Aligning custom view to screen bottom

Question

I have created my own view. It is a semicircle. I want it to align it to the bottom of the screen. Since, I drew it using drawArc, it does not align to the bottom. I have tried the alternative of setting a circle with center's y co-ordinate co-incident with screen bottom co-ordinate. I do not wish to use it as I wish to implement some additional things to it. Here is my code for custom view.

package legacy_systems.customview;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.View;

public class CircleView extends View{

    private Paint markerPaint;
    private Paint textPaint;
    private Paint circlePaint;
    private int textHeight;

    public CircleView(Context context)
    {
        super(context);
        initCircleView();
    }

    public CircleView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        initCircleView();
    }

    public CircleView(Context context, AttributeSet attrs, int defaultStyle)
    {
        super(context, attrs, defaultStyle);
        initCircleView();
    }

    protected void initCircleView()
    {
        setFocusable(true);

        circlePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        circlePaint.setColor(getResources().getColor(android.R.color.black));
        circlePaint.setStrokeWidth(3);
        circlePaint.setStyle(Paint.Style.STROKE);

        markerPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        markerPaint.setColor(getResources().getColor(android.R.color.darker_gray));
    }

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        int measuredWidth = measure(widthMeasureSpec);
        int measuredHeight = measure(heightMeasureSpec);

        int d = Math.min(measuredWidth, measuredHeight);

        setMeasuredDimension(d,d);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        // TODO Auto-generated method stub
        int px, py;

        px = getMeasuredWidth()/2;
        py = getMeasuredHeight()/2;

        int radius = Math.min(px, py);

        RectF oval = new RectF();
        oval.set(px-radius, py-radius, px+radius, py+radius);

        canvas.drawArc(oval,180,180,false, circlePaint);
        //canvas.drawCircle(px, py, radius, circlePaint);
        canvas.save();



    }

    private int measure(int measureSpec)
    {
        int result = 0;

        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);

        if(specMode == MeasureSpec.UNSPECIFIED)
        {
            result = 200;
        }
        else
        {
            result = specSize;
        }

        return result;
    }

}

I want to align the semi-circle to bottom of screen. Any ideas how I can do it ?

Answer 1

First of all, thanks all of you for your answers. Your answer is partially correct. Yes, with

android:layout_alignParentBottom="true"

would do the half trick. Suppose I have a circle to draw. In custom view, (0,0) represents the heightest leftmost co-ordinate of the view, not of the screen. And suppose one wants to half circle to be located at thebottom of screen just as I wanted to do, co-ordinate guessing turns out to be a problem. Here is how I actually solved it.

px = getMeasuredWidth()/2;
py = getMeasuredHeight();

canvas.drawCircle(px, py, radius, paint);

Here, px would be the centre of whole width of view, midpoint of view width and py would be the last screen y axis co-ordinate assigned to view.

Hope it helps somebody else too.

Answer 2

You can try to use the:

android:gravity="bottom" 

or

android:layout_gravity="bottom"

property.

Answer 3

Make sure that the screen on which you want to put/add it is a RelativeLayout .

Do this in the layout

<legacy_systems.customview.CircleView
android:id="@+id/myview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_alignParentBottom="true"/>

In your onCreate() method

CircleView view = (CircleView) findViewById(R.id.myview);