javax.swing

Class SpringLayout.Constraints

Table des matières
  • Enclosing class:
    SpringLayout

    public static class SpringLayout.Constraints
extends Object
    A Constraints object holds the constraints that govern the way a component's size and position change in a container controlled by a SpringLayout. A Constraints object is like a Rectangle, in that it has x, y, width, and height properties. In the Constraints object, however, these properties have Spring values instead of integers. In addition, a Constraints object can be manipulated as four edges -- north, south, east, and west -- using the constraint property.

    The following formulas are always true for a Constraints object (here WEST and x are synonyms, as are and NORTH and y): 

                   EAST = WEST + WIDTH
              SOUTH = NORTH + HEIGHT
  HORIZONTAL_CENTER = WEST + WIDTH/2
    VERTICAL_CENTER = NORTH + HEIGHT/2
  ABSOLUTE_BASELINE = NORTH + RELATIVE_BASELINE*

    For example, if you have specified the WIDTH and WEST (X) location the EAST is calculated as WEST + WIDTH. If you instead specified the WIDTH and EAST locations the WEST (X) location is then calculated as EAST - WIDTH.

    [RELATIVE_BASELINE is a private constraint that is set automatically when the SpringLayout.Constraints(Component) constuctor is called or when a constraints object is registered with a SpringLayout object.]

    Note: In this document, operators represent methods in the Spring class. For example, "a + b" is equal to Spring.sum(a, b), and "a - b" is equal to Spring.sum(a, Spring.minus(b)). See the Spring API documentation for further details of spring arithmetic.

    Because a Constraints object's properties -- representing its edges, size, and location -- can all be set independently and yet are interrelated, a Constraints object can become over-constrained. For example, if the WEST, WIDTH and EAST edges are all set, steps must be taken to ensure that the first of the formulas above holds. To do this, the Constraints object throws away the least recently set constraint so as to make the formulas hold.

    Since:
    1.4

    • Constructor Detail

      • SpringLayout.Constraints

        public SpringLayout.Constraints()
        Creates an empty Constraints object.

      • SpringLayout.Constraints

        public SpringLayout.Constraints(Spring x,
                        Spring y)
        Creates a Constraints object with the specified values for its x and y properties. The height and width springs have null values.
        Parameters:
        x - the spring controlling the component's x value
        y - the spring controlling the component's y value

      • SpringLayout.Constraints

        public SpringLayout.Constraints(Spring x,
                        Spring y,
                        Spring width,
                        Spring height)
        Creates a Constraints object with the specified values for its x, y, width, and height properties. Note: If the SpringLayout class encounters null values in the Constraints object of a given component, it replaces them with suitable defaults.
        Parameters:
        x - the spring value for the x property
        y - the spring value for the y property
        width - the spring value for the width property
        height - the spring value for the height property

      • SpringLayout.Constraints

        public SpringLayout.Constraints(Component c)
        Creates a Constraints object with suitable x, y, width and height springs for component, c. The x and y springs are constant springs initialised with the component's location at the time this method is called. The width and height springs are special springs, created by the Spring.width() and Spring.height() methods, which track the size characteristics of the component when they change.
        Parameters:
        c - the component whose characteristics will be reflected by this Constraints object
        Throws:
        NullPointerException - if c is null.
        Since:
        1.5

Traduction non disponible

Les API Java ne sont pas encore traduites en français sur l'infobrol. Seule la version anglaise est disponible pour l'instant.

Version en cache

09/10/2025 07:38:11 Cette version de la page est en cache (à la date du 09/10/2025 07:38:11) afin d'accélérer le traitement.
Vous pouvez activer le mode utilisateur dans le menu en haut pour afficher la version plus récente de la page.

Document créé le 30/08/2006, dernière modification le 04/03/2020
Source du document imprimé : https://www.gaudry.be/java-api-rf-javax/swing/SpringLayout.Constraints.html

L'infobrol est un site personnel dont le contenu n'engage que moi. Le texte est mis à disposition sous licence CreativeCommons(BY-NC-SA). Plus d'info sur les conditions d'utilisation et sur l'auteur.

Références

  1. Consulter le document html Langue du document :fr Manuel PHP : https://docs.oracle.com/en/java/, Class SpringLayout.Constraints

Ces références et liens indiquent des documents consultés lors de la rédaction de cette page, ou qui peuvent apporter un complément d'information, mais les auteurs de ces sources ne peuvent être tenus responsables du contenu de cette page.
L'auteur de ce site est seul responsable de la manière dont sont présentés ici les différents concepts, et des libertés qui sont prises avec les ouvrages de référence. N'oubliez pas que vous devez croiser les informations de sources multiples afin de diminuer les risques d'erreurs.