text manipulation

function textManipulation(feature){
    var sel = myDiagram.selection;
    if(sel.count === 0){
        return;
    }
    var obj = sel.first();
    switch(feature){
        case "bold":
            toggleTextWeight(obj);
            break;
        case "italic":
            toggleTextWeight(obj);
            break;
        case "bigger":
            changeTextSize(obj, 1.1);
            break;
        case "smaller":
            changeTextSize(obj, 1/1.1);
            break;
        default:
            break;
    }
}

function changeTextSize(obj, factor) {
    var adorn = obj.part;
    adorn.diagram.startTransaction("Change Text Size");
    var node = adorn.adornedPart;
    var tb = node.findObject("text");
    tb.scale *= factor;
    adorn.diagram.commitTransaction("Change Text Size");
}

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