/*******************************************************************************
* Copyright (c) 2011 Laurent CARON
* 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:
* Laurent CARON (laurent.caron at gmail dot com) - initial API and implementation
*******************************************************************************/
package org.mihalis.opal.flatButton;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.events.PaintEvent;
import org.eclipse.swt.events.PaintListener;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.events.SelectionListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.mihalis.opal.utils.SWTGraphicUtil;
/**
* Instances of this class represent a flat button.
* <dl>
* <dt><b>Styles:</b></dt>
* <dd>UP, DOWN, LEFT, RIGHT, CENTER</dd>
* <dt><b>Events:</b></dt>
* <dd>Selection</dd>
* </dl>
* <p>
* Note: Only one of the styles LEFT, RIGHT, and CENTER may be specified.
* </p>
*
*/
public class FlatButton extends Canvas {
private Image image;
private String text;
private boolean selection;
private int alignment;
private final List<SelectionListener> listeners;
private boolean mouseIn;
private Color backgroundColor;
private Color selectedColor;
private Color selectedTextColor;
private Color mouseOverColor;
/**
* Constructs a new instance of this class given its parent and a style
* value describing its behavior and appearance.
* <p>
* The style value is either one of the style constants defined in class
* <code>SWT</code> which is applicable to instances of this class, or must
* be built by <em>bitwise OR</em>'ing together (that is, using the
* <code>int</code> "|" operator) two or more of those <code>SWT</code>
* style constants. The class description lists the style constants that are
* applicable to the class. Style bits are also inherited from superclasses.
* </p>
*
* @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
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the parent is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the parent</li>
* <li>ERROR_INVALID_SUBCLASS - if this class is not an
* allowed subclass</li>
* </ul>
*
* @see SWT#DOWN
* @see SWT#LEFT
* @see SWT#RIGHT
* @see SWT#CENTER
*/
public FlatButton(final Composite parent, final int style) {
super(parent, style);
this.listeners = new ArrayList<SelectionListener>();
buildAlignmentFromStyle(style);
addListeners();
initializeDefaultColors();
}
private void buildAlignmentFromStyle(final int style) {
if ((style & SWT.LEFT) == SWT.LEFT) {
this.alignment = SWT.LEFT;
} else if ((style & SWT.RIGHT) == SWT.RIGHT) {
this.alignment = SWT.RIGHT;
} else {
this.alignment = SWT.CENTER;
}
}
private void addListeners() {
addPaintListener(new PaintListener() {
@Override
public void paintControl(final PaintEvent e) {
FlatButton.this.paintControl(e);
}
});
addListener(SWT.MouseEnter, new Listener() {
@Override
public void handleEvent(final Event event) {
FlatButton.this.mouseIn = true;
redraw();
}
});
addListener(SWT.MouseExit, new Listener() {
@Override
public void handleEvent(final Event event) {
FlatButton.this.mouseIn = false;
redraw();
}
});
addListener(SWT.MouseUp, new Listener() {
@Override
public void handleEvent(final Event event) {
boolean doIt = true;
FlatButton.this.selection = !FlatButton.this.selection;
for (final SelectionListener listener : FlatButton.this.listeners) {
final SelectionEvent sEvent = new SelectionEvent(event);
listener.widgetSelected(sEvent);
doIt = doIt && sEvent.doit;
}
if (!doIt) {
FlatButton.this.selection = !FlatButton.this.selection;
}
}
});
}
private void initializeDefaultColors() {
this.backgroundColor = getDisplay().getSystemColor(SWT.COLOR_WHITE);
this.selectedColor = new Color(getDisplay(), 0, 112, 192);
this.selectedTextColor = getDisplay().getSystemColor(SWT.COLOR_WHITE);
this.mouseOverColor = new Color(getDisplay(), 235, 234, 226);
SWTGraphicUtil.dispose(this, this.selectedColor);
SWTGraphicUtil.dispose(this, this.mouseOverColor);
SWTGraphicUtil.dispose(this, this.image);
}
private void paintControl(final PaintEvent e) {
final GC gc = e.gc;
drawBackground(gc);
if (this.image != null) {
drawImage(gc);
}
if (this.text != null) {
drawText(gc);
}
}
private void drawBackground(final GC gc) {
Color color;
if (this.selection) {
color = this.selectedColor;
} else if (this.mouseIn) {
color = this.mouseOverColor;
} else {
color = this.backgroundColor;
}
gc.setBackground(color);
gc.fillRectangle(getClientArea());
}
private void drawImage(final GC gc) {
final Rectangle rect = getClientArea();
final Point imageSize = new Point(this.image.getBounds().width, this.image.getBounds().height);
int x;
if (this.alignment == SWT.LEFT) {
x = 5;
} else if (this.alignment == SWT.RIGHT) {
x = rect.width - imageSize.x - 5;
} else {
x = (rect.width - imageSize.x) / 2;
}
gc.drawImage(this.image, x, 5);
}
private void drawText(final GC gc) {
final Rectangle rect = getClientArea();
if (this.selection) {
gc.setForeground(this.selectedTextColor);
} else {
gc.setForeground(getForeground());
}
gc.setFont(getFont());
final Point textSize = gc.stringExtent(this.text);
int x, y;
if (this.alignment == SWT.LEFT) {
x = 5;
} else if (this.alignment == SWT.RIGHT) {
x = rect.width - textSize.x - 5;
} else {
x = (rect.width - textSize.x) / 2;
}
if (this.image == null) {
y = 5;
} else {
y = 10 + this.image.getBounds().height;
}
gc.drawString(this.text, x, y, true);
}
/**
* Adds the listener to the collection of listeners who will be notified
* when the control is selected by the user, by sending it one of the
* messages defined in the <code>SelectionListener</code> interface.
* <p>
* <code>widgetSelected</code> is called when the control is selected by the
* user. <code>widgetDefaultSelected</code> is not called.
* </p>
* <p>
* When the <code>SWT.RADIO</code> style bit is set, the
* <code>widgetSelected</code> method is also called when the receiver loses
* selection because another item in the same radio group was selected by
* the user. During <code>widgetSelected</code> the application can use
* <code>getSelection()</code> to determine the current selected state of
* the receiver.
* </p>
*
* @param listener the listener which should be notified
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*
* @see SelectionListener
* @see #removeSelectionListener
* @see SelectionEvent
*/
public void addSelectionListener(final SelectionListener listener) {
checkWidget();
this.listeners.add(listener);
}
/**
* @see org.eclipse.swt.widgets.Composite#computeSize(int, int, boolean)
*/
@Override
public Point computeSize(final int wHint, final int hHint, final boolean changed) {
int width = 10, height = 15;
if (this.image != null) {
final Rectangle bounds = this.image.getBounds();
width += bounds.width;
height += bounds.height;
}
if (this.text != null) {
final GC gc = new GC(this);
final Point extent = gc.stringExtent(this.text);
gc.dispose();
width = Math.max(width, extent.x + 10);
height = height + extent.y;
}
return new Point(Math.max(width, wHint), Math.max(height, hHint));
}
/**
* Returns a value which describes the position of the text in the receiver.
* The value will be one of <code>LEFT</code>, <code>RIGHT</code> or
* <code>CENTER</code>.
*
* @return the alignment
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public int getAlignment() {
checkWidget();
return this.alignment;
}
/**
* Returns a value which describes the default background color
*
* @return the default background color
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public Color getBackgroundColor() {
checkWidget();
return this.backgroundColor;
}
/**
* Returns the receiver's image if it has one, or null if it does not.
*
* @return the receiver's image
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public Image getImage() {
checkWidget();
return this.image;
}
/**
* Returns a value which describes the color when the mouse is over the
* button
*
* @return the color when the mouse is over the button
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public Color getMouseOverColor() {
checkWidget();
return this.mouseOverColor;
}
/**
* Returns a value which describes the color when the button is selected
*
* @return the color when the button is selected
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public Color getSelectedColor() {
checkWidget();
return this.selectedColor;
}
/**
* Returns a value which describes the color of the text when the button is
* selected
*
* @return the color of the text when the button is selected
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public Color getSelectedTextColor() {
return this.selectedTextColor;
}
/**
* Returns <code>true</code> if the receiver is selected, and false
* otherwise.
* <p>
*
* @return the selection state
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not
* called from the thread that created the receiver</li>
* </ul>
*/
public boolean getSelection() {
checkWidget();
return this.selection;
}
/**
* Returns the receiver's text.
*
* @return the receiver's text
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public String getText() {
checkWidget();
return this.text;
}
/**
* Removes the listener from the collection of listeners who will be
* notified when the control is selected by the user.
*
* @param listener the listener which should no longer be notified
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*
* @see SelectionListener
* @see #addSelectionListener
*/
public void removeSelectionListener(final SelectionListener listener) {
checkWidget();
this.listeners.remove(listener);
}
/**
* Controls how text, images and arrows will be displayed in the receiver.
* The argument should be one of <code>LEFT</code>, <code>RIGHT</code> or
* <code>CENTER</code>.
*
* @param alignment the new alignment
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setAlignment(final int alignment) {
checkWidget();
if ((alignment & (SWT.LEFT | SWT.RIGHT | SWT.CENTER)) == 0) {
return;
}
this.alignment = alignment;
redraw();
}
/**
* Sets the receiver's background color to the color specified by the
* argument.
*
* @param color the new color
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_INVALID_ARGUMENT - if the argument has been
* disposed</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setBackgroundColor(final Color backgroundColor) {
checkWidget();
this.backgroundColor = backgroundColor;
}
/**
* Sets the receiver's image to the argument, which may be <code>null</code>
* indicating that no image should be displayed.
* <p>
* Note that a Button can display an image and text simultaneously on
* Windows (starting with XP), GTK+ and OSX. On other platforms, a Button
* that has an image and text set into it will display the image or text
* that was set most recently.
* </p>
*
* @param image the image to display on the receiver (may be
* <code>null</code>)
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_INVALID_ARGUMENT - if the image has been
* disposed</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setImage(final Image image) {
checkWidget();
this.image = image;
redraw();
}
/**
* Sets the receiver's color when the mouse if over the button.
*
* @param color the new color
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_INVALID_ARGUMENT - if the argument has been
* disposed</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setMouseOverColor(final Color mouseOverColor) {
checkWidget();
this.mouseOverColor = mouseOverColor;
}
/**
* Sets the receiver's color when the button is selected.
*
* @param color the new color
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_INVALID_ARGUMENT - if the argument has been
* disposed</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setSelectedColor(final Color selectedColor) {
checkWidget();
this.selectedColor = selectedColor;
}
/**
* Sets the receiver's text color when the button is selected.
*
* @param color the new color
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_INVALID_ARGUMENT - if the argument has been
* disposed</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setSelectedTextColor(final Color selectedTextColor) {
this.selectedTextColor = selectedTextColor;
}
/**
* Sets the selection state of the receiver.
*
* @param selected the new selection state
*
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setSelection(final boolean selected) {
checkWidget();
this.selection = selected;
redraw();
}
/**
* Sets the receiver's text.
*
*
* @param string the new text
*
* @exception IllegalArgumentException <ul>
* <li>ERROR_NULL_ARGUMENT - if the text is null</li>
* </ul>
* @exception SWTException <ul>
* <li>ERROR_WIDGET_DISPOSED - if the receiver has been
* disposed</li>
* <li>ERROR_THREAD_INVALID_ACCESS - if not called from the
* thread that created the receiver</li>
* </ul>
*/
public void setText(final String text) {
checkWidget();
this.text = text;
redraw();
}
}