对jqplot的CategoryAxisRenderer插件进行扩展，底部Tick在鼠标在上时浮动显示名称。
在前一篇文章中介绍了如何让jqplot的柱形图tick下标出现省略号，参考：
《对jqplot的CategoryAxisRenderer插件进行扩展，让文字出现省略号》
http://xianbin.iteye.com/blog/1701667
下面介绍如何扩展jqplot，让其实现鼠标移动到下标tick的时候出现浮动提示框，显示完整的tick名称。
文件命名为：jqplot.categoryAxisRenderer.extend.js
在引入jqplot.categoryAxisRenderer.js之后，再引入该js，以便覆盖原有的实现。下面代码已经实现了将tick下标显示为带省略号的文字并出现浮动提示框。
《对jqplot的CategoryAxisRenderer插件进行扩展，让文字出现省略号》
http://xianbin.iteye.com/blog/1701667
下面介绍如何扩展jqplot，让其实现鼠标移动到下标tick的时候出现浮动提示框，显示完整的tick名称。
文件命名为：jqplot.categoryAxisRenderer.extend.js
在引入jqplot.categoryAxisRenderer.js之后，再引入该js，以便覆盖原有的实现。下面代码已经实现了将tick下标显示为带省略号的文字并出现浮动提示框。
/**
* 本扩展插件是对jqplot插件jqplot.categoryAxisRenderer的扩展，主要修改了显示图形下标Tick的处理，
* 在显示Tick之前，判断Tick标签的长度，当标题长度超过tickMaxLength定义的长度时，截获前
* tickMaxLength - 1个字符，然后加上省略号。
*
* 作者：suxianbin
*/
(function($) {
$.jqplot.CategoryAxisRenderer.prototype.createTicks = function() {
// we're are operating on an axis here
var ticks = this._ticks;
var userTicks = this.ticks;
var name = this.name;
// databounds were set on axis initialization.
var db = this._dataBounds;
var dim, interval;
var min, max;
var pos1, pos2;
var tt, i;
// X轴的标题文字最大长度
var tickMaxLength = this.tickMaxLength;
// if we already have ticks, use them.
if (userTicks.length) {
// adjust with blanks if we have groups
if (this.groups > 1 && !this._grouped) {
var l = userTicks.length;
var skip = parseInt(l/this.groups, 10);
var count = 0;
for (var i=skip; i<l; i+=skip) {
userTicks.splice(i+count, 0, ' ');
count++;
}
this._grouped = true;
}
this.min = 0.5;
this.max = userTicks.length + 0.5;
var range = this.max - this.min;
this.numberTicks = 2*userTicks.length + 1;
for (i=0; i<userTicks.length; i++){
tt = this.min + 2 * i * range / (this.numberTicks-1);
// need a marker before and after the tick
var t = new this.tickRenderer(this.tickOptions);
t.showLabel = false;
// t.showMark = true;
t.setTick(tt, this.name);
this._ticks.push(t);
var t = new this.tickRenderer(this.tickOptions);
// 当标题长度超过tickMaxLength定义的长度时，截获前tickMaxLength - 1个字符，
// 然后加上省略号。
if (tickMaxLength) {
var userTick = userTicks[i].length <= tickMaxLength ? userTicks[i]
: userTicks[i].substring(0, (tickMaxLength - 1)) + '...';
t.label = userTick;
t.userTick = userTicks[i];
} else {
t.label = userTicks[i];
}
// t.showLabel = true;
t.showMark = false;
t.showGridline = false;
t.setTick(tt+0.5, this.name);
this._ticks.push(t);
}
// now add the last tick at the end
var t = new this.tickRenderer(this.tickOptions);
t.showLabel = false;
// t.showMark = true;
t.setTick(tt+1, this.name);
this._ticks.push(t);
}
// we don't have any ticks yet, let's make some!
else {
if (name == 'xaxis' || name == 'x2axis') {
dim = this._plotDimensions.width;
}
else {
dim = this._plotDimensions.height;
}
// if min, max and number of ticks specified, user can't specify interval.
if (this.min != null && this.max != null && this.numberTicks != null) {
this.tickInterval = null;
}
// if max, min, and interval specified and interval won't fit, ignore interval.
if (this.min != null && this.max != null && this.tickInterval != null) {
if (parseInt((this.max-this.min)/this.tickInterval, 10) != (this.max-this.min)/this.tickInterval) {
this.tickInterval = null;
}
}
// find out how many categories are in the lines and collect labels
var labels = [];
var numcats = 0;
var min = 0.5;
var max, val;
var isMerged = false;
for (var i=0; i<this._series.length; i++) {
var s = this._series[i];
for (var j=0; j<s.data.length; j++) {
if (this.name == 'xaxis' || this.name == 'x2axis') {
val = s.data[j][0];
}
else {
val = s.data[j][1];
}
if ($.inArray(val, labels) == -1) {
isMerged = true;
numcats += 1;
labels.push(val);
}
}
}
if (isMerged && this.sortMergedLabels) {
labels.sort(function(a,b) { return a - b; });
}
// keep a reference to these tick labels to use for redrawing plot (see bug #57)
this.ticks = labels;
// now bin the data values to the right lables.
for (var i=0; i<this._series.length; i++) {
var s = this._series[i];
for (var j=0; j<s.data.length; j++) {
if (this.name == 'xaxis' || this.name == 'x2axis') {
val = s.data[j][0];
}
else {
val = s.data[j][1];
}
// for category axis, force the values into category bins.
// we should have the value in the label array now.
var idx = $.inArray(val, labels)+1;
if (this.name == 'xaxis' || this.name == 'x2axis') {
s.data[j][0] = idx;
}
else {
s.data[j][1] = idx;
}
}
}
// adjust with blanks if we have groups
if (this.groups > 1 && !this._grouped) {
var l = labels.length;
var skip = parseInt(l/this.groups, 10);
var count = 0;
for (var i=skip; i<l; i+=skip+1) {
labels[i] = ' ';
}
this._grouped = true;
}
max = numcats + 0.5;
if (this.numberTicks == null) {
this.numberTicks = 2*numcats + 1;
}
var range = max - min;
this.min = min;
this.max = max;
var track = 0;
// todo: adjust this so more ticks displayed.
var maxVisibleTicks = parseInt(3+dim/10, 10);
var skip = parseInt(numcats/maxVisibleTicks, 10);
if (this.tickInterval == null) {
this.tickInterval = range / (this.numberTicks-1);
}
// if tickInterval is specified, we will ignore any computed maximum.
for (var i=0; i<this.numberTicks; i++){
tt = this.min + i * this.tickInterval;
var t = new this.tickRenderer(this.tickOptions);
// if even tick, it isn't a category, it's a divider
if (i/2 == parseInt(i/2, 10)) {
t.showLabel = false;
t.showMark = true;
}
else {
if (skip>0 && track<skip) {
t.showLabel = false;
track += 1;
}
else {
t.showLabel = true;
track = 0;
}
t.label = t.formatter(t.formatString, labels[(i-1)/2]);
t.showMark = false;
t.showGridline = false;
}
t.setTick(tt, this.name);
this._ticks.push(t);
}
}
};
// called with scope of axis
$.jqplot.CategoryAxisRenderer.prototype.pack = function(pos, offsets) {
var ticks = this._ticks;
var max = this.max;
var min = this.min;
var offmax = offsets.max;
var offmin = offsets.min;
var lshow = (this._label == null) ? false : this._label.show;
var i;
for (var p in pos) {
this._elem.css(p, pos[p]);
}
this._offsets = offsets;
// pixellength will be + for x axes and - for y axes becasue pixels always measured from top left.
var pixellength = offmax - offmin;
var unitlength = max - min;
// point to unit and unit to point conversions references to Plot DOM element top left corner.
this.p2u = function(p){
return (p - offmin) * unitlength / pixellength + min;
};
this.u2p = function(u){
return (u - min) * pixellength / unitlength + offmin;
};
if (this.name == 'xaxis' || this.name == 'x2axis'){
this.series_u2p = function(u){
return (u - min) * pixellength / unitlength;
};
this.series_p2u = function(p){
return p * unitlength / pixellength + min;
};
}
else {
this.series_u2p = function(u){
return (u - max) * pixellength / unitlength;
};
this.series_p2u = function(p){
return p * unitlength / pixellength + max;
};
}
if (this.show) {
if (this.name == 'xaxis' || this.name == 'x2axis') {
for (i=0; i<ticks.length; i++) {
var t = ticks[i];
if (t.show && t.showLabel) {
var shim;
if (t.constructor == $.jqplot.CanvasAxisTickRenderer && t.angle) {
// will need to adjust auto positioning based on which axis this is.
var temp = (this.name == 'xaxis') ? 1 : -1;
switch (t.labelPosition) {
case 'auto':
// position at end
if (temp * t.angle < 0) {
shim = -t.getWidth() + t._textRenderer.height * Math.sin(-t._textRenderer.angle) / 2;
}
// position at start
else {
shim = -t._textRenderer.height * Math.sin(t._textRenderer.angle) / 2;
}
break;
case 'end':
shim = -t.getWidth() + t._textRenderer.height * Math.sin(-t._textRenderer.angle) / 2;
break;
case 'start':
shim = -t._textRenderer.height * Math.sin(t._textRenderer.angle) / 2;
break;
case 'middle':
shim = -t.getWidth()/2 + t._textRenderer.height * Math.sin(-t._textRenderer.angle) / 2;
break;
default:
shim = -t.getWidth()/2 + t._textRenderer.height * Math.sin(-t._textRenderer.angle) / 2;
break;
}
}
else {
shim = -t.getWidth()/2;
}
var val = this.u2p(t.value) + shim + 'px';
t._elem.css('left', val);
t.pack();
/*
* 增加X轴Tick的弹出提醒框，内容为下标的全称。
*/
t._elem.css('cursor', 'default');
t._elem.css('z-index', 888);
t._elem.attr('userTick', t.userTick);
t._elem.mouseover(function (e) {
var userTick = $(this).attr('usertick');
_showUserTickTip(userTick, e);
});
t._elem.mouseout(function () {
_hideUserTickTip();
});
}
}
var labeledge=['bottom', 0];
if (lshow) {
var w = this._label._elem.outerWidth(true);
this._label._elem.css('left', offmin + pixellength/2 - w/2 + 'px');
if (this.name == 'xaxis') {
this._label._elem.css('bottom', '0px');
labeledge = ['bottom', this._label._elem.outerHeight(true)];
}
else {
this._label._elem.css('top', '0px');
labeledge = ['top', this._label._elem.outerHeight(true)];
}
this._label.pack();
}
// draw the group labels
var step = parseInt(this._ticks.length/this.groups, 10);
for (i=0; i<this._groupLabels.length; i++) {
var mid = 0;
var count = 0;
for (var j=i*step; j<=(i+1)*step; j++) {
if (this._ticks[j]._elem && this._ticks[j].label != " ") {
var t = this._ticks[j]._elem;
var p = t.position();
mid += p.left + t.outerWidth(true)/2;
count++;
}
}
mid = mid/count;
this._groupLabels[i].css({'left':(mid - this._groupLabels[i].outerWidth(true)/2)});
this._groupLabels[i].css(labeledge[0], labeledge[1]);
}
}
else {
for (i=0; i<ticks.length; i++) {
var t = ticks[i];
if (t.show && t.showLabel) {
var shim;
if (t.constructor == $.jqplot.CanvasAxisTickRenderer && t.angle) {
// will need to adjust auto positioning based on which axis this is.
var temp = (this.name == 'yaxis') ? 1 : -1;
switch (t.labelPosition) {
case 'auto':
// position at end
case 'end':
if (temp * t.angle < 0) {
shim = -t._textRenderer.height * Math.cos(-t._textRenderer.angle) / 2;
}
else {
shim = -t.getHeight() + t._textRenderer.height * Math.cos(t._textRenderer.angle) / 2;
}
break;
case 'start':
if (t.angle > 0) {
shim = -t._textRenderer.height * Math.cos(-t._textRenderer.angle) / 2;
}
else {
shim = -t.getHeight() + t._textRenderer.height * Math.cos(t._textRenderer.angle) / 2;
}
break;
case 'middle':
// if (t.angle > 0) {
// shim = -t.getHeight()/2 + t._textRenderer.height * Math.sin(-t._textRenderer.angle) / 2;
// }
// else {
// shim = -t.getHeight()/2 - t._textRenderer.height * Math.sin(t._textRenderer.angle) / 2;
// }
shim = -t.getHeight()/2;
break;
default:
shim = -t.getHeight()/2;
break;
}
}
else {
shim = -t.getHeight()/2;
}
var val = this.u2p(t.value) + shim + 'px';
t._elem.css('top', val);
t.pack();
}
}
var labeledge=['left', 0];
if (lshow) {
var h = this._label._elem.outerHeight(true);
this._label._elem.css('top', offmax - pixellength/2 - h/2 + 'px');
if (this.name == 'yaxis') {
this._label._elem.css('left', '0px');
labeledge = ['left', this._label._elem.outerWidth(true)];
}
else {
this._label._elem.css('right', '0px');
labeledge = ['right', this._label._elem.outerWidth(true)];
}
this._label.pack();
}
// draw the group labels, position top here, do left after label position.
var step = parseInt(this._ticks.length/this.groups, 10);
for (i=0; i<this._groupLabels.length; i++) {
var mid = 0;
var count = 0;
for (var j=i*step; j<=(i+1)*step; j++) {
if (this._ticks[j]._elem && this._ticks[j].label != " ") {
var t = this._ticks[j]._elem;
var p = t.position();
mid += p.top + t.outerHeight()/2;
count++;
}
}
mid = mid/count;
this._groupLabels[i].css({'top':mid - this._groupLabels[i].outerHeight()/2});
this._groupLabels[i].css(labeledge[0], labeledge[1]);
}
}
}
};
// 显示Tick下标全称的提示框
function _showUserTickTip(userTick, event) {
var containerId = 'userTickTipDiv';
var container = $('#' + containerId);
if (container == undefined || container == null || container.length == 0) {
container = $('<div class="jqplot-cursor-tooltip chartDetailDiv"></div>');
container.attr('id', containerId);
var table = '<table class="jqplot-highlighter">'
+ '<tr><td><span id="userTickValue"></span></td></tr>'
+ '</table>';
$(table).appendTo(container);
container.appendTo('body');
}
$('#userTickValue').text(userTick);
// 计算显示框的位置，如果超过右边边界则在左边显示
var left = event.pageX;
var detailPopDivWidth = container.width();
var docWidth = $(window).width();
var leftX = left + detailPopDivWidth + 10; // 10 表示与边界的间隔
if (leftX > docWidth) {
left = event.pageX - detailPopDivWidth;
}
container.css({
display : 'block',
left : left,
top : event.pageY - 25
});
}
// 隐藏Tick下标全称的提示框
function _hideUserTickTip() {
$('#userTickTipDiv').css({
display : 'none'
});
}
})(jQuery);