How can I get the number of lines a string will take up in a TextView before it is rendered.
A ViewTreeObserver will not work because thos
Reference: Getting height of text view before rendering to layout
Get line of TextView before rendering.
This is my code base the link above. It's working for me.
private int widthMeasureSpec;
private int heightMeasureSpec;
private int heightOfEachLine;
private int paddingFirstLine;
private void calculateHeightOfEachLine() {
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int deviceWidth = size.x;
widthMeasureSpec = View.MeasureSpec.makeMeasureSpec(deviceWidth, View.MeasureSpec.AT_MOST);
heightMeasureSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
//1 line = 76; 2 lines = 76 + 66; 3 lines = 76 + 66 + 66
//=> height of first line = 76 pixel; height of second line = third line =... n line = 66 pixel
int heightOfFirstLine = getHeightOfTextView("A");
int heightOfSecondLine = getHeightOfTextView("A\nA") - heightOfFirstLine;
paddingFirstLine = heightOfFirstLine - heightOfSecondLine;
heightOfEachLine = heightOfSecondLine;
}
private int getHeightOfTextView(String text) {
// Getting height of text view before rendering to layout
TextView textView = new TextView(context);
textView.setPadding(10, 0, 10, 0);
//textView.setTypeface(typeface);
textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, context.getResources().getDimension(R.dimen.tv_size_14sp));
textView.setText(text, TextView.BufferType.SPANNABLE);
textView.measure(widthMeasureSpec, heightMeasureSpec);
return textView.getMeasuredHeight();
}
private int getLineCountOfTextViewBeforeRendering(String text) {
return (getHeightOfTextView(text) - paddingFirstLine) / heightOfEachLine;
}
Note: This code also must be set for real textview on screen
textView.setTextSize(TypedValue.COMPLEX_UNIT_PX, context.getResources().getDimension(R.dimen.tv_size_14sp));