| 1 | /* |
| 2 | * This file is part of lanterna (http://code.google.com/p/lanterna/). |
| 3 | * |
| 4 | * lanterna is free software: you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU Lesser General Public License as published by |
| 6 | * the Free Software Foundation, either version 3 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public License |
| 15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | * |
| 17 | * Copyright (C) 2010-2015 Martin |
| 18 | */ |
| 19 | package com.googlecode.lanterna.gui2; |
| 20 | |
| 21 | import com.googlecode.lanterna.TerminalSize; |
| 22 | import java.util.List; |
| 23 | |
| 24 | /** |
| 25 | * A layout manager is a class that takes an area of usable space and a list of components to fit on that space. This |
| 26 | * is very similar to how AWT/Swing/SWT works. Lanterna contains a number of layout managers built-in that will arrange |
| 27 | * components in various ways, but you can also write your own. The typical way of providing customization and tuning, |
| 28 | * so the layout manager can distinguish between components and treat them in different ways, is to create a class |
| 29 | * and/or objects based on the {@code LayoutData} object, which can be assigned to each {@code Component}. |
| 30 | * @see AbsoluteLayout |
| 31 | * @see BorderLayout |
| 32 | * @see GridLayout |
| 33 | * @see LinearLayout |
| 34 | * @author Martin |
| 35 | */ |
| 36 | public interface LayoutManager { |
| 37 | |
| 38 | /** |
| 39 | * This method returns the dimensions it would prefer to have to be able to layout all components while giving all |
| 40 | * of them as much space as they are asking for. |
| 41 | * @param components List of components |
| 42 | * @return Size the layout manager would like to have |
| 43 | */ |
| 44 | TerminalSize getPreferredSize(List<Component> components); |
| 45 | |
| 46 | /** |
| 47 | * Given a size constraint, update the location and size of each component in the component list by laying them out |
| 48 | * in the available area. This method will call {@code setPosition(..)} and {@code setSize(..)} on the Components. |
| 49 | * @param area Size available to this layout manager to lay out the components on |
| 50 | * @param components List of components to lay out |
| 51 | */ |
| 52 | void doLayout(TerminalSize area, List<Component> components); |
| 53 | |
| 54 | /** |
| 55 | * Returns true if the internal state of this LayoutManager has changed since the last call to doLayout. This will |
| 56 | * tell the container that it needs to call doLayout again. |
| 57 | * @return {@code true} if this layout manager's internal state has changed since the last call to {@code doLayout} |
| 58 | */ |
| 59 | boolean hasChanged(); |
| 60 | } |