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Measuring text width to be drawn on Canvas ( Android )

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?


M
Mahozad

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


Thanks this is it! I don't know why I skipped it. The purpose was to simply draw a text at the center of the screen. Anyway I just realized I could also have just used setTextAlign(Align.CENTER) on the Paint used to draw the text, it shifts the specified origin to the center of the drawn text. Thanks.
Great, thanks, setting Align on the Paint! who would have thought of that...?
or you can set the Gravity of the textview to Center
P
Paresh J
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();

C
Community

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


J
Jim Baca

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:

https://i.stack.imgur.com/HsJ9Z.png

https://i.stack.imgur.com/aKM8k.png

Images taken from Android Developers Guide to Custom Canvas Drawing


H
Hiren Patel

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.


A
Armin J.

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.


Because kerning (space between letters) is dependent on individual letter sequences this will probably only work satisfactorily with fixed with fonts like Courier.
A
Ashish John

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