+++ /dev/null
-/*
- * This file is part of lanterna (http://code.google.com/p/lanterna/).
- *
- * lanterna is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- * Copyright (C) 2010-2015 Martin
- */
-package com.googlecode.lanterna.screen;
-
-import com.googlecode.lanterna.TextCharacter;
-import com.googlecode.lanterna.graphics.Scrollable;
-import com.googlecode.lanterna.graphics.TextGraphics;
-import com.googlecode.lanterna.input.InputProvider;
-import com.googlecode.lanterna.TerminalPosition;
-import com.googlecode.lanterna.TerminalSize;
-import java.io.IOException;
-
-/**
- * Screen is a fundamental layer in Lanterna, presenting the terminal as a bitmap-like surface where you can perform
- * smaller in-memory operations to a back-buffer, effectively painting out the terminal as you'd like it, and then call
- * {@code refresh} to have the screen automatically apply the changes in the back-buffer to the real terminal. The
- * screen tracks what's visible through a front-buffer, but this is completely managed internally and cannot be expected
- * to know what the terminal looks like if it's being modified externally.
- * <p>
- * If you want to do more complicated drawing operations, please see the class {@code DefaultScreenWriter} which has many
- * utility methods that works on Screens.
- *
- * @author Martin
- */
-public interface Screen extends InputProvider, Scrollable {
- /**
- * This is the character Screen implementations should use as a filler is there are areas not set to any particular
- * character.
- */
- TextCharacter DEFAULT_CHARACTER = new TextCharacter(' ');
-
- /**
- * Before you can use a Screen, you need to start it. By starting the screen, Lanterna will make sure the terminal
- * is in private mode (Screen only supports private mode), clears it (so that is can set the front and back buffers
- * to a known value) and places the cursor in the top left corner. After calling startScreen(), you can begin using
- * the other methods on this interface. When you want to exit from the screen and return to what you had before,
- * you can call {@code stopScreen()}.
- *
- * @throws IOException if there was an underlying IO error when exiting from private mode
- */
- void startScreen() throws IOException;
-
- /**
- * Calling this method will make the underlying terminal leave private mode, effectively going back to whatever
- * state the terminal was in before calling {@code startScreen()}. Once a screen has been stopped, you can start it
- * again with {@code startScreen()} which will restore the screens content to the terminal.
- *
- * @throws IOException if there was an underlying IO error when exiting from private mode
- */
- void stopScreen() throws IOException;
-
- /**
- * Erases all the characters on the screen, effectively giving you a blank area. The default background color will
- * be used. This is effectively the same as calling
- * <pre>fill(TerminalPosition.TOP_LEFT_CORNER, getSize(), TextColor.ANSI.Default)</pre>.
- * <p>
- * Please note that calling this method will only affect the back buffer, you need to call refresh to make the
- * change visible.
- */
- void clear();
-
- /**
- * A screen implementation typically keeps a location on the screen where the cursor will be placed after drawing
- * and refreshing the buffers, this method returns that location. If it returns null, it means that the terminal
- * will attempt to hide the cursor (if supported by the terminal).
- *
- * @return Position where the cursor will be located after the screen has been refreshed or {@code null} if the
- * cursor is not visible
- */
- TerminalPosition getCursorPosition();
-
- /**
- * A screen implementation typically keeps a location on the screen where the cursor will be placed after drawing
- * and refreshing the buffers, this method controls that location. If you pass null, it means that the terminal
- * will attempt to hide the cursor (if supported by the terminal).
- *
- * @param position TerminalPosition of the new position where the cursor should be placed after refresh(), or if
- * {@code null}, hides the cursor
- */
- void setCursorPosition(TerminalPosition position);
-
- /**
- * Gets the behaviour for what to do about tab characters. If a tab character is written to the Screen, it would
- * cause issues because we don't know how the terminal emulator would render it and we wouldn't know what state the
- * front-buffer is in. Because of this, we convert tabs to a determined number of spaces depending on different
- * rules that are available.
- *
- * @return Tab behaviour that is used currently
- * @see TabBehaviour
- */
- TabBehaviour getTabBehaviour();
-
- /**
- * Sets the behaviour for what to do about tab characters. If a tab character is written to the Screen, it would
- * cause issues because we don't know how the terminal emulator would render it and we wouldn't know what state the
- * front-buffer is in. Because of this, we convert tabs to a determined number of spaces depending on different
- * rules that are available.
- *
- * @param tabBehaviour Tab behaviour to use when converting a \t character to a spaces
- * @see TabBehaviour
- */
- void setTabBehaviour(TabBehaviour tabBehaviour);
-
- /**
- * Returns the size of the screen. This call is not blocking but should return the size of the screen as it is
- * represented by the buffer at the time this method is called.
- *
- * @return Size of the screen, in columns and rows
- */
- TerminalSize getTerminalSize();
-
- /**
- * Sets a character in the back-buffer to a specified value with specified colors and modifiers.
- * @param column Column of the character to modify (x coordinate)
- * @param row Row of the character to modify (y coordinate)
- * @param screenCharacter New data to put at the specified position
- */
- void setCharacter(int column, int row, TextCharacter screenCharacter);
-
- /**
- * Sets a character in the back-buffer to a specified value with specified colors and modifiers.
- * @param position Which position in the terminal to modify
- * @param screenCharacter New data to put at the specified position
- */
- void setCharacter(TerminalPosition position, TextCharacter screenCharacter);
-
- /**
- * Creates a new TextGraphics objects that is targeting this Screen for writing to. Any operations done on this
- * TextGraphics will be affecting this screen. Remember to call {@code refresh()} on the screen to see your changes.
- *
- * @return New TextGraphic object targeting this Screen
- */
- TextGraphics newTextGraphics();
-
- /**
- * Reads a character and its associated meta-data from the front-buffer and returns it encapsulated as a
- * ScreenCharacter.
- * @param column Which column to get the character from
- * @param row Which row to get the character from
- * @return A {@code ScreenCharacter} representation of the character in the front-buffer at the specified location
- */
- TextCharacter getFrontCharacter(int column, int row);
-
- /**
- * Reads a character and its associated meta-data from the front-buffer and returns it encapsulated as a
- * ScreenCharacter.
- * @param position What position to read the character from
- * @return A {@code ScreenCharacter} representation of the character in the front-buffer at the specified location
- */
- TextCharacter getFrontCharacter(TerminalPosition position);
-
- /**
- * Reads a character and its associated meta-data from the back-buffer and returns it encapsulated as a
- * ScreenCharacter.
- * @param column Which column to get the character from
- * @param row Which row to get the character from
- * @return A {@code ScreenCharacter} representation of the character in the back-buffer at the specified location
- */
- TextCharacter getBackCharacter(int column, int row);
-
- /**
- * Reads a character and its associated meta-data from the back-buffer and returns it encapsulated as a
- * ScreenCharacter.
- * @param position What position to read the character from
- * @return A {@code ScreenCharacter} representation of the character in the back-buffer at the specified location
- */
- TextCharacter getBackCharacter(TerminalPosition position);
-
- /**
- * This method will take the content from the back-buffer and move it into the front-buffer, making the changes
- * visible to the terminal in the process. The graphics workflow with Screen would involve drawing text and text-like
- * graphics on the back buffer and then finally calling refresh(..) to make it visible to the user.
- * @throws java.io.IOException If there was an underlying I/O error
- * @see RefreshType
- */
- void refresh() throws IOException;
-
- /**
- * This method will take the content from the back-buffer and move it into the front-buffer, making the changes
- * visible to the terminal in the process. The graphics workflow with Screen would involve drawing text and text-like
- * graphics on the back buffer and then finally calling refresh(..) to make it visible to the user.
- * <p>
- * Using this method call instead of {@code refresh()} gives you a little bit more control over how the screen will
- * be refreshed.
- * @param refreshType What type of refresh to do
- * @throws java.io.IOException If there was an underlying I/O error
- * @see RefreshType
- */
- void refresh(RefreshType refreshType) throws IOException;
-
- /**
- * One problem working with Screens is that whenever the terminal is resized, the front and back buffers needs to be
- * adjusted accordingly and the program should have a chance to figure out what to do with this extra space (or less
- * space). The solution is to call, at the start of your rendering code, this method, which will check if the
- * terminal has been resized and in that case update the internals of the Screen. After this call finishes, the
- * screen's internal buffers will match the most recent size report from the underlying terminal.
- *
- * @return If the terminal has been resized since this method was last called, it will return the new size of the
- * terminal. If not, it will return null.
- */
- TerminalSize doResizeIfNecessary();
-
- /**
- * Scroll a range of lines of this Screen according to given distance.
- *
- * Screen implementations of this method do <b>not</b> throw IOException.
- */
- @Override
- void scrollLines(int firstLine, int lastLine, int distance);
-
- /**
- * This enum represents the different ways a Screen can refresh the screen, moving the back-buffer data into the
- * front-buffer that is being displayed.
- */
- enum RefreshType {
- /**
- * Using automatic mode, the Screen will make a guess at which refresh type would be the fastest and use this one.
- */
- AUTOMATIC,
- /**
- * In {@code RefreshType.DELTA} mode, the Screen will calculate a diff between the back-buffer and the
- * front-buffer, then figure out the set of terminal commands that is required to make the front-buffer exactly
- * like the back-buffer. This normally works well when you have modified only parts of the screen, but if you
- * have modified almost everything it will cause a lot of overhead and you should use
- * {@code RefreshType.COMPLETE} instead.
- */
- DELTA,
- /**
- * In {@code RefreshType.COMPLETE} mode, the screen will send a clear command to the terminal, then redraw the
- * whole back-buffer line by line. This is more expensive than {@code RefreshType.COMPLETE}, especially when you
- * have only touched smaller parts of the screen, but can be faster if you have modified most of the content,
- * as well as if you suspect the screen's internal front buffer is out-of-sync with what's really showing on the
- * terminal (you didn't go and call methods on the underlying Terminal while in screen mode, did you?)
- */
- COMPLETE,
- ;
- }
-}
git://git.nikiroo.be / jvcard.git / blobdiff