1 /*
   2  * Copyright (c) 2011, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.javafx.scene.layout.region;
  27 
  28 import javafx.geometry.Side;
  29 import javafx.scene.layout.BackgroundPosition;
  30 import javafx.scene.text.Font;
  31 import javafx.css.ParsedValue;
  32 import com.sun.javafx.css.Size;
  33 import com.sun.javafx.css.SizeUnits;
  34 import com.sun.javafx.css.StyleConverterImpl;
  35 
  36 /**
  37  * Given four Sizes from the Parser, this converter will produce a BackgroundPosition object.
  38  */
  39 public final class BackgroundPositionConverter extends StyleConverterImpl<ParsedValue[], BackgroundPosition> {
  40     private static final BackgroundPositionConverter BACKGROUND_POSITION_CONVERTER =
  41             new BackgroundPositionConverter();
  42 
  43     public static BackgroundPositionConverter getInstance() {
  44         return BACKGROUND_POSITION_CONVERTER;
  45     }
  46     
  47     // Disallow instantiation
  48     private BackgroundPositionConverter() { }
  49 
  50     @Override
  51     public BackgroundPosition convert(ParsedValue<ParsedValue[], BackgroundPosition> value, Font font) {
  52         ParsedValue[] positions = value.getValue();
  53 
  54         // The parser gives us 4 values, none of them null
  55         final Size top = (Size)positions[0].convert(font);
  56         final Size right = (Size)positions[1].convert(font);
  57         final Size bottom = (Size)positions[2].convert(font);
  58         final Size left = (Size)positions[3].convert(font);
  59 
  60         boolean verticalEdgeProportional =
  61                 (bottom.getValue() > 0 && bottom.getUnits() == SizeUnits.PERCENT)
  62                         || (top.getValue() > 0 && top.getUnits() == SizeUnits.PERCENT)
  63                         || (top.getValue() == 0 && bottom.getValue() == 0);
  64 
  65         // either left or right will be set, not both
  66         boolean horizontalEdgeProportional =
  67                 (right.getValue() > 0 && right.getUnits() == SizeUnits.PERCENT)
  68                         || ( left.getValue() > 0 && left.getUnits() == SizeUnits.PERCENT)
  69                         || (left.getValue() == 0 && right.getValue() == 0);
  70 
  71         final double t = top.pixels(font);
  72         final double r = right.pixels(font);
  73         final double b = bottom.pixels(font);
  74         final double l = left.pixels(font);
  75 
  76         return new BackgroundPosition(
  77                 (l == 0 && r != 0) ? Side.RIGHT : Side.LEFT,
  78                 (l == 0 && r != 0) ? r : l,
  79                 horizontalEdgeProportional,
  80                 (t == 0 && b != 0) ? Side.BOTTOM : Side.TOP,
  81                 (t == 0 && b != 0) ? b : t,
  82                 verticalEdgeProportional);
  83     }
  84 
  85     /**
  86      * @inheritDoc
  87      */
  88     @Override public String toString() {
  89         return "BackgroundPositionConverter";
  90     }
  91 }