Reputation: 169
I have a page that dynamically loads a google timeline chart onto a div. The timeline increases in height as you add items on to it. If the chart is smaller than the div, it will be visible with empty space at the bottom. If the chart is larger, it will show scrollbars on the side.
What I would like is for the container div to always show the full chart or, another way, I would like the container div height to dynamically match the height of the chart.
I have tried to approximate the average size of each chart line and then adjust the div height when I load the chart with:
$("#gantt_chart").height(data['num_contents']*46);
But, although that somehow works, it's far from perfect because the approximation on height starts to accumulate with each additional line and the empty space at the bottom of the div increases which is not an elegant solution at all.
How would I ensure that the container div always shows the full chart?
I hope this is clear enough.
Many thanks.
Upvotes: 14
Views: 9522
Reputation: 1083
Been trying to do the same thing myself. The top answer wasn’t exactly right and caused an inner scroll bar to appear at times.
Here’s what worked for me:
var barLabelFontSize = 12; //default font size for bar labels
try{barLabelFontSize = options.timeline.barLabelStyle.fontSize; //bar height is dependent on the bar label's font size that you set...
}catch(e){}
var barHeight = barLabelFontSize * 1.196; //found in google api as: this.PU = 1.916 * this.UF.fontSize;
var barMargin = barLabelFontSize * 0.75; //found in google api as: this.Rfa = .75 * this.UF.fontSize;
var rowHeight = barHeight + barMargin * 2; //found in google api as: b.height = 2 * this.Rfa + this.PU (+additional complication for grouped bars, if anyone wants to try work that out it was: b.height = 2 * this.Rfa + this.PU * a.SI.length + this.Qfa * (a.SI.length - 1); (where Qfa is 0.583 * font size, and a.SI.length is the number of grouped bars displayed on the row)
var chartAreaHeight = rowHeight * dataTable.getNumberOfRows();
var axisHeight = 24; //worked out by querying: document.getElementById('timelineChart') getElementsByTagName('svg')[0].getBBox().height;
var whiteSpaceHeight = 28; //trail-and-error to find how much whitespace was required to stop a scroll bar appearing, 27 works too, but I rounded up to play it safe
var chartHeight = chartAreaHeight + axisHeight + whiteSpaceHeight;
You can also reverse engineer this to set the height of the bars using the bar label font size.
Upvotes: 0
Reputation: 546
Though in the doc they have shown to adjust height of div from where we are specifying the id of timeline but I recommend you to have set the height from the internal method.
// set the height for padding(padding height)
var pH = 40;
// get total height of rows (row height)
var rH = dataTable.getNumberOfRows() * 15;
// total chart height (chart height)
var cH = rH + pH;
// Now set this chart height to the timeline via option object
// apart from height, other attributes are just optional
var options = {
height: chartHeight,
colors: ['#339900', '#e6e600', '#B00000'],
tooltip: {
isHtml: true
},
timeline: {
colorByRowLabel: false
},
avoidOverlappingGridLines: true
};
Upvotes: 3
Reputation: 26340
The chart determines its height by either checking the height
option passed into the draw
call, or by checking the container height if the height
option is not specified. I would suggest using the option instead of changing the div height via jQuery. I find the best method for dynamically calculating the chart height is to take the height of a row (typically 41px) times the number of rows, plus some padding for the top and bottom:
var height = data.getNumberOfRows() * 41 + 30;
Upvotes: 16