X-Git-Url: https://adrianiainlam.tk/git/?a=blobdiff_plain;f=dygraph-canvas.js;h=8dc502cb007226f837969ebffdbc0cabaa0b9360;hb=f0f2aef666950ea136e1ede7bc286ccb07c2c6b6;hp=76f0b4417ded18899e50ee9c84ca046fec74899b;hpb=26ca7938c710424b17f217508837f0950a3e45a8;p=dygraphs.git

diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index 76f0b44..8dc502c 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) {
@@ -111,13 +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);
     }
   }
@@ -308,7 +301,7 @@ DygraphCanvasRenderer = function(dygraph, element, layout, options) {
     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.layout.yAxes.length + ")");
+                        "to use " + this.dygraph_.numAxes() + ")");
   }
 
   this.container.style.position = "relative";
@@ -316,17 +309,21 @@ DygraphCanvasRenderer = function(dygraph, element, layout, options) {
 
   // Set up a clipping area for the canvas (and the interaction canvas).
   // This ensures that we don't overdraw.
-  var ctx = this.element.getContext("2d");
+  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();
 
-  var ctx = this.dygraph_.hidden_.getContext("2d");
+  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() {
   if (this.isIE) {
     // VML takes a while to start up, so we just poll every this.IEDelay
@@ -350,15 +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();
@@ -389,11 +386,16 @@ DygraphCanvasRenderer.isSupported = function(canvasName) {
  * Draw an X/Y grid on top of the existing plot
  */
 DygraphCanvasRenderer.prototype.render = function() {
-  // 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_);
+    // NOTE: we pass the dygraph object to this callback twice to avoid breaking
+    // users who expect a deprecated form of this callback.
+    this.options.underlayCallback(ctx, this.area, this.dygraph_, this.dygraph_);
   }
 
   if (this.options.drawYGrid) {
@@ -402,9 +404,10 @@ 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);
@@ -419,8 +422,8 @@ 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);
@@ -440,6 +443,10 @@ 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 = {
@@ -472,13 +479,15 @@ 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();
 
@@ -516,11 +525,21 @@ 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) {
@@ -532,8 +551,8 @@ 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();
 
@@ -559,8 +578,8 @@ 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();
   }
@@ -671,12 +690,13 @@ 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;