Java Code Examples for android.widget.GridView#getNumColumns()

@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
@Override
public View getView(int position, View convertView, ViewGroup parent) {

    ViewHolder holder = null;
    if (convertView == null) {
        convertView = inflater.inflate(R.layout.lxw_item_helps_gridview, null);
        holder = new ViewHolder();
        holder.imageView = (ImageView) convertView.findViewById(R.id.lxw_id_item_helps_gridview_img);
        convertView.setTag(holder);
    } else {
        holder = (ViewHolder) convertView.getTag();
    }
    GridView gridView = (GridView) parent;
    int horizontalSpacing = gridView.getHorizontalSpacing();
    int numCloms = gridView.getNumColumns();
    int itemWidth = (gridView.getWidth() - (numCloms * horizontalSpacing) - gridView.getPaddingLeft() - gridView.getPaddingRight()) / numCloms;
    LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(itemWidth, itemWidth);
    holder.imageView.setLayoutParams(lp);
    holder.imageView.setImageResource(R.drawable.pictures_no);

    String path = mDatas.get(position).getUrl();
    // ImageLoader.getInstance(3, ImageLoader.Type.LIFO).loaderImage(path,holder.imageView,true);

    Glide.with(mContext).load(path).diskCacheStrategy(DiskCacheStrategy.ALL).into(holder.imageView);

    return convertView;
}
 

/**
 * Callback method to be invoked when the list or grid has been scrolled.
 */
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
    // New row started if this is true.
    if (firstVisibleItem != mLastFirstVisibleItem) {
        long currentTime = System.currentTimeMillis();
        if (currentTime == mLastTime) {
            return;
        }
        // Calculate the duration of scroll per line
        long timeScrollPerRow = currentTime - mLastTime;


        if (view instanceof GridView) {
            GridView gw = (GridView) view;
            mScrollSpeed = (int) (1000 / timeScrollPerRow) * gw.getNumColumns();
        } else {
            mScrollSpeed = (int) (1000 / timeScrollPerRow);
        }

        // Calculate how many items per second of loading images is possible
        int possibleItems = (int) (1000 / mAdapter.getAverageImageLoadTime());


        // Set the scrollspeed in the adapter
        mAdapter.setScrollSpeed(mScrollSpeed);

        // Save values for next comparsion
        mLastFirstVisibleItem = firstVisibleItem;
        mLastTime = currentTime;
        // Start the grid image loader task only if scroll speed is slow enough:
        // The devices is able to render the images needed for the scroll speed
        if (mScrollSpeed < possibleItems) {
            for (int i = 0; i < visibleItemCount; i++) {
                GenericImageViewItem item = (GenericImageViewItem) view.getChildAt(i);
                item.startCoverImageTask();
            }
        }
    }
}
 

@SuppressLint("NewApi")
private int getImageHeight(final GridView gridView) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
        return (int)(gridView.getColumnWidth() * IMAGE_SIZE_RATIO);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
        return (int)((getScreenWidth() / gridView.getNumColumns()) * IMAGE_SIZE_RATIO);

    return imgHeight;
}
 

/**
 * 计算 GridView 高度
 * @param gridView  {@link GridView}
 * @param setParams 是否 setLayoutParams
 * @return GridView 高度
 */
public static int calcGridViewHeight(final GridView gridView, final boolean setParams) {
    if (gridView == null) return 0;
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN) return 0;
    try {
        // Adapter
        ListAdapter listAdapter = gridView.getAdapter();
        // Item 总条数
        int itemCount = listAdapter.getCount();
        // 没数据则直接跳过
        if (itemCount == 0) return 0;
        // 高度
        int height = 0;
        // 获取一共多少列
        int numColumns = gridView.getNumColumns();
        // 每列之间的间隔 |
        int horizontalSpacing = gridView.getHorizontalSpacing();
        // 每行之间的间隔 -
        int verticalSpacing = gridView.getVerticalSpacing();
        // 获取倍数 ( 行数 )
        int lineNumber = NumberUtils.getMultiple(itemCount, numColumns);
        // 计算总共的宽度 - (GridView 宽度 - 列分割间距 ) / numColumns
        int childWidth = (gridView.getWidth() - (numColumns - 1) * horizontalSpacing) / numColumns;

        // 记录每行最大高度
        int[] rowHeightArrays = new int[lineNumber];
        // 临时高度 - 保存行中最高的列高度
        int tempHeight;
        // 循环每一行绘制每个 Item 并保存 Bitmap
        for (int i = 0; i < lineNumber; i++) {
            // 清空高度
            tempHeight = 0;
            // 循环列数
            for (int j = 0; j < numColumns; j++) {
                // 获取对应的索引
                int position = i * numColumns + j;
                // 如果大于总数据则跳过
                if (position < itemCount) {
                    View childView = listAdapter.getView(position, null, gridView);
                    WidgetUtils.measureView(childView, childWidth);

                    int itemHeight = childView.getMeasuredHeight();
                    // 保留最大高度
                    tempHeight = Math.max(itemHeight, tempHeight);
                }

                // 记录高度并累加
                if (j == numColumns - 1) {
                    height += tempHeight;
                    rowHeightArrays[i] = tempHeight;
                }
            }
        }
        // 追加子项间分隔符占用的高度
        height += (verticalSpacing * (lineNumber - 1));

        // 是否需要设置高度
        if (setParams) {
            ViewGroup.LayoutParams params = gridView.getLayoutParams();
            params.height = height;
            gridView.setLayoutParams(params);
        }
        return height;
    } catch (Exception e) {
        LogPrintUtils.eTag(TAG, e, "calcGridViewHeight");
    }
    return 0;
}
 

@Override
public View getView(int position, View convertView, ViewGroup parent) {
  GridView gridView = (GridView) parent;
  boolean multiColumns = gridView.getNumColumns() > 1;

  convertView = prepareViews(convertView, parent, multiColumns);
  ViewHolder holder = (ViewHolder) convertView.getTag();

  Cursor cursor = (Cursor) getItem(position);
  YouTubeData itemMap = mRequest.databaseTable().cursorToItem(cursor, mReusedData);

  Picasso.with(mContext).load(itemMap.mThumbnail)
      .fit()
          //          .noFade()
          //          .resize(250, 250) // put into dimens for dp values
      .into(holder.image);

  boolean hidden = itemMap.isHidden();
  holder.image.setDrawHiddenIndicator(hidden);

  holder.title.setText(itemMap.mTitle);

  // hide description if empty
  if (holder.description != null) {
    String desc = itemMap.mDescription;
    if (desc != null && (desc.length() > 0)) {
      holder.description.setVisibility(View.VISIBLE);
      holder.description.setText(desc);
    } else {
      if (multiColumns) {
        holder.description.setVisibility(View.VISIBLE);
        holder.description.setText(" "); // min lines doesn't work with "", used a space
      } else
        holder.description.setVisibility(View.GONE);
    }
  }

  // set video id on menu button so clicking can know what video to act on
  if (mTheme.mSupportsMenuButton && (itemMap.mVideo != null || itemMap.mPlaylist != null)) {
    holder.menuButton.setVisibility(View.VISIBLE);
    holder.menuButton.setListener(this);
    holder.menuButton.mId = itemMap.mID;
  } else {
    holder.menuButton.setVisibility(View.GONE);
  }

  String duration = itemMap.mDuration;
  if (duration != null) {
    holder.duration.setText(duration);
  } else {
    long count = itemMap.mItemCount;
    holder.duration.setText(Long.toString(count) + (count == 1 ? " video" : " videos"));
  }

  // card number
  holder.cardNumber.setText(Long.toString(position+1));

  Spannable date = mDateCache.spannable(itemMap.mPublishedDate);
  if (date != null) {
    holder.pubDate.setText(date);
  } else {
    holder.pubDate.setText("");
  }

  return convertView;
}