自定义tab bar控件 学习资料

http://blog.csdn.net/zoeice/article/details/8068671

import java.util.Vector;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.NinePatch;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.DisplayMetrics;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.PopupWindow;

import com.example.zoeicetabgroup.R;

/**
 * custom tab bar
 * @author zoeice
 *
 */
public class LPTabGroupWithGesture extends View implements OnGestureListener, OnTouchListener{
    private int tabNum = 0;
    private int curSelect = 0;
    private int curX = 0;
    private int savedClickIndex = -1;
    private int savedX = 0;

    private boolean isDraging = false;
    private int dragCurrentX = 0;
    private int dragSavedX = 0;
    private int dragSelectIndex = -1;

    private final int TEXT_SIZE = 30;
    private final int TAB_MARGIN = 30;

    private int tabWidth = 200;
    private int tabHeight = 0;
    private int tabGap = 30;// IF
    private int tabAddWidth = 90;// IF

    private Bitmap bitCur;
    private NinePatch npCur;
    private Bitmap bitNor;
    private NinePatch npNor;
    private Bitmap bitAdd;

    private int screenWidth;
    private int screenHeight;
    private float screenDensity;

    private PopupWindow popMenu;

    private OnTabItemClickListener clickListener;

    private GestureDetector mGestureDetector;

    private Vector<TabItem> tabLists = new Vector<TabItem>();

    public LPTabGroupWithGesture(Context context, Vector<TabItem> vec) {
        this(context);
        tabLists = vec;
        tabNum = vec.size();
    }

    public LPTabGroupWithGesture(Context context) {
        super(context);
        if(tabNum == 0){
            tabNum = 1;
            tabLists.add(new TabItem());
        }

        initParams(context);
    }

    /**
     * init view's params
     */
    private void initParams(Context context){
        this.setLongClickable(true);
        this.setOnTouchListener(this);
        mGestureDetector = new GestureDetector(context, this);
        mGestureDetector.setIsLongpressEnabled(true);

        DisplayMetrics displayMetrics = getResources().getDisplayMetrics();
        screenWidth = displayMetrics.widthPixels;
        screenHeight = displayMetrics.heightPixels;
        screenDensity = displayMetrics.density;

        bitCur = BitmapFactory.decodeResource(getResources(),
                R.drawable.tab);
        npCur = new NinePatch(bitCur, bitCur.getNinePatchChunk(), null);
        tabHeight = bitCur.getHeight();

        bitNor = BitmapFactory.decodeResource(getResources(),
                R.drawable.tab);
        npNor = new NinePatch(bitNor, bitNor.getNinePatchChunk(), null);
        bitAdd = BitmapFactory.decodeResource(getResources(),
                R.drawable.tab_add);
        tabAddWidth = bitAdd.getWidth();

    }

    /**设置当前选中选项的位置*/
    public void setCurrentSelect(int index) {
        curSelect = index;
        invalidate();
    }

     /**
      * @see android.view.View#measure(int, int)
      */
     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
      setMeasuredDimension(screenWidth, tabHeight);
     }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint paint = new Paint();
        paint.setColor(0xff707070);
        paint.setTextSize(TEXT_SIZE);
        /*draw bg*/
        canvas.drawARGB(0xff, 0xa1, 0x9c, 0xff);

        if(isDraging){
            int dX = dragCurrentX +  (tabWidth - tabGap) * curSelect;

            /*draw normal tab*/
            for (int i = tabNum - 1; i >= 0; i--) {
                if (i != curSelect) {
                    int nX = curX + (tabWidth - tabGap) * i ;
                    if(i > savedClickIndex && savedClickIndex > -1){
                        nX -= tabWidth - tabGap;
                    }
                    if(i > dragSelectIndex && dragSelectIndex > -1){
                        nX += tabWidth - tabGap;
                    }
                    Rect nR = new Rect(nX, 0, nX + tabWidth, tabHeight);
                    npNor.draw(canvas, nR);

                    //draw text
                    canvas.save();
                    canvas.clipRect(new Rect(nX + TAB_MARGIN, 0, nX + tabWidth - TAB_MARGIN, tabHeight));
                    canvas.drawText(tabLists.get(i).name, nX + TAB_MARGIN, (tabHeight + TEXT_SIZE) >> 1, paint);
                    canvas.restore();
                }
            }
            /*draw shape for above normal tab*/
            canvas.drawARGB(0x50, 0x00, 0x00, 0x00);
            /*draw buttom line*/
            Paint paintShape = new Paint();
            paintShape.setColor(0x50000000);
            canvas.drawRect(0, tabHeight - 2, screenWidth, tabHeight, paintShape);

            /*draw current selected tab*/
            Rect dR = new Rect(dX, 0, dX + tabWidth, tabHeight);
            npCur.draw(canvas, dR);

            //draw current text
            paint.setColor(0xff456789);
            canvas.drawText(tabLists.get(curSelect).name, dX + tabGap, (tabHeight + TEXT_SIZE) >> 1, paint);

            /*draw add button*/
            int aX =  curX + (tabWidth - tabGap) * tabNum;
            if(dX + tabWidth > aX)
                canvas.drawBitmap(bitAdd, dX + tabWidth - tabGap, 0, paint);
            else
                canvas.drawBitmap(bitAdd, aX, 0, paint);
        }else{
            /*draw normal tab*/
            for (int i = tabNum - 1; i >= 0; i--) {
                if (i != curSelect) {
                    int nX = curX + (tabWidth - tabGap) * i ;
                    Rect nR = new Rect(nX, 0, nX + tabWidth, tabHeight);
                    npNor.draw(canvas, nR);

                    //draw text
                    canvas.save();
                    canvas.clipRect(new Rect(nX + TAB_MARGIN, 0, nX + tabWidth - TAB_MARGIN, tabHeight));
                    canvas.drawText(tabLists.get(i).name, nX + TAB_MARGIN, (tabHeight + TEXT_SIZE) >> 1, paint);
                    canvas.restore();
                }
            }
            /*draw shape for above normal tab*/
            canvas.drawARGB(0x50, 0x00, 0x00, 0x00);
            /*draw buttom line*/
            Paint paintShape = new Paint();
            paintShape.setColor(0x50000000);
            canvas.drawRect(0, tabHeight - 2, screenWidth, tabHeight, paintShape);

            /*draw current selected tab*/
            int cX = curX +  (tabWidth - tabGap) * curSelect;
            Rect cR = new Rect(cX, 0, cX + tabWidth, tabHeight);
            npCur.draw(canvas, cR);

            //draw current text
            paint.setColor(0xff456789);
            canvas.drawText(tabLists.get(curSelect).name, cX + tabGap, (tabHeight + TEXT_SIZE) >> 1, paint);

            /*draw add button*/
            canvas.drawBitmap(bitAdd, curX + (tabWidth - tabGap) * tabNum, 0, paint);
        }

    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
           if (mGestureDetector.onTouchEvent(event)) {
               return true;
           }

           if(event.getAction() == MotionEvent.ACTION_UP) {
               if(isDraging ) {
                   if(dragSelectIndex != curSelect){
                       if(dragSelectIndex >= tabNum){
                           dragSelectIndex = tabNum - 1;
                       }
                       TabItem tempItem = tabLists.elementAt(curSelect);
                       tabLists.removeElementAt(curSelect);
                       tabLists.add(dragSelectIndex, tempItem);
                   }

                   float x = event.getX();
                   curSelect = (int) ((x - curX) / (tabWidth - tabGap));
                   if(curSelect >= tabNum){
                       curSelect = tabNum - 1;
                   }

                   isDraging  = false;
                   dragSelectIndex = -1;
                   dragCurrentX = 0;
                   dragSavedX = 0;

                   invalidate();
               }
           }

           return false;
    }

    /**选项点击事件设置*/
    public void setOnTabItemClickListener(OnTabItemClickListener click) {
        this.clickListener = click;
    }

    /**选项点击事件接口*/
    public interface OnTabItemClickListener {
        public void onclickListenr(int index);
    }

    @Override
    public boolean onDown(MotionEvent event) {
        float x = event.getX();
        savedClickIndex = (int) ((x - curX) / (tabWidth - tabGap));
        if(savedClickIndex == curSelect){
            isDraging = true;
            dragSavedX = savedX;
            clickListener.onclickListenr(savedClickIndex);
        }
        return false;
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
            float velocityY) {
           if(isDraging ) {
               if(dragSelectIndex != curSelect){
                   if(dragSelectIndex >= tabNum){
                       dragSelectIndex = tabNum - 1;
                   }
                   TabItem tempItem = tabLists.elementAt(curSelect);
                   tabLists.removeElementAt(curSelect);
                   tabLists.add(dragSelectIndex, tempItem);
               }

               float x = e2.getX();
               curSelect = (int) ((x - curX) / (tabWidth - tabGap));
               if(curSelect >= tabNum){
                   curSelect = tabNum - 1;
               }

               isDraging  = false;
               dragSelectIndex = -1;
               dragCurrentX = 0;
               dragSavedX = 0;

               invalidate();
           }
        return true;
    }

    @Override
    public void onLongPress(MotionEvent event) {
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2,
            float distanceX, float distanceY) {
        int tempWidth = (tabWidth - tabGap) * tabNum + tabAddWidth;
        if(isDraging){
            //drag
            int nextX = (int) (dragSavedX + e2.getX() - e1.getX());

            dragSelectIndex = (int) ((e2.getX() - curX) / (tabWidth - tabGap));

            dragCurrentX = nextX;


            invalidate();
        }else{
            //move
            int nextX = (int) (savedX - distanceX);
            if(tempWidth > screenWidth && (nextX <=0  && nextX + tempWidth >= screenWidth)){
                curX = nextX;
                savedX = curX;
                invalidate();
            }
        }

        return false;
    }

    @Override
    public void onShowPress(MotionEvent event) {
    }

    @Override
    public boolean onSingleTapUp(MotionEvent event) {
        float x = event.getX();
        int curClickIndex = (int) ((x - curX) / (tabWidth - tabGap));
        if(savedClickIndex == curClickIndex){
            if(curClickIndex < tabNum){
                setCurrentSelect(curClickIndex);
                clickListener.onclickListenr(curClickIndex);
            }else if(curClickIndex == tabNum){
                tabLists.add(new TabItem());
                tabNum++;
                curX = screenWidth - tabAddWidth - (tabWidth - tabGap) * tabNum;
                setCurrentSelect(tabNum - 1);
                clickListener.onclickListenr(curClickIndex);
                invalidate();
            }
        }
        savedClickIndex = -1;
        savedX = curX;
        return false;
    }

}

tabItem类：

public class TabItem{
    public int index;
    public String name = "New T