com.vaadin.ui.renderers.ComponentRenderer Maven / Gradle / Ivy
/*
* Copyright (C) 2000-2024 Vaadin Ltd
*
* This program is available under Vaadin Commercial License and Service Terms.
*
* See for the full
* license.
*/
package com.vaadin.ui.renderers;
import com.vaadin.shared.ui.grid.renderers.ComponentRendererState;
import com.vaadin.ui.AbstractField;
import com.vaadin.ui.Component;
import com.vaadin.ui.Grid;
import com.vaadin.ui.Label;
import elemental.json.Json;
import elemental.json.JsonValue;
/**
* A renderer for presenting Components.
*
* Note: The use of ComponentRenderer causes the Grid to
* generate components for all items currently available in the client-side.
* This means that a number of components is always generated and sent to the
* client. Using complex structures of many nested components might be heavy to
* generate and store, which will lead to performance problems.
*
* Note: Components will occasionally be generated again during
* runtime e.g. when selection changes. If your component has an internal state
* that is not stored into the object, you should reuse the same component
* instances.
*
* Example of how to add a {@link Label} component to {@link Grid}:
*
*
* Grid<Person> grid;
* grid.addColumn(person -> new Label(person.getFullName()),
* new ComponentRenderer()).setCaption("Full Name");
*
*
* @author Vaadin Ltd
* @since 8.1
*/
public class ComponentRenderer extends AbstractRenderer {
/**
* Constructor for ComponentRenderer.
*/
public ComponentRenderer() {
super(Component.class);
}
@Override
public JsonValue encode(Component value) {
if (value instanceof AbstractField && getParentGrid().isReadOnly()) {
((AbstractField) value).setReadOnly(true);
}
return value != null ? Json.create(value.getConnectorId()) : null;
}
@Override
protected ComponentRendererState getState(boolean markAsDirty) {
return (ComponentRendererState) super.getState(markAsDirty);
}
@Override
protected ComponentRendererState getState() {
return (ComponentRendererState) super.getState();
}
}