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RotarySelector.javaAPI DocAndroid 5.1 API29585Thu Mar 12 22:22:10 GMT 2015com.android.internal.widget

RotarySelector

public class RotarySelector extends android.view.View
Custom view that presents up to two items that are selectable by rotating a semi-circle from left to right, or right to left. Used by incoming call screen, and the lock screen when no security pattern is set.

Fields Summary
public static final int
HORIZONTAL
public static final int
VERTICAL
private static final String
LOG_TAG
private static final boolean
DBG
private static final boolean
VISUAL_DEBUG
private static final android.media.AudioAttributes
VIBRATION_ATTRIBUTES
private OnDialTriggerListener
mOnDialTriggerListener
private float
mDensity
private android.graphics.Bitmap
mBackground
private android.graphics.Bitmap
mDimple
private android.graphics.Bitmap
mDimpleDim
private android.graphics.Bitmap
mLeftHandleIcon
private android.graphics.Bitmap
mRightHandleIcon
private android.graphics.Bitmap
mArrowShortLeftAndRight
private android.graphics.Bitmap
mArrowLongLeft
private android.graphics.Bitmap
mArrowLongRight
private int
mLeftHandleX
private int
mRightHandleX
private int
mRotaryOffsetX
private boolean
mAnimating
private long
mAnimationStartTime
private long
mAnimationDuration
private int
mAnimatingDeltaXStart
private int
mAnimatingDeltaXEnd
private android.view.animation.DecelerateInterpolator
mInterpolator
private android.graphics.Paint
mPaint
final android.graphics.Matrix
mBgMatrix
final android.graphics.Matrix
mArrowMatrix
private int
mGrabbedState
If the user is currently dragging something.
public static final int
NOTHING_GRABBED
public static final int
LEFT_HANDLE_GRABBED
public static final int
RIGHT_HANDLE_GRABBED
private boolean
mTriggered
Whether the user has triggered something (e.g dragging the left handle all the way over to the right).
private android.os.Vibrator
mVibrator
private static final long
VIBRATE_SHORT
private static final long
VIBRATE_LONG
private static final int
ARROW_SCRUNCH_DIP
The drawable for the arrows need to be scrunched this many dips towards the rotary bg below it.
private static final int
EDGE_PADDING_DIP
How far inset the left and right circles should be
private static final int
EDGE_TRIGGER_DIP
How far from the edge of the screen the user must drag to trigger the event.
static final int
OUTER_ROTARY_RADIUS_DIP
Dimensions of arc in background drawable.
static final int
ROTARY_STROKE_WIDTH_DIP
static final int
SNAP_BACK_ANIMATION_DURATION_MILLIS
static final int
SPIN_ANIMATION_DURATION_MILLIS
private int
mEdgeTriggerThresh
private int
mDimpleWidth
private int
mBackgroundWidth
private int
mBackgroundHeight
private final int
mOuterRadius
private final int
mInnerRadius
private int
mDimpleSpacing
private android.view.VelocityTracker
mVelocityTracker
private int
mMinimumVelocity
private int
mMaximumVelocity
private int
mDimplesOfFling
The number of dimples we are flinging when we do the "spin" animation. Used to know when to wrap the icons back around so they "rotate back" onto the screen.
private int
mOrientation
Either {@link #HORIZONTAL} or {@link #VERTICAL}.
Constructors Summary
public RotarySelector(android.content.Context context)



       
        this(context, null);
public RotarySelector(android.content.Context context, android.util.AttributeSet attrs)
Constructor used when this widget is created from a layout file.

        super(context, attrs);

        TypedArray a =
            context.obtainStyledAttributes(attrs, R.styleable.RotarySelector);
        mOrientation = a.getInt(R.styleable.RotarySelector_orientation, HORIZONTAL);
        a.recycle();

        Resources r = getResources();
        mDensity = r.getDisplayMetrics().density;
        if (DBG) log("- Density: " + mDensity);

        // Assets (all are BitmapDrawables).
        mBackground = getBitmapFor(R.drawable.jog_dial_bg);
        mDimple = getBitmapFor(R.drawable.jog_dial_dimple);
        mDimpleDim = getBitmapFor(R.drawable.jog_dial_dimple_dim);

        mArrowLongLeft = getBitmapFor(R.drawable.jog_dial_arrow_long_left_green);
        mArrowLongRight = getBitmapFor(R.drawable.jog_dial_arrow_long_right_red);
        mArrowShortLeftAndRight = getBitmapFor(R.drawable.jog_dial_arrow_short_left_and_right);

        mInterpolator = new DecelerateInterpolator(1f);

        mEdgeTriggerThresh = (int) (mDensity * EDGE_TRIGGER_DIP);

        mDimpleWidth = mDimple.getWidth();

        mBackgroundWidth = mBackground.getWidth();
        mBackgroundHeight = mBackground.getHeight();
        mOuterRadius = (int) (mDensity * OUTER_ROTARY_RADIUS_DIP);
        mInnerRadius = (int) ((OUTER_ROTARY_RADIUS_DIP - ROTARY_STROKE_WIDTH_DIP) * mDensity);

        final ViewConfiguration configuration = ViewConfiguration.get(mContext);
        mMinimumVelocity = configuration.getScaledMinimumFlingVelocity() * 2;
        mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
Methods Summary
private voiddispatchTriggerEvent(int whichHandle)
Dispatches a trigger event to our listener.

        vibrate(VIBRATE_LONG);
        if (mOnDialTriggerListener != null) {
            mOnDialTriggerListener.onDialTrigger(this, whichHandle);
        }
private voiddrawCentered(android.graphics.Bitmap d, android.graphics.Canvas c, int x, int y)
Draw the bitmap so that it's centered on the point (x,y), then draws it using specified canvas. TODO: is there already a utility method somewhere for this?

        int w = d.getWidth();
        int h = d.getHeight();

        c.drawBitmap(d, x - (w / 2), y - (h / 2), mPaint);
private android.graphics.BitmapgetBitmapFor(int resId)

        return BitmapFactory.decodeResource(getContext().getResources(), resId);
private intgetYOnArc(int backgroundWidth, int innerRadius, int outerRadius, int x)
Assuming bitmap is a bounding box around a piece of an arc drawn by two concentric circles (as the background drawable for the rotary widget is), and given an x coordinate along the drawable, return the y coordinate of a point on the arc that is between the two concentric circles. The resulting y combined with the incoming x is a point along the circle in between the two concentric circles.

param
backgroundWidth The width of the asset (the bottom of the box surrounding the arc).
param
innerRadius The radius of the circle that intersects the drawable at the bottom two corders of the drawable (top two corners in terms of drawing coordinates).
param
outerRadius The radius of the circle who's top most point is the top center of the drawable (bottom center in terms of drawing coordinates).
param
x The distance along the x axis of the desired point. @return The y coordinate, in drawing coordinates, that will place (x, y) along the circle in between the two concentric circles.


        // the hypotenuse
        final int halfWidth = (outerRadius - innerRadius) / 2;
        final int middleRadius = innerRadius + halfWidth;

        // the bottom leg of the triangle
        final int triangleBottom = (backgroundWidth / 2) - x;

        // "Our offense is like the pythagorean theorem: There is no answer!" - Shaquille O'Neal
        final int triangleY =
                (int) Math.sqrt(middleRadius * middleRadius - triangleBottom * triangleBottom);

        // convert to drawing coordinates:
        // middleRadius - triangleY =
        //   the vertical distance from the outer edge of the circle to the desired point
        // from there we add the distance from the top of the drawable to the middle circle
        return middleRadius - triangleY + halfWidth;
private booleanisHoriz()

        return mOrientation == HORIZONTAL;
private voidlog(java.lang.String msg)


                                                   
            

                                                       
            
    


    // Debugging / testing code

        
        Log.d(LOG_TAG, msg);
protected voidonDraw(android.graphics.Canvas canvas)

        super.onDraw(canvas);

        final int width = getWidth();

        if (VISUAL_DEBUG) {
            // draw bounding box around widget
            mPaint.setColor(0xffff0000);
            mPaint.setStyle(Paint.Style.STROKE);
            canvas.drawRect(0, 0, width, getHeight(), mPaint);
        }

        final int height = getHeight();

        // update animating state before we draw anything
        if (mAnimating) {
            updateAnimation();
        }

        // Background:
        canvas.drawBitmap(mBackground, mBgMatrix, mPaint);

        // Draw the correct arrow(s) depending on the current state:
        mArrowMatrix.reset();
        switch (mGrabbedState) {
            case NOTHING_GRABBED:
                //mArrowShortLeftAndRight;
                break;
            case LEFT_HANDLE_GRABBED:
                mArrowMatrix.setTranslate(0, 0);
                if (!isHoriz()) {
                    mArrowMatrix.preRotate(-90, 0, 0);
                    mArrowMatrix.postTranslate(0, height);
                }
                canvas.drawBitmap(mArrowLongLeft, mArrowMatrix, mPaint);
                break;
            case RIGHT_HANDLE_GRABBED:
                mArrowMatrix.setTranslate(0, 0);
                if (!isHoriz()) {
                    mArrowMatrix.preRotate(-90, 0, 0);
                    // since bg width is > height of screen in landscape mode...
                    mArrowMatrix.postTranslate(0, height + (mBackgroundWidth - height));
                }
                canvas.drawBitmap(mArrowLongRight, mArrowMatrix, mPaint);
                break;
            default:
                throw new IllegalStateException("invalid mGrabbedState: " + mGrabbedState);
        }

        final int bgHeight = mBackgroundHeight;
        final int bgTop = isHoriz() ?
                height - bgHeight:
                width - bgHeight;

        if (VISUAL_DEBUG) {
            // draw circle bounding arc drawable: good sanity check we're doing the math correctly
            float or = OUTER_ROTARY_RADIUS_DIP * mDensity;
            final int vOffset = mBackgroundWidth - height;
            final int midX = isHoriz() ? width / 2 : mBackgroundWidth / 2 - vOffset;
            if (isHoriz()) {
                canvas.drawCircle(midX, or + bgTop, or, mPaint);
            } else {
                canvas.drawCircle(or + bgTop, midX, or, mPaint);
            }
        }

        // left dimple / icon
        {
            final int xOffset = mLeftHandleX + mRotaryOffsetX;
            final int drawableY = getYOnArc(
                    mBackgroundWidth,
                    mInnerRadius,
                    mOuterRadius,
                    xOffset);
            final int x = isHoriz() ? xOffset : drawableY + bgTop;
            final int y = isHoriz() ? drawableY + bgTop : height - xOffset;
            if (mGrabbedState != RIGHT_HANDLE_GRABBED) {
                drawCentered(mDimple, canvas, x, y);
                drawCentered(mLeftHandleIcon, canvas, x, y);
            } else {
                drawCentered(mDimpleDim, canvas, x, y);
            }
        }

        // center dimple
        {
            final int xOffset = isHoriz() ?
                    width / 2 + mRotaryOffsetX:
                    height / 2 + mRotaryOffsetX;
            final int drawableY = getYOnArc(
                    mBackgroundWidth,
                    mInnerRadius,
                    mOuterRadius,
                    xOffset);

            if (isHoriz()) {
                drawCentered(mDimpleDim, canvas, xOffset, drawableY + bgTop);
            } else {
                // vertical
                drawCentered(mDimpleDim, canvas, drawableY + bgTop, height - xOffset);
            }
        }

        // right dimple / icon
        {
            final int xOffset = mRightHandleX + mRotaryOffsetX;
            final int drawableY = getYOnArc(
                    mBackgroundWidth,
                    mInnerRadius,
                    mOuterRadius,
                    xOffset);

            final int x = isHoriz() ? xOffset : drawableY + bgTop;
            final int y = isHoriz() ? drawableY + bgTop : height - xOffset;
            if (mGrabbedState != LEFT_HANDLE_GRABBED) {
                drawCentered(mDimple, canvas, x, y);
                drawCentered(mRightHandleIcon, canvas, x, y);
            } else {
                drawCentered(mDimpleDim, canvas, x, y);
            }
        }

        // draw extra left hand dimples
        int dimpleLeft = mRotaryOffsetX + mLeftHandleX - mDimpleSpacing;
        final int halfdimple = mDimpleWidth / 2;
        while (dimpleLeft > -halfdimple) {
            final int drawableY = getYOnArc(
                    mBackgroundWidth,
                    mInnerRadius,
                    mOuterRadius,
                    dimpleLeft);

            if (isHoriz()) {
                drawCentered(mDimpleDim, canvas, dimpleLeft, drawableY + bgTop);
            } else {
                drawCentered(mDimpleDim, canvas, drawableY + bgTop, height - dimpleLeft);
            }
            dimpleLeft -= mDimpleSpacing;
        }

        // draw extra right hand dimples
        int dimpleRight = mRotaryOffsetX + mRightHandleX + mDimpleSpacing;
        final int rightThresh = mRight + halfdimple;
        while (dimpleRight < rightThresh) {
            final int drawableY = getYOnArc(
                    mBackgroundWidth,
                    mInnerRadius,
                    mOuterRadius,
                    dimpleRight);

            if (isHoriz()) {
                drawCentered(mDimpleDim, canvas, dimpleRight, drawableY + bgTop);
            } else {
                drawCentered(mDimpleDim, canvas, drawableY + bgTop, height - dimpleRight);
            }
            dimpleRight += mDimpleSpacing;
        }
protected voidonMeasure(int widthMeasureSpec, int heightMeasureSpec)

        final int length = isHoriz() ?
                MeasureSpec.getSize(widthMeasureSpec) :
                MeasureSpec.getSize(heightMeasureSpec);
        final int arrowScrunch = (int) (ARROW_SCRUNCH_DIP * mDensity);
        final int arrowH = mArrowShortLeftAndRight.getHeight();

        // by making the height less than arrow + bg, arrow and bg will be scrunched together,
        // overlaying somewhat (though on transparent portions of the drawable).
        // this works because the arrows are drawn from the top, and the rotary bg is drawn
        // from the bottom.
        final int height = mBackgroundHeight + arrowH - arrowScrunch;

        if (isHoriz()) {
            setMeasuredDimension(length, height);
        } else {
            setMeasuredDimension(height, length);
        }
protected voidonSizeChanged(int w, int h, int oldw, int oldh)

        super.onSizeChanged(w, h, oldw, oldh);

        final int edgePadding = (int) (EDGE_PADDING_DIP * mDensity);
        mLeftHandleX = edgePadding + mDimpleWidth / 2;
        final int length = isHoriz() ? w : h;
        mRightHandleX = length - edgePadding - mDimpleWidth / 2;
        mDimpleSpacing = (length / 2) - mLeftHandleX;

        // bg matrix only needs to be calculated once
        mBgMatrix.setTranslate(0, 0);
        if (!isHoriz()) {
            // set up matrix for translating drawing of background and arrow assets
            final int left = w - mBackgroundHeight;
            mBgMatrix.preRotate(-90, 0, 0);
            mBgMatrix.postTranslate(left, h);

        } else {
            mBgMatrix.postTranslate(0, h - mBackgroundHeight);
        }
public booleanonTouchEvent(android.view.MotionEvent event)
Handle touch screen events.

param
event The motion event.
return
True if the event was handled, false otherwise.

        if (mAnimating) {
            return true;
        }
        if (mVelocityTracker == null) {
            mVelocityTracker = VelocityTracker.obtain();
        }
        mVelocityTracker.addMovement(event);

        final int height = getHeight();

        final int eventX = isHoriz() ?
                (int) event.getX():
                height - ((int) event.getY());
        final int hitWindow = mDimpleWidth;

        final int action = event.getAction();
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                if (DBG) log("touch-down");
                mTriggered = false;
                if (mGrabbedState != NOTHING_GRABBED) {
                    reset();
                    invalidate();
                }
                if (eventX < mLeftHandleX + hitWindow) {
                    mRotaryOffsetX = eventX - mLeftHandleX;
                    setGrabbedState(LEFT_HANDLE_GRABBED);
                    invalidate();
                    vibrate(VIBRATE_SHORT);
                } else if (eventX > mRightHandleX - hitWindow) {
                    mRotaryOffsetX = eventX - mRightHandleX;
                    setGrabbedState(RIGHT_HANDLE_GRABBED);
                    invalidate();
                    vibrate(VIBRATE_SHORT);
                }
                break;

            case MotionEvent.ACTION_MOVE:
                if (DBG) log("touch-move");
                if (mGrabbedState == LEFT_HANDLE_GRABBED) {
                    mRotaryOffsetX = eventX - mLeftHandleX;
                    invalidate();
                    final int rightThresh = isHoriz() ? getRight() : height;
                    if (eventX >= rightThresh - mEdgeTriggerThresh && !mTriggered) {
                        mTriggered = true;
                        dispatchTriggerEvent(OnDialTriggerListener.LEFT_HANDLE);
                        final VelocityTracker velocityTracker = mVelocityTracker;
                        velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                        final int rawVelocity = isHoriz() ?
                                (int) velocityTracker.getXVelocity():
                                -(int) velocityTracker.getYVelocity();
                        final int velocity = Math.max(mMinimumVelocity, rawVelocity);
                        mDimplesOfFling = Math.max(
                                8,
                                Math.abs(velocity / mDimpleSpacing));
                        startAnimationWithVelocity(
                                eventX - mLeftHandleX,
                                mDimplesOfFling * mDimpleSpacing,
                                velocity);
                    }
                } else if (mGrabbedState == RIGHT_HANDLE_GRABBED) {
                    mRotaryOffsetX = eventX - mRightHandleX;
                    invalidate();
                    if (eventX <= mEdgeTriggerThresh && !mTriggered) {
                        mTriggered = true;
                        dispatchTriggerEvent(OnDialTriggerListener.RIGHT_HANDLE);
                        final VelocityTracker velocityTracker = mVelocityTracker;
                        velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
                        final int rawVelocity = isHoriz() ?
                                (int) velocityTracker.getXVelocity():
                                - (int) velocityTracker.getYVelocity();
                        final int velocity = Math.min(-mMinimumVelocity, rawVelocity);
                        mDimplesOfFling = Math.max(
                                8,
                                Math.abs(velocity / mDimpleSpacing));
                        startAnimationWithVelocity(
                                eventX - mRightHandleX,
                                -(mDimplesOfFling * mDimpleSpacing),
                                velocity);
                    }
                }
                break;
            case MotionEvent.ACTION_UP:
                if (DBG) log("touch-up");
                // handle animating back to start if they didn't trigger
                if (mGrabbedState == LEFT_HANDLE_GRABBED
                        && Math.abs(eventX - mLeftHandleX) > 5) {
                    // set up "snap back" animation
                    startAnimation(eventX - mLeftHandleX, 0, SNAP_BACK_ANIMATION_DURATION_MILLIS);
                } else if (mGrabbedState == RIGHT_HANDLE_GRABBED
                        && Math.abs(eventX - mRightHandleX) > 5) {
                    // set up "snap back" animation
                    startAnimation(eventX - mRightHandleX, 0, SNAP_BACK_ANIMATION_DURATION_MILLIS);
                }
                mRotaryOffsetX = 0;
                setGrabbedState(NOTHING_GRABBED);
                invalidate();
                if (mVelocityTracker != null) {
                    mVelocityTracker.recycle(); // wishin' we had generational GC
                    mVelocityTracker = null;
                }
                break;
            case MotionEvent.ACTION_CANCEL:
                if (DBG) log("touch-cancel");
                reset();
                invalidate();
                if (mVelocityTracker != null) {
                    mVelocityTracker.recycle();
                    mVelocityTracker = null;
                }
                break;
        }
        return true;
private voidreset()

        mAnimating = false;
        mRotaryOffsetX = 0;
        mDimplesOfFling = 0;
        setGrabbedState(NOTHING_GRABBED);
        mTriggered = false;
private voidsetGrabbedState(int newState)
Sets the current grabbed state, and dispatches a grabbed state change event to our listener.

        if (newState != mGrabbedState) {
            mGrabbedState = newState;
            if (mOnDialTriggerListener != null) {
                mOnDialTriggerListener.onGrabbedStateChange(this, mGrabbedState);
            }
        }
public voidsetLeftHandleResource(int resId)
Sets the left handle icon to a given resource. The resource should refer to a Drawable object, or use 0 to remove the icon.

param
resId the resource ID.

        if (resId != 0) {
            mLeftHandleIcon = getBitmapFor(resId);
        }
        invalidate();
public voidsetOnDialTriggerListener(com.android.internal.widget.RotarySelector$OnDialTriggerListener l)
Registers a callback to be invoked when the dial is "triggered" by rotating it one way or the other.

param
l the OnDialTriggerListener to attach to this view

        mOnDialTriggerListener = l;
public voidsetRightHandleResource(int resId)
Sets the right handle icon to a given resource. The resource should refer to a Drawable object, or use 0 to remove the icon.

param
resId the resource ID.

        if (resId != 0) {
            mRightHandleIcon = getBitmapFor(resId);
        }
        invalidate();
private voidstartAnimation(int startX, int endX, int duration)

        mAnimating = true;
        mAnimationStartTime = currentAnimationTimeMillis();
        mAnimationDuration = duration;
        mAnimatingDeltaXStart = startX;
        mAnimatingDeltaXEnd = endX;
        setGrabbedState(NOTHING_GRABBED);
        mDimplesOfFling = 0;
        invalidate();
private voidstartAnimationWithVelocity(int startX, int endX, int pixelsPerSecond)

        mAnimating = true;
        mAnimationStartTime = currentAnimationTimeMillis();
        mAnimationDuration = 1000 * (endX - startX) / pixelsPerSecond;
        mAnimatingDeltaXStart = startX;
        mAnimatingDeltaXEnd = endX;
        setGrabbedState(NOTHING_GRABBED);
        invalidate();
private voidupdateAnimation()

        final long millisSoFar = currentAnimationTimeMillis() - mAnimationStartTime;
        final long millisLeft = mAnimationDuration - millisSoFar;
        final int totalDeltaX = mAnimatingDeltaXStart - mAnimatingDeltaXEnd;
        final boolean goingRight = totalDeltaX < 0;
        if (DBG) log("millisleft for animating: " + millisLeft);
        if (millisLeft <= 0) {
            reset();
            return;
        }
        // from 0 to 1 as animation progresses
        float interpolation =
                mInterpolator.getInterpolation((float) millisSoFar / mAnimationDuration);
        final int dx = (int) (totalDeltaX * (1 - interpolation));
        mRotaryOffsetX = mAnimatingDeltaXEnd + dx;

        // once we have gone far enough to animate the current buttons off screen, we start
        // wrapping the offset back to the other side so that when the animation is finished,
        // the buttons will come back into their original places.
        if (mDimplesOfFling > 0) {
            if (!goingRight && mRotaryOffsetX < -3 * mDimpleSpacing) {
                // wrap around on fling left
                mRotaryOffsetX += mDimplesOfFling * mDimpleSpacing;
            } else if (goingRight && mRotaryOffsetX > 3 * mDimpleSpacing) {
                // wrap around on fling right
                mRotaryOffsetX -= mDimplesOfFling * mDimpleSpacing;
            }
        }
        invalidate();
private synchronized voidvibrate(long duration)
Triggers haptic feedback.

        final boolean hapticEnabled = Settings.System.getIntForUser(
                mContext.getContentResolver(), Settings.System.HAPTIC_FEEDBACK_ENABLED, 1,
                UserHandle.USER_CURRENT) != 0;
        if (hapticEnabled) {
            if (mVibrator == null) {
                mVibrator = (android.os.Vibrator) getContext()
                        .getSystemService(Context.VIBRATOR_SERVICE);
            }
            mVibrator.vibrate(duration, VIBRATION_ATTRIBUTES);
        }