Example usage for org.eclipse.swt.widgets Tree setEnabled

Introduction

In this page you can find the example usage for org.eclipse.swt.widgets Tree setEnabled.

Prototype

public void setEnabled(boolean enabled) 

Source Link

Document

Enables the receiver if the argument is true, and disables it otherwise.

Usage

From source file:org.eclipse.swt.snippets.Snippet322.java

public static void main(String[] args) {
    final Display display = new Display();
    Shell shell = new Shell(display);
    shell.setText("Snippet 322");
    shell.setBounds(10, 10, 300, 300);/*w w  w .jav a2  s.c om*/
    final ScrolledComposite sc = new ScrolledComposite(shell, SWT.VERTICAL);
    sc.setBounds(10, 10, 280, 200);
    final int clientWidth = sc.getClientArea().width;

    final Tree tree = new Tree(sc, SWT.NONE);
    for (int i = 0; i < 99; i++) {
        TreeItem item = new TreeItem(tree, SWT.NONE);
        item.setText("item " + i);
        new TreeItem(item, SWT.NONE).setText("child");
    }
    sc.setContent(tree);
    int prefHeight = tree.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
    tree.setSize(clientWidth, prefHeight);
    /*
     * The following listener ensures that the Tree is always large
     * enough to not need to show its own vertical scrollbar.
     */
    tree.addTreeListener(new TreeListener() {
        @Override
        public void treeExpanded(TreeEvent e) {
            int prefHeight = tree.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
            tree.setSize(clientWidth, prefHeight);
        }

        @Override
        public void treeCollapsed(TreeEvent e) {
            int prefHeight = tree.computeSize(SWT.DEFAULT, SWT.DEFAULT).y;
            tree.setSize(clientWidth, prefHeight);
        }
    });
    /*
     * The following listener ensures that a newly-selected item
     * in the Tree is always visible.
     */
    tree.addSelectionListener(widgetSelectedAdapter(e -> {
        TreeItem[] selectedItems = tree.getSelection();
        if (selectedItems.length > 0) {
            Rectangle itemRect = selectedItems[0].getBounds();
            Rectangle area = sc.getClientArea();
            Point origin = sc.getOrigin();
            if (itemRect.x < origin.x || itemRect.y < origin.y
                    || itemRect.x + itemRect.width > origin.x + area.width
                    || itemRect.y + itemRect.height > origin.y + area.height) {
                sc.setOrigin(itemRect.x, itemRect.y);
            }
        }
    }));
    /*
     * The following listener scrolls the Tree one item at a time
     * in response to MouseWheel events.
     */
    tree.addListener(SWT.MouseWheel, event -> {
        Point origin = sc.getOrigin();
        if (event.count < 0) {
            origin.y = Math.min(origin.y + tree.getItemHeight(), tree.getSize().y);
        } else {
            origin.y = Math.max(origin.y - tree.getItemHeight(), 0);
        }
        sc.setOrigin(origin);
    });

    Button disableButton = new Button(shell, SWT.PUSH);
    disableButton.setBounds(10, 220, 120, 30);
    disableButton.setText("Disable");
    disableButton.addListener(SWT.Selection, event -> tree.setEnabled(false));
    Button enableButton = new Button(shell, SWT.PUSH);
    enableButton.setBounds(140, 220, 120, 30);
    enableButton.setText("Enable");
    enableButton.addListener(SWT.Selection, event -> tree.setEnabled(true));

    shell.open();
    while (!shell.isDisposed()) {
        if (!display.readAndDispatch())
            display.sleep();
    }
    display.dispose();
}

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