CircularImageView.java

package com.marshalchen.common.ui;

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;

import com.marshalchen.common.R;

/**
 * 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;
	}
}