/*
* {{{ header & license
* Copyright (c) 2004, 2005 Patrick Wright
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* }}}
*/
package org.xhtmlrenderer.simple;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.event.KeyEvent;
import javax.swing.AbstractAction;
import javax.swing.JComponent;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JScrollPane;
import javax.swing.KeyStroke;
/**
* <p><code>FSScrollPane</code> is a JScrollPane set up to support keyboard navigation of an XHTML/XML
* document rendered with Flying Saucer. In particular, it assigns key bindings to the view's {@link InputMap}
* for page-up, page-down, line-up/down, page-start and page-end.
* The amount the document scrolls is based on the current viewport and the current line height.
* If the view is resized, the scroll increment is automatically adjusted. Using FSScrollPane
* to display an {@link XHTMLPanel} should save you time as your users
* will have standard keyboard navigation out of the box.</p>
*
* <p>To use <code>FSScrollPane</code>, just instantiate it and add your XHTMLPanel on instantiation:
* <pre>
* XHTMLPanel panel = new XHTMLPanel();
* FSScrollPane scroll = new FSScrollPane(view);
* </pre>
* <p>The current input mappings to keys are:
* <dl>
* <dt>Scroll to Start<dt><dd>CONTROL-HOME or HOME</dd>
* <dt>Scroll Up 1 Page<dt><dd>PAGEUP</dd>
* <dt>Scroll Up 1 Line<dt><dd>UP-ARROW</dd>
* <dt>Scroll to Bottom<dt><dd>CONTROL-END or END</dd>
* <dt>Scroll Down 1 Page<dt><dd>PAGEDOWN</dd>
* <dt>Scroll Down 1 Line<dt><dd>DOWN-ARROW</dd>
* </dl>
* This class declares six constant strings you can use if you want to override one of these default
* settings on the <code>InputMap</code>; these Strings will be trigger the relevant <code>Action</code>
* associated with the scrolling. To change the key binding for "Scroll to Top" to <code>Alt-Home</code>,
* do this:
* <pre>
* panel.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_HOME, KeyEvent.ALT_MASK), FSScrollPane.PAGE_START);
* </pre>
*
*
* @author Patrick Wright
*/
public class FSScrollPane extends JScrollPane {
private static final long serialVersionUID = 2L;
/** Constant used for mapping a key binding to "scroll down 1 page" */
public static final String PAGE_DOWN = "page-down";
/** Constant used for mapping a key binding to "scroll up 1 page" */
public static final String PAGE_UP = "page-up";
/** Constant used for mapping a key binding to "scroll down 1 line" */
public static final String LINE_DOWN = "down";
/** Constant used for mapping a key binding to "scroll up 1 line" */
public static final String LINE_UP = "up";
/** Constant used for mapping a key binding to "scroll to end of document" */
public static final String PAGE_END = "page-end";
/** Constant used for mapping a key binding to "scroll to top of document" */
public static final String PAGE_START = "page-start";
public FSScrollPane() {
this(null);
}
/** Instantiates a new FSScrollPane around the given Panel; see class documentation. */
public FSScrollPane(JPanel aview) {
super(aview, VERTICAL_SCROLLBAR_ALWAYS, HORIZONTAL_SCROLLBAR_ALWAYS);
// TODO: need to get line-height, I think; this should not be fixed (PWW 28-01-05)
getVerticalScrollBar().setUnitIncrement(15);
}
/* @Override */
public void setViewportView(Component view)
{
setPreferredSize(new Dimension((int)view.getSize().getWidth(), (int)view.getSize().getHeight()));
if (view instanceof JComponent) {
setDefaultInputMap((JComponent) view);
setDefaultActionMap((JComponent) view);
}
addResizeListener(view);
super.setViewportView(view);
}
/** Assigns the default keyboard bindings on the view for document navigation. */
private void setDefaultInputMap(JComponent view) {
view.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_PAGE_DOWN, 0), PAGE_DOWN);
view.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_PAGE_UP, 0), PAGE_UP);
view.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), LINE_DOWN);
view.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), LINE_UP);
view.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_END, KeyEvent.CTRL_MASK), PAGE_END);
view.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_END, 0), PAGE_END);
view.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_HOME, KeyEvent.CTRL_MASK), PAGE_START);
view.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).
put(KeyStroke.getKeyStroke(KeyEvent.VK_HOME, 0), PAGE_START);
}
/** Assigns the default Actions for document navigation on the view. */
private void setDefaultActionMap(JComponent view) {
view.getActionMap().put(PAGE_DOWN,
new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent evt) {
JScrollBar sb = getVerticalScrollBar();
sb.getModel().setValue(sb.getModel().getValue() + sb.getBlockIncrement(1));
}
});
view.getActionMap().put(PAGE_END,
new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent evt) {
JScrollBar sb = getVerticalScrollBar();
sb.getModel().setValue(sb.getModel().getMaximum());
}
});
view.getActionMap().put(PAGE_UP,
new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent evt) {
JScrollBar sb = getVerticalScrollBar();
sb.getModel().setValue(sb.getModel().getValue() - sb.getBlockIncrement(-1));
}
});
view.getActionMap().put(PAGE_START,
new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent evt) {
JScrollBar sb = getVerticalScrollBar();
sb.getModel().setValue(0);
}
});
view.getActionMap().put(LINE_DOWN,
new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent evt) {
JScrollBar sb = getVerticalScrollBar();
sb.getModel().setValue(sb.getModel().getValue() + sb.getUnitIncrement(1));
}
});
view.getActionMap().put(LINE_UP,
new AbstractAction() {
private static final long serialVersionUID = 1L;
public void actionPerformed(ActionEvent evt) {
JScrollBar sb = getVerticalScrollBar();
sb.getModel().setValue(sb.getModel().getValue() - sb.getUnitIncrement(-1));
}
});
}
/** Adds a component listener on the view for resize events, to adjust the scroll increment. */
private void addResizeListener(Component view) {
view.addComponentListener( new ComponentAdapter() {
/** Invoked when the component's size changes. Reset scrollable increment, because
* page-down/up is relative to current view size.
*/
public void componentResized(ComponentEvent e) {
JScrollBar bar = getVerticalScrollBar();
// NOTE: use the scroll pane size--the XHTMLPanel size is a virtual size of the entire
// page
// want to page down leaving the current line at the bottom be the first at the top
// TODO: this will only work once unit increment is set correctly; multiplier is a workaround (PWW 28-01-05)
int incr = (int)(getSize().getHeight() - (bar.getUnitIncrement(1) * 3));
getVerticalScrollBar().setBlockIncrement(incr);
}
});
}
}