com.smartgwt.client.widgets

## Class HeaderControl

- java.lang.Object
- - com.google.gwt.user.client.ui.UIObject
  - - com.google.gwt.user.client.ui.Widget
    - - com.smartgwt.client.widgets.BaseWidget
      - - com.smartgwt.client.widgets.Canvas
        - - com.smartgwt.client.widgets.StatefulCanvas
          - - com.smartgwt.client.widgets.Img
            - - com.smartgwt.client.widgets.HeaderControl

- All Implemented Interfaces:
    com.google.gwt.event.logical.shared.HasAttachHandlers, com.google.gwt.event.shared.HasHandlers, com.google.gwt.user.client.EventListener, com.google.gwt.user.client.ui.HasVisibility, com.google.gwt.user.client.ui.IsWidget, LogicalStructure, HasClickHandlers, HasDoubleClickHandlers, HasDragMoveHandlers, HasDragRepositionMoveHandlers, HasDragRepositionStartHandlers, HasDragRepositionStopHandlers, HasDragResizeMoveHandlers, HasDragResizeStartHandlers, HasDragResizeStopHandlers, HasDragStartHandlers, HasDragStopHandlers, HasDropHandlers, HasDropMoveHandlers, HasDropOutHandlers, HasDropOverHandlers, HasFocusChangedHandlers, HasHoverHandlers, HasHoverHiddenHandlers, HasKeyDownHandlers, HasKeyPressHandlers, HasMouseDownHandlers, HasMouseMoveHandlers, HasMouseOutHandlers, HasMouseOverHandlers, HasMouseStillDownHandlers, HasMouseUpHandlers, HasMouseWheelHandlers, HasMovedHandlers, HasParentMovedHandlers, HasResizedHandlers, HasRightMouseDownHandlers, HasScrolledHandlers, HasShowContextMenuHandlers, HasVisibilityChangedHandlers

      public class HeaderControl
      extends Img

  Convenience class for icons that are placed in as header controls in a `Window` Header, or `SectionStackSection`.
  See Also:
    `Window.setHeaderControls(Object...)`, `SectionStackSection.setControls(Canvas...)`

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class and Description
    --- | ---
    `static class` | `HeaderControl.HeaderIcon`

    - ### Nested classes/interfaces inherited from class com.google.gwt.user.client.ui.UIObject

      `com.google.gwt.user.client.ui.UIObject.DebugIdImpl, com.google.gwt.user.client.ui.UIObject.DebugIdImplEnabled`

  - ### Field Summary

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static HeaderControl.HeaderIcon` | `ARROW_DOWN`
    `static HeaderControl.HeaderIcon` | `ARROW_LEFT`
    `static HeaderControl.HeaderIcon` | `ARROW_RIGHT`
    `static HeaderControl.HeaderIcon` | `ARROW_UP`
    `static HeaderControl.HeaderIcon` | `CALCULATOR`
    `static HeaderControl.HeaderIcon` | `CART`
    `static HeaderControl.HeaderIcon` | `CASCADE`
    `static HeaderControl.HeaderIcon` | `CLIPBOARD`
    `static HeaderControl.HeaderIcon` | `CLOCK`
    `static HeaderControl.HeaderIcon` | `CLOSE`
    `static HeaderControl.HeaderIcon` | `COMMENT`
    `static HeaderControl.HeaderIcon` | `DOCUMENT`
    `static HeaderControl.HeaderIcon` | `DOUBLE_ARROW_DOWN`
    `static HeaderControl.HeaderIcon` | `DOUBLE_ARROW_LEFT`
    `static HeaderControl.HeaderIcon` | `DOUBLE_ARROW_RIGHT`
    `static HeaderControl.HeaderIcon` | `DOUBLE_ARROW_UP`
    `static HeaderControl.HeaderIcon` | `FAVOURITE`
    `static HeaderControl.HeaderIcon` | `FIND`
    `static HeaderControl.HeaderIcon` | `HELP`
    `static HeaderControl.HeaderIcon` | `HOME`
    `static HeaderControl.HeaderIcon` | `MAIL`
    `static HeaderControl.HeaderIcon` | `MAXIMIZE`
    `static HeaderControl.HeaderIcon` | `MINIMIZE`
    `static HeaderControl.HeaderIcon` | `MINUS`
    `static HeaderControl.HeaderIcon` | `PERSON`
    `static HeaderControl.HeaderIcon` | `PIN_DOWN`
    `static HeaderControl.HeaderIcon` | `PIN_LEFT`
    `static HeaderControl.HeaderIcon` | `PLUS`
    `static HeaderControl.HeaderIcon` | `PRINT`
    `static HeaderControl.HeaderIcon` | `REFRESH`
    `static HeaderControl.HeaderIcon` | `REFRESH_THIN`
    `static HeaderControl.HeaderIcon` | `SAVE`
    `static HeaderControl.HeaderIcon` | `SETTINGS`
    `static HeaderControl.HeaderIcon` | `TRANSFER`
    `static HeaderControl.HeaderIcon` | `TRASH`
    `static HeaderControl.HeaderIcon` | `ZOOM`

    - ### Fields inherited from class com.smartgwt.client.widgets.BaseWidget

      `config, configOnly, id, isElementSet, nativeObject, scClassName`

    - ### Fields inherited from class com.google.gwt.user.client.ui.UIObject

      `DEBUG_ID_PREFIX`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `HeaderControl(HeaderControl.HeaderIcon icon)` Create a new HeaderControl with the specific icon.
    `HeaderControl(HeaderControl.HeaderIcon icon, ClickHandler clickHandler)` Create a new HeaderControl with the specific icon.

  - ### Method Summary

    - ### Methods inherited from class com.smartgwt.client.widgets.Img

      `changeAutoChildDefaults, changeAutoChildDefaults, create, getAltText, getImageHeight, getImageType, getImageWidth, getLogicalStructure, getOrCreateRef, getPrompt, getShowTitle, getSize, getSrc, getUsePNGFix, resetSrc, setAltText, setDefaultProperties, setHoverHTMLCustomizer, setImageHeight, setImageType, setImageWidth, setJavaScriptObject, setLogicalStructure, setName, setPrompt, setShowTitle, setSize, setSrc, setUsePNGFix`

    - ### Methods inherited from class com.smartgwt.client.widgets.StatefulCanvas

      `addToRadioGroup, deselect, getActionType, getAlign, getAutoFit, getBaseStyle, getIcon, getIconHeight, getIconOrientation, getIconSize, getIconWidth, getOverCanvas, getOverCanvasConstructor, getRadioGroup, getRedrawOnStateChange, getSelected, getShowDisabled, getShowDisabledIcon, getShowDown, getShowDownIcon, getShowFocused, getShowFocusedAsOver, getShowFocusedIcon, getShowOverCanvas, getShowRollOver, getShowRollOverIcon, getShowSelectedIcon, getState, getStateSuffix, getTitle, getValign, isSelected, removeFromRadioGroup, removeFromRadioGroup, select, setActionType, setAlign, setAutoFit, setBaseStyle, setDefaultProperties, setIcon, setIconHeight, setIconOrientation, setIconSize, setIconWidth, setLogicalStructure, setOverCanvasConstructor, setRadioGroup, setRedrawOnStateChange, setSelected, setShowDisabled, setShowDisabledIcon, setShowDown, setShowDownIcon, setShowFocused, setShowFocusedAsOver, setShowFocusedIcon, setShowOverCanvas, setShowRollOver, setShowRollOverIcon, setShowSelectedIcon, setState, setTitle, setTitleStyle, setValign`

    - ### Methods inherited from class com.smartgwt.client.widgets.Canvas

      `addChild, addChild, addChild, addChild, addChild, addClickHandler, addDoubleClickHandler, addDragMoveHandler, addDragRepositionMoveHandler, addDragRepositionStartHandler, addDragRepositionStopHandler, addDragResizeMoveHandler, addDragResizeStartHandler, addDragResizeStopHandler, addDragStartHandler, addDragStopHandler, addDropHandler, addDropMoveHandler, addDropOutHandler, addDropOverHandler, addFocusChangedHandler, addHoverHandler, addHoverHiddenHandler, addKeyDownHandler, addKeyPressHandler, addMouseDownHandler, addMouseMoveHandler, addMouseOutHandler, addMouseOverHandler, addMouseStillDownHandler, addMouseUpHandler, addMouseWheelHandler, addMovedHandler, addParentMovedHandler, addPeer, addPeer, addPeer, addPeer, addResizedHandler, addRightMouseDownHandler, addScrolledHandler, addShowContextMenuHandler, addStyleName, addVisibilityChangedHandler, adjustForContent, animateFade, animateFade, animateFade, animateFade, animateFade, animateFade, animateFade, animateHide, animateHide, animateHide, animateMove, animateMove, animateMove, animateMove, animateRect, animateRect, animateRect, animateRect, animateResize, animateResize, animateResize, animateResize, animateScroll, animateScroll, animateScroll, animateScroll, animateScroll, animateScroll, animateShow, animateShow, animateShow, asSGWTComponent, blur, bringToFront, clear, clickMaskUp, clickMaskUp, contains, contains, containsEvent, containsFocus, containsPoint, containsPoint, deparent, depeer, disable, enable, focus, focusInNextTabElement, focusInPreviousTabElement, getAbsoluteLeft, getAbsoluteTop, getAccessKey, getAnimateAcceleration, getAnimateFadeTime, getAnimateHideAcceleration, getAnimateHideTime, getAnimateMoveAcceleration, getAnimateMoveTime, getAnimateRectAcceleration, getAnimateRectTime, getAnimateResizeAcceleration, getAnimateResizeTime, getAnimateScrollAcceleration, getAnimateScrollTime, getAnimateShowAcceleration, getAnimateShowEffect, getAnimateShowTime, getAnimateTime, getAppImgDir, getAriaRole, getAutoDraw, getAutoShowParent, getBackgroundColor, getBackgroundImage, getBackgroundPosition, getBackgroundRepeat, getBorder, getBottom, getById, getByJSObject, getByLocalId, getCanAcceptDrop, getCanDrag, getCanDragReposition, getCanDragResize, getCanDragScroll, getCanDrop, getCanDropBefore, getCanFocus, getCanHover, getCanSelectText, getCanvasAutoChild, getCanvasItem, getChildren, getChildrenSnapResizeToGrid, getChildrenSnapToGrid, getClassName, getContentElement, getContents, getContextMenu, getCursor, getDataPath, getDefaultHeight, getDefaultWidth, getDestroyed, getDestroying, getDisabled, getDisabledCursor, getDoubleClickDelay, getDragAppearance, getDragIntersectStyle, getDragOpacity, getDragRepositionAppearance, getDragRepositionCursor, getDragResizeAppearance, getDragScrollDelay, getDragStartDistance, getDragTarget, getDragType, getDropTypes, getDynamicContents, getEdgeBackgroundColor, getEdgeCenterBackgroundColor, getEdgeImage, getEdgeMarginSize, getEdgeOffset, getEdgeOpacity, getEdgeShowCenter, getEdgeSize, getEventEdge, getEventEdge, getExtraSpace, getFacetId, getFormItemAutoChild, getFullDataPath, getGroupBorderCSS, getGroupLabelBackgroundColor, getGroupLabelStyleName, getGroupTitle, getHeight, getHeightAsString, getHideUsingDisplayNone, getHoverAlign, getHoverAutoDestroy, getHoverComponent, getHoverDelay, getHoverHeight, getHoverHTML, getHoverMoveWithMouse, getHoverOpacity, getHoverStyle, getHoverVAlign, getHoverWidth, getHoverWrap, getHSnapOrigin, getHSnapOrigin, getHSnapPosition, getHSnapPosition, getHtmlPosition, getImage, getImgURL, getImgURL, getInnerContentHeight, getInnerContentWidth, getInnerHeight, getInnerWidth, getIsGroup, getKeepInParentRect, getLayoutAlign, getLeft, getLeftAsString, getLocateChildrenBy, getLocateChildrenType, getLocatePeersBy, getLocatePeersType, getMargin, getMasterElement, getMatchElement, getMaxHeight, getMaxWidth, getMenuConstructor, getMinHeight, getMinWidth, getMouseStillDownDelay, getMouseStillDownInitialDelay, getNextZIndex, getNoDoubleClicks, getOffsetHeight, getOffsetWidth, getOffsetX, getOffsetY, getOpacity, getOuterElement, getOverflow, getPadding, getPageBottom, getPageLeft, getPageRect, getPageRight, getPageTop, getParentElement, getPeers, getPercentBox, getPercentSource, getPosition, getPrefix, getPrintChildrenAbsolutelyPositioned, getPrintHTML, getPrintHTML, getRect, getRedrawOnResize, getResizeBarTarget, getResizeFrom, getRight, getScrollbarSize, getScrollBottom, getScrollHeight, getScrollLeft, getScrollRight, getScrollTop, getScrollWidth, getShadowDepth, getShadowImage, getShadowOffset, getShadowSoftness, getShouldPrint, getShowCustomScrollbars, getShowDragShadow, getShowEdges, getShowHover, getShowHoverComponents, getShowResizeBar, getShowShadow, getSkinImgDir, getSnapAxis, getSnapEdge, getSnapHDirection, getSnapHGap, getSnapOffsetLeft, getSnapOffsetTop, getSnapOnDrop, getSnapResizeToGrid, getSnapTo, getSnapToGrid, getSnapVDirection, getSnapVGap, getStyleName, getTabIndex, getTestInstance, getTooltip, getTop, getTopAsString, getTopElement, getUseBackMask, getUseOpacityFilter, getValuesManager, getViewportHeight, getViewportWidth, getVisibility, getVisibleHeight, getVisibleWidth, getVSnapOrigin, getVSnapOrigin, getVSnapPosition, getVSnapPosition, getWidth, getWidthAsString, getZIndex, handleHover, hide, hideClickMask, hideClickMask, hideContextMenu, imgHTML, imgHTML, imgHTML, intersects, isDirty, isDisabled, isDrawn, isVisible, keyUp, layoutChildren, linkHTML, linkHTML, linkHTML, linkHTML, linkHTML, linkHTML, markForDestroy, markForRedraw, markForRedraw, moveAbove, moveBelow, moveBy, moveTo, onAttach, onDetach, onInit, parentResized, printComponents, redraw, redraw, removeChild, removeChild, removePeer, removePeer, resizeBy, resizeTo, resizeTo, scrollBy, scrollByPercent, scrollTo, scrollTo, scrollTo, scrollToBottom, scrollToLeft, scrollToPercent, scrollToRight, scrollToTop, sendToBack, setAccessKey, setAllowExternalFilters, setAnimateAcceleration, setAnimateFadeTime, setAnimateHideAcceleration, setAnimateHideTime, setAnimateMoveAcceleration, setAnimateMoveTime, setAnimateRectAcceleration, setAnimateRectTime, setAnimateResizeAcceleration, setAnimateResizeTime, setAnimateScrollAcceleration, setAnimateScrollTime, setAnimateShowAcceleration, setAnimateShowEffect, setAnimateShowTime, setAnimateTime, setAppImgDir, setAriaRole, setAriaState, setAutoChildConstructor, setAutoChildProperties, setAutoChildProperties, setAutoChildVisibility, setAutoDraw, setAutoHeight, setAutoShowParent, setAutoWidth, setBackgroundColor, setBackgroundImage, setBackgroundPosition, setBackgroundRepeat, setBorder, setBottom, setCanAcceptDrop, setCanDrag, setCanDragReposition, setCanDragResize, setCanDragScroll, setCanDrop, setCanDropBefore, setCanFocus, setCanHover, setCanSelectText, setCanvasItem, setChildren, setChildrenSnapResizeToGrid, setChildrenSnapToGrid, setContents, setContextMenu, setCursor, setDataPath, setDefaultHeight, setDefaultProperties, setDefaultWidth, setDisabled, setDisabledCursor, setDoubleClickDelay, setDragAppearance, setDragIntersectStyle, setDragOpacity, setDragRepositionAppearance, setDragRepositionCursor, setDragResizeAppearance, setDragScrollDelay, setDragStartDistance, setDragTarget, setDragType, setDropTypes, setDynamicContents, setEdgeBackgroundColor, setEdgeCenterBackgroundColor, setEdgeImage, setEdgeMarginSize, setEdgeOffset, setEdgeOpacity, setEdgeShowCenter, setEdgeSize, setExtraSpace, setFacetId, setGroupBorderCSS, setGroupLabelBackgroundColor, setGroupLabelStyleName, setGroupTitle, setHeight, setHeight, setHeight100, setHideUsingDisplayNone, setHoverAlign, setHoverAutoDestroy, setHoverDelay, setHoverHeight, setHoverMoveWithMouse, setHoverOpacity, setHoverStyle, setHoverVAlign, setHoverWidth, setHoverWrap, setHtmlPosition, setImage, setImage, setIsGroup, setKeepInParentRect, setKeepInParentRect, setKeepInParentRect, setLayoutAlign, setLayoutAlign, setLeft, setLeft, setLocateChildrenBy, setLocateChildrenType, setLocatePeersBy, setLocatePeersType, setLogicalStructure, setMargin, setMatchElement, setMaxHeight, setMaxWidth, setMenuConstructor, setMinHeight, setMinWidth, setMouseStillDownDelay, setMouseStillDownInitialDelay, setNeverUseFilters, setNoDoubleClicks, setOpacity, setOverflow, setPadding, setPageLeft, setPageTop, setParentElement, setPeers, setPercentBox, setPercentSource, setPosition, setPrefix, setPrintChildrenAbsolutelyPositioned, setRect, setRect, setRedrawOnResize, setResizeBarTarget, setResizeFrom, setResizeFrom, setRight, setScrollbarConstructor, setScrollbarSize, setShadowDepth, setShadowImage, setShadowOffset, setShadowSoftness, setShouldPrint, setShowCustomScrollbars, setShowDragShadow, setShowEdges, setShowHover, setShowHoverComponents, setShowResizeBar, setShowShadow, setSkinImgDir, setSmoothFade, setSnapAxis, setSnapEdge, setSnapHDirection, setSnapHGap, setSnapOffsetLeft, setSnapOffsetTop, setSnapOnDrop, setSnapResizeToGrid, setSnapTo, setSnapToGrid, setSnapVDirection, setSnapVGap, setStyleName, setTabIndex, setTooltip, setTop, setTop, setUseBackMask, setUseOpacityFilter, setValuesManager, setVisibility, setVisible, setWidth, setWidth, setWidth100, setZIndex, shouldDragScroll, show, showClickMask, showNextTo, showNextTo, showNextTo, showNextTo, showPrintPreview, showPrintPreview, showPrintPreview, showPrintPreview, showRecursively, updateHover, updateHover, updateShadow, visibleAtPoint, willAcceptDrop`

    - ### Methods inherited from class com.smartgwt.client.widgets.BaseWidget

      `addDrawHandler, destroy, doAddHandler, doInit, doOnRender, draw, equals, error, errorIfNotCreated, getAttribute, getAttributeAsBoolean, getAttributeAsDate, getAttributeAsDateArray, getAttributeAsDouble, getAttributeAsElement, getAttributeAsFloat, getAttributeAsFloatArray, getAttributeAsInt, getAttributeAsIntArray, getAttributeAsJavaScriptObject, getAttributeAsMap, getAttributeAsRecord, getAttributeAsString, getAttributeAsStringArray, getConfig, getDOM, getElement, getElement, getHandlerCount, getID, getInnerHTML, getJsObj, getOrCreateJsObj, getRef, getScClassName, hashCode, initNativeObject, internalSetID, internalSetID, isConfigOnly, isCreated, onBind, onDestroy, onDraw, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setAttribute, setConfig, setConfigOnly, setDragTracker, setElement, setHtmlElement, setID, setLogicalStructure, setNullProperty, setPosition, setProperty, setProperty, setProperty, setProperty, setProperty, setProperty, setProperty, setScClassName, toString`

    - ### Methods inherited from class com.google.gwt.user.client.ui.Widget

      `addAttachHandler, addBitlessDomHandler, addDomHandler, addHandler, asWidget, asWidgetOrNull, createHandlerManager, delegateEvent, doAttachChildren, doDetachChildren, fireEvent, getLayoutData, getParent, isAttached, isOrWasAttached, onBrowserEvent, onLoad, onUnload, removeFromParent, setLayoutData, sinkEvents`

    - ### Methods inherited from class com.google.gwt.user.client.ui.UIObject

      `addStyleDependentName, ensureDebugId, ensureDebugId, ensureDebugId, getStyleElement, getStyleName, getStylePrimaryName, getStylePrimaryName, isVisible, onEnsureDebugId, removeStyleDependentName, removeStyleName, resolvePotentialElement, setElement, setPixelSize, setSize, setStyleDependentName, setStyleName, setStyleName, setStyleName, setStylePrimaryName, setStylePrimaryName, setVisible, sinkBitlessEvent, unsinkEvents`

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

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

    - ### Methods inherited from interface com.google.gwt.event.shared.HasHandlers

      `fireEvent`

- - ### Field Detail

    - #### ARROW_DOWN

          public static HeaderControl.HeaderIcon ARROW_DOWN

    - #### ARROW_LEFT

          public static HeaderControl.HeaderIcon ARROW_LEFT

    - #### ARROW_RIGHT

          public static HeaderControl.HeaderIcon ARROW_RIGHT

    - #### ARROW_UP

          public static HeaderControl.HeaderIcon ARROW_UP

    - #### CALCULATOR

          public static HeaderControl.HeaderIcon CALCULATOR

    - #### CART

          public static HeaderControl.HeaderIcon CART

    - #### CASCADE

          public static HeaderControl.HeaderIcon CASCADE

    - #### CLIPBOARD

          public static HeaderControl.HeaderIcon CLIPBOARD

    - #### CLOCK

          public static HeaderControl.HeaderIcon CLOCK

    - #### CLOSE

          public static HeaderControl.HeaderIcon CLOSE

    - #### COMMENT

          public static HeaderControl.HeaderIcon COMMENT

    - #### DOCUMENT

          public static HeaderControl.HeaderIcon DOCUMENT

    - #### DOUBLE_ARROW_DOWN

          public static HeaderControl.HeaderIcon DOUBLE_ARROW_DOWN

    - #### DOUBLE_ARROW_LEFT

          public static HeaderControl.HeaderIcon DOUBLE_ARROW_LEFT

    - #### DOUBLE_ARROW_RIGHT

          public static HeaderControl.HeaderIcon DOUBLE_ARROW_RIGHT

    - #### DOUBLE_ARROW_UP

          public static HeaderControl.HeaderIcon DOUBLE_ARROW_UP

    - #### FAVOURITE

          public static HeaderControl.HeaderIcon FAVOURITE

    - #### FIND

          public static HeaderControl.HeaderIcon FIND

    - #### HELP

          public static HeaderControl.HeaderIcon HELP

    - #### HOME

          public static HeaderControl.HeaderIcon HOME

    - #### MAIL

          public static HeaderControl.HeaderIcon MAIL

    - #### MAXIMIZE

          public static HeaderControl.HeaderIcon MAXIMIZE

    - #### MINIMIZE

          public static HeaderControl.HeaderIcon MINIMIZE

    - #### MINUS

          public static HeaderControl.HeaderIcon MINUS

    - #### PERSON

          public static HeaderControl.HeaderIcon PERSON

    - #### PIN_DOWN

          public static HeaderControl.HeaderIcon PIN_DOWN

    - #### PIN_LEFT

          public static HeaderControl.HeaderIcon PIN_LEFT

    - #### PLUS

          public static HeaderControl.HeaderIcon PLUS

    - #### PRINT

          public static HeaderControl.HeaderIcon PRINT

    - #### REFRESH

          public static HeaderControl.HeaderIcon REFRESH

    - #### REFRESH_THIN

          public static HeaderControl.HeaderIcon REFRESH_THIN

    - #### SAVE

          public static HeaderControl.HeaderIcon SAVE

    - #### SETTINGS

          public static HeaderControl.HeaderIcon SETTINGS

    - #### TRANSFER

          public static HeaderControl.HeaderIcon TRANSFER

    - #### TRASH

          public static HeaderControl.HeaderIcon TRASH

    - #### ZOOM

          public static HeaderControl.HeaderIcon ZOOM

  - ### Constructor Detail

    - #### HeaderControl

          public HeaderControl(HeaderControl.HeaderIcon icon)

      Create a new HeaderControl with the specific icon.
      Parameters:
        `icon` - the icon

    - #### HeaderControl

          public HeaderControl(HeaderControl.HeaderIcon icon,
                       ClickHandler clickHandler)

      Create a new HeaderControl with the specific icon.
      Parameters:
        `icon` - the icon
        `clickHandler` - the header control click handler