Aligning and spacing of texts of buttons in a flextable using GAS - css

Question

In a flextable I create rows with buttons in the first column showing the number of each row, and textboxes in other columns.
I would like to reduce space between rows to a minimum.
var btnField = app.createButton(numRow).setId(fieldId).setSize(20, 20)
.setStyleAttribute('marginBottom', 3).setStyleAttribute('marginTop', 0)
.setStyleAttribute('fontSize', 8).setText(numRow));
flextable.setCellSpacing(1).setCellPadding(1); //Minimum distance between rows ??
Problem regarding the buttons is that the texts are not in the middle of the buttons vertically. I cannot reduce the size of the buttons (using .setSize(20, 18) or so) as text will become outside the buttons at the bottom.
What styleattributes should I use to position the text of the buttons in the middle of the buttons vertically, right alligned with a small marginRight? The buttons itself should not exceed the size of the textboxes in order to minimize distances between rows.
If I have to use settings on the flextable, that will be OK as well of course.

Answer 1

Style attributes should be written using camelCase, use fontSize instead of fontsize and you'll get this :
which is nicely centered.
edit : I made a few tests on button text alignment and the results are a bit surprising ...
code and illustration below show that only horizontal alignment is doable on text content and that paddingTop applies but has side effects the other widgets as well
function doGet() {
var app = UiApp.createApplication().setTitle('test buttons');
var btn1 = app.createButton('test Button1').setPixelSize(200,60).setStyleAttributes({'fontFamily': 'serif','fontWeight': 'bold','fontSize':'14pt','text-align':'right'});
var btn2 = app.createButton('test Button2').setPixelSize(200,30).setStyleAttributes({'fontSize':'12pt','textAlign':'left'});
var btn3 = app.createButton('test Button3').setPixelSize(200,16).setStyleAttributes({'fontSize':'8pt','padding':'0px'});
var btn4 = app.createButton('test Button4').setPixelSize(200,60).setStyleAttributes({'fontSize':'8pt','paddingTop':'30px'});
app.add(btn1).add(btn2).add(btn3).add(btn4);
return app;
}
A combination od padding and verticalAlignment can give interesting results, see below :
var btn4 = app.createButton('testButton4').setPixelSize(200,60).setStyleAttributes({'fontSize':'8pt','paddingTop':'30px','vertical-align':'-11px'});