Java tutorial
/* * Copyright 2014 sonaive.com. All rights reserved. * * 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.sonaive.v2ex.ui.widgets; import android.content.Context; import android.graphics.drawable.Drawable; import android.os.AsyncTask; import android.text.Html; import android.util.DisplayMetrics; import android.view.WindowManager; import android.widget.TextView; import org.apache.http.HttpResponse; import org.apache.http.client.methods.HttpGet; import org.apache.http.impl.client.DefaultHttpClient; import java.io.IOException; import java.io.InputStream; import java.net.MalformedURLException; /** * Created by liutao on 12/24/14. */ public class URLImageParser implements Html.ImageGetter { Context context; TextView container; /*** * Construct the URLImageParser which will execute AsyncTask and refresh the container * @param context * @param container */ public URLImageParser(Context context, TextView container) { this.context = context; this.container = container; } public Drawable getDrawable(String source) { UrlDrawable urlDrawable = new UrlDrawable(); // get the actual source ImageGetterAsyncTask asyncTask = new ImageGetterAsyncTask(urlDrawable); asyncTask.execute(source); // return reference to UrlDrawable where I will change with actual image from // the src tag return urlDrawable; } public class ImageGetterAsyncTask extends AsyncTask<String, Void, Drawable> { UrlDrawable urlDrawable; public ImageGetterAsyncTask(UrlDrawable d) { this.urlDrawable = d; } @Override protected Drawable doInBackground(String... params) { String source = params[0]; return fetchDrawable(source); } @Override protected void onPostExecute(Drawable result) { if (result == null) { return; } // set the correct bound according to the result from HTTP call urlDrawable.setBounds(0, 0, result.getIntrinsicWidth(), result.getIntrinsicHeight()); // change the reference of the current drawable to the result // from the HTTP call urlDrawable.drawable = result; // redraw the image by invalidating the container container.invalidate(); // For ICS container.setHeight(container.getHeight() + result.getIntrinsicHeight()); // Pre ICS container.setEllipsize(null); container.setText(container.getText()); } /*** * Get the Drawable from URL * @param urlString * @return */ public Drawable fetchDrawable(String urlString) { DisplayMetrics metrics = new DisplayMetrics(); ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay() .getMetrics(metrics); final float dpi = (int) metrics.density; try { InputStream is = fetch(urlString); Drawable drawable = Drawable.createFromStream(is, "src"); int width = drawable.getIntrinsicWidth(); int height = drawable.getIntrinsicHeight(); int scaledWidth = width; int scaledHeight = height; if (width > container.getMeasuredWidth()) { scaledWidth = container.getMeasuredWidth(); scaledHeight = (int) (container.getMeasuredWidth() * height * 1.0f / width); } drawable.setBounds(0, 0, scaledWidth, scaledHeight); drawable.setVisible(true, true); return drawable; } catch (Exception e) { return null; } } private InputStream fetch(String urlString) throws MalformedURLException, IOException { DefaultHttpClient httpClient = new DefaultHttpClient(); HttpGet request = new HttpGet(urlString); HttpResponse response = httpClient.execute(request); return response.getEntity().getContent(); } } }