Bug 8581 Switch J Search to StructuredContentProvider
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/search/JavaSearchPage.java
* Implements method from IDialogPage
	 */
	public void setVisible(boolean visible) {
		if (visible && fPattern != null) {
			if (fFirstTime) {
				fFirstTime= false;
				
				fPattern.setItems(getPreviousSearchPatterns());
				initSelections();
			}
			fPattern.setFocus();
			getContainer().setPerformActionEnabled(fPattern.getText().length() > 0 && getContainer().hasValidScope());
		}
		super.setVisible(visible);
	}
	
	public boolean isValid() {
		return true;
	}
	
	/**
	 * Creates the page's content.
	 */
	public void createControl(Composite parent) {
		readConfiguration();
		
		GridData gd;
		Composite result= new Composite(parent, SWT.NONE);
		GridLayout layout= new GridLayout();
		layout.numColumns= 2; layout.makeColumnsEqualWidth= true;