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/*******************************************************************************
* Copyright (c) 2006 IBM Corporation 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:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.swt.examples.graphics;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;
/**
* This tab demonstrates the use of alpha blending. It allows a user to specify
* a custom alpha value.
*/
public class CustomAlphaTab extends AnimatedGraphicsTab {
private Spinner alphaSpinner;
private Button colorButton;
private GraphicsBackground background;
private Menu menu;
private int angle;
public CustomAlphaTab(GraphicsExample example) {
super(example);
}
public String getCategory() {
return GraphicsExample.getResourceString("Alpha"); //$NON-NLS-1$
}
public String getText() {
return GraphicsExample.getResourceString("CustomAlpha"); //$NON-NLS-1$
}
public String getDescription() {
return GraphicsExample.getResourceString("CustomAlphaDescription"); //$NON-NLS-1$
}
public void dispose() {
if (menu != null) {
menu.dispose();
menu = null;
}
}
/**
* Creates the widgets used to control the drawing.
*/
public void createControlPanel(Composite parent) {
super.createControlPanel(parent);
// create drop down combo for choosing clipping
Composite comp;
// create spinner for line width
comp = new Composite(parent, SWT.NONE);
comp.setLayout(new GridLayout(2, false));
new Label(comp, SWT.CENTER).setText(GraphicsExample
.getResourceString("Alpha")); //$NON-NLS-1$
alphaSpinner = new Spinner(comp, SWT.BORDER | SWT.WRAP);
alphaSpinner.setMinimum(0);
alphaSpinner.setMaximum(255);
alphaSpinner.setSelection(127);
alphaSpinner.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
example.redraw();
}
});
// color menu
ColorMenu cm = new ColorMenu();
cm.setPatternItems(example.checkAdvancedGraphics());
menu = cm.createMenu(parent.getParent(), new ColorListener() {
public void setColor(GraphicsBackground gb) {
background = gb;
colorButton.setImage(gb.getThumbNail());
example.redraw();
}
});
// initialize the background to the 5th item in the menu (blue)
background = (GraphicsBackground)menu.getItem(4).getData();
// color button
comp = new Composite(parent, SWT.NONE);
comp.setLayout(new GridLayout(2, false));
colorButton = new Button(comp, SWT.PUSH);
colorButton.setText(GraphicsExample
.getResourceString("Color")); //$NON-NLS-1$
colorButton.setImage(background.getThumbNail());
colorButton.addListener(SWT.Selection, new Listener() {
public void handleEvent(Event event) {
final Button button = (Button) event.widget;
final Composite parent = button.getParent();
Rectangle bounds = button.getBounds();
Point point = parent.toDisplay(new Point(bounds.x, bounds.y));
menu.setLocation(point.x, point.y + bounds.height);
menu.setVisible(true);
}
});
}
public void next(int width, int height) {
angle = (angle+1)%360;
}
public void paint(GC gc, int width, int height) {
if (!example.checkAdvancedGraphics()) return;
Device device = gc.getDevice();
Pattern pattern = null;
if (background.getBgColor1() != null) {
gc.setBackground(background.getBgColor1());
} else if (background.getBgImage() != null) {
pattern = new Pattern(device, background.getBgImage());
gc.setBackgroundPattern(pattern);
}
gc.setAntialias(SWT.ON);
gc.setAlpha(alphaSpinner.getSelection());
// rotate on center
Transform transform = new Transform(device);
transform.translate(width/2, height/2);
transform.rotate(-angle);
transform.translate(-width/2, -height/2);
gc.setTransform(transform);
transform.dispose();
// choose the smallest between height and width
int diameter = (height < width) ? height : width;
Path path = new Path(device);
path.addArc((width-diameter/5)/2, (height-diameter/5)/2, diameter/5, diameter/5, 0, 360);
path.addArc(5*(width-diameter/8)/12, 4*(height-diameter/8)/12, diameter/8, diameter/8, 0, 360);
path.addArc(7*(width-diameter/8)/12, 8*(height-diameter/8)/12, diameter/8, diameter/8, 0, 360);
path.addArc(6*(width-diameter/12)/12, 3*(height-diameter/12)/12, diameter/12, diameter/12, 0, 360);
path.addArc(6*(width-diameter/12)/12, 9*(height-diameter/12)/12, diameter/12, diameter/12, 0, 360);
path.addArc(11.5f*(width-diameter/18)/20, 5*(height-diameter/18)/18, diameter/18, diameter/18, 0, 360);
path.addArc(8.5f*(width-diameter/18)/20, 13*(height-diameter/18)/18, diameter/18, diameter/18, 0, 360);
path.addArc(62f*(width-diameter/25)/100, 32*(height-diameter/25)/100, diameter/25, diameter/25, 0, 360);
path.addArc(39f*(width-diameter/25)/100, 67*(height-diameter/25)/100, diameter/25, diameter/25, 0, 360);
gc.fillPath(path);
path.dispose();
if (pattern != null) pattern.dispose();
}
}
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