de.walware.ecommons.ui.components.WidgetToolsButton.java Source code

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Here is the source code for de.walware.ecommons.ui.components.WidgetToolsButton.java

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/*=============================================================================#
 # Copyright (c) 2007-2015 Stephan Wahlbrink (WalWare.de) and others.
 # All rights reserved. This program and the accompanying materials
 # are made available under the terms of the Eclipse Public License v1.0
 # which accompanies this distribution, and is available at
 # http://www.eclipse.org/legal/epl-v10.html
 # 
 # Contributors:
 #     Stephan Wahlbrink - initial API and implementation
 #=============================================================================*/

package de.walware.ecommons.ui.components;

import org.eclipse.jface.resource.FontDescriptor;
import org.eclipse.jface.resource.FontRegistry;
import org.eclipse.jface.resource.JFaceResources;
import org.eclipse.jface.util.IPropertyChangeListener;
import org.eclipse.jface.util.PropertyChangeEvent;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.FocusEvent;
import org.eclipse.swt.events.FocusListener;
import org.eclipse.swt.events.KeyEvent;
import org.eclipse.swt.events.KeyListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Menu;

/**
 * Provides a tools menu button.
 */
public class WidgetToolsButton extends Composite {

    static final String FONT_SYMBOLIC_NAME = "de.walware.toolbuttonfont"; //$NON-NLS-1$

    static Font getToolButtonFont() {
        final FontRegistry fontRegistry = JFaceResources.getFontRegistry();
        if (!fontRegistry.hasValueFor(FONT_SYMBOLIC_NAME)) {
            fontRegistry.addListener(new IPropertyChangeListener() {
                @Override
                public void propertyChange(final PropertyChangeEvent event) {
                    if (event.getProperty().equals(JFaceResources.DIALOG_FONT)) {
                        updateFont();
                    }
                }
            });
            updateFont();
        }
        return fontRegistry.get(FONT_SYMBOLIC_NAME);
    }

    private static void updateFont() {
        final FontRegistry fontRegistry = JFaceResources.getFontRegistry();
        final Font dialogFont = fontRegistry.get(JFaceResources.DIALOG_FONT);
        final int size = 1 + Math.max(dialogFont.getFontData()[0].getHeight() * 3 / 5, 6);
        final FontDescriptor descriptor = fontRegistry.getDescriptor(JFaceResources.TEXT_FONT).setHeight(size);
        final Font toolFont = descriptor.createFont(Display.getCurrent());
        fontRegistry.put(FONT_SYMBOLIC_NAME, toolFont.getFontData());
    }

    private Button fButton;
    private Menu fMenu;

    private final Control fTarget;

    public WidgetToolsButton(final Control target) {
        super(target.getParent(), SWT.NONE);
        setLayout(new FillLayout());
        fTarget = target;
        createButton();
    }

    @Override
    public void setFont(final Font font) {
        super.setFont(font);
        fButton.setFont(getToolButtonFont());
    }

    @Override
    public Point computeSize(final int hint, final int hint2, final boolean changed) {
        final Point computeSize = super.computeSize(hint, hint2, changed);

        final int x = Math.max(computeSize.x, 18);
        final int y = Math.min(Math.max(computeSize.y, 18),
                fTarget.computeSize(SWT.DEFAULT, SWT.DEFAULT, changed).y);
        return new Point(x, y);
    }

    protected void createButton() {
        fButton = new Button(this, (SWT.PUSH | SWT.CENTER));
        updateLabels(false);
        fButton.addSelectionListener(new SelectionAdapter() {
            @Override
            public void widgetSelected(final SelectionEvent e) {
                showMenu();
            }
        });
        fButton.addKeyListener(new KeyListener() {
            @Override
            public void keyPressed(final KeyEvent e) {
            }

            @Override
            public void keyReleased(final KeyEvent e) {
                if (e.character == '+') {
                    showMenu();
                }
            }
        });

        fTarget.addFocusListener(new FocusListener() {
            @Override
            public void focusGained(final FocusEvent e) {
                updateLabels(true);
            }

            @Override
            public void focusLost(final FocusEvent e) {
                updateLabels(false);
            }
        });

        fButton.addDisposeListener(new DisposeListener() {
            @Override
            public void widgetDisposed(final DisposeEvent e) {
                disposeMenu();
            }
        });
        setFont(null);
    }

    public Control getButton() {
        return fButton;
    }

    public void showMenu() {
        if (fMenu == null) {
            fMenu = new Menu(fButton);
            fillMenu(fMenu);
        }
        final Rectangle bounds = fButton.getBounds();
        final Point pos = fButton.getParent().toDisplay(bounds.x, bounds.y + bounds.height);
        fMenu.setLocation(pos);
        fMenu.setVisible(true);
    }

    public void resetMenu() {
        disposeMenu();
    }

    protected void disposeMenu() {
        if (fMenu != null) {
            fMenu.dispose();
            fMenu = null;
        }
    }

    protected void updateLabels(final boolean hasFocus) {
        fButton.setText(hasFocus ? "&+" : "+"); //$NON-NLS-1$ //$NON-NLS-2$
    }

    protected void fillMenu(final Menu menu) {
    }

}