Merge pull request #21 from andy1138/ComboBox-maximumRowCount

ComboBox maximum row count

Author: andy1138

examples/src/main/scala/scala/swing/examples/tutorials/components/CustomComboBoxDemo.scala

@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   - Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *
+ *   - Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *
+ *   - Neither the name of Oracle or the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+ * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package scala.swing.examples.tutorials.components
+
+import java.awt.{Dimension, Font}
+import javax.swing.ImageIcon
+
+import scala.swing._
+
+/**
+ * Tutorial: How to Use Combo Boxes
+ * [[http://docs.oracle.com/javase/tutorial/uiswing/components/combobox.html]]
+ *
+ * Source code reference:
+ * [[http://docs.oracle.com/javase/tutorial/uiswing/examples/components/CustomComboBoxDemoProject/src/components/CustomComboBoxDemo.java]]
+ *
+ * CustomComboBoxDemo.scala uses the following files:
+ *   /scala/swing/examples/tutorials/images/Bird.gif
+ *   /scala/swing/examples/tutorials/images/Cat.gif
+ *   /scala/swing/examples/tutorials/images/Dog.gif
+ *   /scala/swing/examples/tutorials/images/Rabbit.gif
+ *   /scala/swing/examples/tutorials/images/Pig.gif
+ */
+class CustomComboBoxDemo extends BorderPanel {
+  val petStrings: Array[String] = Array("Bird", "Cat", "Dog", "Rabbit", "Pig")
+  //  val images: Array[Option[ImageIcon]] = new Array[Option[ImageIcon]](petStrings.length)
+  val intArray: Array[Int] = (0 until petStrings.length ).toArray
+  /*
+   * Despite its use of EmptyBorder, this panel makes a fine content
+   * pane because the empty border just increases the panel's size
+   * and is "painted" on top of the panel's normal background.  In
+   * other words, the JPanel fills its entire background if it's
+   * opaque (which it is by default); adding a border doesn't change
+   * that.
+   */
+
+  val images:Array[Option[ImageIcon]]  = petStrings.map( pet => {
+    val oImage = CustomComboBoxDemo.createImageIcon(s"/scala/swing/examples/tutorials/images/$pet.gif")
+    oImage.map( img =>  {img.setDescription(pet); img} )
+  })
+
+  //Create the combo box.
+  val petList = new ComboBox[Int](intArray) {
+    renderer = new ComboBoxRenderer()
+    preferredSize = new Dimension(200, 130)
+    maximumRowCount = 3
+  }
+
+  //Lay out the demo.
+  layout(petList) = BorderPanel.Position.Center
+  border = Swing.EmptyBorder(20, 20, 20, 20)
+
+  class ComboBoxRenderer extends ListView.AbstractRenderer[Int, Label](new Label("")) {
+    var uhOhFont: Option[Font] = None
+    /*
+     * This method finds the image and text corresponding
+     * to the selected value and returns the label, set up
+     * to display the text and image.
+     */
+    def configure( listMe: ListView[_], isSelected: Boolean, cellHasFocus: Boolean, a: Int, index: Int): Unit = {
+      //Set the icon and text.  If icon was null, say so.
+      images(a) match {
+        case Some( icon ) =>
+          component.icon = icon
+          component.text = petStrings(a)
+          component.font = listMe.font
+        case None =>  setUhOhText( s"${petStrings(a)} (no image available)",  listMe.font)
+      }
+    }
+
+    //Set the font and text when no image was found.
+    def setUhOhText(uhOhText: String, normalFont: Font): Unit = {
+      if (!uhOhFont.isDefined) { //lazily create this font
+        uhOhFont = Some(normalFont.deriveFont(Font.ITALIC))
+      }
+      component.font = uhOhFont.getOrElse( normalFont )
+      component.text = uhOhText
+    }
+  }
+}
+
+object CustomComboBoxDemo extends SimpleSwingApplication {
+
+  def createImageIcon(path: String): Option[javax.swing.ImageIcon] =
+    Option(resourceFromClassloader(path)).map(imgURL => Swing.Icon(imgURL))
+
+  lazy val top = new MainFrame() {
+    title = "CustomComboBoxDemo"
+
+    //Create and set up the content pane.
+    val newContentPane = new CustomComboBoxDemo()
+    newContentPane.opaque = true
+    contents = newContentPane
+  }
+
+}

src/main/scala/scala/swing/ComboBox.scala

@@ -191,6 +191,17 @@ class ComboBox[A](items: Seq[A]) extends Component with Publisher {
   */
   def editable: Boolean = peer.isEditable
 
+
+  /**
+   * Maximum number of rows to display without scrolling
+   */
+  def maximumRowCount: Int = peer.getMaximumRowCount
+
+  /**
+   * Maximum number of rows to display without scrolling
+   */
+  def maximumRowCount_=(c:Int): Unit = peer.setMaximumRowCount(c)
+
   /**
    * Makes this combo box editable. In order to do so, this combo needs an
    * editor which is supplied by the implicit argument. For default