Class PainterHighlighter

  • All Implemented Interfaces:
    Highlighter

    public class PainterHighlighter
    extends AbstractHighlighter
    Highlighter implementation which uses a Painter to decorate the component.

    As Painter implementations can be mutable and Highlighters have the responsibility to notify their own listeners about any changes which might effect the visuals, this class provides api to install/uninstall a listener to the painter, as appropriate. It takes care of Painters of type AbstractHighlighter by registering a PropertyChangeListener. Subclasses might override to correctly handle different types as well.

    Subclasses might be implemented to change the Painter during the decoration process, which must not passed-on to the Highlighter's listeners. The default routing is controlled by a flag isAdjusting. This is set/reset in this implementation's highlight method to ease subclass' burden (and to keep backward compatibility with implementations preceding the introduction of the painter listener). That is, subclasses are free to change painter properties during the decoration.

    As an example, a ValueBasedPainterHighlighter might safely change any painter property to decorate a component depending on content.

    
     @Override
     protected Component doHighlight(Component renderer, ComponentAdapter adapter) {
          float end = getEndOfGradient((Number) adapter.getValue());
          RelativePainter painter = (RelativePainter) getPainter();
          painter.setXFraction(end);
          ((PainterAware) renderer).setPainter(painter);
          return renderer;
     }
     
     @Override
     protected boolean canHighlight(Component renderer, ComponentAdapter adapter) {
         return super.canHighlight(renderer, adapter) &&
            (adapter.getValue() instanceof Number);
     }
     
    NOTE: this will change once the Painter api is stable.
    • Field Detail

      • painter

        private Painter painter
        The painter to use for decoration.
      • painterListener

        private java.beans.PropertyChangeListener painterListener
        The listener registered with the Painter.
      • isAdjusting

        private boolean isAdjusting
        A flag indicating whether or not changes in the Painter should be passed-on to the Highlighter's ChangeListeners.
    • Constructor Detail

      • PainterHighlighter

        public PainterHighlighter()
        Instantiates a PainterHighlighter with null painter and default predicate.
      • PainterHighlighter

        public PainterHighlighter​(HighlightPredicate predicate)
        Instantiates a PainterHighlighter with null painter which uses the given predicate.
        Parameters:
        predicate - the HighlightPredicate which controls the highlight application.
      • PainterHighlighter

        public PainterHighlighter​(Painter painter)
        Instantiates a PainterHighlighter with the given Painter and default predicate.
        Parameters:
        painter - the painter to use
      • PainterHighlighter

        public PainterHighlighter​(HighlightPredicate predicate,
                                  Painter painter)
        Instantiates a PainterHighlighter with the given painter and predicate.
        Parameters:
        predicate -
        painter -
    • Method Detail

      • getPainter

        public Painter getPainter()
        Returns to Painter used in this Highlighter.
        Returns:
        the Painter used in this Highlighter, may be null.
      • setPainter

        public void setPainter​(Painter painter)
        Sets the Painter to use in this Highlighter, may be null. Un/installs the listener to changes painter's properties.
        Parameters:
        painter - the Painter to uses for decoration.
      • installPainterListener

        protected void installPainterListener()
        Installs a listener to the painter if appropriate. This implementation registers its painterListener if the Painter is of type AbstractPainter.
      • uninstallPainterListener

        protected void uninstallPainterListener()
        Uninstalls a listener from the painter if appropriate. This implementation removes its painterListener if the Painter is of type AbstractPainter.
      • getPainterListener

        protected final java.beans.PropertyChangeListener getPainterListener()
        Lazyly creates and returns the property change listener used to listen to changes of the painter.
        Returns:
        the property change listener used to listen to changes of the painter.
      • createPainterListener

        protected java.beans.PropertyChangeListener createPainterListener()
        Creates and returns the property change listener used to listen to changes of the painter.

        This implementation fires a stateChanged on receiving any propertyChange, if the isAdjusting flag is false. Otherwise does nothing.

        Returns:
        the property change listener used to listen to changes of the painter.
      • canHighlight

        protected boolean canHighlight​(java.awt.Component component,
                                       ComponentAdapter adapter)
        Subclasses may override to further limit the highlighting based on Highlighter state, f.i. a PainterHighlighter can only be applied to PainterAware components.

        This implementation returns true always.

        Overridden to return false if the Painter is null or the component is not of type PainterAware.

        Overrides:
        canHighlight in class AbstractHighlighter
        Returns:
        a boolean indication if the adapter can be highlighted based general state. This implementation returns true always.