scala.swing.UIElement.scala Maven / Gradle / Ivy
/* __ *\
** ________ ___ / / ___ Scala API **
** / __/ __// _ | / / / _ | (c) 2007-2011, LAMP/EPFL **
** __\ \/ /__/ __ |/ /__/ __ | http://scala-lang.org/ **
** /____/\___/_/ |_/____/_/ | | **
** |/ **
\* */
package scala.swing
import java.awt.Cursor
import event._
import scala.collection.mutable.HashMap
import scala.ref._
import java.util.WeakHashMap
object UIElement {
private val ClientKey = "scala.swingWrapper"
private[this] val wrapperCache = new WeakHashMap[java.awt.Component, WeakReference[UIElement]]
private def cache(e: UIElement) = e.peer match {
case p: javax.swing.JComponent => p.putClientProperty(ClientKey, e)
case _ => wrapperCache.put(e.peer, new WeakReference(e))
}
/**
* Looks up the internal component cache for a wrapper of the given
* Java Swing peer. If this method finds one of the given type `C`,
* it will return that wrapper. Otherwise it returns `null`. This
* method never throws an exception.
*
* Clients should be extremely careful with type parameter `C` and
* its interaction with type inference. Better err on the side of caution
* and explicitly specify `C`.
*/
private[swing] def cachedWrapper[C>:Null<:UIElement](c: java.awt.Component): C = {
val w = c match {
case c: javax.swing.JComponent => c.getClientProperty(ClientKey)
case _ => wrapperCache.get(c)
}
try { w.asInstanceOf[C] } catch { case _ => null }
}
/**
* Returns a wrapper for a given Java Swing peer. If there is a
* compatible wrapper in use, this method will return it.
*
* `wrap` methods in companion objects of subclasses of UIElement have the
* same behavior, except that they return more specific wrappers.
*/
def wrap(c: java.awt.Component): UIElement = {
val w = cachedWrapper[UIElement](c)
if (w != null) w
else new UIElement { def peer = c }
}
}
/**
* The base trait of all user interface elements. Subclasses belong to one
* of two groups: top-level elements such as windows and dialogs, or
* Components.
*
* @note [Java Swing] This trait does not have an exact counterpart in
* Java Swing. The peer is of type java.awt.Component since this is the
* least common upper bound of possible underlying peers.
*
* @note [Implementation] A UIElement automatically adds itself to the
* component cache on creation.
*
* @see java.awt.Component
*/
trait UIElement extends Proxy with LazyPublisher {
/**
* The underlying Swing peer.
*/
def peer: java.awt.Component
def self = peer
UIElement.cache(this)
def foreground: Color = peer.getForeground
def foreground_=(c: Color) = peer.setForeground(c)
def background: Color = peer.getBackground
def background_=(c: Color) = peer.setBackground(c)
def minimumSize = peer.getMinimumSize
def minimumSize_=(x: Dimension) = peer.setMinimumSize(x)
def maximumSize = peer.getMaximumSize
def maximumSize_=(x: Dimension) = peer.setMaximumSize(x)
def preferredSize = peer.getPreferredSize
def preferredSize_=(x: Dimension) = peer.setPreferredSize(x)
def font: Font = peer.getFont
def font_=(f: Font) = peer.setFont(f)
def locationOnScreen = peer.getLocationOnScreen
def location = peer.getLocation
def bounds = peer.getBounds
def size = peer.getSize
@deprecated("Explicit size assignment for UIElements is not supported anymore. " +
"Use a layout manager or subclass Window.", "2.8.0")
def size_=(dim: Dimension) = peer.setSize(dim)
def locale = peer.getLocale
def toolkit = peer.getToolkit
def cursor: Cursor = peer.getCursor
def cursor_=(c: Cursor) { peer.setCursor(c) }
def visible: Boolean = peer.isVisible
def visible_=(b: Boolean) { peer.setVisible(b) }
def showing: Boolean = peer.isShowing
def displayable: Boolean = peer.isDisplayable
def repaint() { peer.repaint }
def repaint(rect: Rectangle) { peer.repaint(rect.x, rect.y, rect.width, rect.height) }
def ignoreRepaint: Boolean = peer.getIgnoreRepaint
def ignoreRepaint_=(b: Boolean) { peer.setIgnoreRepaint(b) }
protected def onFirstSubscribe() {
peer.addComponentListener(new java.awt.event.ComponentListener {
def componentHidden(e: java.awt.event.ComponentEvent) {
publish(UIElementHidden(UIElement.this))
}
def componentShown(e: java.awt.event.ComponentEvent) {
publish(UIElementShown(UIElement.this))
}
def componentMoved(e: java.awt.event.ComponentEvent) {
publish(UIElementMoved(UIElement.this))
}
def componentResized(e: java.awt.event.ComponentEvent) {
publish(UIElementResized(UIElement.this))
}
})
}
protected def onLastUnsubscribe() {}
}