/*
* Copyright 2011 woozzu
*
* 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 net.cgt.weixin.view.widget;
import org.xbill.DNS.tests.primary;
import net.cgt.weixin.R;
import net.cgt.weixin.utils.L;
import net.cgt.weixin.utils.LogUtil;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.RectF;
import android.os.Handler;
import android.os.Message;
import android.os.SystemClock;
import android.view.MotionEvent;
import android.widget.Adapter;
import android.widget.ListView;
import android.widget.SectionIndexer;
/**
* 右侧的索引条
*
* @author lijian-pc
* @date 2014-11-26
*/
public class IndexScroller {
private static final String LOGTAG = LogUtil
.makeLogTag(IndexScroller.class);
private Context mContext;
/**
* 索引条宽度
**/
private float mIndexbarWidth;
/**
* 索引条外边距
**/
private float mIndexbarMargin;
/**
* 索引条内边距
**/
private float mPreviewPadding;
/**
* 密度
**/
private float mDensity;
/**
* 缩放密度
**/
private float mScaledDensity;
/**
* 透明度
**/
private float mAlphaRate;
/**
* 状态
**/
private int mState = STATE_HIDDEN;
/**
* ListView宽度
**/
private int mListViewWidth;
/**
* ListView高度
**/
private int mListViewHeight;
/**
* 当前部分
*/
private int mCurrentSection = -1;
/**
* 是否正在索引
*/
private boolean mIsIndexing = false;
/**
* 右侧索引文本色值
*/
private static final String COLOR_RIGHT_TEXT = "#565656";
/**
* 右侧索引背景色值
*/
private static final String COLOR_RIGHT_BACKGROUND = "#808080";// "#bfbfbf";
/**
* 中间预览文本色值
*/
private static final String COLOR_MIDDLE_TEXT = "#ffffff";
/**
* 中间预览背景色值
*/
private static final String COLOR_MIDDLE_BACKGROUND = "#000000";// "#808080";
private ListView mListView = null;
private SectionIndexer mIndexer = null;
private String[] mSections = null;
private RectF mIndexbarRect;
/** 4种状态（已隐藏） **/
private static final int STATE_HIDDEN = 0;
/** 4种状态（正在显示） **/
private static final int STATE_SHOWING = 1;
/** 4种状态（已显示） **/
private static final int STATE_SHOWN = 2;
/** 4种状态（正在隐藏） **/
private static final int STATE_HIDING = 3;
public IndexScroller(Context context, ListView lv) {
this.mContext = context;
mDensity = context.getResources().getDisplayMetrics().density;
mScaledDensity = context.getResources().getDisplayMetrics().scaledDensity;
mListView = lv;
setAdapter(mListView.getAdapter());
mIndexbarWidth = 25 * mDensity;
mIndexbarMargin = 0 * mDensity;
mPreviewPadding = 10 * mDensity;
}
public void draw(Canvas canvas) {
if (mSections != null && mSections.length > 0) {
onDrawRightIndexText(canvas);
}
if (mState == STATE_HIDDEN)
return;
onDrawRightIndexBackground(canvas);
if (mSections != null && mSections.length > 0) {
// Preview is shown when mCurrentSection is set
// 中间预览文本
if (mCurrentSection >= 0) {
onDrawMiddlePreview(canvas);
}
}
}
/**
* 绘制右侧索引条文本
*
* @param canvas
*/
private void onDrawRightIndexText(Canvas canvas) {
L.d(LOGTAG, "onDrawRightIndexText");
// 绘画右侧索引条的字母
Paint indexPaint = new Paint();
indexPaint.setColor(Color.parseColor(COLOR_RIGHT_TEXT));
// indexPaint.setAlpha((int) (255 * mAlphaRate));
indexPaint.setAntiAlias(true);
indexPaint.setTextSize(14 * mScaledDensity);
float sectionHeight = (mIndexbarRect.height() - 2 * mIndexbarMargin)
/ mSections.length;
float paddingTop = (sectionHeight - (indexPaint.descent() - indexPaint
.ascent())) / 2;
for (int i = 0; i < mSections.length; i++) {
float paddingLeft = (mIndexbarWidth - indexPaint
.measureText(mSections[i])) / 2;
canvas.drawText(mSections[i], mIndexbarRect.left + paddingLeft,
mIndexbarRect.top + mIndexbarMargin + sectionHeight * i
+ paddingTop - indexPaint.ascent(), indexPaint);
}
}
/**
* 绘制中间预览view
*
* @param canvas
*/
private void onDrawMiddlePreview(Canvas canvas) {
L.d(LOGTAG, "onDrawMiddlePreview");
Paint previewPaint = new Paint(); // 用来绘画预览文本背景的画笔
previewPaint.setColor(Color.parseColor(COLOR_MIDDLE_BACKGROUND));// 设置画笔颜色为黑色
previewPaint.setAlpha(96); // 设置透明度
previewPaint.setAntiAlias(true);// 设置抗锯齿
previewPaint.setShadowLayer(3, 0, 0, Color.argb(64, 0, 0, 0)); // 设置阴影层
Paint previewTextPaint = new Paint(); // 用来绘画预览字母的画笔
previewTextPaint.setColor(Color.parseColor(COLOR_MIDDLE_TEXT)); // 设置画笔为白色
previewTextPaint.setAntiAlias(true); // 设置抗锯齿
previewTextPaint.setTextSize(60 * mScaledDensity); // 设置字体大小
// 单个文本的宽度
float previewTextWidth = previewTextPaint
.measureText(mSections[mCurrentSection]);
float previewSize = 2 * mPreviewPadding + previewTextPaint.descent()
- previewTextPaint.ascent();
RectF previewRect = new RectF((mListViewWidth - previewSize) / 2,
(mListViewHeight - previewSize) / 2,
(mListViewWidth - previewSize) / 2 + previewSize,
(mListViewHeight - previewSize) / 2 + previewSize);
// 中间索引的那个框
canvas.drawRoundRect(previewRect, 5 * mDensity, 5 * mDensity,
previewPaint);
// 绘画索引字母
canvas.drawText(mSections[mCurrentSection], previewRect.left
+ (previewSize - previewTextWidth) / 2 - 1, previewRect.top
+ mPreviewPadding - previewTextPaint.ascent() + 1,
previewTextPaint);
}
/**
* 绘制右侧索引的背景
*
* @param canvas
*/
private void onDrawRightIndexBackground(Canvas canvas) {
L.d(LOGTAG, "onDrawRoundRectBackground");
// mAlphaRate determines the rate of opacity
Paint indexbarPaint = new Paint();
// indexbarPaint.setColor(Color.BLACK);
indexbarPaint.setColor(Color.parseColor(COLOR_RIGHT_BACKGROUND));
indexbarPaint.setAlpha((int) (64 * mAlphaRate));
indexbarPaint.setAntiAlias(true);
// 画右侧字母索引的圆矩形
// canvas.drawRoundRect(mIndexbarRect, 5 * mDensity, 5 * mDensity,
// indexbarPaint);
canvas.drawRect(mIndexbarRect, indexbarPaint);
}
public boolean onTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
// If down event occurs inside index bar region, start indexing
// 如果按下的事件发生在索引条区域内,开始索引
if (contains(ev.getX(), ev.getY())) {
setState(STATE_SHOWN);
// It demonstrates that the motion event started from index bar
mIsIndexing = true;
// Determine which section the point is in, and move the list to
// that section
mCurrentSection = getSectionByPoint(ev.getY());
// ListView.setSelection(int position）
// ListView.setSelectionFromTop(int position, int y);
// 其中
// position指的是指定的item的在ListView中的索引，注意如果有Header存在的情况下，索引是从Header就开始算的。
// y指的是到ListView可见范围内最上边边缘的距离。
mListView.setSelection(mIndexer
.getPositionForSection(mCurrentSection));
return true;
}
break;
case MotionEvent.ACTION_MOVE:
if (mIsIndexing) {
// If this event moves inside index bar
if (contains(ev.getX(), ev.getY())) {
// Determine which section the point is in, and move the
// list to that section
mCurrentSection = getSectionByPoint(ev.getY());
mListView.setSelection(mIndexer
.getPositionForSection(mCurrentSection));
}
return true;
}
break;
case MotionEvent.ACTION_UP:
if (mIsIndexing) {
mIsIndexing = false;
mCurrentSection = -1;
}
if (mState == STATE_SHOWN){
setState(STATE_HIDING);
return true;
}
break;
}
return false;
}
/**
* 创建索引条大小
*
* @param w
* @param h
* @param oldw
* @param oldh
*/
public void onSizeChanged(int w, int h, int oldw, int oldh) {
mListViewWidth = w;
mListViewHeight = h;
mIndexbarRect = new RectF(w - mIndexbarMargin - mIndexbarWidth,
mIndexbarMargin, w - mIndexbarMargin, h - mIndexbarMargin);
}
public void show() {
if (mState == STATE_HIDDEN)
setState(STATE_SHOWING);
else if (mState == STATE_HIDING)
setState(STATE_HIDING);
}
public void hide() {
if (mState == STATE_SHOWN)
setState(STATE_HIDING);
}
/**
* 设置右侧索引条数据
*
* @param adapter
*/
public void setAdapter(Adapter adapter) {
if (adapter instanceof SectionIndexer) {
mIndexer = (SectionIndexer) adapter;
mSections = (String[]) mIndexer.getSections();
}
}
/**
* 设置显隐状态
*
* @param state
*/
private void setState(int state) {
if (state < STATE_HIDDEN || state > STATE_HIDING)
return;
mState = state;
switch (mState) {
case STATE_HIDDEN:
// Cancel any fade effect
mHandler.removeMessages(0);
break;
case STATE_SHOWING:
// Start to fade in
mAlphaRate = 0;
fade(0);
break;
case STATE_SHOWN:
// Cancel any fade effect
mAlphaRate = 1;
mHandler.removeMessages(0);
break;
case STATE_HIDING:
// Start to fade out after three seconds
mAlphaRate = 1;
fade(3000);
break;
}
}
/**
* 检测触摸点是否在索引条区域内
*
* @param x
* @param y
* @return
*/
private boolean contains(float x, float y) {
// Determine if the point is in index bar region, which includes the
// right margin of the bar
return (x >= mIndexbarRect.left && y >= mIndexbarRect.top && y <= mIndexbarRect.top
+ mIndexbarRect.height());
}
/**
* 根据触摸点的y坐标获得区域
*
* @param y
* @return
*/
private int getSectionByPoint(float y) {
// 如果索引字母不存在,返回0
if (mSections == null || mSections.length == 0)
return 0;
// 如果在最顶部的索引字母之外,返回0
if (y < mIndexbarRect.top + mIndexbarMargin)
return 0;
// 如果在最底部的索引字母之外,返回最后一个索引字母角标
if (y >= mIndexbarRect.top + mIndexbarRect.height() - mIndexbarMargin)
return mSections.length - 1;
return (int) ((y - mIndexbarRect.top - mIndexbarMargin) / ((mIndexbarRect
.height() - 2 * mIndexbarMargin) / mSections.length));
}
/**
* 设置多久后隐藏
*
* @param delay
*/
private void fade(long delay) {
mHandler.removeMessages(0);
mHandler.sendEmptyMessageAtTime(0, SystemClock.uptimeMillis() + delay);
}
private Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
super.handleMessage(msg);
switch (mState) {
case STATE_SHOWING:
// Fade in effect
mAlphaRate += (1 - mAlphaRate) * 0.2;
if (mAlphaRate > 0.9) {
mAlphaRate = 1;
setState(STATE_SHOWN);
}
mListView.invalidate();
fade(10);
break;
case STATE_SHOWN:
// If no action, hide automatically
setState(STATE_HIDING);
break;
case STATE_HIDING:
// Fade out effect
mAlphaRate -= mAlphaRate * 0.2;
if (mAlphaRate < 0.1) {
mAlphaRate = 0;
setState(STATE_HIDDEN);
}
mListView.invalidate();
fade(10);
break;
}
}
};
}
