Bug 329216

Description Carolyn MacLeod 2010-11-01 14:52:11 EDT

From bug 324005, StyledText needs to implement AccessibleEditableTextListener so that accessibility tools such as speech recognition systems can replace text.

It is understood that StyledText itself cannot implement the setTextAttributes method of AccessibleEditableTextListener because it is completely up to the application whether or not an "external tool" such as a speech recognition engine will be allowed to modify the styles of the text. (For example a Java Editor has its own syntax highlighting, so in that case it does not make sense for an external tool to selectively modify text styles).

Here is a Snippet that can be used as an example:

import org.eclipse.swt.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.accessibility.*;
import org.eclipse.swt.custom.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;

public class AccessibleEditableTextTest {
	
	public static void main(String[] args) {
		final Display display = new Display();
		Shell shell = new Shell(display);
		shell.setText("AccessibleEditableText");
		shell.setLayout(new GridLayout());
		
		final StyledText text = new StyledText(shell, SWT.BORDER | SWT.MULTI);
		text.setText("The quick brown fox jumps over the lazy dog.\nThat's all folks!");
		text.setLayoutData(new GridData(SWT.FILL, SWT.FILL, true, true));
		TextStyle textStyle = new TextStyle(new Font(display, "Courier", 12, SWT.BOLD), display.getSystemColor(SWT.COLOR_RED), null);
		textStyle.strikeout = true;
		textStyle.underline = true;
		textStyle.underlineStyle = SWT.UNDERLINE_SINGLE;
		text.setStyleRanges(new int[] {4, 5}, new StyleRange[] {new StyleRange(textStyle)});

		final Text valueField = new Text(shell, SWT.MULTI | SWT.WRAP | SWT.BORDER);
		GridData data = new GridData(400, 200);
		data.horizontalAlignment = SWT.FILL;
		valueField.setLayoutData(data);
		
		text.getAccessible().addAccessibleAttributeListener(new AccessibleAttributeAdapter() {
			public void getTextAttributes(AccessibleTextAttributeEvent e) {
				valueField.setText("getTextAttributes " + e);
			}
		});

		text.getAccessible().addAccessibleEditableTextListener(new AccessibleEditableTextListener() {
			public void copyText(AccessibleEditableTextEvent e) {
				valueField.setText("copyText " + e);
				text.setSelection(e.start, e.end);
				text.copy();
				e.result = ACC.OK;
			}
			
			public void cutText(AccessibleEditableTextEvent e) {
				valueField.setText("cutText " + e);
				text.setSelection(e.start, e.end);
				text.cut();
				e.result = ACC.OK;
			}
			
			public void pasteText(AccessibleEditableTextEvent e) {
				valueField.setText("pasteText " + e);
				text.setSelection(e.start);
				text.paste();
				e.result = ACC.OK;
			}
			
			public void replaceText(AccessibleEditableTextEvent e) {
				valueField.setText("replaceText " + e);
				text.replaceTextRange(e.start, e.end - e.start, e.string);
				e.result = ACC.OK;
			}

			public void setTextAttributes(AccessibleTextAttributeEvent e) {
				valueField.setText("setTextAttributes " + e);
				TextStyle textStyle = e.textStyle;
				if (textStyle != null) {
					/* Copy all of the TextStyle fields into the new StyleRange. */
					StyleRange style = new StyleRange(textStyle);
					/* Create new graphics resources because the old ones are only valid during the event. */
					if (textStyle.font != null) style.font = new Font(display, textStyle.font.getFontData());
					if (textStyle.foreground != null) style.foreground = new Color(display, textStyle.foreground.getRGB());
					if (textStyle.background != null) style.background = new Color(display, textStyle.background.getRGB());
					if (textStyle.underlineColor != null) style.underlineColor = new Color(display, textStyle.underlineColor.getRGB());
					if (textStyle.strikeoutColor != null) style.strikeoutColor = new Color(display, textStyle.strikeoutColor.getRGB());
					if (textStyle.borderColor != null) style.borderColor = new Color(display, textStyle.borderColor.getRGB());
					/* Set the StyleRange into the StyledText. */
					style.start = e.start;
					style.length = e.end - e.start;
					text.setStyleRange(style);
					e.result = ACC.OK;
				} else {
					text.setStyleRanges(e.start, e.end - e.start, null, null);
				}
			}
		});

		shell.pack();
		shell.open();
		while (!shell.isDisposed()) {
			if (!display.readAndDispatch()) display.sleep();
		}
	}
}