Add context menu

[JordanMartinez]

This addresses #363.

There is no ContextMenu by default: this matches the same behavior as all other nodes.

Questions

• Should the default offset values be 5 or some positive non-zero value? In the TestFX test, having it as zero will fail the tests because the mouse clicks on the menu rather than the area once it is shown. Developer who set the menu in their code will also need to override the default values every time, which is unnecessary boilerplate.
  • Edit: I've updated the PR to set the default offset values to 2. There's no specific reason for this choice, so it's up for modification.

[JFormDesigner]

IMHO it would be better to use ContextMenuEvent.CONTEXT_MENU_REQUESTED, instead of mouseClicked(MouseButton.SECONDARY), to show the context menu. Then the user can also use the keyboard to show the context menu.

javafx.scene.control.Control also uses ContextMenuEvent.CONTEXT_MENU_REQUESTED.

[JordanMartinez]

Ah! Good point! I assumed it was just a right-click.

[JordanMartinez]

I've included @JFormDesigner's point about the ContextMenuEvent.

[JordanMartinez]

Since I haven't heard anything else about the default offset values, I'm going to merge this. They can always be modified later on if need be.

[Groostav]

If I wanted a context menu containing the usual copy, paste, undo, redo, etc, whats the easiest way to get it?

RichTextFX exposes the functionality of a text-field with methods simply named copy(), paste(), etc, which are pretty clearly meant for this purpose.

But:

1. theres no delete() method
2. the undo and redo disable if no previous state and disable if no next state bindings are non-trivial
3. the cut and copy disable if no text selected is non-trivial,
4. anything else im missing? icons?

I'm wondering if you would be kind enough to write one, and then let us do something like create a static method createDefaultContextMenu, such that I could write

styleClassedTextArea.contextMenu = StyleClassTextArea.makeDefaultContextMenu()

or even

<StyleClassedTextArea>
  <contextMenu>
    <StyleClassedTextArea fx:factory="makeDefaultContextMenu"/>
  </contextMenu>
</StyleClassedTextArea>

[Jugen]

@Groostav

I'm wondering if you would be kind enough to write one ....

Here you go, modify and style as needed, to use do: area.setContextMenu(new DefaultContextMenu())

private class DefaultContextMenu extends ContextMenu
{
    private MenuItem cut, copy, delete, paste, undo, redo;
    private GenericStyledArea area;
    private IndexRange range;
    
    public DefaultContextMenu()
    {
        showingProperty().addListener( (ob,ov,showing) -> checkMenuItems( showing ) );

        cut = new MenuItem( "Cut" );
        cut.setOnAction( AE -> { hide(); area.cut(); } );

        copy = new MenuItem( "Copy" );
        copy.setOnAction( AE -> { hide(); area.copy(); } );

        delete = new MenuItem( "Delete" );
        delete.setOnAction( AE -> { hide(); area.deleteText( range ); } );

        paste = new MenuItem( "Paste" );
        paste.setOnAction( AE -> { hide(); area.paste(); } );

        redo = new MenuItem( "Redo" );
        redo.setOnAction( AE -> { hide(); area.redo(); } );

        undo = new MenuItem( "Undo" );
        undo.setOnAction( AE -> { hide(); area.undo(); } );

        getItems().addAll( copy, cut, delete, paste, redo, undo );
    }
    
    private void checkMenuItems( boolean showing )
    {
        if ( ! showing ) return;

        area = (GenericStyledArea) getOwnerNode();
        UndoManager history = area.getUndoManager();
        undo.setDisable( ! history.isUndoAvailable() );
        redo.setDisable( ! history.isRedoAvailable() );

        range = area.getSelection();
        boolean noSelection = range.getLength() == 0;
        delete.setDisable( noSelection );
        copy.setDisable( noSelection );
        cut.setDisable( noSelection );
    }
}