Java tutorial
/* * Copyright (C) 2012 The Android Open Source Project * * 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.leo.runningman.ui; import android.content.ActivityNotFoundException; import android.content.Context; import android.content.Intent; import android.net.Uri; import android.os.AsyncTask; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v4.app.Fragment; import android.util.Log; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.view.ViewGroup.LayoutParams; import android.view.ViewTreeObserver; import android.view.Window; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.AdapterView; import android.widget.BaseAdapter; import android.widget.Button; import android.widget.GridView; import android.widget.ImageView; import android.widget.RelativeLayout; import android.widget.TextView; import android.widget.Toast; import com.google.ads.AdView; import com.leo.runningman.provider.ImageProvider; import com.leo.runningman.util.DiskLruCache; import com.leo.runningman.util.ImageCache; import com.leo.runningman.util.ImageCache.ImageCacheParams; import com.leo.runningman.util.ImageFetcher; import com.leo.runningman.util.ImageResizer; import com.leo.runningman.util.Network; import com.leo.runningman.util.Utils; /** * The main fragment that powers the ImageGridActivity screen. Fairly straight forward GridView * implementation with the key addition being the ImageWorker class w/ImageCache to load children * asynchronously, keeping the UI nice and smooth and caching thumbnails for quick retrieval. The * cache is retained over configuration changes like orientation change so the images are populated * quickly as the user rotates the device. */ public class ImageGridFragment extends Fragment implements AdapterView.OnItemClickListener { private static final String TAG = "ImageGridFragment"; private static final String IMAGE_CACHE_DIR = "thumbs"; private int mImageThumbSize; private int mImageThumbSpacing; private ImageAdapter mAdapter; private ImageResizer mImageWorker; private RelativeLayout layout_bottom; private Thread showThread; private Thread hideThread; private AdView adview_first; private int start = 0; //the start position to require data private int count = 90; //dynamic add data num /** * Empty constructor as per the Fragment documentation */ public ImageGridFragment() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setHasOptionsMenu(true); mImageThumbSize = getResources().getDimensionPixelSize(R.dimen.image_thumbnail_size); mImageThumbSpacing = getResources().getDimensionPixelSize(R.dimen.image_thumbnail_spacing); mAdapter = new ImageAdapter(getActivity()); ImageCacheParams cacheParams = new ImageCacheParams(IMAGE_CACHE_DIR); // Allocate a third of the per-app memory limit to the bitmap memory cache. This value // should be chosen carefully based on a number of factors. Refer to the corresponding // Android Training class for more discussion: // http://developer.android.com/training/displaying-bitmaps/ // In this case, we aren't using memory for much else other than this activity and the // ImageDetailActivity so a third lets us keep all our sample image thumbnails in memory // at once. cacheParams.memCacheSize = 1024 * 1024 * Utils.getMemoryClass(getActivity()) / 3; // The ImageWorker takes care of loading images into our ImageView children asynchronously mImageWorker = new ImageFetcher(getActivity(), mImageThumbSize); mImageWorker.setAdapter(ImageProvider.imageThumbWorkerUrlsAdapter); mImageWorker.setLoadingImage(R.drawable.empty_photo); // mImageWorker.setImageCache(ImageCache.findOrCreateCache(getActivity(), cacheParams)); } public void autoHideview(long millions) { if (hideThread == null) { hideThread = new Thread() { public void run() { sendHandlerMessage(HIDE_BOTTOM, 0, 0, null); } }; } if (layout_bottom.getVisibility() == View.VISIBLE) { cancelAutoHideview(); layout_bottom.postDelayed(hideThread, millions); } } public void autoShowview(long millions) { if (showThread == null) { showThread = new Thread() { public void run() { sendHandlerMessage(SHOW_BOTTOM, 0, 0, null); } }; } if (layout_bottom.getVisibility() != View.VISIBLE) { cancelAutoShow(); layout_bottom.postDelayed(showThread, millions); } } public void cancelAutoShow() { if (showThread != null) { layout_bottom.removeCallbacks(showThread); } } public void cancelAutoHideview() { if (hideThread != null) { layout_bottom.removeCallbacks(hideThread); } } public boolean sendHandlerMessage(int what, int arg1, int arg2, Object obj) { Message msg = Message.obtain(); if (msg != null) { msg.what = what; msg.arg1 = arg1; msg.arg2 = arg2; msg.obj = obj; return mHandler.sendMessage(msg); } return false; } private static final int SHOW_BOTTOM = 0; private static final int HIDE_BOTTOM = 1; private Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { switch (msg.what) { case SHOW_BOTTOM: showBottomLayout(); break; case HIDE_BOTTOM: hideBottomLayout(); break; default: break; } } }; private void showBottomLayout() { if (layout_bottom != null && layout_bottom.getVisibility() != View.VISIBLE) { layout_bottom.setVisibility(View.VISIBLE); } cancelAutoShow(); autoHideview(4000); } private void hideBottomLayout() { if (layout_bottom != null && layout_bottom.getVisibility() != View.GONE) { layout_bottom.setVisibility(View.GONE); } } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { Window window = getActivity().getWindow(); window.setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.layout_title); final View v = inflater.inflate(R.layout.image_grid_fragment, container, false); TextView txt_title = (TextView) this.getActivity().findViewById(R.id.txt_title); txt_title.setText(getActivity().getResources().getString(R.string.app_name)); Button btn_delete = (Button) this.getActivity().findViewById(R.id.btn_delete); TextView txt_delete_confirm = (TextView) this.getActivity().findViewById(R.id.txt_delete_confirm); btn_delete.setVisibility(View.GONE); txt_delete_confirm.setVisibility(View.GONE); layout_bottom = (RelativeLayout) v.findViewById(R.id.layout_bottom); autoHideview(4000); final GridView mGridView = (GridView) v.findViewById(R.id.gridView); mGridView.setAdapter(mAdapter); mGridView.setOnItemClickListener(this); // This listener is used to get the final width of the GridView and then calculate the // number of columns and the width of each column. The width of each column is variable // as the GridView has stretchMode=columnWidth. The column width is used to set the height // of each view so we get nice square thumbnails. mGridView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() { @Override public void onGlobalLayout() { if (mAdapter.getNumColumns() == 0) { final int numColumns = (int) Math .floor(mGridView.getWidth() / (mImageThumbSize + mImageThumbSpacing)); if (numColumns > 0) { final int columnWidth = (mGridView.getWidth() / numColumns) - mImageThumbSpacing; mAdapter.setNumColumns(numColumns); mAdapter.setItemHeight(columnWidth); if (BuildConfig.DEBUG) { Log.d(TAG, "onCreateView - numColumns set to " + numColumns); } } } } }); mGridView.setOnScrollListener(new OnScrollListener() { @Override public void onScrollStateChanged(AbsListView view, int scrollState) { switch (scrollState) { case OnScrollListener.SCROLL_STATE_IDLE: if (loadMore) { new HttpGetTask(1000L).execute(); } break; case OnScrollListener.SCROLL_STATE_FLING: break; case OnScrollListener.SCROLL_STATE_TOUCH_SCROLL: break; } hideBottomLayout(); cancelAutoHideview(); } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { Log.i(TAG, "firstVisibleItem:--->" + firstVisibleItem + "visibleItemCount:----->" + visibleItemCount + "totalItemCount:" + totalItemCount); loadMore = firstVisibleItem + visibleItemCount >= totalItemCount; start = totalItemCount; autoShowview(2000); } }); adview_first = (AdView) v.findViewById(R.id.adview_first); //TODO return v; } boolean loadMore = false; class HttpGetTask extends AsyncTask<String, Void, Void> { private Long time = -1L; public HttpGetTask(Long time) { this.time = time; } @Override protected void onPreExecute() { // TODO Auto-generated method stub super.onPreExecute(); } @Override protected void onProgressUpdate(Void... values) { // TODO Auto-generated method stub super.onProgressUpdate(values); } @Override protected Void doInBackground(String... params) { Network.getInstance(getActivity()).getUrls(1, start, count); return null; } @Override protected void onPostExecute(Void result) { mAdapter.notifyDataSetChanged(); } } @Override public void onResume() { super.onResume(); mImageWorker.setExitTasksEarly(false); if (mAdapter != null && mAdapter.getCount() > 3) { //TODO numColum:3 mAdapter.notifyDataSetChanged(); } else if (mAdapter.getCount() < 3) { new HttpGetTask(1000L).execute(); } } @Override public void onPause() { super.onPause(); mImageWorker.setExitTasksEarly(true); } @Override public void onItemClick(AdapterView<?> parent, View v, int position, long id) { final Intent i = new Intent(getActivity(), ImageDetailActivity.class); i.putExtra(ImageDetailActivity.EXTRA_IMAGE, (int) id); startActivity(i); } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { // inflater.inflate(R.menu.main_menu, menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.clear_cache: final ImageCache cache = mImageWorker.getImageCache(); if (cache != null) { mImageWorker.getImageCache().clearCaches(); DiskLruCache.clearCache(getActivity(), ImageFetcher.HTTP_CACHE_DIR); Toast.makeText(getActivity(), R.string.clear_cache_complete, Toast.LENGTH_SHORT).show(); } return true; // case R.id.local: // Intent intent = new Intent(this.getActivity(),LocalImageActivity.class); // startActivity(intent); // return true; case R.id.evaluate: launchMarket(); return true; } return super.onOptionsItemSelected(item); } private void launchMarket() { Uri uri = Uri.parse("market://details?id=" + getActivity().getPackageName()); Intent myAppLinkToMarket = new Intent(Intent.ACTION_VIEW, uri); try { startActivity(myAppLinkToMarket); } catch (ActivityNotFoundException e) { Toast.makeText(getActivity(), " unable to find market app", Toast.LENGTH_LONG).show(); } } /** * The main adapter that backs the GridView. This is fairly standard except the number of * columns in the GridView is used to create a fake top row of empty views as we use a * transparent ActionBar and don't want the real top row of images to start off covered by it. */ private class ImageAdapter extends BaseAdapter { private final Context mContext; private int mItemHeight = 0; private int mNumColumns = 0; private int mActionBarHeight = -1; private GridView.LayoutParams mImageViewLayoutParams; public ImageAdapter(Context context) { super(); mContext = context; mImageViewLayoutParams = new GridView.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); } @Override public int getCount() { // Size of adapter + number of columns for top empty row return mImageWorker.getAdapter().getSize() + mNumColumns; } @Override public Object getItem(int position) { return position < mNumColumns ? null : mImageWorker.getAdapter().getItem(position - mNumColumns); } @Override public long getItemId(int position) { return position < mNumColumns ? 0 : position - mNumColumns; } @Override public int getViewTypeCount() { // Two types of views, the normal ImageView and the top row of empty views return 2; } @Override public int getItemViewType(int position) { return (position < mNumColumns) ? 1 : 0; } @Override public boolean hasStableIds() { return true; } @Override public View getView(int position, View convertView, ViewGroup container) { // First check if this is the top row if (position < mNumColumns) { if (convertView == null) { convertView = new View(mContext); } // Calculate ActionBar height // if (mActionBarHeight < 0) { // TypedValue tv = new TypedValue(); // if (mContext.getTheme().resolveAttribute( // android.R.attr.actionBarSize, tv, true)) { // mActionBarHeight = TypedValue.complexToDimensionPixelSize( // tv.data, mContext.getResources().getDisplayMetrics()); // } else { // // No ActionBar style (pre-Honeycomb or ActionBar not in theme) // mActionBarHeight = 0; // } // } mActionBarHeight = 0; // Set empty view with height of ActionBar convertView.setLayoutParams( new AbsListView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, mActionBarHeight)); return convertView; } // Now handle the main ImageView thumbnails ImageView imageView; if (convertView == null) { // if it's not recycled, instantiate and initialize imageView = new ImageView(mContext); imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); imageView.setLayoutParams(mImageViewLayoutParams); } else { // Otherwise re-use the converted view imageView = (ImageView) convertView; } // Check the height matches our calculated column width if (imageView.getLayoutParams().height != mItemHeight) { imageView.setLayoutParams(mImageViewLayoutParams); } // Finally load the image asynchronously into the ImageView, this also takes care of // setting a placeholder image while the background thread runs mImageWorker.loadImage(position - mNumColumns, imageView); return imageView; } /** * Sets the item height. Useful for when we know the column width so the height can be set * to match. * * @param height */ public void setItemHeight(int height) { if (height == mItemHeight) { return; } mItemHeight = height; mImageViewLayoutParams = new GridView.LayoutParams(LayoutParams.MATCH_PARENT, mItemHeight); mImageWorker.setImageSize(height); notifyDataSetChanged(); } public void setNumColumns(int numColumns) { mNumColumns = numColumns; } public int getNumColumns() { return mNumColumns; } } }