Java tutorial
/* * This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of * the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. * * Copyright (c) 2014 Digi International Inc., All Rights Reserved. */ package com.digi.android.wva.fragments; import android.graphics.Color; import android.graphics.Paint.Align; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentTransaction; import android.text.TextUtils; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.LinearLayout; import android.widget.Toast; import com.digi.android.wva.WvaApplication; import com.digi.android.wva.model.VehicleData; import com.digi.android.wva.util.MessageCourier; import com.digi.wva.async.WvaCallback; import org.achartengine.ChartFactory; import org.achartengine.GraphicalView; import org.achartengine.chart.LineChart; import org.achartengine.chart.PointStyle; import org.achartengine.model.SeriesSelection; import org.achartengine.model.XYMultipleSeriesDataset; import org.achartengine.model.XYSeries; import org.achartengine.renderer.XYMultipleSeriesRenderer; import org.achartengine.renderer.XYSeriesRenderer; import org.joda.time.DateTime; import org.joda.time.format.ISODateTimeFormat; import java.text.SimpleDateFormat; import java.util.Date; import java.util.Locale; /** * The {@link Fragment} which holds and displays the data graph, as well * as handling incoming data to be plotted. * * @author mwadsten */ public class ChartFragment extends Fragment { private static final String TAG = "ChartFragment"; /** * Amount of time, in minutes (minutes * 60(seconds) * 1000(milliseconds)) * to display on the graph at one time. */ private static final int TIMESPAN = 15 * 60 * 1000; private final MessageHandler mHandler = new MessageHandler(this); private GraphicalView mChart; private XYMultipleSeriesDataset mDataset; private XYMultipleSeriesRenderer mRenderer; private XYSeriesRenderer mSpeedRenderer, mRpmRenderer; private double startTime, endTime; private boolean paused = false; private boolean subscribed = false; private boolean isTesting = false; // We add the last speed and RPM values to the graph after shifting the // X-axis so that we have a visual indication of the difference between // them and the new ones. private VehicleData lastSpeed, lastRPM; private final Object shiftLock = new Object(); private WvaApplication app; private static final int MESSAGE_LOOP_INTERVAL = 1000; private static class MessageHandler extends Handler { private final ChartFragment fragment; public MessageHandler(ChartFragment frag) { fragment = frag; } @Override public void handleMessage(Message msg) { fragment.processMessages(); } public void sleep() { this.removeMessages(0); sendMessageDelayed(obtainMessage(0), MESSAGE_LOOP_INTERVAL); } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Don't recreate fragment if activity gets recreated -- just hold // onto the existing instance. // This is to ensure that the chart remains in existence. setRetainInstance(true); startTime = DateTime.now().getMillis(); // endTime is 15 minutes after startTime endTime = startTime + TIMESPAN; buildGraphPieces(); clearDataset(); app = (WvaApplication) getActivity().getApplication(); } @Override public void onPause() { // Ensure messages stop being processed. mHandler.removeMessages(0); paused = true; super.onPause(); } @Override public void onResume() { super.onResume(); if (!subscribed) { // Will only happen on first start-up. // Get any messages waiting for the chart. If there are no // errors, drop any other messages (e.g. "reconnecting"/"connected") MessageCourier.ChartMessage[] msgs = MessageCourier.getChartMessages(); if (msgs.length == 0 || msgs[0].getError() == null) { // No errors (they appear at front of queue); // ignore any other messages. Log.d(TAG, "No errors on entry."); } else { Log.d(TAG, "Encountered error upon entry."); processMessage(msgs[0]); return; } subscribed = true; if (!isTesting) { app.subscribeToEndpoint("EngineSpeed", 10, new WvaCallback<Void>() { @Override public void onResponse(Throwable error, Void response) { if (error != null) { Log.e(TAG, "Unable to subscribe to EngineSpeed", error); Toast.makeText(getActivity(), "Unable to subscribe to EngineSpeed: " + error, Toast.LENGTH_SHORT).show(); } else { Log.d(TAG, "Successfully subscribed to EngineSpeed."); Toast.makeText(getActivity(), "Subscribed to EngineSpeed.", Toast.LENGTH_SHORT).show(); } } }); app.subscribeToEndpoint("VehicleSpeed", 10, new WvaCallback<Void>() { @Override public void onResponse(Throwable error, Void response) { if (error != null) { Log.e(TAG, "Unable to subscribe to VehicleSpeed", error); Toast.makeText(getActivity(), "Unable to subscribe to VehicleSpeed: " + error, Toast.LENGTH_SHORT).show(); } else { Log.d(TAG, "Successfully subscribed to VehicleSpeed."); Toast.makeText(getActivity(), "Subscribed to VehicleSpeed.", Toast.LENGTH_SHORT).show(); } } }); } } paused = false; processMessages(); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Add chart view to container if (container == null) { container = new LinearLayout(getActivity()); } container.addView(ChartFactory.getCombinedXYChartView(getActivity(), mDataset, mRenderer, new String[] { LineChart.TYPE, LineChart.TYPE })); return container; } /** * In the process of unit-testing, effectively mocking the WvaApplication * and making that mock application accessible from this fragment has * proven to be extremely difficult, if not impossible, because of * @param isTesting true if testing, false if not testing */ public void setIsTesting(boolean isTesting) { this.isTesting = isTesting; } /** * Repaints the chart view onto the screen. This is done by * removing the chart view from the layout, calling repaint(), * and putting the view back into the layout. * * <p>This method is protected, rather than private, due to a bug between JaCoCo and * the Android build tools which causes the instrumented bytecode to be invalid when this * method is private: * http://stackoverflow.com/questions/17603192/dalvik-transformation-using-wrong-invoke-opcode * </p> */ protected void redrawChart() { // super.getView() should return NoSaveStateFrameLayout, which // extends FrameLayout, which extends ViewGroup ViewGroup l = (ViewGroup) super.getView(); if (mChart == null) { mChart = ChartFactory.getCombinedXYChartView(getActivity(), mDataset, mRenderer, new String[] { LineChart.TYPE, LineChart.TYPE }); mChart.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { SeriesSelection sel = mChart.getCurrentSeriesAndPoint(); if (sel == null) return; String series = "SERIES"; switch (sel.getSeriesIndex()) { case 0: series = "Vehicle Speed"; break; case 1: series = "Engine RPM"; break; } String time = ISODateTimeFormat.dateTimeNoMillis().print((long) sel.getXValue()); Toast.makeText(getActivity(), series + " (" + time + "): " + sel.getValue(), Toast.LENGTH_SHORT) .show(); } }); } if (l != null) { // Ensure that the chart is removed from all views. try { if (mChart.getParent() != null) { //noinspection ConstantConditions ((ViewGroup) mChart.getParent()).removeAllViews(); } } catch (Exception e) { e.printStackTrace(); } l.removeAllViews(); mChart.repaint(); l.addView(mChart); } else { // If the getView() result is null, something's up, like // the activity has been backgrounded. Log.d(TAG, "redrawChart -- l is null"); } } /** * Create the components that go into the chart. * * <p>This method is protected, rather than private, due to a bug between JaCoCo and * the Android build tools which causes the instrumented bytecode to be invalid when this * method is private: * http://stackoverflow.com/questions/17603192/dalvik-transformation-using-wrong-invoke-opcode * </p> */ protected void buildGraphPieces() { if (mRenderer != null || mDataset != null || mRpmRenderer != null || mSpeedRenderer != null) { // Don't want to leak any memory or whatnot. return; } mRenderer = new XYMultipleSeriesRenderer(2); mDataset = new XYMultipleSeriesDataset(); mSpeedRenderer = new XYSeriesRenderer(); mRpmRenderer = new XYSeriesRenderer(); // Initialize renderer settings mRenderer.setShowGrid(true); mRenderer.setFitLegend(true); // Number of grid lines in either direction by default mRenderer.setXLabels(0); mRenderer.setYLabels(10); mRenderer.setXLabelsAlign(Align.RIGHT); mRenderer.setYLabelsAlign(Align.RIGHT); mRenderer.setPointSize(5f); // AChartEngine output defaults to a black background. // This doesn't fit with the general WVA color scheme. mRenderer.setApplyBackgroundColor(true); mRenderer.setBackgroundColor(Color.WHITE); mRenderer.setMarginsColor(Color.WHITE); mRenderer.setAxesColor(Color.DKGRAY); mRenderer.setLabelsColor(Color.BLACK); mRenderer.setXLabelsColor(Color.DKGRAY); mRenderer.setYLabelsColor(0, Color.DKGRAY); mRenderer.setYLabelsColor(1, Color.DKGRAY); mRenderer.setGridColor(Color.LTGRAY); mRenderer.setPanEnabled(false, false); mRenderer.setZoomEnabled(false, false); mRenderer.setXAxisMin(startTime); mRenderer.setXAxisMax(endTime); mRenderer.setXAxisMin(startTime, 1); mRenderer.setXAxisMax(endTime, 1); mRenderer.setYAxisMin(0, 0); mRenderer.setYAxisMax(100, 0); mSpeedRenderer.setColor(Color.RED); mSpeedRenderer.setPointStyle(PointStyle.CIRCLE); mSpeedRenderer.setFillPoints(true); mRpmRenderer.setColor(Color.BLUE); mRpmRenderer.setPointStyle(PointStyle.SQUARE); mRpmRenderer.setFillPoints(true); XYSeries speedSeries = new XYSeries("Vehicle Speed"); XYSeries rpmSeries = new XYSeries("Engine RPM", 1); mDataset.addSeries(0, speedSeries); mDataset.addSeries(1, rpmSeries); mRenderer.addSeriesRenderer(0, mSpeedRenderer); mRenderer.addSeriesRenderer(1, mRpmRenderer); mRenderer.setYAxisMin(0, 1); mRenderer.setYAxisMax(10000, 1); mRenderer.setYTitle("VehicleSpeed"); mRenderer.setYTitle("EngineSpeed", 1); mRenderer.setYAxisAlign(Align.RIGHT, 1); mRenderer.setYLabelsAlign(Align.RIGHT, 1); // Add X-axis labels with time. Log.d(TAG, "Time range: " + startTime + " to " + endTime); SimpleDateFormat fmt = new SimpleDateFormat("HH:mm:ss", Locale.US); for (double t = startTime; t <= endTime; t += 60 * 1000) { String time = fmt.format(new Date((long) t)); Log.d(TAG, "Adding label " + t + ", " + time); mRenderer.addXTextLabel(t, time); } } /** * Does what it says on the tin: clears out the data sets. */ public void clearDataset() { if (mDataset != null && mDataset.getSeriesCount() == 2) { for (XYSeries series : mDataset.getSeries()) { series.clear(); } } } /** * Fetch the XYSeries representing the sequence of speed values * @return the speed series, or null if there is an error or the series * is itself null */ public XYSeries getSpeedSeries() { if (mDataset != null) try { return mDataset.getSeriesAt(0); } catch (Exception e) { e.printStackTrace(); return null; } return null; } /** * Fetch the XYSeries representing the sequence of RPM values * @return the RPM series, or null if there is an error or the series * is itself null */ public XYSeries getRpmSeries() { if (mDataset != null) try { return mDataset.getSeriesAt(1); } catch (Exception e) { e.printStackTrace(); return null; } return null; } /** * Fetch the last vehicle speed data point * @return the last speed data */ public VehicleData getLastSpeed() { return lastSpeed; } /** * Fetch the last ending rpm data point * @return the last rpm data */ public VehicleData getLastRPM() { return lastRPM; } /** * Get the X-axis start time * @return X-axis start time */ public double getStartTime() { return startTime; } /** * Get the X-axis end time * @return the X-axis end time */ public double getEndTime() { return endTime; } /** * Iterate over {@link MessageCourier#getChartMessages() any pending messages} * and call {@link #processMessage(com.digi.android.wva.util.MessageCourier.ChartMessage)} * on each of them. * * <p>This method is protected, rather than private, due to a bug between JaCoCo and * the Android build tools which causes the instrumented bytecode to be invalid when this * method is private: * http://stackoverflow.com/questions/17603192/dalvik-transformation-using-wrong-invoke-opcode * </p> */ protected void processMessages() { for (MessageCourier.ChartMessage message : MessageCourier.getChartMessages()) { if (processMessage(message)) { // processMessage returning true means that the message was // an error, and so we should have displayed an error // dialog; we want to stop processing messages and get ready // for leaving the chart activity. return; } } // Stop mHandler loop if paused. if (paused) return; mHandler.sleep(); } /** * Process a {@link com.digi.android.wva.util.MessageCourier.ChartMessage} * and deal with its information. ChartMessages can be either * notifications of connection error, or they can contain new data. * * <p>This method is protected, rather than private, due to a bug between JaCoCo and * the Android build tools which causes the instrumented bytecode to be invalid when this * method is private: * http://stackoverflow.com/questions/17603192/dalvik-transformation-using-wrong-invoke-opcode * </p> * * @param msg the ChartMessage to be processed * @return true if the message was an error, and we should stop processing * any more messages */ protected boolean processMessage(MessageCourier.ChartMessage msg) { if (msg.isReconnecting()) { Toast.makeText(getActivity(), "Reconnecting...", Toast.LENGTH_SHORT).show(); return false; } if (TextUtils.isEmpty(msg.getError())) { // No error message - must be new vehicle data. VehicleData data = msg.getData(); if (data == null) { // This is odd! Log.e(TAG, "processMessage - got message without error or data."); return false; } else { handleNewData(data); return false; } } else { // error is non-null/empty -- there is an error to display String error = msg.getError(); Log.e(TAG, "Error: " + error); ConnectionErrorDialog dialog = ConnectionErrorDialog.newInstance("Connection error", error); FragmentTransaction ft = getActivity().getSupportFragmentManager().beginTransaction(); ft.addToBackStack(null); dialog.show(ft, "error_dialog"); return true; } } /** * Process an incoming piece of {@link VehicleData} and * plot it on the graph. * * <p>This method is public so that its behavior can be tested.</p> * @param incoming the {@link VehicleData} point to plot on screen */ public void handleNewData(VehicleData incoming) { try { String endpoint = incoming.name; double value = incoming.value; long timeMs = incoming.timestamp.getMillis(); if (!isTesting) Log.d(TAG, "Got new data on " + endpoint + ", value: " + value + ", time: " + timeMs); // Synchronize on shiftLock so that if two data points come in // practically simultaneously, we don't shift the view ahead and // then shift ahead another time. synchronized (shiftLock) { if (timeMs > endTime) { // Shift graph view ahead so current endTime becomes new startTime startTime = endTime; endTime = startTime + TIMESPAN; /* Wipe out dataset and renderers, so that we can rebuild them using buildGraphPieces, and they will reflect the new start and end times. */ clearDataset(); mRenderer.clearXTextLabels(); mRenderer.removeSeriesRenderer(mRpmRenderer); mRenderer.removeSeriesRenderer(mSpeedRenderer); mRenderer = null; mDataset = null; mRpmRenderer = null; mSpeedRenderer = null; mChart = null; buildGraphPieces(); try { ((ViewGroup) getView()).removeAllViews(); } catch (Exception e) { e.printStackTrace(); } if (lastSpeed != null && getSpeedSeries() != null) { getSpeedSeries().add(lastSpeed.timestamp.getMillis(), lastSpeed.value); } if (lastRPM != null && getRpmSeries() != null) { getRpmSeries().add(lastRPM.timestamp.getMillis(), lastRPM.value); } } } // Add the new data point to the graph. if ("VehicleSpeed".equals(endpoint)) { XYSeries series = getSpeedSeries(); if (series != null) { series.add(timeMs, value); } lastSpeed = incoming; } else if ("EngineSpeed".equals(endpoint)) { XYSeries series = getRpmSeries(); if (series != null) { series.add(timeMs, value); } lastRPM = incoming; } else { Log.d(TAG, "Unknown graphing endpoint: " + endpoint); } // Redraw the chart on-screen so the new data point is visible. redrawChart(); } catch (Exception e) { e.printStackTrace(); } } }