Android Center text on canvas

Question

I m trying to display a text using the code below  The problem is that the text is not centered horizontally  When I set the coordinates for drawText  it sets the bottom of the text at this position  I would like the text to be drawn so that the text is centered also horizontally   This is a picture to display my problem further      Override protected void onDraw Canvas canvas           TODO Auto-generated method stub     super onDraw canvas         canvas drawRGB 2  2  200       Paint textPaint   new Paint        textPaint setARGB 200  254  0  0       textPaint setTextAlign Align CENTER       textPaint setTypeface font       textPaint setTextSize 300       canvas drawText  Hello   canvas getWidth   2  canvas getHeight   2    textPaint

User · Answer

In my case  I didn t have to put the text in the middle of a canvas  but in a wheel that spins  Though I had to use this code to succeed    fun getTextRect textSize  Float  textPaint  TextPaint  string  String    PointF       val rect   RectF left  top  right  bottom      val rectHeight   Rect       val cx   rect centerX       val cy   rect centerY        textPaint getTextBounds string  0  string length  rectHeight      val y   cy   rectHeight height   2     val x   cx - textPaint measureText string  2      return PointF x  y      Then I call this method from the View class   private fun drawText canvas  Canvas  paint  TextPaint  text  String  string  String        val pointF   getTextRect paint textSize  textPaint  string      canvas drawText text  pointF   x  pointF y  paint

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Your code is drawing the center of the baseline of the text  at the center of the view   In order to center the text at some point  x  y  you need to calculate the center of the text  and put that at the point   This method will draw text centered at the point x  y   If you pass it the center of your view  it will draw the text centered   private void drawTextCentered String text  int x  int y  Paint paint  Canvas canvas        int xPos   x -  int  paint measureText text  2       int yPos    int   y -   textPaint descent     textPaint ascent      2          canvas drawText text  xPos  yPos  textPaint

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If we are using Static layout   mStaticLayout   new StaticLayout mText  mTextPaint  mTextWidth                  Layout Alignment ALIGN CENTER  1 0f  0  true     Layout Alignment ALIGN CENTER this  will do the trick  Static layout also has got a lot of other advantages   Reference Android Documentation

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Add these to your onDraw method  paint setColor getContext   getResources   getColor R color black    paint setTextAlign Paint Align CENTER   canvas drawText  quot Text quot    float  getHeight     2f   float  getWidth     2f  paint

User · Answer

Center with Paint getTextBounds       private Rect r   new Rect     private void drawCenter Canvas canvas  Paint paint  String text        canvas getClipBounds r       int cHeight   r height        int cWidth   r width        paint setTextAlign Paint Align LEFT       paint getTextBounds text  0  text length    r       float x   cWidth   2f - r width     2f - r left      float y   cHeight   2f   r height     2f - r bottom      canvas drawText text  x  y  paint        Paint Align CENTER doesn t mean that the reference point of the text is vertically centered  The reference point is always on the baseline  So  why not use Paint Align LEFT  You have to calculate the reference point anyway  Paint descent   has the disadvantage  that it doesn t consider the real text  Paint descent   retrieves the same value  regardless of whether the text contains letters with descents or not  That s why I use r bottom instead  I have had some problems with Canvas getHeight   if API  lt  16  That s why I use Canvas getClipBounds Rect  instead   Do not use Canvas getClipBounds   getHeight   as it allocates memory for a Rect   For reasons of performance  you should allocate objects before they are used in onDraw    As drawCenter   will be called within onDraw   the object Rect r is preallocated as a field here       I tried to put the code of the two top answers into my own code  August 2015  and made a screenshot to compare the results     The text should be centered within the red filled rectangle  My code produces the white text  the other two codes produces altogether the gray text  they are actually the same  overlapping   The gray text is a little bit too low and two much on the right   This is how I made the test   import android app Activity  import android content Context  import android content pm ActivityInfo  import android graphics Canvas  import android graphics Color  import android graphics Paint  import android graphics Rect  import android graphics RectF  import android graphics Typeface  import android os Bundle  import android view View  import android view ViewGroup  import android widget FrameLayout   class MyView extends View        private static String LABEL    long       private static float TEXT HEIGHT RATIO   0 82f       private FrameLayout LayoutParams params   new FrameLayout LayoutParams 0  0       private Rect r   new Rect        private Paint paint   new Paint        private Paint rectPaint   new Paint         public MyView Context context            super context              private void drawTextBounds Canvas canvas  Rect rect  int x  int y            rectPaint setColor Color rgb 0  0  0            rectPaint setStyle Paint Style STROKE           rectPaint setStrokeWidth 3f           rect offset x  y           canvas drawRect rect  rectPaint                 andreas1724  white color       private void draw1 Canvas canvas  Paint paint  String text            paint setTextAlign Paint Align LEFT           paint setColor Color rgb 255  255  255            canvas getClipBounds r           int cHeight   r height            int cWidth   r width            paint getTextBounds text  0  text length    r           float x   cWidth   2f - r width     2f - r left          float y   cHeight   2f   r height     2f - r bottom          canvas drawText text  x  y  paint           drawTextBounds canvas  r   int  x   int  y                 Arun George  light green color       private void draw2 Canvas canvas  Paint textPaint  String text            textPaint setTextAlign Paint Align CENTER           textPaint setColor Color argb 100  0  255  0            int xPos    canvas getWidth     2           int yPos    int    canvas getHeight     2  -   textPaint descent     textPaint ascent      2            canvas drawText text  xPos  yPos  textPaint                 VinceStyling  light blue color       private void draw3 Canvas yourCanvas  Paint mPaint  String pageTitle            mPaint setTextAlign Paint Align LEFT           mPaint setColor Color argb 100  0  0  255            r   yourCanvas getClipBounds            RectF bounds   new RectF r           bounds right   mPaint measureText pageTitle  0  pageTitle length             bounds bottom   mPaint descent   - mPaint ascent            bounds left     r width   - bounds right    2 0f          bounds top     r height   - bounds bottom    2 0f          yourCanvas drawText pageTitle  bounds left  bounds top - mPaint ascent    mPaint               Override     protected void onSizeChanged int w  int h  int oldw  int oldh            super onSizeChanged w  h  oldw  oldh           int margin   10          int width   w - 2   margin          int height   h - 2   margin          params width   width          params height   height          params leftMargin   margin          params topMargin   margin          setLayoutParams params           paint setTextSize height   TEXT HEIGHT RATIO           paint setAntiAlias true           paint setTypeface Typeface create Typeface SERIF  Typeface BOLD ITALIC                Override     protected void onDraw Canvas canvas            super onDraw canvas           canvas drawColor Color rgb 255  0  0            draw1 canvas  paint  LABEL           draw2 canvas  paint  LABEL           draw3 canvas  paint  LABEL            public class MainActivity extends Activity         Override     protected void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setRequestedOrientation  ActivityInfo SCREEN ORIENTATION LANDSCAPE           FrameLayout container   new FrameLayout this           container setLayoutParams new ViewGroup LayoutParams                  ViewGroup LayoutParams MATCH PARENT                  ViewGroup LayoutParams MATCH PARENT            container addView new MyView this            setContentView container

User · Answer

This worked for me     paint setTextAlign Paint Align CENTER           int xPos    newWidth   2           int yPos    newHeight   2           canvas drawText  Hello   xPos  yPos  paint     if anyone finds any problem please ket me know

User · Answer

works for me to use   textPaint textAlign   Paint Align CENTER with textPaint getTextBounds  private fun drawNumber i  Int  canvas  Canvas  translate  Float                val text     i              textPaint textAlign   Paint Align CENTER             textPaint getTextBounds text  0  text length  textBound               canvas drawText                        i                       translate   circleRadius                       height   2   textBound height     2  toFloat                        textPaint                           result is

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Use this in your paint properties   textPaint setTextAlign Paint Align CENTER

User · Answer

I create a method to simplify this       public static void drawCenterText String text  RectF rectF  Canvas canvas  Paint paint        Paint Align align   paint getTextAlign        float x      float y        x     if  align    Paint Align LEFT            x   rectF centerX   - paint measureText text    2        else if  align    Paint Align CENTER            x   rectF centerX          else           x   rectF centerX     paint measureText text    2              y     metrics   paint getFontMetrics        float acent   Math abs metrics ascent       float descent   Math abs metrics descent       y   rectF centerY      acent - descent    2f      canvas drawText text  x  y  paint        Log e  ghui    top     metrics top     ascent     metrics ascent                 dscent     metrics descent     leading     metrics leading     bottom    metrics bottom       rectF is the area you want draw the text That s it  Details

User · Answer

Try the following   Paint textPaint   new Paint     textPaint setTextAlign Paint Align CENTER     int xPos    canvas getWidth     2    int yPos    int    canvas getHeight     2  -   textPaint descent     textPaint ascent      2           textPaint descent     textPaint ascent      2  is the distance from the baseline to the center    canvas drawText  quot Hello quot   xPos  yPos  textPaint

User · Answer

Align vertically is difficult because text descent and ascent happened  lots of guys used Paint getTextBounds   to retrieve the TextWidth and TextHeight  but it doesn t make the text center very much  Here we can use Paint measureText   to calculate the TextWidth  the TextHeight we simply do subtracting with descent and ascent  then we got the most approach TextSize  the following work is fairly easy for each other      the Paint instance should be assign as a field of class   Paint mPaint   new Paint Paint ANTI ALIAS FLAG   mPaint setTextSize getResources   getDimension R dimen btn textsize        the display area  Rect areaRect   new Rect 0  0  240  60       draw the background style  pure color or image  mPaint setColor Color BLACK   yourCanvas drawRect areaRect  mPaint    String pageTitle            RectF bounds   new RectF areaRect      measure text width bounds right   mPaint measureText pageTitle  0  pageTitle length        measure text height bounds bottom   mPaint descent   - mPaint ascent     bounds left     areaRect width   - bounds right    2 0f  bounds top     areaRect height   - bounds bottom    2 0f   mPaint setColor Color WHITE   yourCanvas drawText pageTitle  bounds left  bounds top - mPaint ascent    mPaint       By the way  we highly recommend use RectF rather than Rect because the positions need more accurate values  in my experience  RectF done the top amp bottom deviation just one pixel on xhdpi device  Rect would be two more

User · Answer

I find that the best solution for centering text is as follows   textPaint setTextAlign Paint Align CENTER     textPaint is the Paint object being used to draw the text  it must be initialized beforehand  float textY center y  float textX center x      in this case  center x and center y represent the coordinates of the center of the rectangle in which the text is being placed canvas drawText text textX textY textPaint

[java] Android Center text on canvas

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