Package com.vaadin.client.renderers

Class ComplexRenderer<T>

  • All Implemented Interfaces:
    Renderer<T>
    Direct Known Subclasses:
    WidgetRenderer
    public abstract class ComplexRenderer<T>
extends Object
implements Renderer<T>
    Base class for renderers that needs initialization and destruction logic (override #init(FlyweightCell) and #destroy(FlyweightCell) and event handling (see #onBrowserEvent(Cell, NativeEvent), getConsumedEvents() and #onActivate().

    Also provides a helper method for hiding the cell contents by overriding #setContentVisible(FlyweightCell, boolean)

    Since:
    7.4.0
    Author:
    Vaadin Ltd

    • Constructor Detail

      • ComplexRenderer

        public ComplexRenderer()

    • Method Detail

      • init

        public abstract void init​(RendererCellReference cell)
        Called at initialization stage. Perform any initialization here e.g. attach handlers, attach widgets etc.
        Parameters:
        cell - The cell. Note that the cell is not to be stored outside of the method as the cell instance will change. See FlyweightCell

      • destroy

        public void destroy​(RendererCellReference cell)
        Called after the cell is deemed to be destroyed and no longer used by the Grid. Called after the cell element is detached from the DOM.

        The row object in the cell reference will be null since the row might no longer be present in the data source.

        Parameters:
        cell - The cell. Note that the cell is not to be stored outside of the method as the cell instance will change. See FlyweightCell

      • getConsumedEvents

        public Collection<String> getConsumedEvents()
        Returns the events that the renderer should consume. These are also the events that the Grid will pass to #onBrowserEvent(Cell, NativeEvent) when they occur.
        Returns:
        a list of consumed events
        See Also:
        BrowserEvents

      • onBrowserEvent

        public boolean onBrowserEvent​(CellReference<?> cell,
                              com.google.gwt.dom.client.NativeEvent event)
        Called whenever a registered event is triggered in the column the renderer renders.

        The events that triggers this needs to be returned by the getConsumedEvents() method.

        Returns boolean telling if the event has been completely handled and should not cause any other actions.

        Parameters:
        cell - Object containing information about the cell the event was triggered on.
        event - The original DOM event
        Returns:
        true if event should not be handled by grid

      • setContentVisible

        public void setContentVisible​(RendererCellReference cell,
                              boolean hasData)
        Used by Grid to toggle whether to show actual data or just an empty placeholder while data is loading. This method is invoked whenever a cell changes between data being available and data missing.

        Default implementation hides content by setting visibility: hidden to all elements inside the cell. Text nodes are left as is - renderers that add such to the root element need to implement explicit support hiding them.

        Parameters:
        cell - The cell
        hasData - Has the cell content been loaded from the data source

      • onActivate

        public boolean onActivate​(CellReference<?> cell)
        Called when the cell is activated by pressing enter, double clicking or performing a double tap on the cell.
        Parameters:
        cell - the activated cell
        Returns:
        true if event was handled and should not be interpreted as a generic gesture by Grid.

      • destroy

        public void destroy()
        Called when the renderer is deemed to be destroyed and no longer used by the Grid.