Fixed bug when graph is zoomed

[dygraphs.git] / dygraph-canvas.js

diff --git a/dygraph-canvas.js b/dygraph-canvas.js
index c3a8296..979688d 100644 (file)
--- a/dygraph-canvas.js
+++ b/dygraph-canvas.js
@@ -70,6 +70,7 @@ DygraphLayout.prototype._evaluateLineCharts = function() {
     for (var j = 0; j < dataset.length; j++) {
       var item = dataset[j];
       var point = {
+        // TODO(danvk): here
         x: ((parseFloat(item[0]) - this.minxval) * this.xscale),
         y: 1.0 - ((parseFloat(item[1]) - this.minyval) * this.yscale),
         xval: parseFloat(item[0]),
@@ -84,9 +85,7 @@ DygraphLayout.prototype._evaluateLineCharts = function() {
       if (point.y >= 1.0) {
         point.y = 1.0;
       }
-      if ((point.x >= 0.0) && (point.x <= 1.0)) {
-        this.points.push(point);
-      }
+      this.points.push(point);
     }
   }
 };
@@ -186,7 +185,9 @@ DygraphCanvasRenderer = function(dygraph, element, layout, options) {
     "axisLabelWidth": 50,
     "drawYGrid": true,
     "drawXGrid": true,
-    "gridLineColor": "rgb(128,128,128)"
+    "gridLineColor": "rgb(128,128,128)",
+    "fillAlpha": 0.15,
+    "underlayCallback": null
   };
   Dygraph.update(this.options, options);
 
@@ -276,6 +277,11 @@ DygraphCanvasRenderer.isSupported = function(canvasName) {
 DygraphCanvasRenderer.prototype.render = function() {
   // Draw the new X/Y grid
   var ctx = this.element.getContext("2d");
+
+  if (this.options.underlayCallback) {
+    this.options.underlayCallback(ctx, this.area, this.layout);
+  }
+
   if (this.options.drawYGrid) {
     var ticks = this.layout.yticks;
     ctx.save();
@@ -445,7 +451,9 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
   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 setNames = [];
   for (var name in this.layout.datasets) {
@@ -455,7 +463,8 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
   }
   var setCount = setNames.length;
 
-  //Update Points
+  // Update Points
+  // TODO(danvk): here
   for (var i = 0; i < this.layout.points.length; i++) {
     var point = this.layout.points[i];
     point.canvasx = this.area.w * point.x + this.area.x;
@@ -467,6 +476,10 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
 
   var ctx = context;
   if (errorBars) {
+    if (fillGraph) {
+      this.dygraph_.warn("Can't use fillGraph option with error bars");
+    }
+
     for (var i = 0; i < setCount; i++) {
       var setName = setNames[i];
       var color = colorScheme[i % colorCount];
@@ -475,28 +488,80 @@ DygraphCanvasRenderer.prototype._renderLineChart = function() {
       ctx.save();
       ctx.strokeStyle = color;
       ctx.lineWidth = this.options.strokeWidth;
-      var prevX = -1;
+      var prevX = NaN;
       var prevYs = [-1, -1];
       var count = 0;
       var yscale = this.layout.yscale;
       // should be same color as the lines but only 15% opaque.
       var rgb = new RGBColor(color);
-      var err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',0.15)';
+      var err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' +
+                            fillAlpha + ')';
       ctx.fillStyle = err_color;
       ctx.beginPath();
       for (var j = 0; j < this.layout.points.length; j++) {
         var point = this.layout.points[j];
         count++;
         if (point.name == setName) {
-          if (!point.y || isNaN(point.y)) {
-            prevX = -1;
+          if (!isOK(point.y)) {
+            prevX = NaN;
             continue;
           }
+          // TODO(danvk): here
           var newYs = [ point.y - point.errorPlus * yscale,
                         point.y + point.errorMinus * yscale ];
           newYs[0] = this.area.h * newYs[0] + this.area.y;
           newYs[1] = this.area.h * newYs[1] + this.area.y;
-          if (prevX >= 0) {
+          if (!isNaN(prevX)) {
+            ctx.moveTo(prevX, prevYs[0]);
+            ctx.lineTo(point.canvasx, newYs[0]);
+            ctx.lineTo(point.canvasx, newYs[1]);
+            ctx.lineTo(prevX, prevYs[1]);
+            ctx.closePath();
+          }
+          prevYs[0] = newYs[0];
+          prevYs[1] = newYs[1];
+          prevX = point.canvasx;
+        }
+      }
+      ctx.fill();
+    }
+  } else if (fillGraph) {
+    // TODO(danvk): merge this code with the logic above; they're very similar.
+    for (var i = 0; i < setCount; i++) {
+      var setName = setNames[i];
+      var setNameLast;
+      if (i>0) setNameLast = setNames[i-1];
+      var color = colorScheme[i % colorCount];
+
+      // setup graphics context
+      ctx.save();
+      ctx.strokeStyle = color;
+      ctx.lineWidth = this.options.strokeWidth;
+      var prevX = NaN;
+      var prevYs = [-1, -1];
+      var count = 0;
+      var yscale = this.layout.yscale;
+      // should be same color as the lines but only 15% opaque.
+      var rgb = new RGBColor(color);
+      var err_color = 'rgba(' + rgb.r + ',' + rgb.g + ',' + rgb.b + ',' +
+                            fillAlpha + ')';
+      ctx.fillStyle = err_color;
+      ctx.beginPath();
+      for (var j = 0; j < this.layout.points.length; j++) {
+        var point = this.layout.points[j];
+        count++;
+        if (point.name == setName) {
+          if (!isOK(point.y)) {
+            prevX = NaN;
+            continue;
+          }
+          var pX = 1.0 + this.layout.minyval * this.layout.yscale;
+          if (pX < 0.0) pX = 0.0;
+          else if (pX > 1.0) pX = 1.0;
+          var newYs = [ point.y, pX ];
+          newYs[0] = this.area.h * newYs[0] + this.area.y;
+          newYs[1] = this.area.h * newYs[1] + this.area.y;
+          if (!isNaN(prevX)) {
             ctx.moveTo(prevX, prevYs[0]);
             ctx.lineTo(point.canvasx, newYs[0]);
             ctx.lineTo(point.canvasx, newYs[1]);