java.lang.Object
- org.pepstock.charba.client.commons.NativeObjectContainer
- - org.pepstock.charba.client.commons.AbstractNode
  - - org.pepstock.charba.client.plugins.AbstractPluginOptions
    - - org.pepstock.charba.client.datalabels.LabelItem
      - org.pepstock.charba.client.datalabels.DataLabelsOptions

All Implemented Interfaces:

IsScriptableFontProvider<DataLabelsContext>, IsScriptablePaddingProvider<DataLabelsContext>
```
public final class DataLabelsOptions
extends LabelItem
```
This is the DataLabelsPlugin.ID plugin options where to set all the configuration needed to the plugin.
The options could be set by simply the value or by setting a callback.
The DataLabelsPlugin.ID plugin is highly customizable CHART.JS plugin that displays labels on data for any type of charts.

Author:

Andrea "Stock" Stocchero

Field Summary

Fields
Modifier and Type	Field	Description
`static Align`	`DEFAULT_ALIGN`	Default position of the label relative to the anchor point position and orientation, `Align.CENTER`.
`static Anchor`	`DEFAULT_ANCHOR`	Default anchor point, which is defined by an orientation vector and a position on the data element, `Anchor.CENTER`.
`static String`	`DEFAULT_BACKGROUND_COLOR`	Default background color, `null`, and uses the background color of dataset.
`static String`	`DEFAULT_BORDER_COLOR`	Default border color, `null`, and uses the border color of dataset.
`static double`	`DEFAULT_BORDER_RADIUS`	Default border radius of labels, 0.0.
`static int`	`DEFAULT_BORDER_WIDTH`	Default border width of labels, 0.
`static boolean`	`DEFAULT_CLAMP`	Default to enforce the anchor position to be calculated based on the visible geometry of the associated element, false.
`static boolean`	`DEFAULT_CLIP`	Default to enforce the part of the label which is outside the chart area will be masked, false.
`static Display`	`DEFAULT_DISPLAY`	Default visibility of labels, `Display.TRUE`.
`static int`	`DEFAULT_OFFSET`	Default distance (in pixels) to pull the label away from the anchor point, 4.
`static double`	`DEFAULT_OPACITY`	Default opacity, 1.0.
`static double`	`DEFAULT_ROTATION`	Default clockwise rotation angle (in degrees) of the label, 0.0.
`static TextAlign`	`DEFAULT_TEXT_ALIGN`	Default text alignment being used when drawing the label text, `TextAlign.START`.
`static double`	`DEFAULT_TEXT_SHADOW_BLUR`	Default text shadow blur, 0.0.
`static int`	`DEFAULT_TEXT_STROKE_WIDTH`	Default text stroke width, 0.

Constructor Summary

Constructors
Constructor	Description
`DataLabelsOptions()`	Creates new `DataLabelsPlugin.ID` plugin options.
`DataLabelsOptions(IsChart chart)`	Creates new `DataLabelsPlugin.ID` plugin options, relating to chart instance for default.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods Default Methods
Modifier and Type	Method	Description
`protected void`	`applyingDefaults()`	This is invoked before storing the plugins options as default.
`default Align`	`getAlign()`	Returns the position of the label relative to the anchor point position and orientation.
`default AlignCallback`	`getAlignCallback()`	Returns the align callback.
`default Anchor`	`getAnchor()`	Returns the anchor point, which is defined by an orientation vector and a position on the data element
`default AnchorCallback`	`getAnchorCallback()`	Returns the anchor callback.
`default String`	`getBackgroundColorAsString()`	Returns the background color as string.
`default ColorCallback<DataLabelsContext>`	`getBackgroundColorCallback()`	Returns the background color callback.
`default String`	`getBorderColorAsString()`	Returns the border color as string.
`default ColorCallback<DataLabelsContext>`	`getBorderColorCallback()`	Returns the border color callback.
`default double`	`getBorderRadius()`	Returns the border radius.
`default RadiusCallback<DataLabelsContext>`	`getBorderRadiusCallback()`	Returns the border radius callback.
`default int`	`getBorderWidth()`	Returns the border width.
`default WidthCallback<DataLabelsContext>`	`getBorderWidthCallback()`	Returns the border width callback.
`default ClampCallback`	`getClampCallback()`	Returns the clamp callback.
`default ClipCallback`	`getClipCallback()`	Returns the clip callback.
`default String`	`getColorAsString()`	Returns the color as string.
`default ColorCallback<DataLabelsContext>`	`getColorCallback()`	Returns the color callback.
`default Display`	`getDisplay()`	Returns the visibility of labels.
`default DisplayCallback`	`getDisplayCallback()`	Returns the display callback.
`IsDefaultFont`	`getFont()`	Returns the font element.
`default FontCallback<DataLabelsContext>`	`getFontCallback()`	Returns the font callback.
`default FormatterCallback`	`getFormatterCallback()`	Returns the formatter callback.
`Labels`	`getLabels()`	Returns the labels element.
`org.pepstock.charba.client.datalabels.IsDefaultListeners`	`getListeners()`	Returns the listeners element.
`default int`	`getOffset()`	Returns the distance (in pixels) to pull the label away from the anchor point.
`default OffsetCallback<DataLabelsContext>`	`getOffsetCallback()`	Returns the offset callback.
`default double`	`getOpacity()`	Returns the opacity.
`default OpacityCallback`	`getOpacityCallback()`	Returns the opacity callback.
`IsDefaultPadding`	`getPadding()`	Returns the padding element.
`default PaddingCallback<DataLabelsContext>`	`getPaddingCallback()`	Returns the padding callback.
`default double`	`getRotation()`	Returns the clockwise rotation angle (in degrees) of the label, the rotation center point being the label center.
`default RotationCallback<DataLabelsContext>`	`getRotationCallback()`	Returns the rotation callback.
`default TextAlign`	`getTextAlign()`	Returns the text alignment being used when drawing the label text.
`default TextAlignCallback<DataLabelsContext>`	`getTextAlignCallback()`	Returns the text align callback.
`default double`	`getTextShadowBlur()`	Returns the text shadow blur.
`default TextShadowBlurCallback`	`getTextShadowBlurCallback()`	Returns the text shadow blur callback.
`default String`	`getTextShadowColorAsString()`	Returns the text shadow color as string.
`default ColorCallback<DataLabelsContext>`	`getTextShadowColorCallback()`	Returns the text shadow color callback.
`default String`	`getTextStrokeColorAsString()`	Returns the text stroke color as string.
`default ColorCallback<DataLabelsContext>`	`getTextStrokeColorCallback()`	Returns the text stroke color callback.
`default int`	`getTextStrokeWidth()`	Returns the text stroke width.
`default WidthCallback<DataLabelsContext>`	`getTextStrokeWidthCallback()`	Returns the text stroke width callback.
`default boolean`	`isClamp()`	Returns `true` to enforce the anchor position to be calculated based on the visible geometry of the associated element (i.e.
`default boolean`	`isClip()`	When the clip option is `true`, the part of the label which is outside the chart area will be masked.

Methods inherited from class org.pepstock.charba.client.datalabels.LabelItem
getAlign, getAlignCallback, getAlignDegrees, getAnchor, getAnchorCallback, getBackgroundColor, getBackgroundColorAsString, getBackgroundColorCallback, getBorderColor, getBorderColorAsString, getBorderColorCallback, getBorderRadius, getBorderRadiusCallback, getBorderWidth, getBorderWidthCallback, getClampCallback, getClipCallback, getColor, getColorAsString, getColorCallback, getDisplay, getDisplayCallback, getFont, getFontCallback, getFormatterCallback, getListeners, getOffset, getOffsetCallback, getOpacity, getOpacityCallback, getPadding, getPaddingCallback, getRotation, getRotationCallback, getTextAlign, getTextAlignCallback, getTextShadowBlur, getTextShadowBlurCallback, getTextShadowColor, getTextShadowColorAsString, getTextShadowColorCallback, getTextStrokeColor, getTextStrokeColorAsString, getTextStrokeColorCallback, getTextStrokeWidth, getTextStrokeWidthCallback, isClamp, isClip, setAlign, setAlign, setAlign, setAlign, setAnchor, setAnchor, setAnchor, setBackgroundColor, setBackgroundColor, setBackgroundColor, setBackgroundColor, setBorderColor, setBorderColor, setBorderColor, setBorderColor, setBorderRadius, setBorderRadius, setBorderRadius, setBorderWidth, setBorderWidth, setBorderWidth, setClamp, setClamp, setClamp, setClip, setClip, setClip, setColor, setColor, setColor, setColor, setDisplay, setDisplay, setDisplay, setDisplay, setFont, setFont, setFormatter, setListenersHandler, setOffset, setOffset, setOffset, setOpacity, setOpacity, setOpacity, setPadding, setPadding, setRotation, setRotation, setRotation, setTextAlign, setTextAlign, setTextAlign, setTextShadowBlur, setTextShadowBlur, setTextShadowBlur, setTextShadowColor, setTextShadowColor, setTextShadowColor, setTextShadowColor, setTextStrokeColor, setTextStrokeColor, setTextStrokeColor, setTextStrokeColor, setTextStrokeWidth, setTextStrokeWidth, setTextStrokeWidth

Methods inherited from class org.pepstock.charba.client.plugins.AbstractPluginOptions
applyingDefaults, getEvents, getId, getPluginId, loadGlobalsPluginOptions, setEvents, setEvents, store, store, store, store

Methods inherited from class org.pepstock.charba.client.commons.AbstractNode
checkAndAddToParent, getChildKey, getParentNode, getRootNode, retrieveRoot, setArrayValueAndAddToParent, setArrayValueAndAddToParent, setArrayValueAndAddToParent, setElementAndAddToParent, setInternalCallbackToModel, setInternalCallbackToModel, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent, setValueOrArrayAndAddToParent

Methods inherited from class org.pepstock.charba.client.commons.NativeObjectContainer
checkDefaultValuesArgument, empty, getArrayValue, getElement, getIncrementalId, getNativeChart, getNativeEvent, getNativeObject, getValue, getValue, getValue, getValue, getValue, getValue, getValue, getValue, getValue, getValue, getValue, getValue, getValue, getValueForMultipleKeyTypes, getValueForMultipleKeyTypes, getValueForMultipleKeyTypes, getValueOrArray, getValueOrArray, getValueOrArray, getValueOrArray, getValueOrArray, getValueOrArray, getValueOrArray, getValueOrArray, has, has, isType, keys, loadNativeObject, remove, remove, setArrayValue, setArrayValue, setArrayValue, setElement, setEmptyValue, setNewIncrementalId, setNewIncrementalId, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValue, setValueOrArray, setValueOrArray, setValueOrArray, setValueOrArray, setValueOrArray, setValueOrArray, setValueOrArray, setValueOrArray, setValueOrArray, setValueOrArray, toJSON, type

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_ALIGN
```
public static final Align DEFAULT_ALIGN
```
    Default position of the label relative to the anchor point position and orientation, Align.CENTER.
  - DEFAULT_ANCHOR
```
public static final Anchor DEFAULT_ANCHOR
```
    Default anchor point, which is defined by an orientation vector and a position on the data element, Anchor.CENTER.
  - DEFAULT_BACKGROUND_COLOR
```
public static final String DEFAULT_BACKGROUND_COLOR
```
    Default background color, null, and uses the background color of dataset.
  - DEFAULT_BORDER_COLOR
```
public static final String DEFAULT_BORDER_COLOR
```
    Default border color, null, and uses the border color of dataset.
  - DEFAULT_BORDER_RADIUS
```
public static final double DEFAULT_BORDER_RADIUS
```
    Default border radius of labels, 0.0.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_BORDER_WIDTH
```
public static final int DEFAULT_BORDER_WIDTH
```
    Default border width of labels, 0.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_CLAMP
```
public static final boolean DEFAULT_CLAMP
```
    Default to enforce the anchor position to be calculated based on the visible geometry of the associated element, false.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_CLIP
```
public static final boolean DEFAULT_CLIP
```
    Default to enforce the part of the label which is outside the chart area will be masked, false.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_DISPLAY
```
public static final Display DEFAULT_DISPLAY
```
    Default visibility of labels, Display.TRUE.
  - DEFAULT_OFFSET
```
public static final int DEFAULT_OFFSET
```
    Default distance (in pixels) to pull the label away from the anchor point, 4.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_OPACITY
```
public static final double DEFAULT_OPACITY
```
    Default opacity, 1.0.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_ROTATION
```
public static final double DEFAULT_ROTATION
```
    Default clockwise rotation angle (in degrees) of the label, 0.0.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_TEXT_ALIGN
```
public static final TextAlign DEFAULT_TEXT_ALIGN
```
    Default text alignment being used when drawing the label text, TextAlign.START.
  - DEFAULT_TEXT_STROKE_WIDTH
```
public static final int DEFAULT_TEXT_STROKE_WIDTH
```
    Default text stroke width, 0.
    
    See Also:
    
    Constant Field Values
  - DEFAULT_TEXT_SHADOW_BLUR
```
public static final double DEFAULT_TEXT_SHADOW_BLUR
```
    Default text shadow blur, 0.0.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - DataLabelsOptions
```
public DataLabelsOptions()
```
    Creates new DataLabelsPlugin.ID plugin options.
  - DataLabelsOptions
```
public DataLabelsOptions(IsChart chart)
```
    Creates new DataLabelsPlugin.ID plugin options, relating to chart instance for default.
    
    Parameters:
    
    chart - chart instance related to the plugin options
- Method Detail
  - applyingDefaults
```
protected void applyingDefaults()
```
    Description copied from class: AbstractPluginOptions
    
    This is invoked before storing the plugins options as default.
    
    Overrides:
    
    applyingDefaults in class LabelItem
  - getLabels
```
public Labels getLabels()
```
    Returns the labels element.
    
    Returns:
    
    the labels element.
  - getFont
```
public abstract IsDefaultFont getFont()
```
    Returns the font element.
    
    Returns:
    
    the font element.
  - getPadding
```
public abstract IsDefaultPadding getPadding()
```
    Returns the padding element.
    
    Returns:
    
    the padding element.
  - getListeners
```
public abstract org.pepstock.charba.client.datalabels.IsDefaultListeners getListeners()
```
    Returns the listeners element.
    
    Returns:
    
    the listeners element.
  - getAlign
```
public default Align getAlign()
```
    Returns the position of the label relative to the anchor point position and orientation.
    
    Returns:
    
    the position of the label relative to the anchor point position and orientation.
  - getAnchor
```
public default Anchor getAnchor()
```
    Returns the anchor point, which is defined by an orientation vector and a position on the data element
    
    Returns:
    
    the anchor point, which is defined by an orientation vector and a position on the data element.
  - getBackgroundColorAsString
```
public default String getBackgroundColorAsString()
```
    Returns the background color as string.
    
    Returns:
    
    the background color as string. If null, it uses the background color of dataset.
  - getBorderColorAsString
```
public default String getBorderColorAsString()
```
    Returns the border color as string.
    
    Returns:
    
    the border color as string. If null, it uses the border color of dataset.
  - getBorderRadius
```
public default double getBorderRadius()
```
    Returns the border radius.
    
    Returns:
    
    the border radius.
  - getBorderWidth
```
public default int getBorderWidth()
```
    Returns the border width.
    
    Returns:
    
    the border width.
  - isClamp
```
public default boolean isClamp()
```
    Returns true to enforce the anchor position to be calculated based on the visible geometry of the associated element (i.e. part inside the chart area).
    
    Returns:
    
    true to enforce the anchor position to be calculated based on the visible geometry of the associated element (i.e. part inside the chart area).
  - isClip
```
public default boolean isClip()
```
    When the clip option is true, the part of the label which is outside the chart area will be masked.
    
    Returns:
    
    when the clip option is true, the part of the label which is outside the chart area will be masked.
  - getColorAsString
```
public default String getColorAsString()
```
    Returns the color as string.
    
    Returns:
    
    the color as string.
  - getDisplay
```
public default Display getDisplay()
```
    Returns the visibility of labels.
    
    Returns:
    
    the visibility of labels.
  - getOffset
```
public default int getOffset()
```
    Returns the distance (in pixels) to pull the label away from the anchor point. This option is not applicable when align is 'center'. Also note that if align is 'start', the label is moved in the opposite direction.
    
    Returns:
    
    the distance (in pixels) to pull the label away from the anchor point. This option is not applicable when align is 'center'. Also note that if align is 'start', the label is moved in the opposite direction.
  - getOpacity
```
public default double getOpacity()
```
    Returns the opacity.
    
    Returns:
    
    the opacity.
  - getRotation
```
public default double getRotation()
```
    Returns the clockwise rotation angle (in degrees) of the label, the rotation center point being the label center.
    
    Returns:
    
    the clockwise rotation angle (in degrees) of the label, the rotation center point being the label center.
  - getTextAlign
```
public default TextAlign getTextAlign()
```
    Returns the text alignment being used when drawing the label text.
    
    Returns:
    
    the text alignment being used when drawing the label text.
  - getTextStrokeColorAsString
```
public default String getTextStrokeColorAsString()
```
    Returns the text stroke color as string.
    
    Returns:
    
    the text stroke color as string.
  - getTextStrokeWidth
```
public default int getTextStrokeWidth()
```
    Returns the text stroke width.
    
    Returns:
    
    the text stroke width.
  - getTextShadowBlur
```
public default double getTextShadowBlur()
```
    Returns the text shadow blur.
    
    Returns:
    
    the text shadow blur.
  - getTextShadowColorAsString
```
public default String getTextShadowColorAsString()
```
    Returns the text shadow color as string.
    
    Returns:
    
    the text shadow color as string.
  - getBackgroundColorCallback
```
public default ColorCallback<DataLabelsContext> getBackgroundColorCallback()
```
    Returns the background color callback.
    
    Returns:
    
    the background color callback.
  - getBorderColorCallback
```
public default ColorCallback<DataLabelsContext> getBorderColorCallback()
```
    Returns the border color callback.
    
    Returns:
    
    the border color callback.
  - getColorCallback
```
public default ColorCallback<DataLabelsContext> getColorCallback()
```
    Returns the color callback.
    
    Returns:
    
    the color callback.
  - getFormatterCallback
```
public default FormatterCallback getFormatterCallback()
```
    Returns the formatter callback.
    
    Returns:
    
    the formatter callback.
  - getAlignCallback
```
public default AlignCallback getAlignCallback()
```
    Returns the align callback.
    
    Returns:
    
    the align callback.
  - getAnchorCallback
```
public default AnchorCallback getAnchorCallback()
```
    Returns the anchor callback.
    
    Returns:
    
    the anchor callback.
  - getBorderRadiusCallback
```
public default RadiusCallback<DataLabelsContext> getBorderRadiusCallback()
```
    Returns the border radius callback.
    
    Returns:
    
    the border radius callback.
  - getBorderWidthCallback
```
public default WidthCallback<DataLabelsContext> getBorderWidthCallback()
```
    Returns the border width callback.
    
    Returns:
    
    the border width callback.
  - getClampCallback
```
public default ClampCallback getClampCallback()
```
    Returns the clamp callback.
    
    Returns:
    
    the clamp callback.
  - getClipCallback
```
public default ClipCallback getClipCallback()
```
    Returns the clip callback.
    
    Returns:
    
    the clip callback.
  - getDisplayCallback
```
public default DisplayCallback getDisplayCallback()
```
    Returns the display callback.
    
    Returns:
    
    the display callback.
  - getOffsetCallback
```
public default OffsetCallback<DataLabelsContext> getOffsetCallback()
```
    Returns the offset callback.
    
    Returns:
    
    the offset callback.
  - getOpacityCallback
```
public default OpacityCallback getOpacityCallback()
```
    Returns the opacity callback.
    
    Returns:
    
    the opacity callback.
  - getRotationCallback
```
public default RotationCallback<DataLabelsContext> getRotationCallback()
```
    Returns the rotation callback.
    
    Returns:
    
    the rotation callback.
  - getTextAlignCallback
```
public default TextAlignCallback<DataLabelsContext> getTextAlignCallback()
```
    Returns the text align callback.
    
    Returns:
    
    the text align callback.
  - getTextStrokeColorCallback
```
public default ColorCallback<DataLabelsContext> getTextStrokeColorCallback()
```
    Returns the text stroke color callback.
    
    Returns:
    
    the text stroke color callback.
  - getTextStrokeWidthCallback
```
public default WidthCallback<DataLabelsContext> getTextStrokeWidthCallback()
```
    Returns the text stroke width callback.
    
    Returns:
    
    the text stroke width callback.
  - getTextShadowBlurCallback
```
public default TextShadowBlurCallback getTextShadowBlurCallback()
```
    Returns the text shadow blur callback.
    
    Returns:
    
    the text shadow blur callback.
  - getTextShadowColorCallback
```
public default ColorCallback<DataLabelsContext> getTextShadowColorCallback()
```
    Returns the text shadow color callback.
    
    Returns:
    
    the text shadow color callback.
  - getFontCallback
```
public default FontCallback<DataLabelsContext> getFontCallback()
```
    Returns the font callback.
    
    Returns:
    
    the font callback.
  - getPaddingCallback
```
public default PaddingCallback<DataLabelsContext> getPaddingCallback()
```
    Returns the padding callback.
    
    Returns:
    
    the padding callback.

Class DataLabelsOptions

Field Summary

Constructor Summary

Method Summary

Methods inherited from class org.pepstock.charba.client.datalabels.LabelItem

Methods inherited from class org.pepstock.charba.client.plugins.AbstractPluginOptions

Methods inherited from class org.pepstock.charba.client.commons.AbstractNode

Methods inherited from class org.pepstock.charba.client.commons.NativeObjectContainer

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_ALIGN

DEFAULT_ANCHOR

DEFAULT_BACKGROUND_COLOR

DEFAULT_BORDER_COLOR

DEFAULT_BORDER_RADIUS

DEFAULT_BORDER_WIDTH

DEFAULT_CLAMP

DEFAULT_CLIP

DEFAULT_DISPLAY

DEFAULT_OFFSET

DEFAULT_OPACITY

DEFAULT_ROTATION

DEFAULT_TEXT_ALIGN

DEFAULT_TEXT_STROKE_WIDTH

DEFAULT_TEXT_SHADOW_BLUR

Constructor Detail

DataLabelsOptions

DataLabelsOptions

Method Detail

applyingDefaults

getLabels

getFont

getPadding

getListeners

getAlign

getAnchor

getBackgroundColorAsString

getBorderColorAsString

getBorderRadius

getBorderWidth

isClamp

isClip

getColorAsString

getDisplay

getOffset

getOpacity

getRotation

getTextAlign

getTextStrokeColorAsString

getTextStrokeWidth

getTextShadowBlur

getTextShadowColorAsString

getBackgroundColorCallback

getBorderColorCallback

getColorCallback

getFormatterCallback

getAlignCallback

getAnchorCallback

getBorderRadiusCallback

getBorderWidthCallback

getClampCallback

getClipCallback

getDisplayCallback

getOffsetCallback

getOpacityCallback

getRotationCallback

getTextAlignCallback

getTextStrokeColorCallback

getTextStrokeWidthCallback

getTextShadowBlurCallback

getTextShadowColorCallback

getFontCallback

getPaddingCallback