Bug 74708 [Encoding] IDEEncodingPreferencePage does not disable OK when invalid encoding is entered
20040921-2000 If you enter an invalid encoding in the IDEEncodingsPreferencePage you will still be able to select OK STEPS 1) Open the Editors preference page 2) Type ffff 3) You are warned but OK is still enabled.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/ResourceInfoPage.java
encodingEditor = new ResourceEncodingFieldEditor(
				getFieldEditorLabel(resource),composite,resource);
		encodingEditor.setPreferencePage(this);
		encodingEditor.load();
		
		return composite;
	}
	/**
	 * Return the label for the encoding field editor for the 
	 * resource.
	 * @param resource - the resource to edit.
	 * @return String
	 */
	private String getFieldEditorLabel(IResource resource) {
		if (resource instanceof IContainer)
			return CONTAINER_ENCODING_TITLE;
		return FILE_ENCODING_TITLE;
	}
	/**
	 * Create the isEditable button and it's associated label as a child of
	 * parent using the editableValue of the receiver. The Composite will be the
	 * parent of the button.
	 */
	private void createEditableButton(Composite composite) {
		this.editableBox = new Button(composite, SWT.CHECK | SWT.RIGHT);
		this.editableBox.setAlignment(SWT.LEFT);
		this.editableBox.setText(READ_ONLY);
		this.editableBox.setSelection(this.previousReadOnlyValue);
		this.editableBox.setFont(composite.getFont());
		GridData data = new GridData();