Question

I have a question regarding performance and best approach for my Android code.

What I need to do is fairly simple, I want to dynamically assign a text value to a string ressource, depending on a int parameter:

For now I am using a big switch case

int messagesCategory;
if(extras !=null) {
        messagesCategory = extras.getInt("category");
    }

TextView titleText;
    titleText = (TextView) findViewById(R.id.headerTitle);

switch (messagesCategory) {
    case 1: titleText.setText(R.string.TitleMessageList1); break;
    case 2: titleText.setText(R.string.TitleMessageList2); break;
    case 3: titleText.setText(R.string.TitleMessageList3); break;
    case 4: titleText.setText(R.string.TitleMessageList4); break;

    case ...: titleText.setText(R.string.TitleMessageList...); break;

    case n: titleText.setText(R.string.TitleMessageListn); break;
    default: titleText.setText("a default title");  break;
    }

Let’s say I have 30 lines in this switch…
It works but for many cases, it looks there is a better way to achieve this.
Unfortunately it does not look possible to assign something dynamic to R.string..

So my first question is: 1) performance wise, in this case, is it a problem to use a big switch for 30 cases or so?
2) what should be the best approach?

Thanks and have a good day

Answer 1

Simple,

int[] stringIds = {R.string.TitleMessageList1, R.string.TitleMessageList2,...};

int messagesCategory;
TextView titleText = (TextView) findViewById(R.id.headerTitle);
    if(extras !=null) {
            messagesCategory = extras.getInt("category");
            if(messagesCategory  <= n)
            titleText.setText(stringIds[messagesCategory]);
            else  titleText.setText("a default title"); 
 }

Now, there is no switch-case and comparison,, Basic Java and Android fundamentals make it to easy and short..

As R.string.XXX is an int value generated in R.java file you have to make a just int array of that values and just get value using your int messagesCategory. And directly set it to TextView..