/*******************************************************************************
* Copyright (c) 2000, 2016 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
* Chriss Gross (schtoo@schtoo.com) - fix for 61670
*******************************************************************************/
package org.eclipse.ui.forms.widgets;
import org.eclipse.swt.SWT;
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.Composite;
import org.eclipse.swt.widgets.Event;
/**
* This class extends hyperlink widget by adding the capability to render an
* image relative to the text. If no text has been set, only image will be
* shown. Images for hover and active states can be set in addition to the
* normal state image.
* <p>
* When image is taller than the text, additional style can be provided to
* control vertical alignment (supported values are SWT.TOP, SWT.BOTTOM and
* SWT.CENTER).
* <p>
* The class does not need to be subclassed but it is allowed to do so if some
* aspect of the image hyperlink needs to be modified.
* <p>
* <dl>
* <dt><b>Styles:</b></dt>
* <dd>SWT.WRAP, SWT.BOTTOM, SWT.TOP, SWT.MIDDLE, SWT.LEFT, SWT.RIGHT</dd>
* </dl>
*
* @since 3.0
*/
public class ImageHyperlink extends Hyperlink {
/**
* Amount of pixels between the image and the text (default is 5).
*/
public int textSpacing = 5;
private Image image;
private Image hoverImage;
private Image activeImage;
private Image disabledImage;
private int state;
private static final int HOVER = 1 << 1;
private static final int ACTIVE = 1 << 2;
private int verticalAlignment = SWT.CENTER;
private int horizontalAlignment = SWT.LEFT;
/**
* Creates the image hyperlink instance.
*
* @param parent
* the control parent
* @param style
* the control style (SWT.WRAP, BOTTOM, TOP, MIDDLE, LEFT, RIGHT)
*/
public ImageHyperlink(Composite parent, int style) {
super(parent, removeAlignment(style));
extractAlignment(style);
addDisposeListener(e -> {
if (disabledImage != null)
disabledImage.dispose();
});
}
@Override
protected void paintHyperlink(GC gc) {
paintHyperlink(gc, getClientArea());
}
protected void paintHyperlink(GC gc, Rectangle bounds) {
Image image = null;
if (!isEnabled()) {
createDisabledImage();
image = disabledImage;
}
else {
if ((state & ACTIVE) != 0)
image = activeImage;
else if ((state & HOVER) != 0)
image = hoverImage;
if (image == null)
image = this.image;
}
Rectangle ibounds = image != null ? image.getBounds() : new Rectangle(0, 0, 0, 0);
Point maxsize = computeMaxImageSize();
int spacing = image!=null?textSpacing:0;
int textWidth = bounds.width - maxsize.x - spacing
- marginWidth - marginWidth;
int y = bounds.y+marginHeight + maxsize.y / 2 - ibounds.height / 2;
if (horizontalAlignment == SWT.LEFT) {
int x = bounds.x+marginWidth + maxsize.x / 2 - ibounds.width / 2;
int textX = bounds.x + marginWidth + maxsize.x + spacing;
if (image != null)
gc.drawImage(image, x, y);
if (getText() != null)
drawText(gc, bounds, textX, textWidth);
} else if (horizontalAlignment == SWT.RIGHT) {
int x = bounds.x+marginWidth;
if (getText() != null) {
x += drawText(gc, bounds, x, textWidth);
}
x += maxsize.x / 2 - ibounds.width / 2 + spacing;
if (image != null)
gc.drawImage(image, x, y);
}
}
private int drawText(GC gc, Rectangle clientArea, int textX, int textWidth) {
Point textSize = computeTextSize(textWidth, SWT.DEFAULT);
int slotHeight = clientArea.height - marginHeight - marginHeight;
int textY;
textWidth = textSize.x;
int textHeight = textSize.y;
if (verticalAlignment == SWT.BOTTOM) {
textY = marginHeight + slotHeight - textHeight;
} else if (verticalAlignment == SWT.CENTER) {
textY = marginHeight + slotHeight / 2 - textHeight / 2;
} else {
textY = marginHeight;
}
paintText(gc, new Rectangle(textX, textY, textWidth, textHeight));
return textWidth;
}
/**
* Computes the control size by reserving space for images in addition to
* text.
*
* @param wHint
* width hint
* @param hHint
* height hint
* @param changed
* if <code>true</code>, any cached layout data should be
* computed anew
*/
@Override
public Point computeSize(int wHint, int hHint, boolean changed) {
checkWidget();
Rectangle trim = computeTrim(0, 0, 0, 0);
Point isize = computeMaxImageSize();
int spacing = isize.x > 0 ? textSpacing : 0;
Point textSize = null;
if (getText() != null) {
int innerWHint = wHint;
if (wHint != SWT.DEFAULT) {
innerWHint = wHint - 2 * marginWidth - isize.x - spacing - trim.width;
}
int innerHHint = SWT.DEFAULT;
if (hHint != SWT.DEFAULT) {
innerHHint = hHint - trim.height;
}
textSize = super.computeSize(innerWHint, innerHHint, changed);
}
int width = isize.x;
int height = isize.y;
if (textSize != null) {
width += spacing;
width += textSize.x;
height = Math.max(height, textSize.y);
}
width += 2 * marginWidth;
height += 2 * marginHeight;
if (wHint != SWT.DEFAULT)
width = wHint;
if (hHint != SWT.DEFAULT)
height = hHint;
return new Point(width + trim.width, height + trim.height);
}
@Override
protected void handleEnter(Event e) {
state = HOVER;
super.handleEnter(e);
}
@Override
protected void handleExit(Event e) {
state = 0;
super.handleExit(e);
}
@Override
protected void handleActivate(Event e) {
state &= ACTIVE;
redraw();
super.handleActivate(e);
state &= ~ACTIVE;
if (!isDisposed())
redraw();
}
/**
* Returns active image.
*
* @return active image or <code>null</code> if not set.
*/
public Image getActiveImage() {
return activeImage;
}
/**
* Sets the image to show when link is activated.
*
* @param activeImage
*
*/
public void setActiveImage(Image activeImage) {
this.activeImage = activeImage;
}
/**
* Returns the hover image.
*
* @return hover image or <code>null</code> if not set.
*/
public Image getHoverImage() {
return hoverImage;
}
/**
* Sets the image to show when link is hover state (on mouse over).
*
* @param hoverImage
*/
public void setHoverImage(Image hoverImage) {
this.hoverImage = hoverImage;
}
/**
* Returns the image to show in the normal state.
*
* @return normal image or <code>null</code> if not set.
*/
public Image getImage() {
return image;
}
/**
* Sets the image to show when link is in the normal state.
*
* @param image
*/
public void setImage(Image image) {
this.image = image;
if (disabledImage != null) {
disabledImage.dispose();
disabledImage = null;
}
redraw();
}
private void createDisabledImage() {
if ((disabledImage == null || disabledImage.isDisposed()) && image != null && !image.isDisposed()) {
disabledImage = new Image(image.getDevice(), image, SWT.IMAGE_DISABLE);
}
}
private Point computeMaxImageSize() {
int x = 0;
int y = 0;
if (image != null) {
x = Math.max(image.getBounds().width, x);
y = Math.max(image.getBounds().height, y);
}
if (hoverImage != null) {
x = Math.max(hoverImage.getBounds().width, x);
y = Math.max(hoverImage.getBounds().height, y);
}
if (activeImage != null) {
x = Math.max(activeImage.getBounds().width, x);
y = Math.max(activeImage.getBounds().height, y);
}
return new Point(x, y);
}
private static int removeAlignment(int style) {
int resultStyle = style;
if ((style & SWT.CENTER) != 0) {
resultStyle &= (~SWT.CENTER);
}
if ((style & SWT.TOP) != 0) {
resultStyle &= (~SWT.TOP);
}
if ((style & SWT.BOTTOM) != 0) {
resultStyle &= (~SWT.BOTTOM);
}
if ((style & SWT.LEFT) != 0) {
resultStyle &= (~SWT.LEFT);
}
if ((style & SWT.RIGHT) != 0) {
resultStyle &= (~SWT.RIGHT);
}
return resultStyle;
}
private void extractAlignment(int style) {
if ((style & SWT.CENTER) != 0) {
verticalAlignment = SWT.CENTER;
} else if ((style & SWT.TOP) != 0) {
verticalAlignment = SWT.TOP;
} else if ((style & SWT.BOTTOM) != 0) {
verticalAlignment = SWT.BOTTOM;
}
if ((style & SWT.LEFT) != 0) {
horizontalAlignment = SWT.LEFT;
} else if ((style & SWT.RIGHT) != 0) {
horizontalAlignment = SWT.RIGHT;
}
}
@Override
public void setEnabled(boolean enabled) {
if (!enabled)
createDisabledImage();
super.setEnabled(enabled);
if (enabled && disabledImage != null) {
disabledImage.dispose();
disabledImage = null;
}
}
}