/*
* 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) 2010-2017 Martin Berglund
*/
package com.googlecode.lanterna.gui2;
import com.googlecode.lanterna.TerminalSize;
import com.googlecode.lanterna.graphics.ThemeDefinition;
import com.googlecode.lanterna.graphics.ThemeStyle;
import com.googlecode.lanterna.input.KeyStroke;
import com.googlecode.lanterna.input.KeyType;
import java.util.List;
import java.util.concurrent.CopyOnWriteArrayList;
/**
* The list box will display a number of items, of which one and only one can be marked as selected.
* The user can select an item in the list box by pressing the return key or space bar key. If you
* select one item when another item is already selected, the previously selected item will be
* deselected and the highlighted item will be the selected one instead.
* @author Martin
*/
public class RadioBoxList<V> extends AbstractListBox<V, RadioBoxList<V>> {
/**
* Listener interface that can be attached to the {@code RadioBoxList} in order to be notified on user actions
*/
public interface Listener {
/**
* Called by the {@code RadioBoxList} when the user changes which item is selected
* @param selectedIndex Index of the newly selected item, or -1 if the selection has been cleared (can only be
* done programmatically)
* @param previousSelection The index of the previously selected item which is now no longer selected, or -1 if
* nothing was previously selected
*/
void onSelectionChanged(int selectedIndex, int previousSelection);
}
private final List<Listener> listeners;
private int checkedIndex;
/**
* Creates a new RadioCheckBoxList with no items. The size of the {@code RadioBoxList} will be as big as is required
* to display all items.
*/
public RadioBoxList() {
this(null);
}
/**
* Creates a new RadioCheckBoxList with a specified size. If the items in the {@code RadioBoxList} cannot fit in the
* size specified, scrollbars will be used
* @param preferredSize Size of the {@code RadioBoxList} or {@code null} to have it try to be as big as necessary to
* be able to draw all items
*/
public RadioBoxList(TerminalSize preferredSize) {
super(preferredSize);
this.listeners = new CopyOnWriteArrayList<Listener>();
this.checkedIndex = -1;
}
@Override
protected ListItemRenderer<V,RadioBoxList<V>> createDefaultListItemRenderer() {
return new RadioBoxListItemRenderer<V>();
}
@Override
public synchronized Result handleKeyStroke(KeyStroke keyStroke) {
if(keyStroke.getKeyType() == KeyType.Enter ||
(keyStroke.getKeyType() == KeyType.Character && keyStroke.getCharacter() == ' ')) {
setCheckedIndex( getSelectedIndex() );
return Result.HANDLED;
}
return super.handleKeyStroke(keyStroke);
}
@Override
public synchronized V removeItem(int index) {
V item = super.removeItem(index);
if(index < checkedIndex) {
checkedIndex--;
}
while(checkedIndex >= getItemCount()) {
checkedIndex--;
}
return item;
}
@Override
public synchronized RadioBoxList<V> clearItems() {
setCheckedIndex(-1);
return super.clearItems();
}
/**
* This method will see if an object is the currently selected item in this RadioCheckBoxList
* @param object Object to test if it's the selected one
* @return {@code true} if the supplied object is what's currently selected in the list box,
* {@code false} otherwise. Returns null if the supplied object is not an item in the list box.
*/
public synchronized Boolean isChecked(V object) {
if(object == null)
return null;
if(indexOf(object) == -1)
return null;
return checkedIndex == indexOf(object);
}
/**
* This method will see if an item, addressed by index, is the currently selected item in this
* RadioCheckBoxList
* @param index Index of the item to check if it's currently selected
* @return {@code true} if the currently selected object is at the supplied index,
* {@code false} otherwise. Returns false if the index is out of range.
*/
@SuppressWarnings("SimplifiableIfStatement")
public synchronized boolean isChecked(int index) {
if(index < 0 || index >= getItemCount()) {
return false;
}
return checkedIndex == index;
}
/**
* Sets the currently checked item by the value itself. If null, the selection is cleared. When changing selection,
* any previously selected item is deselected.
* @param item Item to be checked
*/
public synchronized void setCheckedItem(V item) {
if(item == null) {
setCheckedIndex(-1);
}
else {
setCheckedItemIndex(indexOf(item));
}
}
/**
* Sets the currently selected item by index. If the index is out of range, it does nothing.
* @param index Index of the item to be selected
*/
public synchronized void setCheckedItemIndex(int index) {
if(index < -1 || index >= getItemCount())
return;
setCheckedIndex(index);
}
/**
* @return The index of the item which is currently selected, or -1 if there is no selection
*/
public int getCheckedItemIndex() {
return checkedIndex;
}
/**
* @return The object currently selected, or null if there is no selection
*/
public synchronized V getCheckedItem() {
if(checkedIndex == -1 || checkedIndex >= getItemCount())
return null;
return getItemAt(checkedIndex);
}
/**
* Un-checks the currently checked item (if any) and leaves the radio check box in a state where no item is checked.
*/
public synchronized void clearSelection() {
setCheckedIndex(-1);
}
/**
* Adds a new listener to the {@code RadioBoxList} that will be called on certain user actions
* @param listener Listener to attach to this {@code RadioBoxList}
* @return Itself
*/
public RadioBoxList<V> addListener(Listener listener) {
if(listener != null && !listeners.contains(listener)) {
listeners.add(listener);
}
return this;
}
/**
* Removes a listener from this {@code RadioBoxList} so that if it had been added earlier, it will no longer be
* called on user actions
* @param listener Listener to remove from this {@code RadioBoxList}
* @return Itself
*/
public RadioBoxList<V> removeListener(Listener listener) {
listeners.remove(listener);
return this;
}
private void setCheckedIndex(int index) {
final int previouslyChecked = checkedIndex;
this.checkedIndex = index;
invalidate();
runOnGUIThreadIfExistsOtherwiseRunDirect(new Runnable() {
@Override
public void run() {
for(Listener listener: listeners) {
listener.onSelectionChanged(checkedIndex, previouslyChecked);
}
}
});
}
/**
* Default renderer for this component which is used unless overridden. The selected state is drawn on the left side
* of the item label using a "< >" block filled with an "o" if the item is the selected one
* @param <V> Type of items in the {@link RadioBoxList}
*/
public static class RadioBoxListItemRenderer<V> extends ListItemRenderer<V,RadioBoxList<V>> {
@Override
public int getHotSpotPositionOnLine(int selectedIndex) {
return 1;
}
@Override
public String getLabel(RadioBoxList<V> listBox, int index, V item) {
String check = " ";
if(listBox.checkedIndex == index)
check = "o";
String text = (item != null ? item : "<null>").toString();
return "<" + check + "> " + text;
}
@Override
public void drawItem(TextGUIGraphics graphics, RadioBoxList<V> listBox, int index, V item, boolean selected, boolean focused) {
ThemeDefinition themeDefinition = listBox.getTheme().getDefinition(RadioBoxList.class);
ThemeStyle itemStyle;
if(selected && !focused) {
itemStyle = themeDefinition.getSelected();
}
else if(selected) {
itemStyle = themeDefinition.getActive();
}
else if(focused) {
itemStyle = themeDefinition.getInsensitive();
}
else {
itemStyle = themeDefinition.getNormal();
}
if(themeDefinition.getBooleanProperty("CLEAR_WITH_NORMAL", false)) {
graphics.applyThemeStyle(themeDefinition.getNormal());
graphics.fill(' ');
graphics.applyThemeStyle(itemStyle);
}
else {
graphics.applyThemeStyle(itemStyle);
graphics.fill(' ');
}
String brackets = themeDefinition.getCharacter("LEFT_BRACKET", '<') +
" " +
themeDefinition.getCharacter("RIGHT_BRACKET", '>');
if(themeDefinition.getBooleanProperty("FIXED_BRACKET_COLOR", false)) {
graphics.applyThemeStyle(themeDefinition.getPreLight());
graphics.putString(0, 0, brackets);
graphics.applyThemeStyle(itemStyle);
}
else {
graphics.putString(0, 0, brackets);
}
String text = (item != null ? item : "<null>").toString();
graphics.putString(4, 0, text);
boolean itemChecked = listBox.checkedIndex == index;
char marker = themeDefinition.getCharacter("MARKER", 'o');
if(themeDefinition.getBooleanProperty("MARKER_WITH_NORMAL", false)) {
graphics.applyThemeStyle(themeDefinition.getNormal());
}
if(selected && focused && themeDefinition.getBooleanProperty("HOTSPOT_PRELIGHT", false)) {
graphics.applyThemeStyle(themeDefinition.getPreLight());
}
graphics.setCharacter(1, 0, (itemChecked ? marker : ' '));
}
}
}