Package org.apache.sis.gui.map

Class ValuesUnderCursor

Object
ValuesUnderCursor
public abstract class ValuesUnderCursor extends Object
Provider of textual content to show in a Status­Bar for values under cursor position. When the mouse cursor moves, evaluate(Direct­Position) is invoked with the same "real world" coordinates than the ones shown in the status bar.

Multi-threading

Instances of Value­Under­Cursor do not need to be thread-safe. Values­Under­Cursor methods will be invoked from JavaFX thread.
Since:
1.1

Defined in the sis-javafx module

  • Field Details

    • valueChoices

      protected final Menu valueChoices
      Menu offering choices among the values that this Values­Under­Cursor can show. This menu will be available as a contextual menu in the Status­Bar. It is subclass responsibility to listen to menu selections and adapt their evaluate(Direct­Position) output accordingly.

  • Constructor Details

    • ValuesUnderCursor

      protected ValuesUnderCursor()
      Creates a new evaluator instance. The value­Choices list of items is initially empty; subclass constructor should set a text and add items.

  • Method Details

    • isEmpty

      public abstract boolean isEmpty()
      Returns true if this Values­Under­Cursor has currently no data to show. A Values­Under­Cursor may be empty for example if user unselected all bands from the contextual menu.
      Returns:
      true if there is no data to show yet.

    • evaluate

      public abstract String evaluate(DirectPosition point)
      Returns a string representation of data under given "real world" position. The position CRS should be non-null for avoiding ambiguity about what is the default CRS. The position CRS may be anything; this method shall transform coordinates itself if needed.
      Parameters:
      point - the cursor location in arbitrary CRS (usually the CRS shown in the status bar). May be null for declaring that the point is outside canvas region.
      Returns:
      string representation of data under given position, or null if none.