Java tutorial
/** * @file GraphDemo2.java * * @brief * A demo for the Graph GWT Wrapper * * @license * 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. * * Copyright 2010-2011 Almende B.V. * * @author Jos de Jong, <jos@almende.org> * @date 2011-02-02 */ package com.chap.links.client; import java.util.Date; import com.google.gwt.core.client.EntryPoint; import com.google.gwt.event.dom.client.ClickEvent; import com.google.gwt.event.dom.client.ClickHandler; import com.google.gwt.i18n.client.DateTimeFormat; import com.google.gwt.user.client.Window; import com.google.gwt.user.client.ui.Button; import com.google.gwt.user.client.ui.RootPanel; import com.google.gwt.user.client.ui.TextBox; import com.google.gwt.visualization.client.DataTable; import com.google.gwt.visualization.client.VisualizationUtils; import com.google.gwt.visualization.client.events.RangeChangeHandler; public class GraphDemo2_interactive_and_custom_css implements EntryPoint { final TextBox txtStartDate = new TextBox(); final TextBox txtEndDate = new TextBox(); final Button btnSetRange = new Button("Set"); Graph graph = null; /** * This is the entry point method. */ public void onModuleLoad() { // Create a callback to be called when the visualization API // has been loaded. Runnable onLoadCallback = new Runnable() { public void run() { RootPanel.get("txtStartDate").add(txtStartDate); RootPanel.get("txtEndDate").add(txtEndDate); RootPanel.get("btnSetRange").add(btnSetRange); // Add a handler to the add button btnSetRange.addClickHandler(new ClickHandler() { public void onClick(ClickEvent event) { setRange(); } }); // Create and populate a data table. DataTable data = DataTable.create(); data.addColumn(DataTable.ColumnType.DATETIME, "time"); data.addColumn(DataTable.ColumnType.NUMBER, "Function A"); data.addColumn(DataTable.ColumnType.NUMBER, "Function B"); DateTimeFormat dtf = DateTimeFormat.getFormat("yyyy-MM-dd"); // create data Date d = dtf.parse("2010-08-23"); int n = 10000; // number of datapoints for (int i = 0; i < n; i++) { data.addRow(); data.setValue(i, 0, new Date(d.getTime())); data.setValue(i, 1, customFunction(i)); data.setValue(i, 2, customFunction2(i)); d.setTime(d.getTime() + 1000 * 60); // steps of one minute } Graph.Options options = Graph.Options.create(); options.setHeight("400px"); options.setVerticalStep(10); options.setLegendCheckboxes(true); //options.setScale(Graph.Options.SCALE.HOUR, 2); options.setLineColor("red", 1); options.setLineStyle(Graph.Options.LINESTYLE.DOT, 0); options.setLineRadius(1.0, 0); options.setLineColor("blue", 0); // create the linechart, with data and options graph = new Graph(data, options); // add event handlers graph.addRangeChangeHandler(createRangeChangeHandler(graph)); RootPanel.get("mygraph").add(graph); getRange(); } }; // Load the visualization api, passing the onLoadCallback to be called // when loading is done. VisualizationUtils.loadVisualizationApi(onLoadCallback); } double customFunction(double x) { return Math.sin(x / 100) * Math.cos(x / 50) * 50 + Math.sin(x / 1000) * 50; } double customFunction2(double x) { return Math.sin(x / 100) * 25; } /** * Get the range from the timeline and put it in the textboxes on screen */ private void getRange() { Graph.DateRange range = graph.getVisibleChartRange(); DateTimeFormat dtf = DateTimeFormat.getFormat("yyyy-MM-dd HH:mm:ss"); // set the new startdate and enddate txtStartDate.setText(dtf.format(range.getStart())); txtEndDate.setText(dtf.format(range.getEnd())); } /** * Get the entered dates from the textboxes on screen, and apply them to * the timeline */ private void setRange() { DateTimeFormat datetime = DateTimeFormat.getFormat("yyyy-MM-dd HH:mm:ss"); DateTimeFormat date = DateTimeFormat.getFormat("yyyy-MM-dd"); Date startDate; Date endDate; // Try to parse the startdate try { startDate = datetime.parse(txtStartDate.getText()); } catch (IllegalArgumentException err) { try { startDate = date.parse(txtStartDate.getText()); } catch (IllegalArgumentException err2) { Window.alert("I don't understand the startdate that you entered :("); return; } } // Try to parse the enddate try { endDate = datetime.parse(txtEndDate.getText()); } catch (IllegalArgumentException err) { try { endDate = date.parse(txtEndDate.getText()); } catch (IllegalArgumentException err2) { Window.alert("I cannot make sense of the enddate that you entered :("); return; } } graph.setVisibleChartRange(startDate, endDate); graph.redraw(); } /** * create a RangeChange handler (this event occurs when the user changes the * visible range by moving or scrolling the graph). * @param Graph * @return */ private RangeChangeHandler createRangeChangeHandler(final Graph graph) { return new RangeChangeHandler() { @Override public void onRangeChange(RangeChangeEvent event) { getRange(); } }; } }