/*
|
* 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 com.lcjian.library.widget;
|
|
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.util.AttributeSet;
|
import android.view.GestureDetector;
|
import android.view.MotionEvent;
|
import android.widget.Adapter;
|
import android.widget.ListAdapter;
|
import android.widget.ListView;
|
import android.widget.SectionIndexer;
|
|
public class IndexableListView extends ListView {
|
|
private boolean mIsFastScrollEnabled = false;
|
private IndexScroller mScroller = null;
|
private GestureDetector mGestureDetector = null;
|
|
public IndexableListView(Context context) {
|
super(context);
|
}
|
|
public IndexableListView(Context context, AttributeSet attrs) {
|
super(context, attrs);
|
}
|
|
public IndexableListView(Context context, AttributeSet attrs, int defStyle) {
|
super(context, attrs, defStyle);
|
}
|
|
@Override
|
public boolean isFastScrollEnabled() {
|
return mIsFastScrollEnabled;
|
}
|
|
@Override
|
public void setFastScrollEnabled(boolean enabled) {
|
mIsFastScrollEnabled = enabled;
|
if (mIsFastScrollEnabled) {
|
if (mScroller == null)
|
mScroller = new IndexScroller(getContext(), this);
|
} else {
|
if (mScroller != null) {
|
mScroller.hide();
|
mScroller = null;
|
}
|
}
|
}
|
|
@Override
|
public void draw(Canvas canvas) {
|
super.draw(canvas);
|
|
// Overlay index bar
|
if (mScroller != null)
|
mScroller.draw(canvas);
|
}
|
|
@Override
|
public boolean onTouchEvent(MotionEvent ev) {
|
// Intercept ListView's touch event
|
if (mScroller != null && mScroller.onTouchEvent(ev))
|
return true;
|
|
if (mGestureDetector == null) {
|
mGestureDetector = new GestureDetector(getContext(), new GestureDetector.SimpleOnGestureListener() {
|
|
@Override
|
public boolean onFling(MotionEvent e1, MotionEvent e2,
|
float velocityX, float velocityY) {
|
// If fling happens, index bar shows
|
if (mScroller != null) {
|
mScroller.show();
|
}
|
return super.onFling(e1, e2, velocityX, velocityY);
|
}
|
});
|
}
|
mGestureDetector.onTouchEvent(ev);
|
|
return super.onTouchEvent(ev);
|
}
|
|
@Override
|
public boolean onInterceptTouchEvent(MotionEvent ev) {
|
return true;
|
}
|
|
@Override
|
public void setAdapter(ListAdapter adapter) {
|
super.setAdapter(adapter);
|
if (mScroller != null)
|
mScroller.setAdapter(adapter);
|
}
|
|
@Override
|
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
|
super.onSizeChanged(w, h, oldw, oldh);
|
if (mScroller != null)
|
mScroller.onSizeChanged(w, h, oldw, oldh);
|
}
|
|
public static class IndexScroller {
|
|
private float mIndexbarWidth;
|
private float mIndexbarMargin;
|
private float mPreviewPadding;
|
private float mDensity;
|
private float mScaledDensity;
|
private float mAlphaRate;
|
private int mState = STATE_HIDDEN;
|
private int mListViewWidth;
|
private int mListViewHeight;
|
private int mCurrentSection = -1;
|
private boolean mIsIndexing = false;
|
private ListView mListView = null;
|
private SectionIndexer mIndexer = null;
|
private String[] mSections = null;
|
private RectF mIndexbarRect;
|
|
private static final int STATE_HIDDEN = 0;
|
private static final int STATE_SHOWING = 1;
|
private static final int STATE_SHOWN = 2;
|
private static final int STATE_HIDING = 3;
|
|
public IndexScroller(Context context, ListView lv) {
|
mDensity = context.getResources().getDisplayMetrics().density;
|
mScaledDensity = context.getResources().getDisplayMetrics().scaledDensity;
|
mListView = lv;
|
setAdapter(mListView.getAdapter());
|
|
mIndexbarWidth = 20 * mDensity;
|
mIndexbarMargin = 10 * mDensity;
|
mPreviewPadding = 5 * mDensity;
|
}
|
|
public void draw(Canvas canvas) {
|
if (mState == STATE_HIDDEN)
|
return;
|
|
// mAlphaRate determines the rate of opacity
|
Paint indexbarPaint = new Paint();
|
indexbarPaint.setColor(Color.BLACK);
|
indexbarPaint.setAlpha((int) (64 * mAlphaRate));
|
indexbarPaint.setAntiAlias(true);
|
canvas.drawRoundRect(mIndexbarRect, 5 * mDensity, 5 * mDensity, indexbarPaint);
|
|
if (mSections != null && mSections.length > 0) {
|
// Preview is shown when mCurrentSection is set
|
if (mCurrentSection >= 0) {
|
Paint previewPaint = new Paint();
|
previewPaint.setColor(Color.BLACK);
|
previewPaint.setAlpha(96);
|
previewPaint.setAntiAlias(true);
|
previewPaint.setShadowLayer(3, 0, 0, Color.argb(64, 0, 0, 0));
|
|
Paint previewTextPaint = new Paint();
|
previewTextPaint.setColor(Color.WHITE);
|
previewTextPaint.setAntiAlias(true);
|
previewTextPaint.setTextSize(50 * mScaledDensity);
|
|
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);
|
|
canvas.drawRoundRect(previewRect, 5 * mDensity, 5 * mDensity, previewPaint);
|
canvas.drawText(mSections[mCurrentSection], previewRect.left + (previewSize - previewTextWidth) / 2 - 1
|
, previewRect.top + mPreviewPadding - previewTextPaint.ascent() + 1, previewTextPaint);
|
}
|
|
Paint indexPaint = new Paint();
|
indexPaint.setColor(Color.WHITE);
|
indexPaint.setAlpha((int) (255 * mAlphaRate));
|
indexPaint.setAntiAlias(true);
|
indexPaint.setTextSize(12 * 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);
|
}
|
}
|
}
|
|
public boolean onTouchEvent(MotionEvent ev) {
|
switch (ev.getAction()) {
|
case MotionEvent.ACTION_DOWN:
|
// If down event occurs inside index bar region, start indexing
|
if (mState != STATE_HIDDEN && 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());
|
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);
|
break;
|
}
|
return false;
|
}
|
|
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);
|
}
|
|
public void setAdapter(Adapter adapter) {
|
if (adapter instanceof SectionIndexer) {
|
mIndexer = (SectionIndexer) adapter;
|
mSections = (String[]) mIndexer.getSections();
|
}
|
}
|
|
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
|
mHandler.removeMessages(0);
|
break;
|
case STATE_HIDING:
|
// Start to fade out after three seconds
|
mAlphaRate = 1;
|
fade(3000);
|
break;
|
}
|
}
|
|
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());
|
}
|
|
private int getSectionByPoint(float y) {
|
if (mSections == null || mSections.length == 0)
|
return 0;
|
if (y < mIndexbarRect.top + mIndexbarMargin)
|
return 0;
|
if (y >= mIndexbarRect.top + mIndexbarRect.height() - mIndexbarMargin)
|
return mSections.length - 1;
|
return (int) ((y - mIndexbarRect.top - mIndexbarMargin) / ((mIndexbarRect.height() - 2 * mIndexbarMargin) / mSections.length));
|
}
|
|
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;
|
}
|
}
|
|
};
|
}
|
}
|
