[patch][ccla]Pie Chart 2D: labels overlapped issue

[ruanqi]

Pie labels would overlapped when there is many slices in pie chart, hard to tell which slice that label belongs to. this pie chart enhencement provide a new label style called "columns", and re-caculate the label position.

var pieChart = new dc.Chart2D("pieChart");
pieChart.setTheme(dc.themes.MiamiNice).addPlot("default", {
    type: "Pie",
    font: "normal normal 10pt Tahoma",
    fontColor: "black",
    radius: 100,
    labelStyle: "columns",
    htmlLabels: true
})

demo link: ​http://dleadt.torolab.ibm.com/dl/dojodemos/rock/pie_smart_label.html

[Eugene Lazutkin]

Your demo link doesn't work outside of IBM.

[Adam Peller]

updated patch from Qi Ruan (IBM)

[Adam Peller]

Update from Rock: using "labelWiring" to define the stoke style of label connection line.

1. add "labelWiring" in defaultTheme.series of Theme.js
2. add "labelWiring" in optionalParams of Pie.js
3. add random data testing in test_pie_smart_label.html

[dotcom2]

I tried to apply the patch in my dojo_1-5-0_20100902 build, and tested using my test program test_piesmall.html.

I declares

var chart10 = new dc.Chart2D("test10");

chart10.addPlot("default", { type: "Pie", font: "normal normal 11pt Tahoma", fontColor: "black", labelWiring: "#ccc", labelStyle: "columns", htmlLabels: true, startAngle: -10, radius: 80

});

and defines three small slices:

{y: 0.05, text: "Green", color: "green", stroke: "black"}, {y: 0.05, text: "Red", color: "Red", stroke: "black"}, {y: 0.05, text: "Blue", color: "Blue", stroke: "black"},

I expect to see labels "Green", "Red", "Blue" for each of these small slices but the result I see is those three labels are still overlapped, cannot see the label text clearly.

I think the length of the "labelwire" should be flexible so that the labels can be displayed at different places, but the actual result shows the length of "labelwires" are all same, it made teh label overlapping if the pie slices are small.

The patch does not seem totally solved the problem.

[Eugene Lazutkin]

Replying to dotcom2:

I cannot reproduce it using test_piesmall.html. If you have more details, or different tests, please file a separate bug.

[Eugene Lazutkin]

(In [23506]) Charting: fan-style pie chart labels, thx Qi Ruan (CCLA, IBM)!, !strict, fixes #11425.