/*******************************************************************************
* Copyright 2011 See AUTHORS file.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package com.badlogic.gdx.scenes.scene2d.ui;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.g2d.BitmapFont.TextBounds;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.Rectangle;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.InputListener;
import com.badlogic.gdx.scenes.scene2d.utils.ChangeListener.ChangeEvent;
import com.badlogic.gdx.scenes.scene2d.utils.Cullable;
import com.badlogic.gdx.scenes.scene2d.utils.Drawable;
import com.badlogic.gdx.utils.GdxRuntimeException;
import com.badlogic.gdx.utils.Pools;
/** A list (aka list box) displays textual items and highlights the currently selected item.
* <p>
* {@link ChangeEvent} is fired when the list selection changes.
* <p>
* The preferred size of the list is determined by the text bounds of the items and the size of the {@link ListStyle#selection}.
* @author mzechner */
public class List extends Widget implements Cullable {
private ListStyle style;
private String[] items;
private int selectedIndex;
private Rectangle cullingArea;
private float prefWidth, prefHeight;
private float itemHeight;
private float textOffsetX, textOffsetY;
private boolean selectable = true;
public List (Object[] items, Skin skin) {
this(items, skin.get(ListStyle.class));
}
public List (Object[] items, Skin skin, String styleName) {
this(items, skin.get(styleName, ListStyle.class));
}
public List (Object[] items, ListStyle style) {
setStyle(style);
setItems(items);
setWidth(getPrefWidth());
setHeight(getPrefHeight());
addListener(new InputListener() {
public boolean touchDown (InputEvent event, float x, float y, int pointer, int button) {
if (pointer == 0 && button != 0) return false;
if (!isSelectable()) return false; // don't eat touch event when NOT selectable
List.this.touchDown(y);
return true;
}
});
}
/** Sets whether this List's items are selectable. If not selectable, touch events will not be consumed. */
public void setSelectable (boolean selectable) {
this.selectable = selectable;
}
/** @return True if items are selectable. */
public boolean isSelectable () {
return selectable;
}
void touchDown (float y) {
int oldIndex = selectedIndex;
selectedIndex = (int)((getHeight() - y) / itemHeight);
selectedIndex = Math.max(0, selectedIndex);
selectedIndex = Math.min(items.length - 1, selectedIndex);
if (oldIndex != selectedIndex) {
ChangeEvent changeEvent = Pools.obtain(ChangeEvent.class);
if (fire(changeEvent)) selectedIndex = oldIndex;
Pools.free(changeEvent);
}
}
public void setStyle (ListStyle style) {
if (style == null) throw new IllegalArgumentException("style cannot be null.");
this.style = style;
if (items != null)
setItems(items);
else
invalidateHierarchy();
}
/** Returns the list's style. Modifying the returned style may not have an effect until {@link #setStyle(ListStyle)} is called. */
public ListStyle getStyle () {
return style;
}
@Override
public void draw (SpriteBatch batch, float parentAlpha) {
BitmapFont font = style.font;
Drawable selectedDrawable = style.selection;
Color fontColorSelected = style.fontColorSelected;
Color fontColorUnselected = style.fontColorUnselected;
Color color = getColor();
batch.setColor(color.r, color.g, color.b, color.a * parentAlpha);
float x = getX();
float y = getY();
font.setColor(fontColorUnselected.r, fontColorUnselected.g, fontColorUnselected.b, fontColorUnselected.a * parentAlpha);
float itemY = getHeight();
for (int i = 0; i < items.length; i++) {
if (cullingArea == null || (itemY - itemHeight <= cullingArea.y + cullingArea.height && itemY >= cullingArea.y)) {
if (selectedIndex == i) {
selectedDrawable.draw(batch, x, y + itemY - itemHeight, getWidth(), itemHeight);
font.setColor(fontColorSelected.r, fontColorSelected.g, fontColorSelected.b, fontColorSelected.a * parentAlpha);
}
font.draw(batch, items[i], x + textOffsetX, y + itemY - textOffsetY);
if (selectedIndex == i) {
font.setColor(fontColorUnselected.r, fontColorUnselected.g, fontColorUnselected.b, fontColorUnselected.a
* parentAlpha);
}
} else if (itemY < cullingArea.y) {
break;
}
itemY -= itemHeight;
}
}
/** @return The index of the currently selected item. The top item has an index of 0. Nothing selected has an index of -1. */
public int getSelectedIndex () {
return selectedIndex;
}
/** @param index Set to -1 for nothing selected. */
public void setSelectedIndex (int index) {
if (index < -1 || index >= items.length)
throw new GdxRuntimeException("index must be >= -1 and < " + items.length + ": " + index);
selectedIndex = index;
}
/** @return The text of the currently selected item, or null if the list is empty or nothing is selected. */
public String getSelection () {
if (items.length == 0 || selectedIndex == -1) return null;
return items[selectedIndex];
}
/** Sets the selection to the item if found, else sets the selection to nothing.
* @return The new selected index. */
public int setSelection (String item) {
selectedIndex = -1;
for (int i = 0, n = items.length; i < n; i++) {
if (items[i].equals(item)) {
selectedIndex = i;
break;
}
}
return selectedIndex;
}
public void setItems (Object[] objects) {
if (objects == null) throw new IllegalArgumentException("items cannot be null.");
if (!(objects instanceof String[])) {
String[] strings = new String[objects.length];
for (int i = 0, n = objects.length; i < n; i++)
strings[i] = String.valueOf(objects[i]);
items = strings;
} else
items = (String[])objects;
selectedIndex = 0;
final BitmapFont font = style.font;
final Drawable selectedDrawable = style.selection;
itemHeight = font.getCapHeight() - font.getDescent() * 2;
itemHeight += selectedDrawable.getTopHeight() + selectedDrawable.getBottomHeight();
textOffsetX = selectedDrawable.getLeftWidth();
textOffsetY = selectedDrawable.getTopHeight() - font.getDescent();
prefWidth = 0;
for (int i = 0; i < items.length; i++) {
TextBounds bounds = font.getBounds(items[i]);
prefWidth = Math.max(bounds.width, prefWidth);
}
prefWidth += selectedDrawable.getLeftWidth() + selectedDrawable.getRightWidth();
prefHeight = items.length * itemHeight;
invalidateHierarchy();
}
public String[] getItems () {
return items;
}
public float getItemHeight () {
return itemHeight;
}
public float getPrefWidth () {
return prefWidth;
}
public float getPrefHeight () {
return prefHeight;
}
public void setCullingArea (Rectangle cullingArea) {
this.cullingArea = cullingArea;
}
/** The style for a list, see {@link List}.
* @author mzechner
* @author Nathan Sweet */
static public class ListStyle {
public BitmapFont font;
public Color fontColorSelected = new Color(1, 1, 1, 1);
public Color fontColorUnselected = new Color(1, 1, 1, 1);
public Drawable selection;
public ListStyle () {
}
public ListStyle (BitmapFont font, Color fontColorSelected, Color fontColorUnselected, Drawable selection) {
this.font = font;
this.fontColorSelected.set(fontColorSelected);
this.fontColorUnselected.set(fontColorUnselected);
this.selection = selection;
}
public ListStyle (ListStyle style) {
this.font = style.font;
this.fontColorSelected.set(style.fontColorSelected);
this.fontColorUnselected.set(style.fontColorUnselected);
this.selection = style.selection;
}
}
}