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Measuring text width to be drawn on Canvas ( Android )

Posted by: admin March 11, 2020 Leave a comment

Questions:

Is there a method which returns the width ( in pixels ) of a text to be drawn on an Android canvas using the drawText() method according to the Paint used to draw it?

How to&Answers:

Have you looked at android.graphics.Paint.measureText(String txt)?

Answer:

Paint paint = new Paint();
Rect bounds = new Rect();

int text_height = 0;
int text_width = 0;

paint.setTypeface(Typeface.DEFAULT);// your preference here
paint.setTextSize(25);// have this the same as your text size

String text = "Some random text";

paint.getTextBounds(text, 0, text.length(), bounds);

text_height =  bounds.height();
text_width =  bounds.width();

Answer:

Supplemental answer

There is a slight difference between the width returned by Paint.measureText and Paint.getTextBounds. measureText returns a width that includes the glyph’s advanceX value padding the beginning and end of the string. The Rect width returned by getTextBounds does not have this padding because the bounds is the Rect that tightly wraps the text.

source

Answer:

There’s actually three different ways of measuring text.

GetTextBounds:

val paint = Paint()
paint.typeface = ResourcesCompat.getFont(context, R.font.kaushanscript)
paint.textSize = 500f
paint.color = Color.argb(255, 3, 221, 252)
val contents = "g"
val rect = Rect()
paint.getTextBounds(contents, 0, 1, rect)
val width = rect.width()

MeasureTextWidth:

val paint = Paint()
paint.typeface = ResourcesCompat.getFont(context, R.font.kaushanscript)
paint.textSize = 500f
paint.color = Color.argb(255, 3, 221, 252)
val contents = "g"
val width = paint.measureText(contents, 0, 1)

And getTextWidths:

val paint = Paint()
paint.typeface = ResourcesCompat.getFont(context, R.font.kaushanscript)
paint.textSize = 500f
paint.color = Color.argb(255, 3, 221, 252)
val contents = "g"
val rect = Rect()
val arry = FloatArray(contents.length)
paint.getTextBounds(contents, 0, contents.length, rect)
paint.getTextWidths(contents, 0, contents.length, arry)
val width = ary.sum()

Note that getTextWidths could be useful if you are trying to determine when to wrap text to the next line.

The measureTextWidth and getTextWidth are equal and have the advanced width that measure that others have posted about. Some consider this space excessive. However, this is very subjective and dependent on the font.

For example the width from measure text bounds may actually look too small:

measure text bounds looks small

However when adding an additional text the bounds for one letter looks normal:
measure text bounds looks normal for strings

Images taken from Android Developers Guide to Custom Canvas Drawing

Answer:

Well I have done in different way:

String finalVal ="Hiren Patel";

Paint paint = new Paint();
paint.setTextSize(40);
Typeface typeface = Typeface.createFromAsset(getAssets(), "Helvetica.ttf");
paint.setTypeface(typeface);
paint.setColor(Color.BLACK);
paint.setStyle(Paint.Style.FILL);

Rect result = new Rect();
paint.getTextBounds(finalVal, 0, finalVal.length(), result);

Log.i("Text dimensions", "Width: "+result.width()+"-Height: "+result.height());

Hope this will help you.

Answer:

I used the methods measureText() and getTextPath()+computeBounds() and build up an Excel with all text attributes for fixed size font that can be found under https://github.com/ArminJo/android-blue-display/blob/master/TextWidth.xlsx .
There you will find also simple formulas for other text attributes like ascend etc.

The app as well as the function drawFontTest() for generating the raw values used in the excel are also available in this repo.

Answer:

you can use “textPaint.getTextSize()” to get text width