| 1 | // Copyright 2004-2007 Jean-Francois Poilpret |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package net.sourceforge.hivegui.component; |
| 16 | |
| 17 | import java.awt.AWTError; |
| 18 | import java.awt.Component; |
| 19 | import java.awt.Container; |
| 20 | import java.awt.Dimension; |
| 21 | import java.awt.Insets; |
| 22 | import java.awt.LayoutManager; |
| 23 | |
| 24 | /** |
| 25 | * Simple LayoutManager that allows to center a single Component inside a |
| 26 | * Container, based on its preferred size. |
| 27 | * |
| 28 | * @author jean-Francois Poilpret |
| 29 | */ |
| 30 | public class CenterLayout implements LayoutManager |
| 31 | { |
| 32 | public void addLayoutComponent(String name, Component comp) |
| 33 | { |
| 34 | } |
| 35 | |
| 36 | public void removeLayoutComponent(Component comp) |
| 37 | { |
| 38 | } |
| 39 | |
| 40 | public Dimension preferredLayoutSize(Container target) |
| 41 | { |
| 42 | Component content = checkTarget(target); |
| 43 | return content.getPreferredSize(); |
| 44 | } |
| 45 | |
| 46 | public Dimension minimumLayoutSize(Container target) |
| 47 | { |
| 48 | Component content = checkTarget(target); |
| 49 | return content.getMinimumSize(); |
| 50 | } |
| 51 | |
| 52 | public void layoutContainer(Container target) |
| 53 | { |
| 54 | Component content = checkTarget(target); |
| 55 | |
| 56 | // Find the available size of the container |
| 57 | Dimension alloc = target.getSize(); |
| 58 | Insets in = target.getInsets(); |
| 59 | alloc.width -= in.left + in.right; |
| 60 | alloc.height -= in.top + in.bottom; |
| 61 | |
| 62 | int width = content.getPreferredSize().width; |
| 63 | int height = content.getPreferredSize().height; |
| 64 | |
| 65 | int x = (alloc.width - width) / 2; |
| 66 | if (x < 0) |
| 67 | { |
| 68 | x = 0; |
| 69 | width = alloc.width; |
| 70 | } |
| 71 | int y = (alloc.height - height) / 2; |
| 72 | if (y < 0) |
| 73 | { |
| 74 | y = 0; |
| 75 | height = alloc.height; |
| 76 | } |
| 77 | |
| 78 | content.setBounds(x + in.left, y + in.top, width, height); |
| 79 | } |
| 80 | |
| 81 | private Component checkTarget(Container target) |
| 82 | { |
| 83 | if (target.getComponentCount() != 1) |
| 84 | { |
| 85 | throw new AWTError("CenterLayout must have exactly one component"); |
| 86 | } |
| 87 | return target.getComponent(0); |
| 88 | } |
| 89 | } |