Android Open Source - customhellochartdemo Preview Line Chart Activity

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License

The source code is released under:

Apache License

Java Source Code

package lecho.lib.hellocharts.samples;
/* w w w.ja v  a 2  s  .c  o m*/
import java.util.ArrayList;
import java.util.List;

import lecho.lib.hellocharts.ViewportChangeListener;
import lecho.lib.hellocharts.gesture.ZoomType;
import lecho.lib.hellocharts.model.Axis;
import lecho.lib.hellocharts.model.Line;
import lecho.lib.hellocharts.model.LineChartData;
import lecho.lib.hellocharts.model.PointValue;
import lecho.lib.hellocharts.model.Viewport;
import lecho.lib.hellocharts.util.Utils;
import lecho.lib.hellocharts.view.LineChartView;
import lecho.lib.hellocharts.view.PreviewLineChartView;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;

public class PreviewLineChartActivity extends ActionBarActivity {

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_preview_line_chart);
    if (savedInstanceState == null) {
      getSupportFragmentManager().beginTransaction().add(R.id.container, new PlaceholderFragment()).commit();
    }
  }

  /**
   * A fragment containing a line chart and preview line chart.
   */
  public static class PlaceholderFragment extends Fragment {

    private LineChartView chart;
    private PreviewLineChartView previewChart;
    private LineChartData data;
    /**
     * Deep copy of data.
     */
    private LineChartData previewData;

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
      setHasOptionsMenu(true);
      View rootView = inflater.inflate(R.layout.fragment_preview_line_chart, container, false);

      chart = (LineChartView) rootView.findViewById(R.id.chart);
      previewChart = (PreviewLineChartView) rootView.findViewById(R.id.chart_preview);

      // Generate data for previewed chart and copy of that data for preview chart.
      generateDefaultData();

      chart.setLineChartData(data);
      // Disable zoom/scroll for previewed chart, visible chart ranges depends on preview chart viewport so
      // zoom/scroll is unnecessary.
      chart.setZoomEnabled(false);
      chart.setScrollEnabled(false);

      previewChart.setLineChartData(previewData);
      previewChart.setViewportChangeListener(new ViewportListener());

      previewX(false);

      return rootView;
    }

    // MENU
    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
      inflater.inflate(R.menu.preview_line_chart, menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
      int id = item.getItemId();
      if (id == R.id.action_reset) {
        generateDefaultData();
        chart.setLineChartData(data);
        previewChart.setLineChartData(previewData);
        previewX(true);
        return true;
      }
      if (id == R.id.action_preview_both) {
        previewXY();
        previewChart.setZoomType(ZoomType.HORIZONTAL_AND_VERTICAL);
        return true;
      }
      if (id == R.id.action_preview_horizontal) {
        previewX(true);
        return true;
      }
      if (id == R.id.action_preview_vertical) {
        previewY();
        return true;
      }
      if (id == R.id.action_change_color) {
        int color = Utils.pickColor();
        while (color == previewChart.getPreviewColor()) {
          color = Utils.pickColor();
        }
        previewChart.setPreviewColor(color);
        return true;
      }
      return super.onOptionsItemSelected(item);
    }

    private void generateDefaultData() {
      int numValues = 50;

      List<PointValue> values = new ArrayList<PointValue>();
      for (int i = 0; i < numValues; ++i) {
        values.add(new PointValue(i, (float) Math.random() * 100f));
      }

      Line line = new Line(values);
      line.setColor(Utils.COLOR_GREEN);
      line.setHasPoints(false);// too many values so don't draw points.

      List<Line> lines = new ArrayList<Line>();
      lines.add(line);

      data = new LineChartData(lines);
      data.setAxisXBottom(new Axis());
      data.setAxisYLeft(new Axis().setHasLines(true));

      // prepare preview data, is better to use separate deep copy for preview chart.
      // Set color to grey to make preview area more visible.
      previewData = new LineChartData(data);
      previewData.getLines().get(0).setColor(Utils.DEFAULT_DARKEN_COLOR);

    }

    private void previewY() {
      Viewport tempViewport = new Viewport(chart.getMaximumViewport());
      float dy = tempViewport.height() / 4;
      tempViewport.inset(0, dy);
      previewChart.setCurrentViewport(tempViewport, true);
      previewChart.setZoomType(ZoomType.VERTICAL);
    }

    private void previewX(boolean animate) {
      Viewport tempViewport = new Viewport(chart.getMaximumViewport());
      float dx = tempViewport.width() / 4;
      tempViewport.inset(dx, 0);
      previewChart.setCurrentViewport(tempViewport, animate);
      previewChart.setZoomType(ZoomType.HORIZONTAL);
    }

    private void previewXY() {
      // Better to not modify viewport of any chart directly so create a copy.
      Viewport tempViewport = new Viewport(chart.getMaximumViewport());
      // Make temp viewport smaller.
      float dx = tempViewport.width() / 4;
      float dy = tempViewport.height() / 4;
      tempViewport.inset(dx, dy);
      previewChart.setCurrentViewport(tempViewport, true);
    }

    /**
     * Viewport listener for preview chart(lower one). in {@link #onViewportChanged(Viewport)} method change
     * viewport of upper chart.
     */
    private class ViewportListener implements ViewportChangeListener {

      @Override
      public void onViewportChanged(Viewport newViewport) {
        // don't use animation, it is unnecessary when using preview chart.
        chart.setCurrentViewport(newViewport, false);
      }

    }

  }
}

Java Source Code List

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