Android Open Source - customhellochartdemo Preview Line Chart Renderer

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Back to project page customhellochartdemo.

License

The source code is released under:

Apache License

Java Source Code

package lecho.lib.hellocharts.renderer;
/*from   www . j  av a2 s.  c o  m*/
import lecho.lib.hellocharts.ChartComputator;
import lecho.lib.hellocharts.model.Viewport;
import lecho.lib.hellocharts.provider.LineChartDataProvider;
import lecho.lib.hellocharts.util.Utils;
import lecho.lib.hellocharts.view.Chart;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;

/**
 * Renderer for preview chart based on LineChart. In addition to drawing chart data it also draw current viewport as
 * preview area.
 */
public class PreviewLineChartRenderer extends LineChartRenderer {
  private static final int DEFAULT_PREVIEW_TRANSPARENCY = 64;
  private static final int FULL_ALPHA = 255;
  private static final int DEFAULT_PREVIEW_STROKE_WIDTH_DP = 2;

  private Paint previewPaint = new Paint();

  public PreviewLineChartRenderer(Context context, Chart chart, LineChartDataProvider dataProvider) {
    super(context, chart, dataProvider);
    previewPaint.setAntiAlias(true);
    previewPaint.setColor(Color.LTGRAY);
    previewPaint.setStrokeWidth(Utils.dp2px(density, DEFAULT_PREVIEW_STROKE_WIDTH_DP));
  }

  @Override
  public void drawUnclipped(Canvas canvas) {
    super.drawUnclipped(canvas);
    final ChartComputator computator = chart.getChartComputator();
    final Viewport currentViewport = computator.getCurrentViewport();
    final float left = computator.computeRawX(currentViewport.left);
    final float top = computator.computeRawY(currentViewport.top);
    final float right = computator.computeRawX(currentViewport.right);
    final float bottom = computator.computeRawY(currentViewport.bottom);
    previewPaint.setAlpha(DEFAULT_PREVIEW_TRANSPARENCY);
    previewPaint.setStyle(Paint.Style.FILL);
    canvas.drawRect(left, top, right, bottom, previewPaint);
    previewPaint.setStyle(Paint.Style.STROKE);
    previewPaint.setAlpha(FULL_ALPHA);
    canvas.drawRect(left, top, right, bottom, previewPaint);
  }

  public void setPreviewColor(int color) {
    previewPaint.setColor(color);
  }

  public int getPreviewColor() {
    return previewPaint.getColor();
  }
}

Java Source Code List

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