org.eclipse.swt.examples.graphics.LineCapTab.java Source code

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Here is the source code for org.eclipse.swt.examples.graphics.LineCapTab.java

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/*******************************************************************************
 * Copyright (c) 2006, 2016 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.graphics;

import org.eclipse.swt.SWT;
import org.eclipse.swt.graphics.Device;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Pattern;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Menu;

/**
 * This tab demonstrates various line caps applicable to a line.
 */
public class LineCapTab extends GraphicsTab {

    Button colorButton;
    GraphicsBackground foreground;
    Menu menu;

    public LineCapTab(GraphicsExample example) {
        super(example);
    }

    @Override
    public String getCategory() {
        return GraphicsExample.getResourceString("Lines"); //$NON-NLS-1$
    }

    @Override
    public String getText() {
        return GraphicsExample.getResourceString("LineCap"); //$NON-NLS-1$
    }

    @Override
    public String getDescription() {
        return GraphicsExample.getResourceString("LineCapDescription"); //$NON-NLS-1$
    }

    @Override
    public void dispose() {
        if (menu != null) {
            menu.dispose();
            menu = null;
        }
    }

    @Override
    public void createControlPanel(Composite parent) {

        Composite comp;

        // create color button
        comp = new Composite(parent, SWT.NONE);
        comp.setLayout(new GridLayout());

        ColorMenu cm = new ColorMenu();
        cm.setPatternItems(example.checkAdvancedGraphics());
        menu = cm.createMenu(parent.getParent(), gb -> {
            foreground = gb;
            colorButton.setImage(gb.getThumbNail());
            example.redraw();
        });

        // initialize the foreground to the 3rd item in the menu (red)
        foreground = (GraphicsBackground) menu.getItem(2).getData();

        // color button
        colorButton = new Button(comp, SWT.PUSH);
        colorButton.setText(GraphicsExample.getResourceString("Color")); //$NON-NLS-1$
        colorButton.setImage(foreground.getThumbNail());
        colorButton.addListener(SWT.Selection, event -> {
            final Button button = (Button) event.widget;
            final Composite parent1 = button.getParent();
            Rectangle bounds = button.getBounds();
            Point point = parent1.toDisplay(new Point(bounds.x, bounds.y));
            menu.setLocation(point.x, point.y + bounds.height);
            menu.setVisible(true);
        });
    }

    @Override
    public void paint(GC gc, int width, int height) {
        Device device = gc.getDevice();

        // draw side lines
        gc.setLineWidth(1);
        gc.setLineStyle(SWT.LINE_DOT);
        gc.setForeground(device.getSystemColor(SWT.COLOR_BLACK));
        gc.drawLine(3 * width / 16, height / 6, 3 * width / 16, 5 * height / 6);
        gc.drawLine(13 * width / 16, height / 6, 13 * width / 16, 5 * height / 6);
        gc.setLineStyle(SWT.LINE_SOLID);

        // draw labels
        Font font = new Font(device, getPlatformFont(), 20, SWT.NORMAL);
        gc.setFont(font);

        String text = GraphicsExample.getResourceString("Flat"); //$NON-NLS-1$
        Point size = gc.stringExtent(text);
        gc.drawString(text, (width - size.x) / 2, 3 * height / 12, true);
        text = GraphicsExample.getResourceString("Square"); //$NON-NLS-1$
        size = gc.stringExtent(text);
        gc.drawString(text, (width - size.x) / 2, 5 * height / 12, true);
        text = GraphicsExample.getResourceString("Round"); //$NON-NLS-1$
        size = gc.stringExtent(text);
        gc.drawString(text, (width - size.x) / 2, 7 * height / 12, true);
        font.dispose();

        Pattern pattern = null;
        if (foreground.getBgColor1() != null) {
            gc.setForeground(foreground.getBgColor1());
        } else if (foreground.getBgImage() != null) {
            pattern = new Pattern(device, foreground.getBgImage());
            gc.setForegroundPattern(pattern);
        }

        // draw lines with caps
        gc.setLineWidth(20);
        gc.setLineCap(SWT.CAP_FLAT);
        gc.drawLine(3 * width / 16, 2 * height / 6, 13 * width / 16, 2 * height / 6);
        gc.setLineCap(SWT.CAP_SQUARE);
        gc.drawLine(3 * width / 16, 3 * height / 6, 13 * width / 16, 3 * height / 6);
        gc.setLineCap(SWT.CAP_ROUND);
        gc.drawLine(3 * width / 16, 4 * height / 6, 13 * width / 16, 4 * height / 6);

        if (pattern != null)
            pattern.dispose();
    }

    /**
     * Returns the name of a valid font for the resident platform.
     */
    static String getPlatformFont() {
        if (SWT.getPlatform() == "win32") {
            return "Arial";
        } else if (SWT.getPlatform() == "gtk") {
            return "Baekmuk Batang";
        } else {
            return "Verdana";
        }
    }
}