Android: индикатор вкладки в виде пейджера

Question

Я делаю приложение, и мне нужно реализовать «sweepy tabs». Я прочитал this, но не нашел ничего подходящего. Я также пробовал ViewPagerIndicator.

Ниже приведен мой фрагмент кода:

public class ViewPagerIndicatorActivity extends FragmentActivity { 
PagerAdapter mPagerAdapter; 
ViewPager mViewPager; 
ViewPagerIndicator mIndicator; 
static ArrayList<String> readableDateFormat; 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 

    // Create our custom adapter to supply pages to the viewpager. 
    mPagerAdapter = new PagerAdapter(getSupportFragmentManager()); 
    mViewPager = (ViewPager)findViewById(R.id.pager); 
    mViewPager.setAdapter(mPagerAdapter); 

    // Start at a custom position 
    mViewPager.setCurrentItem(3); 

    // Find the indicator from the layout 
    mIndicator = (ViewPagerIndicator)findViewById(R.id.indicator); 

    // Set the indicator as the pageChangeListener 
    mViewPager.setOnPageChangeListener(mIndicator); 

    // Initialize the indicator. We need some information here: 
    // * What page do we start on. 
    // * How many pages are there in total 
    // * A callback to get page titles 
    mIndicator.init(5, mPagerAdapter.getCount(), mPagerAdapter); 
    Resources res = getResources(); 
    Drawable prev = res.getDrawable(R.drawable.indicator_prev_arrow); 
    Drawable next = res.getDrawable(R.drawable.indicator_next_arrow); 
    mIndicator.setFocusedTextColor(new int[]{255, 0, 0}); 

    // Set images for previous and next arrows. 
    mIndicator.setArrows(prev, next); 

    mIndicator.setOnClickListener(new OnIndicatorClickListener()); 
} 

class OnIndicatorClickListener implements ViewPagerIndicator.OnClickListener{ 
    @Override 
    public void onCurrentClicked(View v) { 
     Toast.makeText(ViewPagerIndicatorActivity.this, "Hello", Toast.LENGTH_SHORT).show(); 
    } 

    @Override 
    public void onNextClicked(View v) { 
     mViewPager.setCurrentItem(Math.min(mPagerAdapter.getCount() - 1, mIndicator.getCurrentPosition() + 1)); 
    } 

    @Override 
    public void onPreviousClicked(View v) { 
     mViewPager.setCurrentItem(Math.max(0, mIndicator.getCurrentPosition() - 1)); 
    } 

} 

class PagerAdapter extends FragmentPagerAdapter implements ViewPagerIndicator.PageInfoProvider{ 
    public PagerAdapter(FragmentManager fm) { 
     super(fm); 
    } 

    @Override 
    public Fragment getItem(int pos) { 

     String list1[]={"Catagories","Latest","Most Downloaded","Top Paid"}; 

     Calendar cal = Calendar.getInstance(); 
     cal.add(Calendar.DAY_OF_MONTH, pos - getCount()/2); 
     //return ItemFragment.newInstance(cal.getTime()); 
     return ItemFragment.newInstance1(list1); 
    } 

    @Override 
    public int getCount() { 
     return 4; 
    } 

    @Override 
    public String getTitle(int pos){ 
     String hello[]={"Catagories","Latest","Most Downloaded","Top Paid"}; 

     return hello.toString(); 
    } 
} 

public static class ItemFragment extends ListFragment{ 
    Date date; 
    String[] hello1; 

    static ItemFragment newInstance1(String[] hello) { 
     ItemFragment f = new ItemFragment(); 

     // Supply num input as an argument. 
     Bundle args = new Bundle(); 

     args.putStringArray("date", hello); 
     f.setArguments(args); 

     return f; 
    } 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     try { 
      this.hello1=list; 
      System.out.println("hello:list -"+hello1); 
     } catch (Exception e) { 
      e.printStackTrace(); 

     } 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) { 
     View v = inflater.inflate(R.layout.date_fragment, container, false); 
     View tv = v.findViewById(R.id.text); 

     ((TextView)tv).setText(hello1.toString()); 

     System.out.println("text view :"+hello1.toString()); 

     return v; 
    } 

    @Override 
    public void onActivityCreated(Bundle savedInstanceState) { 
     super.onActivityCreated(savedInstanceState); 
     setListAdapter(new ArrayAdapter<String>(getActivity(), 
     android.R.layout.simple_list_item_1, list)); 
    } 

    @Override 
    public void onListItemClick(ListView l, View v, int position, long id) { 
     Log.i("FragmentList", "Item clicked: " + id); 
    } 
} 

public static final String[] list = new String[]{"France", "London", "Sweden", "Denmark", "Germany", "Finland", "Thailand", "Taiwan", "USA", "Norway", "Denmark (again)", "Lithuania", "Bosnia", "Russia", "Vietnam", "Australia"}; 

} и другое:

public class ViewPagerIndicator extends RelativeLayout implements OnPageChangeListener { 
private static final int PADDING = 5; 

TextView mPrevious; 
TextView mCurrent; 
TextView mNext; 
int mCurItem; 
int mRestoreCurItem = -1; 

LinearLayout mPreviousGroup; 
LinearLayout mNextGroup; 

int mArrowPadding; 
int mSize; 

ImageView mCurrentIndicator; 
ImageView mPrevArrow; 
ImageView mNextArrow; 

int[] mFocusedTextColor; 
int[] mUnfocusedTextColor; 

OnClickListener mOnClickHandler; 

public interface PageInfoProvider{ 
    String getTitle(int pos); 
} 

public interface OnClickListener{ 
    void onNextClicked(View v); 
    void onPreviousClicked(View v); 
    void onCurrentClicked(View v); 
} 

public void setOnClickListener(OnClickListener handler){ 
    this.mOnClickHandler = handler; 
    mPreviousGroup.setOnClickListener(new OnPreviousClickedListener()); 
    mCurrent.setOnClickListener(new OnCurrentClickedListener()); 
    mNextGroup.setOnClickListener(new OnNextClickedListener()); 
} 

public int getCurrentPosition(){ 
    return mCurItem; 
} 

PageInfoProvider mPageInfoProvider; 
public void setPageInfoProvider(PageInfoProvider pageInfoProvider){ 
    this.mPageInfoProvider = pageInfoProvider; 
} 

public void setFocusedTextColor(int[] col){ 
    System.arraycopy(col, 0, mFocusedTextColor, 0, 3); 
    updateColor(0); 
} 

public void setUnfocusedTextColor(int[] col){ 
    System.arraycopy(col, 0, mUnfocusedTextColor, 0, 3); 
    mNext.setTextColor(Color.argb(255, col[0], col[1], col[2])); 
    mPrevious.setTextColor(Color.argb(255, col[0], col[1], col[2])); 
    updateColor(0); 
} 

@Override 
protected Parcelable onSaveInstanceState() { 
    Parcelable state = super.onSaveInstanceState(); 
    Bundle b = new Bundle(); 
    b.putInt("current", this.mCurItem); 
    b.putParcelable("viewstate", state); 
    return b; 
} 

@Override 
protected void onRestoreInstanceState(Parcelable state) { 
    super.onRestoreInstanceState(((Bundle)state).getParcelable("viewstate")); 
    mCurItem = ((Bundle)state).getInt("current", mCurItem); 
    this.setText(mCurItem - 1); 
    this.updateArrows(mCurItem); 
    this.invalidate(); 
} 

/** 
* Initialization 
* 
* @param startPos The initially selected element in the ViewPager 
* @param size Total amount of elements in the ViewPager 
* @param pageInfoProvider Interface that returns page titles 
*/ 
public void init(int startPos, int size, PageInfoProvider pageInfoProvider){ 
    setPageInfoProvider(pageInfoProvider); 
    this.mSize = size; 
    setText(startPos - 1); 
    mCurItem = startPos; 
} 

public ViewPagerIndicator(Context context, AttributeSet attrs) { 
    super(context, attrs); 
    addContent(); 
} 

public ViewPagerIndicator(Context context, AttributeSet attrs, int defStyle){ 
    super(context, attrs, defStyle); 
    addContent(); 
} 

public ViewPagerIndicator(Context context) { 
    super(context); 
    addContent(); 
} 

/** 
* Add drawables for arrows 
* 
* @param prev Left pointing arrow 
* @param next Right pointing arrow 
*/ 
public void setArrows(Drawable prev, Drawable next){ 
    this.mPrevArrow = new ImageView(getContext()); 
    this.mPrevArrow.setImageDrawable(prev); 

    this.mNextArrow = new ImageView(getContext()); 
    this.mNextArrow.setImageDrawable(next); 

    LinearLayout.LayoutParams arrowLayoutParams = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); 
    arrowLayoutParams.gravity = Gravity.CENTER; 

    mPreviousGroup.removeAllViews(); 
    mPreviousGroup.addView(mPrevArrow, arrowLayoutParams); 
    mPreviousGroup.addView(mPrevious, arrowLayoutParams); 

    mPrevious.setPadding(PADDING, 0, 0, 0); 
    mNext.setPadding(0, 0, PADDING, 0); 

    mArrowPadding = PADDING + prev.getIntrinsicWidth(); 

    mNextGroup.addView(mNextArrow, arrowLayoutParams); 
    updateArrows(mCurItem); 
} 

/** 
* Create all views, build the layout 
*/ 
private void addContent(){ 
    mFocusedTextColor = new int[]{0, 0, 0}; 
    mUnfocusedTextColor = new int[]{190, 190, 190}; 

    // Text views 
    mPrevious = new TextView(getContext()); 
    mCurrent = new TextView(getContext()); 
    mNext = new TextView(getContext()); 

    RelativeLayout.LayoutParams previousParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); 
    previousParams.addRule(RelativeLayout.ALIGN_LEFT); 

    RelativeLayout.LayoutParams currentParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); 
    currentParams.addRule(RelativeLayout.CENTER_HORIZONTAL); 

    RelativeLayout.LayoutParams nextParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); 
    nextParams.addRule(RelativeLayout.ALIGN_PARENT_RIGHT); 

    // Groups holding text and arrows 
    mPreviousGroup = new LinearLayout(getContext()); 
    mPreviousGroup.setOrientation(LinearLayout.HORIZONTAL); 
    mNextGroup = new LinearLayout(getContext()); 
    mNextGroup.setOrientation(LinearLayout.HORIZONTAL); 

    mPreviousGroup.addView(mPrevious, new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); 
    mNextGroup.addView(mNext, new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); 

    addView(mPreviousGroup, previousParams); 
    addView(mCurrent, currentParams); 
    addView(mNextGroup, nextParams); 

    mPrevious.setSingleLine(); 
    mCurrent.setSingleLine(); 
    mNext.setSingleLine(); 

    mPrevious.setText("previous"); 
    mCurrent.setText("current"); 
    mNext.setText("next"); 

    mPrevious.setClickable(false); 
    mNext.setClickable(false); 
    mCurrent.setClickable(true); 
    mPreviousGroup.setClickable(true); 
    mNextGroup.setClickable(true); 

    // Set colors 
    mNext.setTextColor(Color.argb(255, mUnfocusedTextColor[0], mUnfocusedTextColor[1], mUnfocusedTextColor[2])); 
    mPrevious.setTextColor(Color.argb(255, mUnfocusedTextColor[0], mUnfocusedTextColor[1], mUnfocusedTextColor[2])); 
    updateColor(0); 
} 

@Override 
public void onPageScrollStateChanged(int state) { 

} 

@Override 
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { 
    positionOffsetPixels = adjustOffset(positionOffsetPixels); 
    position = updatePosition(position, positionOffsetPixels); 
    setText(position - 1); 
    updateColor(positionOffsetPixels); 
    updateArrows(position); 
    updatePositions(positionOffsetPixels); 
    mCurItem = position; 
} 

void updatePositions(int positionOffsetPixels){ 
    int textWidth = mCurrent.getWidth() - mCurrent.getPaddingLeft() - mCurrent.getPaddingRight(); 
    int maxOffset = this.getWidth()/2 - textWidth/2 - mArrowPadding; 
    if(positionOffsetPixels > 0){ 
     maxOffset -= this.getPaddingLeft(); 
     int offset = Math.min(positionOffsetPixels, maxOffset - 1); 
     mCurrent.setPadding(0, 0, 2 * offset, 0); 

     // Move previous text out of the way. Slightly buggy. 
     /* 
     int overlapLeft = mPreviousGroup.getRight() - mCurrent.getLeft() + mArrowPadding; 
     mPreviousGroup.setPadding(0, 0, Math.max(0, overlapLeft), 0); 
     mNextGroup.setPadding(0, 0, 0, 0); 
     */ 
    }else{ 
     maxOffset -= this.getPaddingRight(); 
     int offset = Math.max(positionOffsetPixels, -maxOffset); 
     mCurrent.setPadding(-2 * offset, 0, 0, 0); 

     // Move next text out of the way. Slightly buggy. 
     /* 
     int overlapRight = mCurrent.getRight() - mNextGroup.getLeft() + mArrowPadding; 
     mNextGroup.setPadding(Math.max(0, overlapRight), 0, 0, 0); 
     mPreviousGroup.setPadding(0, 0, 0, 0); 
     */ 
    } 
} 

/** 
* Hide arrows if we can't scroll further 
* 
* @param position 
*/ 
void updateArrows(int position){ 
    if(mPrevArrow != null){ 
     mPrevArrow.setVisibility(position == 0 ? View.INVISIBLE : View.VISIBLE); 
     mNextArrow.setVisibility(position == mSize - 1 ? View.INVISIBLE : View.VISIBLE); 
    } 
} 

/** 
* Adjust position to be the view that is showing the most. 
* 
* @param givenPosition 
* @param offset 
* @return 
*/ 
int updatePosition(int givenPosition, int offset){ 
    int pos; 
    if(offset < 0){ 
     pos = givenPosition + 1; 
    }else{ 
     pos = givenPosition; 
    } 
    return pos; 
} 

/** 
* Fade "currently showing" color depending on it's position 
* 
* @param offset 
*/ 
void updateColor(int offset){ 
    offset = Math.abs(offset); 
    // Initial condition: offset is always 0, this.getWidth is also 0! 0/0 = NaN 
    int width = this.getWidth(); 
    float fraction = width == 0 ? 0 : offset/((float)width/4.0f); 
    fraction = Math.min(1, fraction); 
    int r = (int)(mUnfocusedTextColor[0] * fraction + mFocusedTextColor[0] * (1 - fraction)); 
    int g = (int)(mUnfocusedTextColor[1] * fraction + mFocusedTextColor[1] * (1 - fraction)); 
    int b = (int)(mUnfocusedTextColor[2] * fraction + mFocusedTextColor[2] * (1 - fraction)); 
    mCurrent.setTextColor(Color.argb(255, r, g, b)); 
} 

/** 
* Update text depending on it's position 
* 
* @param prevPos 
*/ 
void setText(int prevPos){ 
    if(prevPos < 0){ 
     mPrevious.setText(""); 
    }else{ 
     mPrevious.setText(mPageInfoProvider.getTitle(prevPos)); 
    } 
    mCurrent.setText(mPageInfoProvider.getTitle(prevPos + 1)); 
    String hellolo= ("current"+mPageInfoProvider.getTitle(prevPos + 1)); 
    if(prevPos + 2 == this.mSize){ 
     mNext.setText(""); 
    }else{ 
     mNext.setText(mPageInfoProvider.getTitle(prevPos + 2)); 
    } 
} 

// Original: 
// 244, 245, 0, 1, 2 
// New: 
// -2, -1, 0, 1, 2 
int adjustOffset(int positionOffsetPixels){ 
    // Move offset half width 
    positionOffsetPixels += this.getWidth()/2; 
    // Clamp to width 
    positionOffsetPixels %= this.getWidth(); 
    // Center around zero 
    positionOffsetPixels -= this.getWidth()/2; 
    return positionOffsetPixels; 
} 

@Override 
public void onPageSelected(int position) { 
    // Reset padding when the page is finally selected (May not be necessary) 
    mCurrent.setPadding(0, 0, 0, 0); 
} 

class OnPreviousClickedListener implements android.view.View.OnClickListener{ 
    @Override 
    public void onClick(View v) { 
     if(mOnClickHandler != null){ 
      mOnClickHandler.onPreviousClicked(ViewPagerIndicator.this); 
     } 
    } 
} 
class OnCurrentClickedListener implements android.view.View.OnClickListener{ 
    @Override 
    public void onClick(View v) { 
     if(mOnClickHandler != null){ 
      mOnClickHandler.onCurrentClicked(ViewPagerIndicator.this); 
     } 
    } 
} 
class OnNextClickedListener implements android.view.View.OnClickListener{ 
    @Override 
    public void onClick(View v) { 
     if(mOnClickHandler != null){ 
      mOnClickHandler.onNextClicked(ViewPagerIndicator.this); 
     } 
    } 
} 

} и вместо имени я получаю Ljava.lang.String@44daf8

Любая помощь по этому вопросу будет полезна.

Answer 1

«sweepy tabs», на который вы ссылаетесь, на самом деле всего лишь ViewPager с соответствующими закладками заголовка для каждой страницы. Это не включено в Android SDK по умолчанию, но вы можете использовать ViewPagerIndicator Jake Wharton, чтобы добавить заголовки для каждой вкладки в вашем ViewPager.

Jake Wharton предоставил связку sample code на GitHub, на которой вы должны взглянуть. Если вы уже внедрили свой ViewPager, изменение кода так, чтобы оно использовало TabPagerIndicator (класс, который будет добавлять заголовки для ваших вкладок) не будет слишком сложным. Вы также можете обратиться к разделу usage на сайте Джейка Уортона.

Я чувствую, что этого более чем достаточно, чтобы обеспечить правильную реализацию вашего ViewPager, но не стесняйтесь задавать любые вопросы, если что-то появляется.