Achartengine toScreenPoint (double) always returns nullPointerException

Question

Each time I call this method, it returns a nullpointer exception:

java.lang.NullPointerException on org.achartengine.chart.XYChart.toScreenPoint (XYChart.java:867)

I see the mScreenR chart is null

Without using this method, toScreenPoint (double) diagrams work well, this is the code:

package com.insights.insights.gui; import java.util.ArrayList; import org.achartengine.ChartFactory; import org.achartengine.GraphicalView; import org.achartengine.chart.LineChart; import org.achartengine.chart.PointStyle; import org.achartengine.chart.XYChart; import org.achartengine.model.XYMultipleSeriesDataset; import org.achartengine.model.XYSeries; import org.achartengine.renderer.XYMultipleSeriesRenderer; import org.achartengine.renderer.XYSeriesRenderer; import com.insights.insights.R; import com.insights.insights.local.ApplicationsController; import com.insights.insights.model.AppMetrics; import com.insights.insights.model.Application; import com.insights.insights.model.Applications; import com.insights.insights.model.Day; import android.os.Bundle; import android.support.v4.app.Fragment; import android.util.Log; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AbsoluteLayout; import android.widget.LinearLayout; import android.widget.Toast; public class ChartFragment extends Fragment { private XYMultipleSeriesRenderer renderer; private XYMultipleSeriesDataset dataset; private GraphicalView graphicalView; private XYSeries firstSeries; private XYChart chart=null; private String apiKey; private ArrayList<Day> days; private View view; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); apiKey = getArguments().getString(getString(R.string.tabs_activity_api_key)); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v = inflater.inflate(R.layout.chart_fragment, container, false); v.findViewById(R.idChartFragment.container).requestFocus(); this.view = v; return v; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); // Obtaining data to plot Applications applications = ApplicationsController.getInstance(getActivity()).getApplications(); ArrayList<Application> applicationArray = applications.getApplication(); if (applicationArray != null && !applicationArray.isEmpty()) { for (int i = 0; i < applicationArray.size(); i++) { if (applicationArray.get(i).getApiKey().equals(apiKey)) { ArrayList<AppMetrics> appMetrics = applicationArray.get(i).getAppMetrics(); for (int j = 0; j < appMetrics.size(); j++) { if (appMetrics.get(j).getMetric().equals("Sessions")) { days = appMetrics.get(j).getDay(); break; } } } } } // If there isn't any item to plot and show a toast if (days == null) { Toast toast = Toast.makeText(getActivity(), R.string.chart_fragment_no_items, Toast.LENGTH_LONG); toast.show(); return; } // Ploting the items dataset = getDataset(days); renderer = getRenderer(); setRendererStyling(renderer); // add plot to the layout if (graphicalView == null) { LinearLayout layout = (LinearLayout) view.findViewById(R.idChartFragment.Chart); chart= new LineChart(dataset, renderer); graphicalView = new GraphicalView(getActivity(), chart); renderer.setSelectableBuffer(11); layout.addView(graphicalView); } else{ graphicalView.repaint(); } if(chart!=null&&firstSeries!=null){ for(int i=0;i<firstSeries.getItemCount();i++){ double x = firstSeries.getX(i); double y = firstSeries.getY(i); double[] screenPoint = chart.toScreenPoint(new double[] { x, y },0); Log.i("puntos", x + "," + y + " = "+" ("+screenPoint[0]+", "+screenPoint[1]+")"); } } } /** * Method for set the style of the plotter window and the string at the x * axis * * @param mRenderer * render to put style in * * @param dataSetX * string to set at x axis */ private void setRendererStyling(XYMultipleSeriesRenderer mRenderer) { mRenderer.setApplyBackgroundColor(false); mRenderer.setMarginsColor(R.drawable.transperent_color); mRenderer.setMargins(new int[] { 0, 0, 0, 0 }); mRenderer.setShowAxes(false); mRenderer.setZoomButtonsVisible(false); mRenderer.setExternalZoomEnabled(false); mRenderer.setPointSize(20); mRenderer.setClickEnabled(false); mRenderer.setDisplayValues(false); mRenderer.setXLabels(0); mRenderer.setYLabels(0); mRenderer.setPanEnabled(false); mRenderer.setZoomEnabled(false); mRenderer.setShowLegend(false); } /** * Method to introduce the values of the y axis * * @param dataSetY * data to set at axis y * @return the data to set */ private XYMultipleSeriesDataset getDataset(ArrayList<Day> days) { XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset(); firstSeries = new XYSeries(""); for (int i = 0; i < 12; i++) { int value = Integer.parseInt(days.get(days.size() - (13 - i)).getValue()); firstSeries.add(i, value); } dataset.addSeries(firstSeries); return dataset; } /** * Method for set the style of the line you want to plot and create a new * renderer * * @return the renderer */ private XYMultipleSeriesRenderer getRenderer() { XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer(); XYSeriesRenderer r = new XYSeriesRenderer(); r.setColor(getResources().getColor(R.color.grey_number_label_background)); r.setLineWidth(getResources().getInteger(R.integer.chart_fragment_line_width)); // r.setDisplayChartValues(true); r.setPointStyle(PointStyle.POINT); r.setFillPoints(true); renderer.addSeriesRenderer(r); return renderer; } } 

And this is the layout file:

 <?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+idChartFragment/container" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center_horizontal"> <LinearLayout android:id="@+idChartFragment/Chart" android:layout_width="300dp" android:layout_height="300dp" android:orientation="horizontal"/> <AbsoluteLayout android:id="@+idChartFragment/absolute" android:layout_width="300dp" android:layout_height="300dp"/> </RelativeLayout> 

Second edit:

I want to do something like this:

With my code, I do this:

This is my code:

  package com.insights.insights.gui; import java.util.ArrayList; import java.util.List; import org.achartengine.GraphicalView; import org.achartengine.chart.ClickableArea; import org.achartengine.chart.LineChart; import org.achartengine.chart.PointStyle; import org.achartengine.chart.XYChart; import org.achartengine.model.SeriesSelection; import org.achartengine.model.XYMultipleSeriesDataset; import org.achartengine.model.XYSeries; import org.achartengine.renderer.SimpleSeriesRenderer; import org.achartengine.renderer.XYMultipleSeriesRenderer; import org.achartengine.renderer.XYSeriesRenderer; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.Typeface; import android.os.Bundle; import android.support.v4.app.Fragment; import android.text.Layout; import android.util.AttributeSet; import android.util.Log; import android.view.Gravity; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.view.ViewTreeObserver.OnGlobalLayoutListener; import android.widget.AbsoluteLayout; import android.widget.AbsoluteLayout.LayoutParams; import android.widget.Button; import android.widget.ImageView; import android.widget.LinearLayout; import android.widget.TextView; import android.widget.Toast; import com.google.android.maps.ItemizedOverlay.OnFocusChangeListener; import com.insights.insights.R; import com.insights.insights.local.ApplicationsController; import com.insights.insights.model.AppMetrics; import com.insights.insights.model.Application; import com.insights.insights.model.Applications; import com.insights.insights.model.Day; /** * * @author Manuel Plazas Palacio * */ public class ChartFragment extends Fragment { private XYMultipleSeriesRenderer renderer; private XYMultipleSeriesDataset dataset; private GraphicalView graphicalView; private XYSeries firstSeries; private XYChart chart = null; private AbsoluteLayout absoluteLayout; private ImageView point; private LinearLayout pointInfoConatiner; private TextView pointNumberText; private TextView pointNameText; private TextView pointDateText; private Typeface avenirHeavy; private Typeface avenirLight; private String apiKey; private String metricName; private ArrayList<Day> days; // The max and the min values displayed private double max = 0; private double min = 0; private View view; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); apiKey = getArguments().getString(getString(R.string.tabs_activity_api_key)); metricName = "Sessions"; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View v = inflater.inflate(R.layout.chart_fragment, container, false); v.findViewById(R.idChartFragment.container).requestFocus(); this.view = v; absoluteLayout = (AbsoluteLayout) v.findViewById(R.idChartFragment.absolute); // pointInfoConatiner = (LinearLayout) v.findViewById(R.idChartFragment.pointInfoContainer); // pointNumberText = (TextView) v.findViewById(R.idChartFragment.pointNumberText); // pointNameText = (TextView) v.findViewById(R.idChartFragment.pointNameText); // pointDateText = (TextView) v.findViewById(R.idChartFragment.pointDateText); // // pointNameText.setText(metricName); // Obtaining data to plot Applications applications = ApplicationsController.getInstance(getActivity()).getApplications(); ArrayList<Application> applicationArray = applications.getApplication(); if (applicationArray != null && !applicationArray.isEmpty()) { for (int i = 0; i < applicationArray.size(); i++) { if (applicationArray.get(i).getApiKey().equals(apiKey)) { ArrayList<AppMetrics> appMetrics = applicationArray.get(i).getAppMetrics(); for (int j = 0; j < appMetrics.size(); j++) { if (appMetrics.get(j).getMetric().equals(metricName)) { days = appMetrics.get(j).getDay(); break; } } } } } // If there isn't any item to plot and show a toast if (days == null) { Toast toast = Toast.makeText(getActivity(), R.string.chart_fragment_no_items, Toast.LENGTH_LONG); toast.show(); } // Ploting the items dataset = getDataset(days); renderer = getRenderer(); setRendererStyling(renderer); // add plot to the layout if (graphicalView == null) { LinearLayout layout = (LinearLayout) view.findViewById(R.idChartFragment.Chart); chart = new LineChart(dataset, renderer); graphicalView = new GraphicalView(getActivity(), chart); renderer.setSelectableBuffer(11); layout.addView(graphicalView); } else { graphicalView.repaint(); } return v; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); avenirHeavy = Typeface.createFromAsset(getActivity().getAssets(), "fonts/Avenir Heavy.ttf"); avenirLight = Typeface.createFromAsset(getActivity().getAssets(), "fonts/Avenir Light.ttf"); graphicalView.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { SeriesSelection seriesSelection = graphicalView.getCurrentSeriesAndPoint(); double[] xy = graphicalView.toRealPoint(0); //creating the views createOnClickPointsView(); if (seriesSelection != null) { // debug Log.d("Punto", seriesSelection.getXValue() + ", " + seriesSelection.getValue()); double x = firstSeries.getX(seriesSelection.getPointIndex() + 1); double y = firstSeries.getY(seriesSelection.getPointIndex() + 1); double[] screenPoint = chart.toScreenPoint(new double[] { x, y }); // debug Log.d("Chart point", "Chart element in series index " + seriesSelection.getSeriesIndex() + " data point index " + seriesSelection.getPointIndex() + " was clicked" + " closest point value X=" + seriesSelection.getXValue() + ", Y=" + seriesSelection.getValue() + " clicked point value X=" + (float) xy[0] + ", Y=" + (float) xy[1]); Log.d("Punto pantalla", " (" + screenPoint[0] + ", " + screenPoint[1] + ")"); int value = Integer.parseInt(days.get((int) (days.size() - (13 - x))).getValue()); String date = days.get((int) (days.size() - (13 - x))).getDate(); pointNumberText.setText(value + ""); pointDateText.setText(date); // drawing point info absoluteLayout.addView(pointInfoConatiner, new LayoutParams(getResources().getDrawable(R.drawable.graficapin) .getIntrinsicWidth(), getResources().getDrawable(R.drawable.graficapin).getIntrinsicHeight(), (int) (screenPoint[0] - (getResources().getDrawable(R.drawable.graficapin).getIntrinsicWidth() / 2)), (int) (screenPoint[1] - (getResources().getDrawable(R.drawable.graficapin).getIntrinsicHeight())))); // drawing point clicked absoluteLayout.addView(point, new LayoutParams(getResources().getDrawable(R.drawable.puntoon).getIntrinsicWidth(), getResources().getDrawable(R.drawable.puntoon).getIntrinsicHeight(), (int) (screenPoint[0] - (getResources() .getDrawable(R.drawable.puntoon).getIntrinsicWidth() / 2)), (int) (screenPoint[1] - ((getResources() .getDrawable(R.drawable.puntoon).getIntrinsicHeight()) / 4)))); } } }); } /** * Method for set the style of the plotter window and the string at the x * axis * * @param mRenderer * render to put style in * * @param dataSetX * string to set at x axis */ private void setRendererStyling(XYMultipleSeriesRenderer mRenderer) { mRenderer.setApplyBackgroundColor(false); mRenderer.setMarginsColor(R.drawable.transperent_color); mRenderer.setMargins(new int[] { 0, 0, 0, 0 }); mRenderer.setShowAxes(false); mRenderer.setZoomButtonsVisible(false); mRenderer.setExternalZoomEnabled(false); mRenderer.setPointSize(getResources().getInteger(R.integer.chart_fragment_point_size)); mRenderer.setClickEnabled(true); mRenderer.setDisplayValues(false); mRenderer.setXLabels(0); mRenderer.setYLabels(0); mRenderer.setPanEnabled(true); mRenderer.setZoomEnabled(false); mRenderer.setShowLegend(false); mRenderer.setYAxisMax(max + 10); mRenderer.setYAxisMin(min - 10); } /** * Method to introduce the values of the y axis * * @param dataSetY * data to set at axis y * @return the data to set */ private XYMultipleSeriesDataset getDataset(ArrayList<Day> days) { XYMultipleSeriesDataset dataset = new XYMultipleSeriesDataset(); firstSeries = new XYSeries(""); for (int i = 0; i < 12; i++) { int value = Integer.parseInt(days.get(days.size() - (13 - i)).getValue()); firstSeries.add(i, value); } dataset.addSeries(firstSeries); XYSeries secondSeries = new XYSeries(""); for (int i = 1; i < 11; i++) { int value = Integer.parseInt(days.get(days.size() - (13 - i)).getValue()); if (i == 1) { max = value; min = value; } if (value > max) max = value; if (value < min) min = value; secondSeries.add(i, value); } dataset.addSeries(secondSeries); return dataset; } /** * Method for set the style of the line you want to plot and create a new * renderer * * @return the renderer */ private XYMultipleSeriesRenderer getRenderer() { XYMultipleSeriesRenderer renderer = new XYMultipleSeriesRenderer(); //First chart with the line XYSeriesRenderer r = new XYSeriesRenderer(); r.setColor(getResources().getColor(R.color.grey_number_label_background)); r.setLineWidth(getResources().getInteger(R.integer.chart_fragment_line_width)); // r.setDisplayChartValues(true); r.setPointStyle(PointStyle.POINT); r.setFillPoints(true); renderer.addSeriesRenderer(r); // Second chart with the points XYSeriesRenderer r1 = new XYSeriesRenderer(); r1.setColor(getResources().getColor(R.color.purple_chart_points)); r1.setLineWidth(0); r1.setFillPoints(true); r1.setPointStyle(PointStyle.CIRCLE); renderer.addSeriesRenderer(r1); return renderer; } public XYSeries getFirstSeries() { return firstSeries; } public void setFirstSeries(XYSeries firstSeries) { this.firstSeries = firstSeries; } public XYChart getChart() { return chart; } public void setChart(XYChart chart) { this.chart = chart; } /** * Method for create the views when clicking on a point of the chart */ private void createOnClickPointsView() { //If the info is already visible if (pointInfoConatiner != null) absoluteLayout.removeView(pointInfoConatiner); // If the point is drawn if (point != null) absoluteLayout.removeView(point); pointInfoConatiner = new LinearLayout(getActivity()); pointInfoConatiner.setBackgroundDrawable(getResources().getDrawable(R.drawable.graficapin)); pointInfoConatiner.setOrientation(LinearLayout.VERTICAL); pointInfoConatiner.setGravity(Gravity.CENTER_HORIZONTAL); LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT); layoutParams.setMargins(0, 8, 0, 0); pointNumberText = new TextView(getActivity()); pointNumberText.setTextSize(18); pointNumberText.setTextColor(getResources().getColor(R.color.purple_chart_points)); pointNumberText.setTypeface(avenirHeavy); pointNumberText.setGravity(Gravity.CENTER); pointNameText = new TextView(getActivity()); pointNameText.setTextSize(18); pointNameText.setTextColor(getResources().getColor(R.color.grey_users_label)); pointNameText.setTypeface(avenirLight); pointNameText.setText(metricName); pointNameText.setGravity(Gravity.CENTER); pointDateText = new TextView(getActivity()); pointDateText.setTextSize(11); pointDateText.setTextColor(getResources().getColor(R.color.grey_users_label)); pointDateText.setTypeface(avenirHeavy); pointDateText.setGravity(Gravity.CENTER); pointInfoConatiner.addView(pointNumberText, 0, layoutParams); layoutParams.setMargins(0, 2, 0, 0); pointInfoConatiner.addView(pointNameText, 1, layoutParams); pointInfoConatiner.addView(pointDateText, 2, layoutParams); point = new ImageView(getActivity()); point.setImageDrawable(getResources().getDrawable(R.drawable.puntoon)); } } 

Does anyone know how I can:

1-exit from the lower border

2-way out of the pink chart line

3 - The chart does not move when I touch the points

4- When I ask the screen point why many times the y value returns infinite

Answer 1

This error used to be in the old version of AChartEngine. I suggest you upgrade to version 1.1.0.

Also, note that the chart should be displayed when the method is called. If the chart did not appear on the screen, then there is no way to calculate it.