1 /* 2 * Copyright 2012 AndroidPlot.com 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.androidplot.xy; 18 19 import android.graphics.RectF; 20 import com.androidplot.util.ValPixConverter; 21 22 /** 23 * Calculates "stepping" values for a plot. These values are most commonly used for 24 * drawing grid lines on a graph. 25 */ 26 public class XYStepCalculator { 27 28 29 /** 30 * Convenience method - wraps other form of getStep(). 31 * @param plot 32 * @param axisType 33 * @param rect 34 * @param minVal 35 * @param maxVal 36 * @return 37 */ 38 public static XYStep getStep(XYPlot plot, XYAxisType axisType, RectF rect, Number minVal, Number maxVal) { 39 XYStep step = null; 40 switch(axisType) { 41 case DOMAIN: 42 step = getStep(plot.getDomainStepMode(), rect.width(), plot.getDomainStepValue(), minVal, maxVal); 43 break; 44 case RANGE: 45 step = getStep(plot.getRangeStepMode(), rect.height(), plot.getRangeStepValue(), minVal, maxVal); 46 break; 47 } 48 return step; 49 } 50 51 public static XYStep getStep(XYStepMode typeXY, float plotPixelSize, double stepValue, Number minVal, Number maxVal) { 52 //XYStep step = new XYStep(); 53 double stepVal = 0; 54 float stepPix = 0; 55 float stepCount = 0; 56 switch(typeXY) { 57 case INCREMENT_BY_VAL: 58 stepVal = stepValue; 59 stepPix = (float)(stepValue/ ValPixConverter.valPerPix(minVal.doubleValue(), maxVal.doubleValue(), plotPixelSize)); 60 stepCount = plotPixelSize /stepPix; 61 break; 62 case INCREMENT_BY_PIXELS: 63 stepPix = new Double(stepValue).floatValue(); 64 stepCount = plotPixelSize /stepPix; 65 stepVal = ValPixConverter.valPerPix(minVal.doubleValue(), maxVal.doubleValue(), plotPixelSize)*stepPix; 66 break; 67 case SUBDIVIDE: 68 stepCount = new Double(stepValue).floatValue(); 69 stepPix = (plotPixelSize /(stepCount-1)); 70 stepVal = ValPixConverter.valPerPix(minVal.doubleValue(), maxVal.doubleValue(), plotPixelSize)*stepPix; 71 break; 72 } 73 return new XYStep(stepCount, stepPix, stepVal); 74 } 75 } 76
