Q: Creating RoundImageView causes NullPointerException I want to create RoundedImageView for some ImageView used in my app. I am creating custom view for that.
Below is the Xml file and source code for custom ImageView.    
<LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/deleteCallLog"
        android:orientation="horizontal" >

        <RelativeLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_margin="4dip" >

            <com.nimbuzz.ui.RoundedImageView
                android:id="@+id/avatarImage"
                android:layout_width="48dip"
                android:layout_height="48dip"
                android:layout_centerHorizontal="true"
                android:src="@drawable/default_avatar" />

            <ImageView
                android:id="@+id/subCallTypeIcon"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignBottom="@id/avatarImage"
                android:layout_alignRight="@id/avatarImage"
                android:visibility="gone" />
        </RelativeLayout>
</LinearLayout>

Line:     Bitmap bitmap = b.copy(Config.ARGB_8888, true);  causing NullPointerException.
It does'nt always happens . On some screens this code works.
RoundedImageView.java:
public class RoundedImageView extends ImageView {
public RoundedImageView(Context context) {
    super(context);
}

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

public RoundedImageView(Context context, AttributeSet attrs, int     defStyle) {
    super(context, attrs, defStyle);
}

@Override
protected void onDraw(Canvas canvas) 
{


    Drawable drawable = getDrawable();

    if (drawable == null) {
        return;
    }

    if (getWidth() == 0 || getHeight() == 0) {
        return;
    }
    Bitmap b = ((BitmapDrawable)drawable).getBitmap();
    Bitmap bitmap = b.copy(Config.ARGB_8888, true);

    int w = getWidth(), h = getHeight();

    Bitmap roundBitmap = getCroppedBitmap(b, w);
    canvas.drawBitmap(roundBitmap, 0, 0, null);

}

public static Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
    Bitmap sbmp;

    if (bmp.getWidth() != radius || bmp.getHeight() != radius) {
        float smallest = Math.min(bmp.getWidth(), bmp.getHeight());
        float factor = smallest / radius;
        sbmp = Bitmap.createScaledBitmap(bmp, (int)(bmp.getWidth() /     factor), (int)(bmp.getHeight() / factor), false);
    } else {
        sbmp = bmp;
    }

    Bitmap output = Bitmap.createBitmap(radius, radius,
            Config.ARGB_8888);
    Canvas canvas = new Canvas(output);

    final int color = 0xffa19774;
    final Paint paint = new Paint();
    final Rect rect = new Rect(0, 0, radius, radius);

    paint.setAntiAlias(true);
    paint.setFilterBitmap(true);
    paint.setDither(true);
    canvas.drawARGB(0, 0, 0, 0);
    paint.setColor(Color.parseColor("#BAB399"));
    canvas.drawCircle(radius / 2 + 0.7f,
            radius / 2 + 0.7f, radius / 2 + 0.1f, paint);
    paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
    canvas.drawBitmap(sbmp, rect, rect, paint);

    return output;
    }

}


A: Try this o create own Imageview and directly set the bitmap or resource in imageview..


import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.widget.ImageView;

@SuppressLint("DrawAllocation")
public class RoundedCornerImageView extends ImageView {
    public RoundedCornerImageView(Context context) {
        super(context);
    }

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

    public RoundedCornerImageView(Context context, AttributeSet attrs,
            int defStyle) {
        super(context, attrs, defStyle);
    }

    @Override
    protected void onDraw(Canvas canvas) {
         float radius = 90.0f; // angle of round corners
         Path clipPath = new Path();
         RectF rect = new RectF(0, 0, this.getWidth(), this.getHeight());
         clipPath.addRoundRect(rect, radius, radius, Path.Direction.CW);
         canvas.clipPath(clipPath);

         super.onDraw(canvas);

    }

}


A: 
Custom CirularImageView

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorFilter;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffColorFilter;
import android.graphics.RectF;
import android.graphics.Shader;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.net.Uri;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.widget.ImageView;

/**
 * Custom ImageView for circular images in Android while maintaining the
 * best draw performance and supporting custom borders & selectors.
 */
public class CircularImageView extends ImageView {
    // For logging purposes
    private static final String TAG = CircularImageView.class.getSimpleName();

    // Default property values
    private static final boolean SHADOW_ENABLED = false;
    private static final float SHADOW_RADIUS = 4f;
    private static final float SHADOW_DX = 0f;
    private static final float SHADOW_DY = 2f;
    private static final int SHADOW_COLOR = Color.BLACK;

    // Border & Selector configuration variables
    private boolean hasBorder;
    private boolean hasSelector;
    private boolean isSelected;
    private int borderWidth;
    private int canvasSize;
    private int selectorStrokeWidth;

    // Shadow properties
    private boolean shadowEnabled;
    private float shadowRadius;
    private float shadowDx;
    private float shadowDy;
    private int shadowColor;

    // Objects used for the actual drawing
    private BitmapShader shader;
    private Bitmap image;
    private Paint paint;
    private Paint paintBorder;
    private Paint paintSelectorBorder;
    private ColorFilter selectorFilter;

    public CircularImageView(Context context) {
        this(context, null, R.styleable.CircularImageViewStyle_circularImageViewDefault);
    }

    public CircularImageView(Context context, AttributeSet attrs) {
        this(context, attrs, R.styleable.CircularImageViewStyle_circularImageViewDefault);
    }

    public CircularImageView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context, attrs, defStyleAttr);
    }

    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
    public CircularImageView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
        super(context, attrs, defStyleAttr, defStyleRes);
        init(context, attrs, defStyleAttr);
    }

    /**
     * Initializes paint objects and sets desired attributes.
     * @param context Context
     * @param attrs Attributes
     * @param defStyle Default Style
     */
    private void init(Context context, AttributeSet attrs, int defStyle) {
        // Initialize paint objects
        paint = new Paint();
        paint.setAntiAlias(true);
        paintBorder = new Paint();
        paintBorder.setAntiAlias(true);
        paintBorder.setStyle(Paint.Style.STROKE);
        paintSelectorBorder = new Paint();
        paintSelectorBorder.setAntiAlias(true);

        // Enable software rendering on HoneyComb and up. (needed for shadow)
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
            setLayerType(LAYER_TYPE_SOFTWARE, null);

        // Load the styled attributes and set their properties
        TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.CircularImageView, defStyle, 0);

        // Check for extra features being enabled
        hasBorder = attributes.getBoolean(R.styleable.CircularImageView_civ_border, false);
        hasSelector = attributes.getBoolean(R.styleable.CircularImageView_civ_selector, false);
        shadowEnabled = attributes.getBoolean(R.styleable.CircularImageView_civ_shadow, SHADOW_ENABLED);

        // Set border properties, if enabled
        if(hasBorder) {
            int defaultBorderSize = (int) (2 * context.getResources().getDisplayMetrics().density + 0.5f);
            setBorderWidth(attributes.getDimensionPixelOffset(R.styleable.CircularImageView_civ_borderWidth, defaultBorderSize));
            setBorderColor(attributes.getColor(R.styleable.CircularImageView_civ_borderColor, Color.WHITE));
        }

        // Set selector properties, if enabled
        if(hasSelector) {
            int defaultSelectorSize = (int) (2 * context.getResources().getDisplayMetrics().density + 0.5f);
            setSelectorColor(attributes.getColor(R.styleable.CircularImageView_civ_selectorColor, Color.TRANSPARENT));
            setSelectorStrokeWidth(attributes.getDimensionPixelOffset(R.styleable.CircularImageView_civ_selectorStrokeWidth, defaultSelectorSize));
            setSelectorStrokeColor(attributes.getColor(R.styleable.CircularImageView_civ_selectorStrokeColor, Color.BLUE));
        }

        // Set shadow properties, if enabled
        if(shadowEnabled) {
            shadowRadius = attributes.getFloat(R.styleable.CircularImageView_civ_shadowRadius, SHADOW_RADIUS);
            shadowDx = attributes.getFloat(R.styleable.CircularImageView_civ_shadowDx, SHADOW_DX);
            shadowDy = attributes.getFloat(R.styleable.CircularImageView_civ_shadowDy, SHADOW_DY);
            shadowColor = attributes.getColor(R.styleable.CircularImageView_civ_shadowColor, SHADOW_COLOR);
            setShadowEnabled(true);
        }

        // We no longer need our attributes TypedArray, give it back to cache
        attributes.recycle();
    }

    /**
     * Sets the CircularImageView's border width in pixels.
     * @param borderWidth Width in pixels for the border.
     */
    public void setBorderWidth(int borderWidth) {
        this.borderWidth = borderWidth;
        if(paintBorder != null)
            paintBorder.setStrokeWidth(borderWidth);
        requestLayout();
        invalidate();
    }

    /**
     * Sets the CircularImageView's basic border color.
     * @param borderColor The new color (including alpha) to set the border.
     */
    public void setBorderColor(int borderColor) {
        if (paintBorder != null)
            paintBorder.setColor(borderColor);
        this.invalidate();
    }

    /**
     * Sets the color of the selector to be draw over the
     * CircularImageView. Be sure to provide some opacity.
     * @param selectorColor The color (including alpha) to set for the selector overlay.
     */
    public void setSelectorColor(int selectorColor) {
        this.selectorFilter = new PorterDuffColorFilter(selectorColor, PorterDuff.Mode.SRC_ATOP);
        this.invalidate();
    }

    /**
     * Sets the stroke width to be drawn around the CircularImageView
     * during click events when the selector is enabled.
     * @param selectorStrokeWidth Width in pixels for the selector stroke.
     */
    public void setSelectorStrokeWidth(int selectorStrokeWidth) {
        this.selectorStrokeWidth = selectorStrokeWidth;
        this.requestLayout();
        this.invalidate();
    }

    /**
     * Sets the stroke color to be drawn around the CircularImageView
     * during click events when the selector is enabled.
     * @param selectorStrokeColor The color (including alpha) to set for the selector stroke.
     */
    public void setSelectorStrokeColor(int selectorStrokeColor) {
        if (paintSelectorBorder != null)
            paintSelectorBorder.setColor(selectorStrokeColor);
        this.invalidate();
    }

    /**
     * Enables a dark shadow for this CircularImageView.
     * @param enabled Set to true to draw a shadow or false to disable it.
     */
    public void setShadowEnabled(boolean enabled) {
        shadowEnabled = enabled;
        updateShadow();
    }

    /**
     * Enables a dark shadow for this CircularImageView.
     * If the radius is set to 0, the shadow is removed.
     * @param radius Radius for the shadow to extend to.
     * @param dx Horizontal shadow offset.
     * @param dy Vertical shadow offset.
     * @param color The color of the shadow to apply.
     */
    public void setShadow(float radius, float dx, float dy, int color) {
        shadowRadius = radius;
        shadowDx = dx;
        shadowDy = dy;
        shadowColor = color;
        updateShadow();
    }

    @Override
    public void onDraw(Canvas canvas) {
        // Don't draw anything without an image
        if(image == null)
            return;

        // Nothing to draw (Empty bounds)
        if(image.getHeight() == 0 || image.getWidth() == 0)
            return;

        // Update shader if canvas size has changed
        int oldCanvasSize = canvasSize;
        canvasSize = getWidth() < getHeight() ? getWidth() : getHeight();
        if(oldCanvasSize != canvasSize)
            updateBitmapShader();

        // Apply shader to paint
        paint.setShader(shader);

        // Keep track of selectorStroke/border width
        int outerWidth = 0;

        // Get the exact X/Y axis of the view
        int center = canvasSize / 2;


        if(hasSelector && isSelected) { // Draw the selector stroke & apply the selector filter, if applicable
            outerWidth = selectorStrokeWidth;
            center = (canvasSize - (outerWidth * 2)) / 2;

            paint.setColorFilter(selectorFilter);
            canvas.drawCircle(center + outerWidth, center + outerWidth, ((canvasSize - (outerWidth * 2)) / 2) + outerWidth - 4.0f, paintSelectorBorder);
        }
        else if(hasBorder) { // If no selector was drawn, draw a border and clear the filter instead... if enabled
            outerWidth = borderWidth;
            center = (canvasSize - (outerWidth * 2)) / 2;

            paint.setColorFilter(null);
            RectF rekt = new RectF(0 + outerWidth / 2, 0 + outerWidth / 2, canvasSize - outerWidth / 2, canvasSize - outerWidth / 2);
            canvas.drawArc(rekt, 360, 360, false, paintBorder);
            //canvas.drawCircle(center + outerWidth, center + outerWidth, ((canvasSize - (outerWidth * 2)) / 2) + outerWidth - 4.0f, paintBorder);
        }
        else // Clear the color filter if no selector nor border were drawn
            paint.setColorFilter(null);

        // Draw the circular image itself
        canvas.drawCircle(center + outerWidth, center + outerWidth, ((canvasSize - (outerWidth * 2)) / 2), paint);
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        // Check for clickable state and do nothing if disabled
        if(!this.isClickable()) {
            this.isSelected = false;
            return super.onTouchEvent(event);
        }

        // Set selected state based on Motion Event
        switch(event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                this.isSelected = true;
                break;
            case MotionEvent.ACTION_UP:
            case MotionEvent.ACTION_SCROLL:
            case MotionEvent.ACTION_OUTSIDE:
            case MotionEvent.ACTION_CANCEL:
                this.isSelected = false;
                break;
        }

        // Redraw image and return super type
        this.invalidate();
        return super.dispatchTouchEvent(event);
    }

    @Override
    public void setImageURI(Uri uri) {
        super.setImageURI(uri);

        // Extract a Bitmap out of the drawable & set it as the main shader
        image = drawableToBitmap(getDrawable());
        if(canvasSize > 0)
            updateBitmapShader();
    }

    @Override
    public void setImageResource(int resId) {
        super.setImageResource(resId);

        // Extract a Bitmap out of the drawable & set it as the main shader
        image = drawableToBitmap(getDrawable());
        if(canvasSize > 0)
            updateBitmapShader();
    }

    @Override
    public void setImageDrawable(Drawable drawable) {
        super.setImageDrawable(drawable);

        // Extract a Bitmap out of the drawable & set it as the main shader
        image = drawableToBitmap(getDrawable());
        if(canvasSize > 0)
            updateBitmapShader();
    }

    @Override
    public void setImageBitmap(Bitmap bm) {
        super.setImageBitmap(bm);

        // Extract a Bitmap out of the drawable & set it as the main shader
        image = bm;
        if(canvasSize > 0)
            updateBitmapShader();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = measureWidth(widthMeasureSpec);
        int height = measureHeight(heightMeasureSpec);
        setMeasuredDimension(width, height);
    }

    private int measureWidth(int measureSpec) {
        int result;
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);

        if (specMode == MeasureSpec.EXACTLY) {
            // The parent has determined an exact size for the child.
            result = specSize;
        }
        else if (specMode == MeasureSpec.AT_MOST) {
            // The child can be as large as it wants up to the specified size.
            result = specSize;
        }
        else {
            // The parent has not imposed any constraint on the child.
            result = canvasSize;
        }

        return result;
    }

    private int measureHeight(int measureSpecHeight) {
        int result;
        int specMode = MeasureSpec.getMode(measureSpecHeight);
        int specSize = MeasureSpec.getSize(measureSpecHeight);

        if (specMode == MeasureSpec.EXACTLY) {
            // We were told how big to be
            result = specSize;
        } else if (specMode == MeasureSpec.AT_MOST) {
            // The child can be as large as it wants up to the specified size.
            result = specSize;
        } else {
            // Measure the text (beware: ascent is a negative number)
            result = canvasSize;
        }

        return (result + 2);
    }

    // TODO: Update shadow layers based on border/selector state and visibility.
    private void updateShadow() {
        float radius = shadowEnabled ? shadowRadius : 0;
        //paint.setShadowLayer(radius, shadowDx, shadowDy, shadowColor);
        paintBorder.setShadowLayer(radius, shadowDx, shadowDy, shadowColor);
        paintSelectorBorder.setShadowLayer(radius, shadowDx, shadowDy, shadowColor);
    }

    /**
     * Convert a drawable object into a Bitmap.
     * @param drawable Drawable to extract a Bitmap from.
     * @return A Bitmap created from the drawable parameter.
     */
    public Bitmap drawableToBitmap(Drawable drawable) {
        if (drawable == null)   // Don't do anything without a proper drawable
            return null;
        else if (drawable instanceof BitmapDrawable) {  // Use the getBitmap() method instead if BitmapDrawable
            Log.i(TAG, "Bitmap drawable!");
            return ((BitmapDrawable) drawable).getBitmap();
        }

        int intrinsicWidth = drawable.getIntrinsicWidth();
        int intrinsicHeight = drawable.getIntrinsicHeight();

        if (!(intrinsicWidth > 0 && intrinsicHeight > 0))
            return null;

        try {
            // Create Bitmap object out of the drawable
            Bitmap bitmap = Bitmap.createBitmap(intrinsicWidth, intrinsicHeight, Bitmap.Config.ARGB_8888);
            Canvas canvas = new Canvas(bitmap);
            drawable.setBounds(0, 0, canvas.getWidth(), canvas.getHeight());
            drawable.draw(canvas);
            return bitmap;
        } catch (OutOfMemoryError e) {
            // Simply return null of failed bitmap creations
            Log.e(TAG, "Encountered OutOfMemoryError while generating bitmap!");
            return null;
        }
    }

    // TODO TEST REMOVE
    public void setIconModeEnabled(boolean e) {}

    /**
     * Re-initializes the shader texture used to fill in
     * the Circle upon drawing.
     */
    public void updateBitmapShader() {
        if (image == null)
            return;

        shader = new BitmapShader(image, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);

        if(canvasSize != image.getWidth() || canvasSize != image.getHeight()) {
            Matrix matrix = new Matrix();
            float scale = (float) canvasSize / (float) image.getWidth();
            matrix.setScale(scale, scale);
            shader.setLocalMatrix(matrix);
        }
    }

    /**
     * @return Whether or not this view is currently
     * in its selected state.
     */
    public boolean isSelected() {
        return this.isSelected;
    }
}


Usage

<com.yourpackage.CircularImageView
                    android:layout_width="100dp"
                    android:id="@+id/btn_myprofile"
                    android:layout_height="100dp"
                    app:civ_border="true"
                    app:civ_borderColor="#FF9900"
                    app:civ_borderWidth="2dp"
                    app:civ_shadow="false"
                    android:background="@drawable/profile_icon" />



*

*https://github.com/hdodenhof/CircleImageView

*https://github.com/lopspower/CircularImageView
