/*******************************************************************************
* 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.Batch;
import com.badlogic.gdx.graphics.g2d.BitmapFont;
import com.badlogic.gdx.graphics.g2d.BitmapFont.TextBounds;
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.ArraySelection;
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.scenes.scene2d.utils.ArraySelection;
import com.badlogic.gdx.utils.Array;
import com.badlogic.gdx.utils.ObjectSet;
/** 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
* @author Nathan Sweet */
public class List<T> extends Widget implements Cullable {
private ListStyle style;
private final Array<T> items = new Array();
private Rectangle cullingArea;
private float prefWidth, prefHeight;
private float itemHeight;
private float textOffsetX, textOffsetY;
final ArraySelection<T> selection;
public List (Skin skin) {
this(skin.get(ListStyle.class));
}
public List (Skin skin, String styleName) {
this(skin.get(styleName, ListStyle.class));
}
public List (ListStyle style) {
selection = new ArraySelection(items);
selection.setActor(this);
selection.setRequired(true);
setStyle(style);
setSize(getPrefWidth(), 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 (selection.isDisabled()) return false;
List.this.touchDown(y);
return true;
}
});
}
void touchDown (float y) {
if (items.size == 0) return;
float height = getHeight();
if (style.background != null) {
height -= style.background.getTopHeight() + style.background.getBottomHeight();
y -= style.background.getBottomHeight();
}
int index = (int)((height - y) / itemHeight);
index = Math.max(0, index);
index = Math.min(items.size - 1, index);
selection.choose(items.get(index));
}
public void setStyle (ListStyle style) {
if (style == null) throw new IllegalArgumentException("style cannot be null.");
this.style = style;
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;
}
public void layout () {
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.size; i++) {
TextBounds bounds = font.getBounds(items.get(i).toString());
prefWidth = Math.max(bounds.width, prefWidth);
}
prefWidth += selectedDrawable.getLeftWidth() + selectedDrawable.getRightWidth();
prefHeight = items.size * itemHeight;
Drawable background = style.background;
if (background != null) {
prefWidth += background.getLeftWidth() + background.getRightWidth();
prefHeight += background.getTopHeight() + background.getBottomHeight();
}
}
@Override
public void draw (Batch batch, float parentAlpha) {
validate();
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(), y = getY(), width = getWidth(), height = getHeight();
float itemY = height;
Drawable background = style.background;
if (background != null) {
background.draw(batch, x, y, width, height);
float leftWidth = background.getLeftWidth();
x += leftWidth;
itemY -= background.getTopHeight();
width -= leftWidth + background.getRightWidth();
}
font.setColor(fontColorUnselected.r, fontColorUnselected.g, fontColorUnselected.b, fontColorUnselected.a * parentAlpha);
for (int i = 0; i < items.size; i++) {
if (cullingArea == null || (itemY - itemHeight <= cullingArea.y + cullingArea.height && itemY >= cullingArea.y)) {
T item = items.get(i);
boolean selected = selection.contains(item);
if (selected) {
selectedDrawable.draw(batch, x, y + itemY - itemHeight, width, itemHeight);
font.setColor(fontColorSelected.r, fontColorSelected.g, fontColorSelected.b, fontColorSelected.a * parentAlpha);
}
font.draw(batch, item.toString(), x + textOffsetX, y + itemY - textOffsetY);
if (selected) {
font.setColor(fontColorUnselected.r, fontColorUnselected.g, fontColorUnselected.b, fontColorUnselected.a
* parentAlpha);
}
} else if (itemY < cullingArea.y) {
break;
}
itemY -= itemHeight;
}
}
public ArraySelection<T> getSelection () {
return selection;
}
/** Returns the first selected item, or null. */
public T getSelected () {
return selection.first();
}
/** @return The index of the first selected item. The top item has an index of 0. Nothing selected has an index of -1. */
public int getSelectedIndex () {
ObjectSet<T> selected = selection.items();
return selected.size == 0 ? -1 : items.indexOf(selected.first(), false);
}
/** Sets the selection to only the selected index. */
public void setSelectedIndex (int index) {
if (index < -1 || index >= items.size)
throw new IllegalArgumentException("index must be >= -1 and < " + items.size + ": " + index);
if (index == -1) {
selection.clear();
} else {
selection.set(items.get(index));
}
}
public void setItems (T... newItems) {
if (newItems == null) throw new IllegalArgumentException("newItems cannot be null.");
items.clear();
items.addAll(newItems);
if (selection.getRequired() && items.size > 0)
selection.set(items.first());
else
selection.clear();
invalidateHierarchy();
}
/** Sets the current items, clearing the selection if it is no longer valid. If a selection is
* {@link ArraySelection#getRequired()}, the first item is selected. */
public void setItems (Array newItems) {
if (newItems == null) throw new IllegalArgumentException("newItems cannot be null.");
items.clear();
items.addAll(newItems);
T selected = getSelected();
if (!items.contains(selected, false)) {
if (selection.getRequired() && items.size > 0)
selection.set(items.first());
else
selection.clear();
}
invalidateHierarchy();
}
public Array<T> getItems () {
return items;
}
public float getItemHeight () {
return itemHeight;
}
public float getPrefWidth () {
validate();
return prefWidth;
}
public float getPrefHeight () {
validate();
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;
/** Optional. */
public Drawable background;
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;
}
}
}