+ * Generates legend html dash for any stroke pattern. It will try to scale the
+ * pattern to fit in 1em width. Or if small enough repeat the partern for 1em
+ * width.
+ * @param strokePattern The pattern
+ * @param color The color of the series.
+ * @param oneEmWidth The width in pixels of 1em in the legend.
+ */
+Dygraph.prototype.generateLegendDashHTML_ = function(strokePattern, color, oneEmWidth) {
+ var dash = "";
+ var i, j, paddingLeft, marginRight;
+ var strokePixelLength = 0, segmentLoop = 0;
+ var normalizedPattern = [];
+ var loop;
+ // IE 7,8 fail at these divs, so they get boring legend, have not tested 9.
+ var isIE = (/MSIE/.test(navigator.userAgent) && !window.opera);
+ if(isIE) {
+ return "—";
+ }
+ if (!strokePattern || strokePattern.length <= 1) {
+ // Solid line
+ dash = "<div style=\"display: inline-block; position: relative; " +
+ "bottom: .5ex; padding-left: 1em; height: 1px; " +
+ "border-bottom: 2px solid " + color + ";\"></div>";
+ } else {
+ // Compute the length of the pixels including the first segment twice,
+ // since we repeat it.
+ for (i = 0; i <= strokePattern.length; i++) {
+ strokePixelLength += strokePattern[i%strokePattern.length];
+ }
+
+ // See if we can loop the pattern by itself at least twice.
+ loop = Math.floor(oneEmWidth/(strokePixelLength-strokePattern[0]));
+ if (loop > 1) {
+ // This pattern fits at least two times, no scaling just convert to em;
+ for (i = 0; i < strokePattern.length; i++) {
+ normalizedPattern[i] = strokePattern[i]/oneEmWidth;
+ }
+ // Since we are repeating the pattern, we don't worry about repeating the
+ // first segment in one draw.
+ segmentLoop = normalizedPattern.length;
+ } else {
+ // If the pattern doesn't fit in the legend we scale it to fit.
+ loop = 1;
+ for (i = 0; i < strokePattern.length; i++) {
+ normalizedPattern[i] = strokePattern[i]/strokePixelLength;
+ }
+ // For the scaled patterns we do redraw the first segment.
+ segmentLoop = normalizedPattern.length+1;
+ }
+ // Now make the pattern.
+ for (j = 0; j < loop; j++) {
+ for (i = 0; i < segmentLoop; i+=2) {
+ // The padding is the drawn segment.
+ paddingLeft = normalizedPattern[i%normalizedPattern.length];
+ if (i < strokePattern.length) {
+ // The margin is the space segment.
+ marginRight = normalizedPattern[(i+1)%normalizedPattern.length];
+ } else {
+ // The repeated first segment has no right margin.
+ marginRight = 0;
+ }
+ dash += "<div style=\"display: inline-block; position: relative; " +
+ "bottom: .5ex; margin-right: " + marginRight + "em; padding-left: " +
+ paddingLeft + "em; height: 1px; border-bottom: 2px solid " + color +
+ ";\"></div>";
+ }
+ }
+ }
+ return dash;
+};
+
+/**
+ * @private