SegmentBar.java

package com.itap.voiceemoticon.widget;

import com.itap.voiceemoticon.R;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Align;
import android.graphics.Paint.Style;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.drawable.ColorDrawable;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.view.WindowManager;
import android.widget.Adapter;
import android.widget.HeaderViewListAdapter;
import android.widget.ListView;
import android.widget.SectionIndexer;
import android.widget.TextView;

public class SegmentBar extends View {
    private char[] mCharArr = {
            'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',
            'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '?'
    };

    private SectionIndexer mSectionIndexter = null;

    private TextView mDialogText;

    private ListView mListView;

    private Bitmap mbitmap;

    private int mType = 1;

    private int mColor = 0xff858c94;

    private int mBgColor = 0xFFDDDDDD;

    private int mCurrentSelectIndex = -1;

    private int mLastSelectIndex = -1;

    private WindowManager mWindowManager = null;

    public SegmentBar(Context context) {
        super(context);
        init();
    }

    public void setCurrentSection(char setctionLetter) {
        setctionLetter = Character.toUpperCase(setctionLetter);
        for (int i = 0, len = mCharArr.length; i < len; i++) {
            if (setctionLetter == mCharArr[i]) {
                mCurrentSelectIndex = i;
                postInvalidate();
                break;
            }
        }
    }

    public SegmentBar(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public SegmentBar(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        init();
    }

    public void setListView(ListView listView) {
        mListView = listView;
        Adapter adapter = listView.getAdapter();
        try {
            if (adapter instanceof SectionIndexer) {
                mSectionIndexter = (SectionIndexer)adapter;
            } else {
                adapter = ((HeaderViewListAdapter)adapter).getWrappedAdapter();
                mSectionIndexter = (SectionIndexer)adapter;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    private WindowManager.LayoutParams lp = new WindowManager.LayoutParams(
            WindowManager.LayoutParams.TYPE_APPLICATION,
            WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE
                    | WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE, PixelFormat.TRANSLUCENT);

    private void init() {
        mbitmap = BitmapFactory.decodeResource(getResources(), android.R.drawable.ic_menu_search);
        mWindowManager = (WindowManager)getContext().getSystemService(Context.WINDOW_SERVICE);
        
        // Window LayoutParams
        int size = getResources().getDimensionPixelSize(R.dimen.tp_section_indexer_tip_size);
        lp.width = size;
        lp.height = size;
        
        // Dialog Text
        createDialogText();
    }
    
    @Override
    protected void onAttachedToWindow() {
        super.onAttachedToWindow();
        System.out.println("onAttachedToWindow");
        mWindowManager.addView(mDialogText, lp);
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        System.out.println("onDetachedFromWindow");
        removeDialogText();
    }

    private void createDialogText() {
        if (null != mDialogText ) {
            return;
        }
        mDialogText = new TextView(getContext());
        mDialogText.setTextColor(Color.WHITE);
        mDialogText.setGravity(Gravity.CENTER);
        mDialogText.setVisibility(View.INVISIBLE);
        int textSize = getResources().getDimensionPixelSize(
                R.dimen.tp_section_indexer_tip_text_size);
        mDialogText.setTextSize(textSize);
        mDialogText.setBackgroundResource(R.drawable.chatfrom_bg_voiceforward_pressed);
        
    }
    
    private void removeDialogText() {
        if (mDialogText.getParent() != null) {
            mWindowManager.removeView(mDialogText);
        }
    }

    public void setTextView(TextView mDialogText) {
        this.mDialogText = mDialogText;
    }

    public boolean onTouchEvent(MotionEvent event) {
        super.onTouchEvent(event);

        int eventY = (int)event.getY();

        int idx = eventY / (getMeasuredHeight() / mCharArr.length);

        if (idx >= mCharArr.length) {
            idx = mCharArr.length - 1;

        } else if (idx < 0) {
            idx = 0;
        }

        mLastSelectIndex = mCurrentSelectIndex;
        mCurrentSelectIndex = idx;

        if (event.getAction() == MotionEvent.ACTION_DOWN
                || event.getAction() == MotionEvent.ACTION_MOVE) {
            setBackgroundColor(0xFFFFFFFF);
            if (mSectionIndexter == null) {
                mSectionIndexter = (SectionIndexer)mListView.getAdapter();
            }

            int position = mSectionIndexter.getPositionForSection(mCharArr[idx]);
            if (position == -1) {

                return true;
            } else {
                mDialogText.setVisibility(View.VISIBLE);
                mDialogText.setText(String.valueOf(mCharArr[idx]));
            }
            mListView.setSelection(position);
        } else {
            mDialogText.setVisibility(View.INVISIBLE);

        }
        if (event.getAction() == MotionEvent.ACTION_UP) {
            if (mLastSelectIndex != mCurrentSelectIndex) {
                this.invalidate();
            }
            setBackgroundDrawable(new ColorDrawable(0x00000000));
        }
        return true;
    }

    public float getFontHeight(Paint paint) {
        Rect bounds = new Rect();
        paint.getTextBounds("A", 0, 1, bounds);
        return bounds.height();
    }

    protected void onDraw(Canvas canvas) {
        Paint paint = new Paint();
        paint.setColor(mColor);
        paint.setTextAlign(Align.CENTER);

        final int width = getMeasuredWidth();
        int x = width / 2;
        int y = 0;
        int textBaseLine = y;

        if (mCharArr.length > 0) {
            float height = getMeasuredHeight() / (mCharArr.length);
            paint.setTextSize(height - 2);
            float fontHeight = getFontHeight(paint);

            for (int i = 0; i < mCharArr.length; i++) {
                y = (int)(i * height);
                textBaseLine = (int)(y + height);
                if (mCurrentSelectIndex == i) {
                    Rect rect = new Rect();
                    rect.set(0, y, 0 + width, y + (int)height);
                    Paint bgPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
                    bgPaint.setColor(mBgColor);
                    bgPaint.setStyle(Style.FILL);
                    canvas.drawRect(rect, bgPaint);
                }
                canvas.drawText(String.valueOf(mCharArr[i]), x, textBaseLine
                        - ((height - fontHeight) / 2), paint);
            }
        }
        super.onDraw(canvas);
    }
    
}