Package org.eclipse.swt.custom

Class ControlEditor

  • Direct Known Subclasses:
    TableEditor, TreeEditor
    public class ControlEditor
extends Object
    A ControlEditor is a manager for a Control that appears above a composite and tracks with the moving and resizing of that composite. It can be used to display one control above another control. This could be used when editing a control that does not have editing capabilities by using a text editor or for launching a dialog by placing a button above a control.

    Here is an example of using a ControlEditor:

    
 Canvas canvas = new Canvas(shell, SWT.BORDER);
 canvas.setBounds(10, 10, 300, 300);
 Color color = new Color(null, 255, 0, 0);
 canvas.setBackground(color);
 ControlEditor editor = new ControlEditor (canvas);
 // The editor will be a button in the bottom right corner of the canvas.
 // When selected, it will launch a Color dialog that will change the background
 // of the canvas.
 Button button = new Button(canvas, SWT.PUSH);
 button.setText("Select Color...");
 button.addSelectionListener (new SelectionAdapter() {
        public void widgetSelected(SelectionEvent e) {
                ColorDialog dialog = new ColorDialog(shell);
                dialog.open();
                RGB rgb = dialog.getRGB();
                if (rgb != null) {
                        if (color != null) color.dispose();
                        color = new Color(null, rgb);
                        canvas.setBackground(color);
                }

        }
 });

 editor.horizontalAlignment = SWT.RIGHT;
 editor.verticalAlignment = SWT.BOTTOM;
 editor.grabHorizontal = false;
 editor.grabVertical = false;
 Point size = button.computeSize(SWT.DEFAULT, SWT.DEFAULT);
 editor.minimumWidth = size.x;
 editor.minimumHeight = size.y;
 editor.setEditor (button);
    See Also:
    Sample code and further information

    • Field Detail

      • horizontalAlignment

        public int horizontalAlignment
        Specifies how the editor should be aligned relative to the control. Allowed values are SWT.LEFT, SWT.RIGHT and SWT.CENTER. The default value is SWT.CENTER.

      • grabHorizontal

        public boolean grabHorizontal
        Specifies whether the editor should be sized to use the entire width of the control. True means resize the editor to the same width as the cell. False means do not adjust the width of the editor. The default value is false.

      • minimumWidth

        public int minimumWidth
        Specifies the minimum width the editor can have. This is used in association with a true value of grabHorizontal. If the cell becomes smaller than the minimumWidth, the editor will not made smaller than the minimum width value. The default value is 0.

      • verticalAlignment

        public int verticalAlignment
        Specifies how the editor should be aligned relative to the control. Allowed values are SWT.TOP, SWT.BOTTOM and SWT.CENTER. The default value is SWT.CENTER.

      • grabVertical

        public boolean grabVertical
        Specifies whether the editor should be sized to use the entire height of the control. True means resize the editor to the same height as the underlying control. False means do not adjust the height of the editor. The default value is false.

      • minimumHeight

        public int minimumHeight
        Specifies the minimum height the editor can have. This is used in association with a true value of grabVertical. If the control becomes smaller than the minimumHeight, the editor will not made smaller than the minimum height value. The default value is 0.

    • Constructor Detail

      • ControlEditor

        public ControlEditor​(Composite parent)
        Creates a ControlEditor for the specified Composite.
        Parameters:
        parent - the Composite above which this editor will be displayed

    • Method Detail

      • dispose

        public void dispose()
        Removes all associations between the Editor and the underlying composite. The composite and the editor Control are not disposed.

      • getEditor

        public Control getEditor()
        Returns the Control that is displayed above the composite being edited.
        Returns:
        the Control that is displayed above the composite being edited

      • layout

        public void layout()
        Lays out the control within the underlying composite. This method should be called after changing one or more fields to force the Editor to resize.
        Since:
        2.1

      • setEditor

        public void setEditor​(Control editor)
        Specify the Control that is to be displayed.

        Note: The Control provided as the editor must be created with its parent being the Composite specified in the ControlEditor constructor.

        Parameters:
        editor - the Control that is displayed above the composite being edited