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   1  /**
   2   * jqPlot
   3   * Pure JavaScript plotting plugin using jQuery
   4   *
   5   * Version: 1.0.2
   6   * Revision: 1108
   7   *
   8   * Copyright (c) 2009-2011 Chris Leonello
   9   * jqPlot is currently available for use in all personal or commercial projects 
  10   * under both the MIT (http://www.opensource.org/licenses/mit-license.php) and GPL 
  11   * version 2.0 (http://www.gnu.org/licenses/gpl-2.0.html) licenses. This means that you can 
  12   * choose the license that best suits your project and use it accordingly. 
  13   *
  14   * Although not required, the author would appreciate an email letting him 
  15   * know of any substantial use of jqPlot.  You can reach the author at: 
  16   * chris at jqplot dot com or see http://www.jqplot.com/info.php .
  17   *
  18   * If you are feeling kind and generous, consider supporting the project by
  19   * making a donation at: http://www.jqplot.com/donate.php .
  20   *
  21   * sprintf functions contained in jqplot.sprintf.js by Ash Searle:
  22   *
  23   *     version 2007.04.27
  24   *     author Ash Searle
  25   *     http://hexmen.com/blog/2007/03/printf-sprintf/
  26   *     http://hexmen.com/js/sprintf.js
  27   *     The author (Ash Searle) has placed this code in the public domain:
  28   *     "This code is unrestricted: you are free to use it however you like."
  29   * 
  30   */
  31  (function($) {
  32      /**
  33      * Class: $.jqplot.CanvasAxisLabelRenderer
  34      * Renderer to draw axis labels with a canvas element to support advanced
  35      * featrues such as rotated text.  This renderer uses a separate rendering engine
  36      * to draw the text on the canvas.  Two modes of rendering the text are available.
  37      * If the browser has native font support for canvas fonts (currently Mozila 3.5
  38      * and Safari 4), you can enable text rendering with the canvas fillText method.
  39      * You do so by setting the "enableFontSupport" option to true. 
  40      * 
  41      * Browsers lacking native font support will have the text drawn on the canvas
  42      * using the Hershey font metrics.  Even if the "enableFontSupport" option is true
  43      * non-supporting browsers will still render with the Hershey font.
  44      * 
  45      */
  46      $.jqplot.CanvasAxisLabelRenderer = function(options) {
  47          // Group: Properties
  48          
  49          // prop: angle
  50          // angle of text, measured clockwise from x axis.
  51          this.angle = 0;
  52          // name of the axis associated with this tick
  53          this.axis;
  54          // prop: show
  55          // wether or not to show the tick (mark and label).
  56          this.show = true;
  57          // prop: showLabel
  58          // wether or not to show the label.
  59          this.showLabel = true;
  60          // prop: label
  61          // label for the axis.
  62          this.label = '';
  63          // prop: fontFamily
  64          // CSS spec for the font-family css attribute.
  65          // Applies only to browsers supporting native font rendering in the
  66          // canvas tag.  Currently Mozilla 3.5 and Safari 4.
  67          this.fontFamily = '"Trebuchet MS", Arial, Helvetica, sans-serif';
  68          // prop: fontSize
  69          // CSS spec for font size.
  70          this.fontSize = '11pt';
  71          // prop: fontWeight
  72          // CSS spec for fontWeight:  normal, bold, bolder, lighter or a number 100 - 900
  73          this.fontWeight = 'normal';
  74          // prop: fontStretch
  75          // Multiplier to condense or expand font width.  
  76          // Applies only to browsers which don't support canvas native font rendering.
  77          this.fontStretch = 1.0;
  78          // prop: textColor
  79          // css spec for the color attribute.
  80          this.textColor = '#666666';
  81          // prop: enableFontSupport
  82          // true to turn on native canvas font support in Mozilla 3.5+ and Safari 4+.
  83          // If true, label will be drawn with canvas tag native support for fonts.
  84          // If false, label will be drawn with Hershey font metrics.
  85          this.enableFontSupport = true;
  86          // prop: pt2px
  87          // Point to pixel scaling factor, used for computing height of bounding box
  88          // around a label.  The labels text renderer has a default setting of 1.4, which 
  89          // should be suitable for most fonts.  Leave as null to use default.  If tops of
  90          // letters appear clipped, increase this.  If bounding box seems too big, decrease.
  91          // This is an issue only with the native font renderering capabilities of Mozilla
  92          // 3.5 and Safari 4 since they do not provide a method to determine the font height.
  93          this.pt2px = null;
  94          
  95          this._elem;
  96          this._ctx;
  97          this._plotWidth;
  98          this._plotHeight;
  99          this._plotDimensions = {height:null, width:null};
 100          
 101          $.extend(true, this, options);
 102          
 103          if (options.angle == null && this.axis != 'xaxis' && this.axis != 'x2axis') {
 104              this.angle = -90;
 105          }
 106          
 107          var ropts = {fontSize:this.fontSize, fontWeight:this.fontWeight, fontStretch:this.fontStretch, fillStyle:this.textColor, angle:this.getAngleRad(), fontFamily:this.fontFamily};
 108          if (this.pt2px) {
 109              ropts.pt2px = this.pt2px;
 110          }
 111          
 112          if (this.enableFontSupport) {
 113              if ($.jqplot.support_canvas_text()) {
 114                  this._textRenderer = new $.jqplot.CanvasFontRenderer(ropts);
 115              }
 116              
 117              else {
 118                  this._textRenderer = new $.jqplot.CanvasTextRenderer(ropts); 
 119              }
 120          }
 121          else {
 122              this._textRenderer = new $.jqplot.CanvasTextRenderer(ropts); 
 123          }
 124      };
 125      
 126      $.jqplot.CanvasAxisLabelRenderer.prototype.init = function(options) {
 127          $.extend(true, this, options);
 128          this._textRenderer.init({fontSize:this.fontSize, fontWeight:this.fontWeight, fontStretch:this.fontStretch, fillStyle:this.textColor, angle:this.getAngleRad(), fontFamily:this.fontFamily});
 129      };
 130      
 131      // return width along the x axis
 132      // will check first to see if an element exists.
 133      // if not, will return the computed text box width.
 134      $.jqplot.CanvasAxisLabelRenderer.prototype.getWidth = function(ctx) {
 135          if (this._elem) {
 136           return this._elem.outerWidth(true);
 137          }
 138          else {
 139              var tr = this._textRenderer;
 140              var l = tr.getWidth(ctx);
 141              var h = tr.getHeight(ctx);
 142              var w = Math.abs(Math.sin(tr.angle)*h) + Math.abs(Math.cos(tr.angle)*l);
 143              return w;
 144          }
 145      };
 146      
 147      // return height along the y axis.
 148      $.jqplot.CanvasAxisLabelRenderer.prototype.getHeight = function(ctx) {
 149          if (this._elem) {
 150           return this._elem.outerHeight(true);
 151          }
 152          else {
 153              var tr = this._textRenderer;
 154              var l = tr.getWidth(ctx);
 155              var h = tr.getHeight(ctx);
 156              var w = Math.abs(Math.cos(tr.angle)*h) + Math.abs(Math.sin(tr.angle)*l);
 157              return w;
 158          }
 159      };
 160      
 161      $.jqplot.CanvasAxisLabelRenderer.prototype.getAngleRad = function() {
 162          var a = this.angle * Math.PI/180;
 163          return a;
 164      };
 165      
 166      $.jqplot.CanvasAxisLabelRenderer.prototype.draw = function(ctx, plot) {
 167            // Memory Leaks patch
 168            if (this._elem) {
 169                if ($.jqplot.use_excanvas && window.G_vmlCanvasManager.uninitElement !== undefined) {
 170                    window.G_vmlCanvasManager.uninitElement(this._elem.get(0));
 171                }
 172              
 173                this._elem.emptyForce();
 174                this._elem = null;
 175            }
 176  
 177          // create a canvas here, but can't draw on it untill it is appended
 178          // to dom for IE compatability.
 179          var elem = plot.canvasManager.getCanvas();
 180  
 181          this._textRenderer.setText(this.label, ctx);
 182          var w = this.getWidth(ctx);
 183          var h = this.getHeight(ctx);
 184          elem.width = w;
 185          elem.height = h;
 186          elem.style.width = w;
 187          elem.style.height = h;
 188          
 189          elem = plot.canvasManager.initCanvas(elem);
 190          
 191          this._elem = $(elem);
 192          this._elem.css({ position: 'absolute'});
 193          this._elem.addClass('jqplot-'+this.axis+'-label');
 194          
 195          elem = null;
 196          return this._elem;
 197      };
 198      
 199      $.jqplot.CanvasAxisLabelRenderer.prototype.pack = function() {
 200          this._textRenderer.draw(this._elem.get(0).getContext("2d"), this.label);
 201      };
 202      
 203  })(jQuery);