X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=dygraph-canvas.js;h=29341e1b83bd5b0b883ad4d3d2ca30a078816275;hb=79b3ee420f46d964b796adc06b4cd64e74a44cb8;hp=edce7a751170c83e6ca35eb94a3ee86a7f973dcc;hpb=9012dd21921ff553d61acbdfc41dad298c1ec089;p=dygraphs.git

diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index edce7a7..29341e1 100644
--- a/dygraph-canvas.js
+++ b/dygraph-canvas.js
@@ -4,7 +4,7 @@
 /**
  * @fileoverview Based on PlotKit, but modified to meet the needs of dygraphs.
  * In particular, support for:
- * - grid overlays 
+ * - grid overlays
  * - error bars
  * - dygraphs attribute system
  */
@@ -19,7 +19,7 @@ DygraphLayout = function(dygraph, options) {
   this.options = {};  // TODO(danvk): remove, use attr_ instead.
   Dygraph.update(this.options, options ? options : {});
   this.datasets = new Array();
-  this.annotations = new Array()
+  this.annotations = new Array();
 };
 
 DygraphLayout.prototype.attr_ = function(name) {
@@ -33,6 +33,7 @@ DygraphLayout.prototype.addDataset = function(setname, set_xy) {
 DygraphLayout.prototype.setAnnotations = function(ann) {
   // The Dygraph object's annotations aren't parsed. We parse them here and
   // save a copy.
+  this.annotations = [];
   var parse = this.attr_('xValueParser');
   for (var i = 0; i < ann.length; i++) {
     var a = {};
@@ -69,11 +70,13 @@ DygraphLayout.prototype._evaluateLimits = function() {
     for (var name in this.datasets) {
       if (!this.datasets.hasOwnProperty(name)) continue;
       var series = this.datasets[name];
-      var x1 = series[0][0];
-      if (!this.minxval || x1 < this.minxval) this.minxval = x1;
-
-      var x2 = series[series.length - 1][0];
-      if (!this.maxxval || x2 > this.maxxval) this.maxxval = x2;
+      if (series.length > 1) {
+        var x1 = series[0][0];
+        if (!this.minxval || x1 < this.minxval) this.minxval = x1;
+  
+        var x2 = series[series.length - 1][0];
+        if (!this.maxxval || x2 > this.maxxval) this.maxxval = x2;
+      }
     }
   }
   this.xrange = this.maxxval - this.minxval;
@@ -81,8 +84,8 @@ DygraphLayout.prototype._evaluateLimits = function() {
 
   for (var i = 0; i < this.options.yAxes.length; i++) {
     var axis = this.options.yAxes[i];
-    axis.minyval = axis.valueRange[0];
-    axis.maxyval = axis.valueRange[1];
+    axis.minyval = axis.computedValueRange[0];
+    axis.maxyval = axis.computedValueRange[1];
     axis.yrange = axis.maxyval - axis.minyval;
     axis.yscale = (axis.yrange != 0 ? 1.0 / axis.yrange : 1.0);
   }
@@ -108,13 +111,6 @@ DygraphLayout.prototype._evaluateLineCharts = function() {
         name: setName
       };
 
-      // limit the x, y values so they do not overdraw
-      if (point.y <= 0.0) {
-        point.y = 0.0;
-      }
-      if (point.y >= 1.0) {
-        point.y = 1.0;
-      }
       this.points.push(point);
     }
   }
@@ -210,6 +206,35 @@ DygraphLayout.prototype.updateOptions = function(new_options) {
   Dygraph.update(this.options, new_options ? new_options : {});
 };
 
+/**
+ * Return a copy of the point at the indicated index, with its yval unstacked.
+ * @param int index of point in layout_.points
+ */
+DygraphLayout.prototype.unstackPointAtIndex = function(idx) {
+  var point = this.points[idx];
+  
+  // Clone the point since we modify it
+  var unstackedPoint = {};  
+  for (var i in point) {
+    unstackedPoint[i] = point[i];
+  }
+  
+  if (!this.attr_("stackedGraph")) {
+    return unstackedPoint;
+  }
+  
+  // The unstacked yval is equal to the current yval minus the yval of the 
+  // next point at the same xval.
+  for (var i = idx+1; i < this.points.length; i++) {
+    if (this.points[i].xval == point.xval) {
+      unstackedPoint.yval -= this.points[i].yval; 
+      break;
+    }
+  }
+  
+  return unstackedPoint;
+}  
+
 // Subclass PlotKit.CanvasRenderer to add:
 // 1. X/Y grid overlay
 // 2. Ability to draw error bars (if required)
@@ -270,8 +295,33 @@ DygraphCanvasRenderer = function(dygraph, element, layout, options) {
   this.area.h = this.height - this.options.axisLabelFontSize -
                 2 * this.options.axisTickSize;
 
+  // Shrink the drawing area to accomodate additional y-axes.
+  if (this.dygraph_.numAxes() == 2) {
+    // TODO(danvk): per-axis setting.
+    this.area.w -= (this.options.yAxisLabelWidth + 2 * this.options.axisTickSize);
+  } else if (this.dygraph_.numAxes() > 2) {
+    this.dygraph_.error("Only two y-axes are supported at this time. (Trying " +
+                        "to use " + this.dygraph_.numAxes() + ")");
+  }
+
   this.container.style.position = "relative";
   this.container.style.width = this.width + "px";
+
+  // Set up a clipping area for the canvas (and the interaction canvas).
+  // This ensures that we don't overdraw.
+  var ctx = this.dygraph_.canvas_.getContext("2d");
+  ctx.beginPath();
+  ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h);
+  ctx.clip();
+
+  ctx = this.dygraph_.hidden_.getContext("2d");
+  ctx.beginPath();
+  ctx.rect(this.area.x, this.area.y, this.area.w, this.area.h);
+  ctx.clip();
+};
+
+DygraphCanvasRenderer.prototype.attr_ = function(x) {
+  return this.dygraph_.attr_(x);
 };
 
 DygraphCanvasRenderer.prototype.clear = function() {
@@ -297,15 +347,15 @@ DygraphCanvasRenderer.prototype.clear = function() {
 
   for (var i = 0; i < this.xlabels.length; i++) {
     var el = this.xlabels[i];
-    el.parentNode.removeChild(el);
+    if (el.parentNode) el.parentNode.removeChild(el);
   }
   for (var i = 0; i < this.ylabels.length; i++) {
     var el = this.ylabels[i];
-    el.parentNode.removeChild(el);
+    if (el.parentNode) el.parentNode.removeChild(el);
   }
   for (var i = 0; i < this.annotations.length; i++) {
     var el = this.annotations[i];
-    el.parentNode.removeChild(el);
+    if (el.parentNode) el.parentNode.removeChild(el);
   }
   this.xlabels = new Array();
   this.ylabels = new Array();
@@ -336,17 +386,11 @@ DygraphCanvasRenderer.isSupported = function(canvasName) {
  * Draw an X/Y grid on top of the existing plot
  */
 DygraphCanvasRenderer.prototype.render = function() {
-  // Shrink the drawing area to accomodate additional y-axes.
-  if (this.layout.options.yAxes.length == 2) {
-    // TODO(danvk): per-axis setting.
-    this.area.w -= (this.options.yAxisLabelWidth + 2 * this.options.axisTickSize);
-  } else if (this.layout.options.yAxes.length > 2) {
-    this.dygraph_.error("Only two y-axes are supported at this time. (Trying " +
-                        "to use " + this.layout.yAxes.length + ")");
-  }
-
-  // Draw the new X/Y grid
+  // Draw the new X/Y grid. Lines appear crisper when pixels are rounded to
+  // half-integers. This prevents them from drawing in two rows/cols.
   var ctx = this.element.getContext("2d");
+  function halfUp(x){return Math.round(x)+0.5};
+  function halfDown(y){return Math.round(y)-0.5};
 
   if (this.options.underlayCallback) {
     this.options.underlayCallback(ctx, this.area, this.layout, this.dygraph_);
@@ -358,9 +402,10 @@ DygraphCanvasRenderer.prototype.render = function() {
     ctx.strokeStyle = this.options.gridLineColor;
     ctx.lineWidth = this.options.axisLineWidth;
     for (var i = 0; i < ticks.length; i++) {
-      if (ticks[i][0] != 0) continue;  // TODO(danvk): per-axis property
-      var x = this.area.x;
-      var y = this.area.y + ticks[i][1] * this.area.h;
+      // TODO(danvk): allow secondary axes to draw a grid, too.
+      if (ticks[i][0] != 0) continue;
+      var x = halfUp(this.area.x);
+      var y = halfDown(this.area.y + ticks[i][1] * this.area.h);
       ctx.beginPath();
       ctx.moveTo(x, y);
       ctx.lineTo(x + this.area.w, y);
@@ -375,8 +420,8 @@ DygraphCanvasRenderer.prototype.render = function() {
     ctx.strokeStyle = this.options.gridLineColor;
     ctx.lineWidth = this.options.axisLineWidth;
     for (var i=0; i<ticks.length; i++) {
-      var x = this.area.x + ticks[i][1] * this.area.w;
-      var y = this.area.y + this.area.h;
+      var x = halfUp(this.area.x + ticks[i][0] * this.area.w);
+      var y = halfDown(this.area.y + this.area.h);
       ctx.beginPath();
       ctx.moveTo(x, y);
       ctx.lineTo(x, this.area.y);
@@ -396,6 +441,10 @@ DygraphCanvasRenderer.prototype._renderAxis = function() {
   if (!this.options.drawXAxis && !this.options.drawYAxis)
     return;
 
+  // Round pixels to half-integer boundaries for crisper drawing.
+  function halfUp(x){return Math.round(x)+0.5};
+  function halfDown(y){return Math.round(y)-0.5};
+
   var context = this.element.getContext("2d");
 
   var labelStyle = {
@@ -428,13 +477,15 @@ DygraphCanvasRenderer.prototype._renderAxis = function() {
         var tick = this.layout.yticks[i];
         if (typeof(tick) == "function") return;
         var x = this.area.x;
-        if (tick[0] == 1) {
-          x = this.area.x + this.area.w - labelStyle.width;
+        var sgn = 1;
+        if (tick[0] == 1) {  // right-side y-axis
+          x = this.area.x + this.area.w;
+          sgn = -1;
         }
         var y = this.area.y + tick[1] * this.area.h;
         context.beginPath();
-        context.moveTo(x, y);
-        context.lineTo(x - this.options.axisTickSize, y);
+        context.moveTo(halfUp(x), halfDown(y));
+        context.lineTo(halfUp(x - sgn * this.options.axisTickSize), halfDown(y));
         context.closePath();
         context.stroke();
 
@@ -472,11 +523,21 @@ DygraphCanvasRenderer.prototype._renderAxis = function() {
       }
     }
 
+    // draw a vertical line on the left to separate the chart from the labels.
     context.beginPath();
-    context.moveTo(this.area.x, this.area.y);
-    context.lineTo(this.area.x, this.area.y + this.area.h);
+    context.moveTo(halfUp(this.area.x), halfDown(this.area.y));
+    context.lineTo(halfUp(this.area.x), halfDown(this.area.y + this.area.h));
     context.closePath();
     context.stroke();
+
+    // if there's a secondary y-axis, draw a vertical line for that, too.
+    if (this.dygraph_.numAxes() == 2) {
+      context.beginPath();
+      context.moveTo(halfDown(this.area.x + this.area.w), halfDown(this.area.y));
+      context.lineTo(halfDown(this.area.x + this.area.w), halfDown(this.area.y + this.area.h));
+      context.closePath();
+      context.stroke();
+    }
   }
 
   if (this.options.drawXAxis) {
@@ -488,8 +549,8 @@ DygraphCanvasRenderer.prototype._renderAxis = function() {
         var x = this.area.x + tick[0] * this.area.w;
         var y = this.area.y + this.area.h;
         context.beginPath();
-        context.moveTo(x, y);
-        context.lineTo(x, y + this.options.axisTickSize);
+        context.moveTo(halfUp(x), halfDown(y));
+        context.lineTo(halfUp(x), halfDown(y + this.options.axisTickSize));
         context.closePath();
         context.stroke();
 
@@ -515,8 +576,8 @@ DygraphCanvasRenderer.prototype._renderAxis = function() {
     }
 
     context.beginPath();
-    context.moveTo(this.area.x, this.area.y + this.area.h);
-    context.lineTo(this.area.x + this.area.w, this.area.y + this.area.h);
+    context.moveTo(halfUp(this.area.x), halfDown(this.area.y + this.area.h));
+    context.lineTo(halfUp(this.area.x + this.area.w), halfDown(this.area.y + this.area.h));
     context.closePath();
     context.stroke();
   }
@@ -627,12 +688,13 @@ DygraphCanvasRenderer.prototype._renderAnnotations = function() {
  * Overrides the CanvasRenderer method to draw error bars
  */
 DygraphCanvasRenderer.prototype._renderLineChart = function() {
+  // TODO(danvk): use this.attr_ for many of these.
   var context = this.element.getContext("2d");
   var colorCount = this.options.colorScheme.length;
   var colorScheme = this.options.colorScheme;
   var fillAlpha = this.options.fillAlpha;
   var errorBars = this.layout.options.errorBars;
-  var fillGraph = this.layout.options.fillGraph;
+  var fillGraph = this.attr_("fillGraph");
   var stackedGraph = this.layout.options.stackedGraph;
   var stepPlot = this.layout.options.stepPlot;
 
@@ -800,6 +862,15 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
       var point = points[j];
       if (point.name == setName) {
         if (!isOK(point.canvasy)) {
+          if (stepPlot && prevX != null) {
+            // Draw a horizontal line to the start of the missing data
+            ctx.beginPath();
+            ctx.strokeStyle = color;
+            ctx.lineWidth = this.options.strokeWidth;
+            ctx.moveTo(prevX, prevY);
+            ctx.lineTo(point.canvasx, prevY);
+            ctx.stroke();
+          }
           // this will make us move to the next point, not draw a line to it.
           prevX = prevY = null;
         } else {