How to get number of lines of TextView?

user_1289716 0
Viewed 81306

I want to get the number of lines of a text view 

textView.setText("Test line 1 Test line 2 Test line 3 Test line 4 Test line 5.............")

textView.getLineCount(); always returns zero

Then I have also tried:

ViewTreeObserver vto = this.textView.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

    @Override
    public void onGlobalLayout() {
        ViewTreeObserver obs = textView.getViewTreeObserver();
        obs.removeGlobalOnLayoutListener(this);
        System.out.println(": " + textView.getLineCount());

    }
});

It returns the exact output.

But this works only for a static layout.

When I am inflating the layout dynamically this doesn't work anymore.

How could I find the number of line in a TextView?

textview android
10 Answers

You could also use PrecomputedTextCompat for getting the number of lines. Regular method:

fun getTextLineCount(textView: TextView, text: String, lineCount: (Int) -> (Unit)) {
    val params: PrecomputedTextCompat.Params = TextViewCompat.getTextMetricsParams(textView)
    val ref: WeakReference<TextView>? = WeakReference(textView)

    GlobalScope.launch(Dispatchers.Default) {
        val text = PrecomputedTextCompat.create(text, params)
        GlobalScope.launch(Dispatchers.Main) {
            ref?.get()?.let { textView ->
                TextViewCompat.setPrecomputedText(textView, text)
                lineCount.invoke(textView.lineCount)
            }
        }
    }
}

Call this method:

getTextLineCount(textView, "Test line 1 Test line 2 Test line 3 Test line 4 Test line 5.............") { lineCount ->
     //count of lines is stored in lineCount variable
}

Or maybe you can create extension method for it like this:

fun TextView.getTextLineCount(text: String, lineCount: (Int) -> (Unit)) {
    val params: PrecomputedTextCompat.Params = TextViewCompat.getTextMetricsParams(this)
    val ref: WeakReference<TextView>? = WeakReference(this)

    GlobalScope.launch(Dispatchers.Default) {
        val text = PrecomputedTextCompat.create(text, params)
        GlobalScope.launch(Dispatchers.Main) {
            ref?.get()?.let { textView ->
                TextViewCompat.setPrecomputedText(textView, text)
                lineCount.invoke(textView.lineCount)
            }
        }
    }
}

and then you call it like this:

textView.getTextLineCount("Test line 1 Test line 2 Test line 3 Test line 4 Test line 5.............") { lineCount ->
     //count of lines is stored in lineCount variable
}
user_42604910

You can also calculate the amount of lines through this function:

private fun countLines(textView: TextView): Int {
        return Math.ceil(textView.paint.measureText(textView.text.toString()) /
                textView.measuredWidth.toDouble()).toInt()
    }

Keep in mind that It may not work very well on a RecyclerView though.

user_14039970 
textview.getText().toString().split(System.getProperty("line.separator")).length

It works fine for me to get number of lines of TextView.

user_106817510
Related