| 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.terminal; |
| 20 | |
| 21 | import com.googlecode.lanterna.SGR; |
| 22 | import com.googlecode.lanterna.TerminalPosition; |
| 23 | import com.googlecode.lanterna.TerminalSize; |
| 24 | import com.googlecode.lanterna.graphics.AbstractTextGraphics; |
| 25 | import com.googlecode.lanterna.TextCharacter; |
| 26 | import com.googlecode.lanterna.graphics.TextGraphics; |
| 27 | |
| 28 | import java.io.IOException; |
| 29 | import java.util.HashMap; |
| 30 | import java.util.Map; |
| 31 | import java.util.concurrent.atomic.AtomicInteger; |
| 32 | |
| 33 | /** |
| 34 | * This is the terminal's implementation of TextGraphics. Upon creation it takes a snapshot for the terminal's size, so |
| 35 | * that it won't require to do an expensive lookup on every call to {@code getSize()}, but this also means that it can |
| 36 | * go stale quickly if the terminal is resized. You should try to use the object quickly and then let it be GC:ed. It |
| 37 | * will not pick up on terminal resize! Also, the state of the Terminal after an operation performed by this |
| 38 | * TextGraphics implementation is undefined and you should probably re-initialize colors and modifiers. |
| 39 | * <p/> |
| 40 | * Any write operation that results in an IOException will be wrapped by a RuntimeException since the TextGraphics |
| 41 | * interface doesn't allow throwing IOException |
| 42 | */ |
| 43 | class TerminalTextGraphics extends AbstractTextGraphics { |
| 44 | |
| 45 | private final Terminal terminal; |
| 46 | private final TerminalSize terminalSize; |
| 47 | |
| 48 | private final Map<TerminalPosition, TextCharacter> writeHistory; |
| 49 | |
| 50 | private AtomicInteger manageCallStackSize; |
| 51 | private TextCharacter lastCharacter; |
| 52 | private TerminalPosition lastPosition; |
| 53 | |
| 54 | TerminalTextGraphics(Terminal terminal) throws IOException { |
| 55 | this.terminal = terminal; |
| 56 | this.terminalSize = terminal.getTerminalSize(); |
| 57 | this.manageCallStackSize = new AtomicInteger(0); |
| 58 | this.writeHistory = new HashMap<TerminalPosition, TextCharacter>(); |
| 59 | this.lastCharacter = null; |
| 60 | this.lastPosition = null; |
| 61 | } |
| 62 | |
| 63 | @Override |
| 64 | public TextGraphics setCharacter(int columnIndex, int rowIndex, TextCharacter textCharacter) { |
| 65 | return setCharacter(new TerminalPosition(columnIndex, rowIndex), textCharacter); |
| 66 | } |
| 67 | |
| 68 | @Override |
| 69 | public synchronized TextGraphics setCharacter(TerminalPosition position, TextCharacter textCharacter) { |
| 70 | try { |
| 71 | if(manageCallStackSize.get() > 0) { |
| 72 | if(lastCharacter == null || !lastCharacter.equals(textCharacter)) { |
| 73 | applyGraphicState(textCharacter); |
| 74 | lastCharacter = textCharacter; |
| 75 | } |
| 76 | if(lastPosition == null || !lastPosition.equals(position)) { |
| 77 | terminal.setCursorPosition(position.getColumn(), position.getRow()); |
| 78 | lastPosition = position; |
| 79 | } |
| 80 | } |
| 81 | else { |
| 82 | terminal.setCursorPosition(position.getColumn(), position.getRow()); |
| 83 | applyGraphicState(textCharacter); |
| 84 | } |
| 85 | terminal.putCharacter(textCharacter.getCharacter()); |
| 86 | if(manageCallStackSize.get() > 0) { |
| 87 | lastPosition = position.withRelativeColumn(1); |
| 88 | } |
| 89 | writeHistory.put(position, textCharacter); |
| 90 | } |
| 91 | catch(IOException e) { |
| 92 | throw new RuntimeException(e); |
| 93 | } |
| 94 | return this; |
| 95 | } |
| 96 | |
| 97 | @Override |
| 98 | public TextCharacter getCharacter(int column, int row) { |
| 99 | return getCharacter(new TerminalPosition(column, row)); |
| 100 | } |
| 101 | |
| 102 | @Override |
| 103 | public synchronized TextCharacter getCharacter(TerminalPosition position) { |
| 104 | return writeHistory.get(position); |
| 105 | } |
| 106 | |
| 107 | private void applyGraphicState(TextCharacter textCharacter) throws IOException { |
| 108 | terminal.resetColorAndSGR(); |
| 109 | terminal.setForegroundColor(textCharacter.getForegroundColor()); |
| 110 | terminal.setBackgroundColor(textCharacter.getBackgroundColor()); |
| 111 | for(SGR sgr: textCharacter.getModifiers()) { |
| 112 | terminal.enableSGR(sgr); |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | @Override |
| 117 | public TerminalSize getSize() { |
| 118 | return terminalSize; |
| 119 | } |
| 120 | |
| 121 | @Override |
| 122 | public synchronized TextGraphics drawLine(TerminalPosition fromPoint, TerminalPosition toPoint, char character) { |
| 123 | try { |
| 124 | enterAtomic(); |
| 125 | super.drawLine(fromPoint, toPoint, character); |
| 126 | return this; |
| 127 | } |
| 128 | finally { |
| 129 | leaveAtomic(); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | @Override |
| 134 | public synchronized TextGraphics drawTriangle(TerminalPosition p1, TerminalPosition p2, TerminalPosition p3, char character) { |
| 135 | try { |
| 136 | enterAtomic(); |
| 137 | super.drawTriangle(p1, p2, p3, character); |
| 138 | return this; |
| 139 | } |
| 140 | finally { |
| 141 | leaveAtomic(); |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | @Override |
| 146 | public synchronized TextGraphics fillTriangle(TerminalPosition p1, TerminalPosition p2, TerminalPosition p3, char character) { |
| 147 | try { |
| 148 | enterAtomic(); |
| 149 | super.fillTriangle(p1, p2, p3, character); |
| 150 | return this; |
| 151 | } |
| 152 | finally { |
| 153 | leaveAtomic(); |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | @Override |
| 158 | public synchronized TextGraphics fillRectangle(TerminalPosition topLeft, TerminalSize size, char character) { |
| 159 | try { |
| 160 | enterAtomic(); |
| 161 | super.fillRectangle(topLeft, size, character); |
| 162 | return this; |
| 163 | } |
| 164 | finally { |
| 165 | leaveAtomic(); |
| 166 | } |
| 167 | } |
| 168 | |
| 169 | @Override |
| 170 | public synchronized TextGraphics drawRectangle(TerminalPosition topLeft, TerminalSize size, char character) { |
| 171 | try { |
| 172 | enterAtomic(); |
| 173 | super.drawRectangle(topLeft, size, character); |
| 174 | return this; |
| 175 | } |
| 176 | finally { |
| 177 | leaveAtomic(); |
| 178 | } |
| 179 | } |
| 180 | |
| 181 | @Override |
| 182 | public synchronized TextGraphics putString(int column, int row, String string) { |
| 183 | try { |
| 184 | enterAtomic(); |
| 185 | return super.putString(column, row, string); |
| 186 | } |
| 187 | finally { |
| 188 | leaveAtomic(); |
| 189 | } |
| 190 | } |
| 191 | |
| 192 | /** |
| 193 | * It's tricky with this implementation because we can't rely on any state in between two calls to setCharacter |
| 194 | * since the caller might modify the terminal's state outside of this writer. However, many calls inside |
| 195 | * TextGraphics will indeed make multiple calls in setCharacter where we know that the state won't change (actually, |
| 196 | * we can't be 100% sure since the caller might create a separate thread and maliciously write directly to the |
| 197 | * terminal while call one of the draw/fill/put methods in here). We could just set the state before writing every |
| 198 | * single character but that would be inefficient. Rather, we keep a counter of if we are inside an 'atomic' |
| 199 | * (meaning we know multiple calls to setCharacter will have the same state). Some drawing methods call other |
| 200 | * drawing methods internally for their implementation so that's why this is implemented with an integer value |
| 201 | * instead of a boolean; when the counter reaches zero we remove the memory of what state the terminal is in. |
| 202 | */ |
| 203 | private void enterAtomic() { |
| 204 | manageCallStackSize.incrementAndGet(); |
| 205 | } |
| 206 | |
| 207 | private void leaveAtomic() { |
| 208 | if(manageCallStackSize.decrementAndGet() == 0) { |
| 209 | lastPosition = null; |
| 210 | lastCharacter = null; |
| 211 | } |
| 212 | } |
| 213 | } |