Creating a drawable & zoomable image view in andro

问题:

Goal:

Create an imageview that is drawable and zoomable,

That means when I press a button to on , it is drawable,

or when I turn off, that is zoomable.

*Notice the drawings should zoom align with the imageview

===============================================================

Recently I wrote a custom drawable image view like this:

 public class DrawView extends ImageView {

        private int color = Color.BLACK;
        private float width = 4f;
        private List<Holder> holderList = new ArrayList<Holder>();

        private class Holder {      
            Path path;
            Paint paint;

            Holder(int color, float width) {
                path = new Path();
                paint = new Paint();
                paint.setAntiAlias(true);
                paint.setStrokeWidth(width);
                paint.setColor(color);
                paint.setStyle(Paint.Style.STROKE);
                paint.setStrokeJoin(Paint.Join.ROUND);
                paint.setStrokeCap(Paint.Cap.ROUND);
            }
        }

        public DrawView(Context context) {
            super(context);
            init();
        }

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

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

        private void init() {
            holderList.add(new Holder(color, width));
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            for (Holder holder : holderList) {
                canvas.drawPath(holder.path, holder.paint);
            }
        }

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            float eventX = event.getX();
            float eventY = event.getY();

            switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    holderList.add(new Holder(color,width));
                    holderList.get(holderList.size() - 1).path.moveTo(eventX, eventY);
                    return true;
                case MotionEvent.ACTION_MOVE:
                    holderList.get(holderList.size() - 1).path.lineTo(eventX, eventY);
                    break;
                case MotionEvent.ACTION_UP:
                    break;
                default:
                    return false;
            }

            invalidate();
            return true;
        }

        public void resetPaths() {
            for (Holder holder : holderList) {
                holder.path.reset();
            }
            invalidate();
        }

        public void setBrushColor(int color) {
            this.color = color;
        }

        public void setWidth(float width) {
            this.width = width;
        }
    }

And the XML is :

<com.example.tool.DrawView
    android:id="@+id/draw"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:adjustViewBounds="true" />

The problem is , how to make it zoom-able as well? notice that the drawings should align with the imageview when zooming.

Attempt using some custom imageview library but no luck.

e.g. When I use photoview it can be zoom but the drawings not align, and zoom level will reset after I turn on / off the zooming https://github.com/chrisbanes/PhotoView

Also , find some other library like that but not fit the custom view case https://github.com/matabii/scale-imageview-android

Update1: demo

Recommended to reference this app, the drawing function is actually the same as what I am struggling to achieve, but I can't figure out how they get it done

https://play.google.com/store/apps/details?id=com.zentertain.photoeditor&hl=en

Thanks

Update2: From Sandeep Maram Source

Thanks a lot Sandeep Maram, after testing the code, everything work well, the only thing remain is the drawings is not align with the zoom view. Please take a look at the screenshot

Before:

After:

The circle is not scale up / down when zoom, would be really nice if fix that. also that is not matter if the image overlap the button.

回答1:

Answer updated with zoom enable/disable and drawableview

activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity" >
<Button 
    android:id="@+id/enable_zoom"
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:text="disable zoom"/>

<com.rbt.zoomdraw.CustomImageView
    android:id="@+id/zoom_iv"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:src="@drawable/ic_launcher"
    android:layout_below="@+id/enable_zoom" />

<com.rbt.zoomdraw.DrawableView
    android:id="@+id/drawble_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_alignBottom="@+id/zoom_iv"
    android:layout_alignTop="@+id/zoom_iv" />

MainActivity.java

public class MainActivity extends Activity implements OnClickListener {

private Button enableZoomBtn;
private DrawableView drawbleView;
private CustomImageView touchImageView;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    drawbleView = (DrawableView) findViewById(R.id.drawble_view);
    enableZoomBtn = (Button) findViewById(R.id.enable_zoom);
    touchImageView = (CustomImageView) findViewById(R.id.zoom_iv);
    enableZoomBtn.setOnClickListener(this);
    drawbleView.setDrawingEnabled(false);
}
@Override
public void onClick(View v) {
    int id = v.getId();
    switch (id) {
    case R.id.enable_zoom:
        if(enableZoomBtn.getText().equals("disable zoom")){
            touchImageView.setZoomEnable(false);
            drawbleView.setDrawingEnabled(true);
            enableZoomBtn.setText("enable zoom");
        } else{
            touchImageView.setZoomEnable(true);
            drawbleView.setDrawingEnabled(false);
            enableZoomBtn.setText("disable zoom");
        }
        break;

    default:
        break;
    }
  }
}

DrawableView.java

public class DrawableView extends View {
public int width;
public  int height;
private boolean isEditable;
private Path drawPath;
private Paint drawPaint;
private Paint canvasPaint;
private Canvas drawCanvas;
private Bitmap canvasBitmap;
private int paintColor = Color.RED;
public DrawableView(Context context) {
    super(context);
}
public DrawableView(Context context, AttributeSet attrs) {
    super(context, attrs);
    this.canvasPaint = new Paint(Paint.DITHER_FLAG);
    setupDrawing();
}
public DrawableView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    super.onSizeChanged(w, h, oldw, oldh);
    this.height = h;
    this.width = w;
    canvasBitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
    drawCanvas = new Canvas(canvasBitmap);
}
private void setupDrawing() {
    drawPath = new Path();
    drawPaint = new Paint();
    drawPaint.setColor(paintColor);
    drawPaint.setAntiAlias(true);
    drawPaint.setDither(true);
    drawPaint.setStyle(Paint.Style.STROKE);
    drawPaint.setStrokeJoin(Paint.Join.ROUND);
    drawPaint.setStrokeCap(Paint.Cap.ROUND);
    drawPaint.setStrokeWidth(10);
}
public void setDrawingEnabled(boolean isEditable){
    this.isEditable = isEditable;
}
@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    canvas.drawBitmap(canvasBitmap, 0, 0, canvasPaint);
    canvas.drawPath(drawPath, drawPaint);
}

@Override
public boolean onTouchEvent(MotionEvent event) {
    if(isEditable){
        float touchX = event.getX();
        float touchY = event.getY();
        switch (event.getAction()) {
        case MotionEvent.ACTION_DOWN:
            drawPath.moveTo(touchX, touchY);
            break;
        case MotionEvent.ACTION_MOVE:
            drawPath.lineTo(touchX, touchY);
            break;
        case MotionEvent.ACTION_UP:
            drawPath.lineTo(touchX, touchY);
            drawCanvas.drawPath(drawPath, drawPaint);
            drawPath = new Path();
            break;
        default:
            return false;
        }
    } else{
        return false;
    }
    invalidate();
    return true;
  }
}

CustomImageView

public class CustomImageView extends ImageView {
Matrix matrix;
// We can be in one of these 3 states
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
private boolean zoomEnable= true;
// Remember some things for zooming
PointF last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float maxScale = 5f;
float[] m;

int viewWidth, viewHeight;
static final int CLICK = 3;
float saveScale = 1f;
protected float origWidth, origHeight;
int oldMeasuredWidth, oldMeasuredHeight;
ScaleGestureDetector mScaleDetector;
Context context;
public CustomImageView(Context context) {
    super(context);
    sharedConstructing(context);
}
public void setZoomEnable(boolean status){
    zoomEnable = status;
}
public CustomImageView(Context context, AttributeSet attrs) {
    super(context, attrs);
    sharedConstructing(context);
}

private void sharedConstructing(Context context) {
    super.setClickable(true);
    this.context = context;
    mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
    matrix = new Matrix();
    m = new float[9];
    setImageMatrix(matrix);
    setScaleType(ScaleType.MATRIX);

    setOnTouchListener(new OnTouchListener() {
        @Override
        public boolean onTouch(View v, MotionEvent event) {
            if(zoomEnable){
                mScaleDetector.onTouchEvent(event);
                PointF curr = new PointF(event.getX(), event.getY());

                switch (event.getAction()) {
                case MotionEvent.ACTION_DOWN:
                    last.set(curr);
                    start.set(last);
                    mode = DRAG;
                    break;

                case MotionEvent.ACTION_MOVE:
                    if (mode == DRAG) {
                        float deltaX = curr.x - last.x;
                        float deltaY = curr.y - last.y;
                        float fixTransX = getFixDragTrans(deltaX, viewWidth,
                                origWidth * saveScale);
                        float fixTransY = getFixDragTrans(deltaY, viewHeight,
                                origHeight * saveScale);
                        matrix.postTranslate(fixTransX, fixTransY);
                        fixTrans();
                        last.set(curr.x, curr.y);
                    }
                    break;

                case MotionEvent.ACTION_UP:
                    mode = NONE;
                    int xDiff = (int) Math.abs(curr.x - start.x);
                    int yDiff = (int) Math.abs(curr.y - start.y);
                    if (xDiff < CLICK && yDiff < CLICK)
                        performClick();
                    break;

                case MotionEvent.ACTION_POINTER_UP:
                    mode = NONE;
                    break;
                }

                setImageMatrix(matrix);
                invalidate();
                return true; // indicate event was handled

            } else{
                return false;
            }
        }

    });
}

public void setMaxZoom(float x) {
    maxScale = x;
}

private class ScaleListener extends
ScaleGestureDetector.SimpleOnScaleGestureListener {
    @Override
    public boolean onScaleBegin(ScaleGestureDetector detector) {
        mode = ZOOM;
        return true;
    }

    @Override
    public boolean onScale(ScaleGestureDetector detector) {
        float mScaleFactor = detector.getScaleFactor();
        float origScale = saveScale;
        saveScale *= mScaleFactor;
        if (saveScale > maxScale) {
            saveScale = maxScale;
            mScaleFactor = maxScale / origScale;
        } else if (saveScale < minScale) {
            saveScale = minScale;
            mScaleFactor = minScale / origScale;
        }

        if (origWidth * saveScale <= viewWidth
                || origHeight * saveScale <= viewHeight)
            matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
                    viewHeight / 2);
        else
            matrix.postScale(mScaleFactor, mScaleFactor,
                    detector.getFocusX(), detector.getFocusY());

        fixTrans();
        return true;
    }
}

void fixTrans() {
    matrix.getValues(m);
    float transX = m[Matrix.MTRANS_X];
    float transY = m[Matrix.MTRANS_Y];

    float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
    float fixTransY = getFixTrans(transY, viewHeight, origHeight
            * saveScale);

    if (fixTransX != 0 || fixTransY != 0)
        matrix.postTranslate(fixTransX, fixTransY);
}

float getFixTrans(float trans, float viewSize, float contentSize) {
    float minTrans, maxTrans;

    if (contentSize <= viewSize) {
        minTrans = 0;
        maxTrans = viewSize - contentSize;
    } else {
        minTrans = viewSize - contentSize;
        maxTrans = 0;
    }

    if (trans < minTrans)
        return -trans + minTrans;
    if (trans > maxTrans)
        return -trans + maxTrans;
    return 0;
}

float getFixDragTrans(float delta, float viewSize, float contentSize) {
    if (contentSize <= viewSize) {
        return 0;
    }
    return delta;
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    viewWidth = MeasureSpec.getSize(widthMeasureSpec);
    viewHeight = MeasureSpec.getSize(heightMeasureSpec);

    //
    // Rescales image on rotation
    //
    if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight
            || viewWidth == 0 || viewHeight == 0)
        return;
    oldMeasuredHeight = viewHeight;
    oldMeasuredWidth = viewWidth;

    if (saveScale == 1) {
        // Fit to screen.
        float scale;

        Drawable drawable = getDrawable();
        if (drawable == null || drawable.getIntrinsicWidth() == 0
                || drawable.getIntrinsicHeight() == 0)
            return;
        int bmWidth = drawable.getIntrinsicWidth();
        int bmHeight = drawable.getIntrinsicHeight();

        Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight);

        float scaleX = (float) viewWidth / (float) bmWidth;
        float scaleY = (float) viewHeight / (float) bmHeight;
        scale = Math.min(scaleX, scaleY);
        matrix.setScale(scale, scale);

        // Center the image
        float redundantYSpace = (float) viewHeight
                - (scale * (float) bmHeight);
        float redundantXSpace = (float) viewWidth
                - (scale * (float) bmWidth);
        redundantYSpace /= (float) 2;
        redundantXSpace /= (float) 2;

        matrix.postTranslate(redundantXSpace, redundantYSpace);

        origWidth = viewWidth - 2 * redundantXSpace;
        origHeight = viewHeight - 2 * redundantYSpace;
        setImageMatrix(matrix);
     }
    fixTrans();
  }
}

I hope it will work for you.

回答2:

I don't have complete solution. However I can suggest you to take a look at PhotoView which has zoom implementation and my custom CanvasView which I used in one of the old projects. It allows to draw using "pen" tool and type text on it. Text feature is unnecessary for you and probably was too specific for that part so you can skip it. Maybe it'll help you. It supports screen rotation which leads to new drawable dimensions and both text and curves are scaled in this case.

public class CanvasView extends View {

    // -----------------------------------------------------------------------
    //
    // Constants
    //
    // -----------------------------------------------------------------------
    @SuppressWarnings("unused")
    private static final String TAG = CanvasView.class.getSimpleName();

    private static final String EXTRA_SUPER_STATE = "EXTRA_SUPER_STATE";
    private static final String EXTRA_COLOR = "EXTRA_COLOR";
    private static final String EXTRA_ACTION = "EXTRA_ACTION";
    private static final String EXTRA_MODIFICATIONS = "EXTRA_MODIFICATIONS";
    private static final String EXTRA_CURRENT_MODIFICATION = "EXTRA_CURRENT_MODIFICATION";

    // -----------------------------------------------------------------------
    //
    // Enums
    //
    // -----------------------------------------------------------------------
    public static enum ACTION {
        PEN, TEXT
    };

    // -----------------------------------------------------------------------
    //
    // Fields
    //
    // -----------------------------------------------------------------------
    private ArrayList<DrawableItem> mItems;
    private ACTION mAction;
    private int mColor;
    private float mDensityScale;

    private DrawableItem mCurrentItem;

    private EditText mEditText;

    // -----------------------------------------------------------------------
    //
    // Constructor
    //
    // -----------------------------------------------------------------------
    public CanvasView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mItems = new ArrayList<CanvasView.DrawableItem>();
        mAction = ACTION.PEN;
        mDensityScale = getResources().getDisplayMetrics().density;
    }

    // -----------------------------------------------------------------------
    //
    // Setters
    //
    // -----------------------------------------------------------------------
    public void setAction(ACTION action) {
        if (mCurrentItem != null)
            saveCurrentModification();
        mAction = action;
        invalidate();
    }

    public void setColor(int color) {
        mColor = color;
        hideKeyboard();
    }

    public void saveCurrentModification() {
        if (mCurrentItem instanceof Curve || !((Text) mCurrentItem).isEmpty())
            mItems.add(mCurrentItem);

        mCurrentItem = null;
    }

    // -----------------------------------------------------------------------
    //
    // Methods
    //
    // -----------------------------------------------------------------------
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        for (DrawableItem item : mItems)
            item.draw(canvas, getMeasuredWidth(), getMeasuredHeight());
        if (mCurrentItem != null)
            mCurrentItem.draw(canvas, getMeasuredWidth(), getMeasuredHeight());
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        switch (mAction) {
        case PEN:
            onTouchPen(event);
            break;
        case TEXT:
            onTouchText(event);
            break;
        default:
            break;
        }
        return true;

    }

    private void onTouchPen(MotionEvent event) {
        switch (event.getActionMasked()) {
        case MotionEvent.ACTION_DOWN:
            mCurrentItem = new Curve(mColor);
            break;
        case MotionEvent.ACTION_MOVE:
            Curve currentItem = (Curve) mCurrentItem;
            currentItem.addPoint(event.getX(), event.getY());
            break;
        case MotionEvent.ACTION_UP:
        case MotionEvent.ACTION_CANCEL:
            saveCurrentModification();
            break;
        default:
        }
        invalidate();
    }

    private void onTouchText(MotionEvent event) {
        switch (event.getActionMasked()) {
        case MotionEvent.ACTION_DOWN: {
            if (mCurrentItem != null)
                saveCurrentModification();
            mCurrentItem = new Text(new PointF(event.getX(), event.getY()),
                    mDensityScale);
            showKeyboard();
        }
            break;
        default:
        }
    }

    private void showKeyboard() {
        mEditText.setVisibility(View.VISIBLE);
        mEditText.setText("");
        mEditText.requestFocus();
        InputMethodManager inputMethodManager = (InputMethodManager) getContext()
                .getSystemService(Context.INPUT_METHOD_SERVICE);
        inputMethodManager.showSoftInput(mEditText,
                InputMethodManager.SHOW_IMPLICIT);
    }

    private void hideKeyboard() {
        mEditText.setVisibility(View.INVISIBLE);
        InputMethodManager imm = (InputMethodManager) getContext()
                .getSystemService(Context.INPUT_METHOD_SERVICE);
        imm.hideSoftInputFromWindow(mEditText.getWindowToken(), 0);
    }

    @Override
    protected Parcelable onSaveInstanceState() {
        Bundle bundle = new Bundle();
        bundle.putParcelable(EXTRA_SUPER_STATE, super.onSaveInstanceState());
        bundle.putInt(EXTRA_COLOR, mColor);
        bundle.putSerializable(EXTRA_ACTION, mAction);
        bundle.putParcelableArrayList(EXTRA_MODIFICATIONS, mItems);
        return bundle;
    }

    @Override
    protected void onRestoreInstanceState(Parcelable state) {
        if (state instanceof Bundle) {
            Bundle bundle = (Bundle) state;
            setColor(bundle.getInt(EXTRA_COLOR));
            setAction((ACTION) bundle.getSerializable(EXTRA_ACTION));
            mItems = bundle.getParcelableArrayList(EXTRA_MODIFICATIONS);
            super.onRestoreInstanceState(bundle
                    .getParcelable(EXTRA_SUPER_STATE));
            return;
        } else
            super.onRestoreInstanceState(state);
    }

    public OnEditorActionListener getEditorActionListener() {
        return mEditorActionListener;
    }

    public TextWatcher getTextWatcher() {
        return mTextWatcher;
    }

    public void setTextProvider(EditText editText) {
        mEditText = editText;
        mEditText.setOnEditorActionListener(getEditorActionListener());
        mEditText.addTextChangedListener(mTextWatcher);
    }

    public void clearSession() {
        mItems.clear();
        mCurrentItem = null;
        hideKeyboard();
        invalidate();
    }

    // -----------------------------------------------------------------------
    //
    // Listeners
    //
    // -----------------------------------------------------------------------
    private OnEditorActionListener mEditorActionListener = new OnEditorActionListener() {
        public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
            if (actionId == EditorInfo.IME_ACTION_DONE) {
                saveCurrentModification();
                hideKeyboard();
            }
            return false;
        }
    };

    private TextWatcher mTextWatcher = new TextWatcher() {

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {
        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
        }

        @Override
        public void afterTextChanged(Editable s) {
            if (mCurrentItem instanceof Text) {
                ((Text) mCurrentItem).setText(s.toString());
                invalidate();
            }
        }
    };

    // -----------------------------------------------------------------------
    //
    // Inner classes
    //
    // -----------------------------------------------------------------------
    public static interface OnStartTextInputListener {
        public void onTextInputStarted(CanvasView view);
    }

    private static interface DrawableItem extends Parcelable {
        public void draw(Canvas canvas, float viewWidth, float viewHeight);
    }

    private static class Curve implements DrawableItem {
        // -----------------------------------------------------------------------
        //
        // Fields
        //
        // -----------------------------------------------------------------------
        private ArrayList<PointF> mPoints;
        private int mColor;
        private Paint mPaint;

        // -----------------------------------------------------------------------
        //
        // Constructor
        //
        // -----------------------------------------------------------------------
        public Curve(int color) {
            mPoints = new ArrayList<PointF>();
            mColor = color;
            mPaint = new Paint();
            mPaint.setColor(mColor);
            mPaint.setStrokeWidth(2);
        }

        private Curve(Parcel parcel) {
            mColor = parcel.readInt();
            parcel.readList(mPoints, PointF.class.getClassLoader());
        }

        // -----------------------------------------------------------------------
        //
        // Methods
        //
        // -----------------------------------------------------------------------
        @Override
        public void draw(Canvas canvas, float viewWidth, float viewHeight) {
            for (int i = 1; i < mPoints.size(); ++i) {
                PointF prev = mPoints.get(i - 1);
                PointF current = mPoints.get(i);
                canvas.drawLine(prev.x / viewWidth * canvas.getWidth(), prev.y
                        / viewHeight * canvas.getHeight(), current.x
                        / viewWidth * canvas.getWidth(), current.y / viewHeight
                        * canvas.getHeight(), mPaint);
            }
        }

        public void addPoint(float x, float y) {
            mPoints.add(new PointF(x, y));
        }

        @Override
        public int describeContents() {
            return 0;
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            dest.writeInt(mColor);
            dest.writeList(mPoints);
        }

        // -----------------------------------------------------------------------
        //
        // Inner classes
        //
        // -----------------------------------------------------------------------
        public static final Parcelable.Creator<Curve> CREATOR = new Parcelable.Creator<Curve>() {
            public Curve createFromParcel(Parcel in) {
                return new Curve(in);
            }

            public Curve[] newArray(int size) {
                return new Curve[size];
            }
        };
    }

    private static class Text implements DrawableItem {
        // -----------------------------------------------------------------------
        //
        // Constatns
        //
        // -----------------------------------------------------------------------
        private static final int FONT_SIZE = 14;
        private static final int PADDING = 4;
        private static final int BORDER_WIDTH = 2;
        private static final int BORDER_COLOR = Color.rgb(0, 0, 0);
        private static final int BOX_COLOR = Color.rgb(255, 255, 255);
        private static final int FONT_COLOR = Color.rgb(0, 0, 0);

        // -----------------------------------------------------------------------
        //
        // Fields
        //
        // -----------------------------------------------------------------------
        private Paint mBoxPaint;
        private Paint mBorderPaint;
        private Paint mTextPaint;

        private float mDensityScale;

        private PointF mPoint;
        private String mTextString = "";

        // -----------------------------------------------------------------------
        //
        // Constructor
        //
        // -----------------------------------------------------------------------
        public Text(PointF point, float densityScale) {
            mPoint = point;
            mDensityScale = densityScale;

            mBoxPaint = new Paint();
            mBoxPaint.setStyle(Style.FILL);
            mBoxPaint.setColor(BOX_COLOR);

            mBorderPaint = new Paint();
            mBorderPaint.setStyle(Style.STROKE);
            mBorderPaint.setColor(BORDER_COLOR);
            mBorderPaint.setStrokeWidth(getBorderWidth());

            mTextPaint = new Paint();
            mTextPaint.setTextSize(getFontSize());
            mTextPaint.setAntiAlias(true);
            mTextPaint.setTextAlign(Paint.Align.LEFT);
            mTextPaint.setColor(FONT_COLOR);
        }

        // -----------------------------------------------------------------------
        //
        // Methods
        //
        // -----------------------------------------------------------------------
        public void setText(String text) {
            mTextString = text;
        }

        public boolean isEmpty() {
            return Utils.isEmpty(mTextString);
        }

        @Override
        public int describeContents() {
            return 0;
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
        }

        private float getFontSize() {
            return FONT_SIZE * mDensityScale;
        }

        private float getPadding() {
            return PADDING * mDensityScale;
        }

        private float getBorderWidth() {
            return BORDER_WIDTH * mDensityScale;
        }

        private float getStringWidth(String string) {
            Rect bounds = new Rect();
            mTextPaint.getTextBounds(string, 0, string.length(), bounds);
            return bounds.width();
        }

        @Override
        public void draw(Canvas canvas, float viewWidth, float viewHeight) {
            ArrayList<String> labelList = new ArrayList<String>();

            String[] lines = mTextString.split(" ");
            String prevLine = "";
            float textHeight = (2 * getBorderWidth() + 2 * getPadding())
                    / viewHeight * canvas.getHeight();
            float textWidth = 0;
            for (int i = 0; i < lines.length; ++i) {
                String string = lines[i];
                String newline = prevLine.concat(" " + string).trim();

                float prevLineWidth = (getStringWidth(prevLine) + 2
                        * getBorderWidth() + 2 * getPadding())
                        / viewWidth * canvas.getWidth();
                float newLineWidth = (getStringWidth(newline) + 2
                        * getBorderWidth() + 2 * getPadding())
                        / viewWidth * canvas.getWidth();
                float availableWidth = canvas.getWidth() - mPoint.x / viewWidth
                        * canvas.getWidth() + 1;

                if (newLineWidth > availableWidth) {
                    if (!Utils.isEmpty(prevLine)) {
                        labelList.add(prevLine);
                        textHeight += (getFontSize() + getPadding())
                                / viewHeight * canvas.getHeight();
                        if (prevLineWidth >= textWidth)
                            textWidth = prevLineWidth;
                    }
                    prevLine = string;
                    if (i == lines.length - 1) {
                        prevLineWidth = (getStringWidth(prevLine) + 2
                                * getBorderWidth() + 2 * getPadding())
                                / viewWidth * canvas.getWidth();
                        labelList.add(prevLine);
                        if (prevLineWidth > textWidth)
                            textWidth = prevLineWidth;
                        textHeight += getFontSize() / viewHeight
                                * canvas.getHeight();
                    }
                } else if (i == lines.length - 1) {
                    labelList.add(newline);
                    if (newLineWidth > textWidth)
                        textWidth = newLineWidth;
                    textHeight += getFontSize() / viewHeight
                            * canvas.getHeight();
                } else {
                    prevLine = newline;
                }

            }

            textHeight = Math.min(textHeight, canvas.getHeight() - mPoint.y
                    / viewHeight * canvas.getHeight());
            textWidth = Math.min(textWidth, canvas.getWidth() - mPoint.x
                    / viewWidth * canvas.getWidth());
            if (isEmpty()) {
                textWidth = (getPadding() * 2 + getBorderWidth() * 2)
                        / viewWidth * canvas.getWidth();
            }
            canvas.drawRect(mPoint.x / viewWidth * canvas.getWidth(), mPoint.y
                    / viewHeight * canvas.getHeight(), mPoint.x / viewWidth
                    * canvas.getWidth() + textWidth, mPoint.y / viewHeight
                    * canvas.getHeight() + textHeight, mBoxPaint);
            mBorderPaint.setStrokeWidth(getBorderWidth() / viewWidth
                    * canvas.getWidth());
            canvas.drawRect(mPoint.x / viewWidth * canvas.getWidth(), mPoint.y
                    / viewHeight * canvas.getHeight(), mPoint.x / viewWidth
                    * canvas.getWidth() + textWidth, mPoint.y / viewHeight
                    * canvas.getHeight() + textHeight, mBorderPaint);
            mBorderPaint.setStrokeWidth(getBorderWidth());
            float offset = (getBorderWidth() + getPadding() + getFontSize())
                    / viewWidth * canvas.getWidth();
            mTextPaint.setTextSize(getFontSize() / viewHeight
                    * canvas.getHeight());
            for (String string : labelList) {
                canvas.drawText(string, (mPoint.x + getBorderWidth())
                        / viewWidth * canvas.getWidth(), mPoint.y / viewHeight
                        * canvas.getHeight() + offset, mTextPaint);
                offset += (getFontSize() + getPadding()) / viewHeight
                        * canvas.getHeight();
            }
            mTextPaint.setTextSize(getFontSize());
        }
    }