org.eclipse.swt.examples.accessibility.Shape.java Source code

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Here is the source code for org.eclipse.swt.examples.accessibility.Shape.java

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/*******************************************************************************
 * Copyright (c) 2008, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.swt.examples.accessibility;

import java.text.MessageFormat;
import java.util.ResourceBundle;

import org.eclipse.swt.SWT;
import org.eclipse.swt.accessibility.ACC;
import org.eclipse.swt.accessibility.AccessibleAdapter;
import org.eclipse.swt.accessibility.AccessibleControlAdapter;
import org.eclipse.swt.accessibility.AccessibleControlEvent;
import org.eclipse.swt.accessibility.AccessibleEvent;
import org.eclipse.swt.events.FocusAdapter;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.KeyAdapter;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.MouseListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;

/**
 * Instances of this class represent an accessible, focusable, user interface object
 * that has a shape and a color. From an accessibility point of view, they imitate a
 * "label" or "static text" whose name is its color and shape.
 */
public class Shape extends Canvas {
    static final int SQUARE = 0;
    static final int CIRCLE = 1;
    static final int TRIANGLE = 2;
    static ResourceBundle bundle = ResourceBundle.getBundle("examples_accessibility");
    int color = SWT.COLOR_BLUE;
    int shape = SQUARE;

    /**
     * Constructs a new instance of this class given its parent
     * and a style value describing its behavior and appearance.
     *
     * @param parent a composite control which will be the parent of the new instance (cannot be null)
     * @param style the style of control to construct
     */
    public Shape(Composite parent, int style) {
        super(parent, style);

        addListeners();
    }

    void addListeners() {
        addPaintListener(e -> {
            GC gc = e.gc;
            Display display = getDisplay();
            Color c = display.getSystemColor(color);
            gc.setBackground(c);
            Rectangle rect = getClientArea();
            int length = Math.min(rect.width, rect.height);
            if (shape == CIRCLE) {
                gc.fillOval(0, 0, length, length);
            } else {
                gc.fillRectangle(0, 0, length, length);
            }
            if (isFocusControl())
                gc.drawFocus(rect.x, rect.y, rect.width, rect.height);
        });

        addFocusListener(new FocusAdapter() {
            @Override
            public void focusGained(FocusEvent e) {
                redraw();
            }

            @Override
            public void focusLost(FocusEvent e) {
                redraw();
            }
        });

        addMouseListener(MouseListener.mouseDownAdapter(e -> {
            if (getClientArea().contains(e.x, e.y)) {
                setFocus();
            }
        }));

        addKeyListener(new KeyAdapter() {
            @Override
            public void keyPressed(KeyEvent e) {
                // key listener enables traversal out
            }
        });

        addTraverseListener(e -> {
            switch (e.detail) {
            case SWT.TRAVERSE_TAB_NEXT:
            case SWT.TRAVERSE_TAB_PREVIOUS:
                e.doit = true;
                break;
            }
        });

        getAccessible().addAccessibleListener(new AccessibleAdapter() {
            @Override
            public void getName(AccessibleEvent e) {
                MessageFormat formatter = new MessageFormat("");
                formatter.applyPattern(bundle.getString("name")); //$NON_NLS$
                String colorName = bundle.getString("color" + color); //$NON_NLS$
                String shapeName = bundle.getString("shape" + shape); //$NON_NLS$
                e.result = formatter.format(new String[] { colorName, shapeName }); //$NON_NLS$
            }
        });

        getAccessible().addAccessibleControlListener(new AccessibleControlAdapter() {
            @Override
            public void getRole(AccessibleControlEvent e) {
                e.detail = ACC.ROLE_GRAPHIC;
            }

            @Override
            public void getState(AccessibleControlEvent e) {
                e.detail = ACC.STATE_FOCUSABLE;
                if (isFocusControl())
                    e.detail |= ACC.STATE_FOCUSED;
            }
        });
    }

    /**
     * Return the receiver's color.
     * The default color is SWT.COLOR_BLUE.
     *
     * @return the color, which may be any of the SWT.COLOR_ constants
     */
    public int getColor() {
        return color;
    }

    /**
     * Return the receiver's shape.
     * The default shape is SQUARE.
     *
     * @return the shape, which may be either CIRCLE or SQUARE
     */
    public int getShape() {
        return shape;
    }

    /**
     * Set the receiver's color to the specified color.
     * The default color is SWT.COLOR_BLUE.
     *
     * @param color any of the SWT.COLOR_ constants
     */
    public void setColor(int color) {
        this.color = color;
    }

    /**
     * Set the receiver's shape to the specified shape.
     * The default shape is SQUARE.
     *
     * @param shape an int that can be either CIRCLE or SQUARE
     */
    public void setShape(int shape) {
        this.shape = shape;
    }
}