From f2dba96db6b7c67504bb7281328b8df774b86e6d Mon Sep 17 00:00:00 2001
From: Jackson Tian <shyvo1987@gmail.com>
Date: Tue, 5 Feb 2013 16:45:51 +0800
Subject: [PATCH] Fix line chart x axis issue

---
 lib/charts/line.js | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/lib/charts/line.js b/lib/charts/line.js
index ad06df7..c2ccec6 100644
--- a/lib/charts/line.js
+++ b/lib/charts/line.js
@@ -7,7 +7,6 @@
   }
 })('Line', function (require) {
   var DataV = require('DataV');
-  var theme = DataV.Themes;
 
   /**
    * Line构造函数，继承自Chart
@@ -37,8 +36,8 @@
    *   - `yAxisFontSize 数字，y轴说明文字字号，默认值为10
    *   - `xAxisStartDx 数字，x轴刻度起始位置与坐标轴最左端水平距离，默认值为20
    *   - `yAxisStartDy 数字，y轴刻度起始位置与坐标轴最下端垂直距离，默认值为10
-   *   - `xAxisEndDx 数字，x轴刻度起始位置与坐标轴最右端水平距离，默认值为10
-   *   - `yAxisEndDy 数字，y轴刻度起始位置与坐标轴最上端水平距离，默认值为10
+   *   - `xAxisEndDx 数字，x轴刻度结束位置与坐标轴最右端水平距离，默认值为10
+   *   - `yAxisEndDy 数字，y轴刻度结束位置与坐标轴最上端水平距离，默认值为10
    *   - `textLean 布尔值，是否将x轴说明文字倾斜摆放，默认值为false
    *   - `hasXGrid 布尔值，是否需要绘制与x坐标轴平行的网格线，默认值为true
    *   - `hasYGrid 布尔值，是否需要绘制与x坐标轴平行的网格线，默认值为true
@@ -50,9 +49,8 @@
    *   - `unchosen0pacity 数字，当有折线被选中时，其他淡出折线的透明度，默认值为0.15
    *   - `grid0pacity 数字，网格线透明度，默认值为0.1
    *   - `chosenGrid0pacity 数字，高亮网格线透明度，默认值为0.5
-
-   * Create line in a dom node with id "chart", width is 500px; height is 600px;
    * Examples:
+   * Create line in a dom node with id "chart", width is 500px; height is 600px;
    * ```
    * var line = new Line("chart", {"width": 500, "height": 600});
    * ```
@@ -177,7 +175,6 @@
     var lines = _.groupBy(dataTable, map.line);
     var linesData = [];
 
-    var max, min;
     var maxList = [], minList = [];
     this.maxLength = Math.max.apply(null, _.map(lines, function (line) {
       return line.length;
@@ -252,14 +249,9 @@
         tickLength = 5;
       }
 
-      var tick = conf.xAxisTick;
-      var tickStep;
-      if (tick % maxLength === 0) {
-        tickStep = xDataArea / (tick - 1);
-      } else {
-        tickStep = xDataArea / (this.maxLength - 1);
-        tick = this.maxLength;
-      }
+      // 当内容少于刻度数量时，用内容的数量作为刻度数量
+      var tick = Math.min(maxLength, conf.xAxisTick);
+      var tickStep = xDataArea / (tick - 1);
 
       var xAxis = canvas.set();
       var xGrid = canvas.set();
@@ -270,13 +262,14 @@
       for (var i = 0; i < tick; i++) {
         xGrid.push(canvas.path("M" + (startX + i * tickStep) + "," + startY + "L" + (startX + i * tickStep) + "," + (startY - tickLength)));
         if (i < l) {
-          var thisText = canvas.text((startX + i * tickStep), startY + xAxisPadding, titles[i]);
+          // 绘制横坐标上的文字
+          var text = canvas.text((startX + i * tickStep), startY + xAxisPadding, titles[i]);
           if (textLean) {
-            var d = thisText.getBBox().width / 2;
+            var d = text.getBBox().width / 2;
             var angle = 45 / 360 * Math.PI;
-            thisText.transform("r45t" + Math.cos(angle) * d + "," + Math.sin(angle) * d);
+            text.transform("r45t" + Math.cos(angle) * d + "," + Math.sin(angle) * d);
           }
-          xAxisText.push(thisText);
+          xAxisText.push(text);
         }
       }