icon should be used for the value. If the icon should not be used, a placeholder of the same size will be used instead. The default implementations returns true.

Parameters:
  `value` - the value being rendered
Returns:
  true to use the icon, false to use a placeholder

#### getImageHtml

    SafeHtml getImageHtml(ImageResource res,
                          HasVerticalAlignment.VerticalAlignmentConstant valign,
                          boolean isPlaceholder)

Get the HTML representation of an image. Visible for testing.

Parameters:
  `res` - the `ImageResource` to render as HTML
  `valign` - the vertical alignment
  `isPlaceholder` - if true, do not include the background image
Returns:
  the rendered HTML