How to draw text on canvas?

Question

i'm trying to develop a simple pie chart class for android. For now, it can take a map of labels and values and draw the pie chart. I'm yet to add the legends for the pie, which is where i need to place the texts near small rectangles on the screen corner. Any help appreciated, since i'm new to Android dev.

Answer 1

You will have to use the drawText method of the Canvas class.

Paint paint = new Paint();  canvas.drawPaint(paint);  paint.setColor(Color.BLACK);  paint.setTextSize(16);  canvas.drawText("My Text", x, y, paint);  

Here's the relevant documentation about it:

http://developer.android.com/reference/android/graphics/Canvas.html#drawText(java.lang.String, float, float, android.graphics.Paint)

Answer 2

There used to be another answer here that got deleted because it was a link only. The original link is here. The code is basically the same, but I took out the non text drawing portions and also scaled up the sizes to work better on modern screen densities.

This just shows a few things you can do with text drawing.

Here is the updated code:

public class MainActivity extends AppCompatActivity {      DemoView demoview;      @Override     protected void onCreate(Bundle savedInstanceState) {         super.onCreate(savedInstanceState);         demoview = new DemoView(this);         setContentView(demoview);     }      private class DemoView extends View {         public DemoView(Context context){             super(context);         }          @Override protected void onDraw(Canvas canvas) {             super.onDraw(canvas);              // custom drawing code here             // remember: y increases from top to bottom             // x increases from left to right             int x = 0;             int y = 0;             Paint paint = new Paint();             paint.setStyle(Paint.Style.FILL);              canvas.save();             canvas.translate(100, 200);              // make the entire canvas white             canvas.drawColor(Color.WHITE);              // draw some text using STROKE style             paint.setStyle(Paint.Style.STROKE);             paint.setStrokeWidth(1);             paint.setColor(Color.MAGENTA);             paint.setTextSize(100);             canvas.drawText("Style.STROKE", 0, 0, paint);              canvas.translate(0, 200);              // draw some text using FILL style             paint.setStyle(Paint.Style.FILL);             //turn antialiasing on             paint.setAntiAlias(true);             //paint.setTextSize(30);             canvas.drawText("Style.FILL", 0, 0, paint);              canvas.translate(0, 200);              // draw some rotated text             // get text width and height             // set desired drawing location             x = 75;             y = 185;             paint.setColor(Color.GRAY);             //paint.setTextSize(25);             String str2rotate = "Rotated!";              // draw bounding rect before rotating text             Rect rect = new Rect();             paint.getTextBounds(str2rotate, 0, str2rotate.length(), rect);             canvas.translate(x, y);             paint.setStyle(Paint.Style.FILL);             // draw unrotated text             canvas.drawText("!Rotated", 0, 0, paint);             paint.setStyle(Paint.Style.STROKE);             canvas.drawRect(rect, paint);             // undo the translate             canvas.translate(-x, -y);              // rotate the canvas on center of the text to draw             canvas.rotate(-45, x + rect.exactCenterX(),                     y + rect.exactCenterY());             // draw the rotated text             paint.setStyle(Paint.Style.FILL);             canvas.drawText(str2rotate, x, y, paint);              //undo the translation and rotation             canvas.restore();         }     } } 

Something else that I want to try later is drawing text along a path.

See also this fuller answer here that gives the following image.