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 net.wespot.pim.view; import android.annotation.TargetApi; import android.app.ActivityOptions; import android.content.Context; import android.content.Intent; import android.os.Build.VERSION_CODES; import android.os.Bundle; import android.support.v4.app.Fragment; import android.util.Log; import android.view.*; import android.widget.*; import net.wespot.pim.BuildConfig; import net.wespot.pim.R; import net.wespot.pim.controller.ImageDetailActivity; import net.wespot.pim.utils.images.ImageCache; import net.wespot.pim.utils.images.ImageFetcher; import net.wespot.pim.utils.images.Utils; import net.wespot.pim.utils.layout.RecyclingImageView; import org.celstec.arlearn.delegators.INQ; import org.celstec.arlearn2.android.listadapter.AbstractResponsesLazyListAdapter; import org.celstec.dao.gen.ResponseLocalObject; import org.celstec.dao.gen.RunLocalObject; /** * 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 if, for example, the user rotates the device. */ public class InqImageGridFragment extends Fragment implements AdapterView.OnItemClickListener { private static final String TAG = "InqImageGridFragment"; private static final String IMAGE_CACHE_DIR = "thumbs"; private int mImageThumbSize; private int mImageThumbSpacing; private ImageAdapter mAdapter; private ImageFetcher mImageFetcher; private RunLocalObject runLocalObject; /** * Empty constructor as per the Fragment documentation */ public InqImageGridFragment() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setHasOptionsMenu(true); runLocalObject = INQ.inquiry.getCurrentInquiry().getRunLocalObject(); mImageThumbSize = getResources().getDimensionPixelSize(R.dimen.data_collect_thumbnail_image_size); mImageThumbSpacing = getResources().getDimensionPixelSize(R.dimen.data_collect_thumbnail_image_spacing); mAdapter = new ImageAdapter(getActivity()); ImageCache.ImageCacheParams cacheParams = new ImageCache.ImageCacheParams(getActivity(), IMAGE_CACHE_DIR); cacheParams.setMemCacheSizePercent(0.25f); // Set memory cache to 25% of app memory // The ImageFetcher takes care of loading images into our ImageView children asynchronously mImageFetcher = new ImageFetcher(getActivity(), mImageThumbSize); mImageFetcher.setLoadingImage(R.drawable.empty_photo); mImageFetcher.addImageCache(getActivity().getSupportFragmentManager(), cacheParams); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { final View v = inflater.inflate(R.layout.fragment_data_collect_grid, container, false); final GridView mGridView = (GridView) v.findViewById(R.id.gridView); mGridView.setAdapter(mAdapter); mGridView.setOnItemClickListener(this); mGridView.setOnScrollListener(new AbsListView.OnScrollListener() { @Override public void onScrollStateChanged(AbsListView absListView, int scrollState) { // Pause fetcher to ensure smoother scrolling when flinging if (scrollState == AbsListView.OnScrollListener.SCROLL_STATE_FLING) { // Before Honeycomb pause image loading on scroll to help with performance if (!Utils.hasHoneycomb()) { mImageFetcher.setPauseWork(true); } } else { mImageFetcher.setPauseWork(false); } } @Override public void onScroll(AbsListView absListView, int firstVisibleItem, int visibleItemCount, int totalItemCount) { } }); // 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() { @TargetApi(VERSION_CODES.JELLY_BEAN) @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); } if (Utils.hasJellyBean()) { mGridView.getViewTreeObserver().removeOnGlobalLayoutListener(this); } else { mGridView.getViewTreeObserver().removeGlobalOnLayoutListener(this); } } } } }); return v; } @Override public void onResume() { super.onResume(); mImageFetcher.setExitTasksEarly(false); mAdapter.notifyDataSetChanged(); } @Override public void onPause() { super.onPause(); mImageFetcher.setPauseWork(false); mImageFetcher.setExitTasksEarly(true); mImageFetcher.flushCache(); } @Override public void onDestroy() { super.onDestroy(); mImageFetcher.closeCache(); } @TargetApi(VERSION_CODES.JELLY_BEAN) @Override public void onItemClick(AdapterView<?> parent, View v, int position, long id) { final Intent i = new Intent(getActivity(), ImageDetailActivity.class); i.putExtra(ImageDetailActivity.RESPONSE_POSITION, (int) id); if (Utils.hasJellyBean()) { // makeThumbnailScaleUpAnimation() looks kind of ugly here as the loading spinner may // show plus the thumbnail image in GridView is cropped. so using // makeScaleUpAnimation() instead. ActivityOptions options = ActivityOptions.makeScaleUpAnimation(v, 0, 0, v.getWidth(), v.getHeight()); getActivity().startActivity(i, options.toBundle()); } else { startActivity(i); } } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { inflater.inflate(R.menu.menu_inquiry, menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { return super.onOptionsItemSelected(item); } /** * 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 = 0; // private GridView.LayoutParams mImageViewLayoutParams; // // public ImageAdapter(Context context) { // super(); // mContext = context; //// mImageViewLayoutParams = new GridView.LayoutParams( //// LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); //// // Calculate ActionBar height //// TypedValue tv = new TypedValue(); //// if (context.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true)) { //// mActionBarHeight = TypedValue.complexToDimensionPixelSize( //// tv.data, context.getResources().getDisplayMetrics()); //// } // } // // @Override // public int getCount() { // // If columns have yet to be determined, return no items // if (getNumColumns() == 0) { // return 0; // } // // // Size + number of columns for top empty row // return runLocalObject.getResponses().size()+ mNumColumns; // } // // @Override // public Object getItem(int position) { // return position < mNumColumns ? // null : runLocalObject.getResponses().get(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); //// } //// // Set empty view with height of ActionBar //// convertView.setLayoutParams(new AbsListView.LayoutParams( //// 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 RecyclingImageView(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); // } // // Log.e(TAG, "Load async: "+runLocalObject.getResponses().get(position - mNumColumns)); // // // Finally load the image asynchronously into the ImageView, this also takes care of // // setting a placeholder image while the background thread runs // mImageFetcher.loadImage(runLocalObject.getResponses().get(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); // mImageFetcher.setImageSize(height); // notifyDataSetChanged(); // } // // public void setNumColumns(int numColumns) { // mNumColumns = numColumns; // } // // public int getNumColumns() { // return mNumColumns; // } // } public class ImageAdapter extends AbstractResponsesLazyListAdapter { private final Context mContext; private GridView.LayoutParams mImageViewLayoutParams; private int mItemHeight = 0; private int mNumColumns = 0; private ImageFetcher mImageFetcher; public ImageAdapter(Context context) { super(getActivity()); mContext = context; // mImageViewLayoutParams = new GridView.LayoutParams( // LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); // // Calculate ActionBar height // TypedValue tv = new TypedValue(); // if (context.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true)) { // mActionBarHeight = TypedValue.complexToDimensionPixelSize( // tv.data, context.getResources().getDisplayMetrics()); // } } // public ImageAdapter(Context context, ImageFetcher imageFetcher, GeneralItemLocalObject giLocalObject, Context mContext) { // super(context, giLocalObject.getId()); // mImageFetcher = imageFetcher; // this.mContext = mContext; // mImageViewLayoutParams = new GridView.LayoutParams( // ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT); // } @Override public View newView(Context context, ResponseLocalObject item, ViewGroup parent) { if (item == null) return null; LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); mImageViewLayoutParams = new GridView.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT); return inflater.inflate(R.layout.entry_data_collection_response, parent, false); } @Override public void bindView(View convertView, Context mContext, ResponseLocalObject responseLocalObject) { // First check if this is the top row // if (position < mNumColumns) { // if (convertView == null) { // convertView = new View(mContext); // } // // Set empty view with height of ActionBar // convertView.setLayoutParams(new AbsListView.LayoutParams( // 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 RecyclingImageView(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); } Log.e(TAG, "Load async: " + responseLocalObject); // Finally load the image asynchronously into the ImageView, this also takes care of // setting a placeholder image while the background thread runs mImageFetcher.loadImage(responseLocalObject, imageView); return; } public void setItemHeight(int height) { if (height == mItemHeight) { return; } mItemHeight = height; mImageViewLayoutParams = new GridView.LayoutParams(GridLayout.LayoutParams.MATCH_PARENT, mItemHeight); mImageFetcher.setImageSize(height); notifyDataSetChanged(); } public void setNumColumns(int numColumns) { mNumColumns = numColumns; } public int getNumColumns() { return mNumColumns; } @Override public int getCount() { // If columns have yet to be determined, return no items if (getNumColumns() == 0) { return 0; } // Size + number of columns for top empty row return runLocalObject.getResponses().size() + mNumColumns; } @Override public ResponseLocalObject getItem(int position) { return position < mNumColumns ? null : runLocalObject.getResponses().get(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; } } }