From 4b8b858ddcab0bfbde80304a0f631233388a13d1 Mon Sep 17 00:00:00 2001
From: tzefferer <tzefferer@8a26b1a7-26f0-462f-b9ef-d0e30c41f5a4>
Date: Fri, 16 Oct 2009 09:54:37 +0000
Subject: Keyboard accessibility for Online-BKU

git-svn-id: https://joinup.ec.europa.eu/svn/mocca/trunk@528 8a26b1a7-26f0-462f-b9ef-d0e30c41f5a4
---
 .../at/gv/egiz/bku/gui/HelpLinkFocusManager.java   | 138 +++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100644 BKUCommonGUI/src/main/java/at/gv/egiz/bku/gui/HelpLinkFocusManager.java

(limited to 'BKUCommonGUI/src/main/java/at/gv/egiz/bku/gui/HelpLinkFocusManager.java')

diff --git a/BKUCommonGUI/src/main/java/at/gv/egiz/bku/gui/HelpLinkFocusManager.java b/BKUCommonGUI/src/main/java/at/gv/egiz/bku/gui/HelpLinkFocusManager.java
new file mode 100644
index 00000000..f5882b3d
--- /dev/null
+++ b/BKUCommonGUI/src/main/java/at/gv/egiz/bku/gui/HelpLinkFocusManager.java
@@ -0,0 +1,138 @@
+package at.gv.egiz.bku.gui;
+
+import java.awt.Color;
+import java.awt.event.KeyAdapter;
+import java.awt.event.KeyEvent;
+import java.net.URL;
+
+import javax.accessibility.AccessibleHyperlink;
+import javax.accessibility.AccessibleHypertext;
+import javax.swing.JEditorPane;
+import javax.swing.event.HyperlinkEvent;
+import javax.swing.text.DefaultStyledDocument;
+import javax.swing.text.Element;
+import javax.swing.text.MutableAttributeSet;
+import javax.swing.text.SimpleAttributeSet;
+import javax.swing.text.StyleConstants;
+
+/**
+ * 
+ * @author Thomas Zefferer <thomas.zefferer@iaik.tugraz.at>
+ */
+public final class HelpLinkFocusManager extends KeyAdapter { 
+
+	private static final int FOCUS_UNDEFINED = -1;
+	
+	private int focusedHyperlinkIndex = FOCUS_UNDEFINED;
+	private JEditorPane displayPane;
+	
+	public HelpLinkFocusManager(JEditorPane displayPane) {
+
+		super();
+		this.displayPane = displayPane;
+	}
+
+	public void keyPressed(KeyEvent e) {
+
+		AccessibleHypertext accessibleHypertext = (AccessibleHypertext) this.displayPane
+				.getAccessibleContext().getAccessibleText();
+
+		if (accessibleHypertext.getLinkCount() > 0) {
+			switch (e.getKeyCode()) {
+
+			case KeyEvent.VK_RIGHT:
+				if (this.focusedHyperlinkIndex != FOCUS_UNDEFINED) {
+					removeHyperlinkFocus();
+				}
+
+				this.focusedHyperlinkIndex++;
+
+				if (this.focusedHyperlinkIndex >= accessibleHypertext
+						.getLinkCount()) {
+
+					this.focusedHyperlinkIndex = 0;
+				}
+
+				setHyperlinkFocus();
+				break;
+
+			case KeyEvent.VK_LEFT:
+				if (this.focusedHyperlinkIndex != FOCUS_UNDEFINED) {
+					removeHyperlinkFocus();
+				}
+
+				this.focusedHyperlinkIndex--;
+
+				if (this.focusedHyperlinkIndex < 0) {
+					this.focusedHyperlinkIndex = accessibleHypertext
+							.getLinkCount() - 1;
+				}
+
+				setHyperlinkFocus();
+				break;
+
+			case KeyEvent.VK_SPACE:
+			case KeyEvent.VK_ENTER:
+				
+
+				AccessibleHyperlink link = accessibleHypertext
+						.getLink(this.focusedHyperlinkIndex);
+				if (link != null) {
+					URL url = (URL) link.getAccessibleActionObject(0);
+					Element element = ((DefaultStyledDocument) this.displayPane
+							.getDocument()).getCharacterElement(link
+							.getStartIndex());
+					HyperlinkEvent linkEvent = new HyperlinkEvent(
+							this.displayPane,
+							HyperlinkEvent.EventType.ACTIVATED, url, null,
+							element);
+					this.displayPane.fireHyperlinkUpdate(linkEvent);
+				}
+				
+				removeHyperlinkFocus();
+				this.focusedHyperlinkIndex = FOCUS_UNDEFINED;
+				break;
+			default: 
+				// nothig to do
+				break;
+			}
+		}
+	}
+
+	private void setHyperlinkFocus() {
+
+		AccessibleHypertext accessibleHypertext = (AccessibleHypertext) this.displayPane
+				.getAccessibleContext().getAccessibleText();
+		AccessibleHyperlink link = accessibleHypertext
+				.getLink(this.focusedHyperlinkIndex);		
+		
+		if (link != null) {
+			
+			MutableAttributeSet style = new SimpleAttributeSet();
+			StyleConstants.setForeground(style, Color.RED);
+			((DefaultStyledDocument) this.displayPane.getDocument())
+					.setCharacterAttributes(link.getStartIndex(), link
+							.getEndIndex()
+							- link.getStartIndex(), style, false);
+		}
+	}
+
+	private void removeHyperlinkFocus() {
+		Color textColor = Color.BLUE;
+		AccessibleHypertext accessibleHypertext = (AccessibleHypertext) this.displayPane
+				.getAccessibleContext().getAccessibleText();
+		AccessibleHyperlink link = accessibleHypertext
+				.getLink(this.focusedHyperlinkIndex);
+
+		if (link != null) {
+			
+			MutableAttributeSet style = new SimpleAttributeSet();
+			StyleConstants.setForeground(style, textColor);
+			((DefaultStyledDocument) this.displayPane.getDocument())
+					.setCharacterAttributes(link.getStartIndex(), link
+							.getEndIndex()
+							- link.getStartIndex(), style, false);
+		}
+	}
+
+}
-- 
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