alter style definition in vaadin - css

Question

I have code that will hide components dynamically; it uses [component].addStyleName("name") to add a style to a component, and that style is defined to hide the component.
I have a page which will have a large number of components; I can put them in an array and do this, but I'm hoping for a different way. I would like to assign all those components their own style - something like "costPanel" - and then use server-side vaadin code to alter the definition of the style "costPanel" at runtime.
The Page.Styles class in Vaadin has no methods for obtaining existing styles nor altering ones that are there -- the only methods are for adding them.
Is this possible in Vaadin, even if I have to do something on the client side for it?

Answer 1

This is perhaps best suited as a comment, but it does not really fit in there.
Not trying to be patronising, but it sounds like you're trying in a very complicated way to reinvent the wheel. component.setVisible(false) will do exactly what you need, as in the component will not take up any space since it won't actually exist in the DOM itself. Take a look at the example below:
Code:
public class LayoutWithInvisibleComponents extends VerticalLayout {
private int index = 0;
public LayoutWithInvisibleComponents() {
// add a visibility toggling button
addComponent(new Button("Toggle next", event -> {
Component component = getComponent(++index);
if (component instanceof Button) {
// just toggle the next one if it's a button
component.setVisible(!component.isVisible());
}
if (index == getComponentCount() - 1) {
// reset counter
index = 0;
}
}));
// add some invisible dummy buttons
for (int i = 0; i < 5; i++) {
Button button = new Button("Button " + i);
button.setVisible(false);
addComponent(button);
}
// and add a visual delimiter
Panel rightPanel = new Panel(new Label("---------- some visual delimiter ----------"));
rightPanel.setSizeFull();
addComponent(rightPanel);
}
}
Result:
Is there anything else I'm missing?

Answer 2

This also would make a better comment, but doesn't fit well enough there.
The following is from the Book of Vaadin:
Beware that invisible beings can leave footprints. The containing layout cell that holds the invisible
component will not go away, but will show in the layout as extra empty space. Also expand ratios
work just like if the component was visible - it is the layout cell that expands, not the component.
The phrase "show in the layout as extra empty space" convinced me that there would be blank, open, background-colored space where my component was supposed to be. I don't remember if I tried it, but I might have and had some other error that caused me to conclude my assumption was correct, and that the setting was for making it un-rendered but with the space still visible.
Vaadin has much better documentation than most of the industry, but in this case I got the meaning crossed up. In succeeding paragraphs they even have additional explanation that does say what I learned through this question, but the part quoted here seemed to contradict it.