Add RotarySelector widget to android.internal for use by lock screen and incoming call screen.

/*

 * Copyright (C) 2009 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.android.internal.widget;

import android.content.Context;

import android.content.res.Resources;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.Color;

import android.graphics.drawable.Drawable;

import android.os.Vibrator;

import android.util.AttributeSet;

import android.util.Log;

import android.view.MotionEvent;

import android.view.View;

import android.view.animation.AccelerateInterpolator;

import com.android.internal.R;

/**

 * 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.

 */

public class RotarySelector extends View {

    private static final String LOG_TAG = "RotarySelector";

    private static final boolean DBG = false;

    // Listener for onDialTrigger() callbacks.

    private OnDialTriggerListener mOnDialTriggerListener;

    private float mDensity;

    // UI elements

    private Drawable mBackground;

    private Drawable mDimple;

    private Drawable mLeftHandleIcon;

    private Drawable mRightHandleIcon;

    private Drawable mArrowShortLeftAndRight;

    private Drawable mArrowLongLeft;  // Long arrow starting on the left, pointing clockwise

    private Drawable mArrowLongRight;  // Long arrow starting on the right, pointing CCW

    // positions of the left and right handle

    private int mLeftHandleX;

    private int mRightHandleX;

    // current offset of user's dragging

    private int mTouchDragOffset = 0;

    // state of the animation used to bring the handle back to its start position when

    // the user lets go before triggering an action

    private boolean mAnimating = false;

    private long mAnimationEndTime;

    private int mAnimatingDelta;

    AccelerateInterpolator mInterpolator;

    /**

     * True after triggering an action if the user of {@link OnDialTriggerListener} wants to

     * freeze the UI (until they transition to another screen).

     */

    private boolean mFrozen = false;

    /**

     * If the user is currently dragging something.

     */

    private int mGrabbedState = NOTHING_GRABBED;

    private static final int NOTHING_GRABBED = 0;

    private static final int LEFT_HANDLE_GRABBED = 1;

    private static final int RIGHT_HANDLE_GRABBED = 2;

    /**

     * Whether the user has triggered something (e.g dragging the left handle all the way over to

     * the right).

     */

    private boolean mTriggered = false;

    // Vibration (haptic feedback)

    private Vibrator mVibrator;

    private static final long VIBRATE_SHORT = 60;  // msec

    private static final long VIBRATE_LONG = 100;  // msec

    // Various tweakable layout or behavior parameters:

    // How close to the edge of the screen, we let the handle get before

    // triggering an action:

    private static final int EDGE_THRESHOLD_DIP = 70;

    /**

     * The drawable for the arrows need to be scrunched this many dips towards the rotary bg below

     * it.

     */

    private static final int ARROW_SCRUNCH_DIP = 6;

    /**

     * How far inset the left and right circles should be

     */

    private static final int EDGE_PADDING_DIP = 9;

    /**

     * Dimensions of arc in background drawable.

     */

    static final int OUTER_ROTARY_RADIUS_DIP = 390;

    static final int ROTARY_STROKE_WIDTH_DIP = 83;

    private static final int ANIMATION_DURATION_MILLIS = 300;

    private static final boolean DRAW_CENTER_DIMPLE = false;

    /**

     * Constructor used when this widget is created from a layout file.

     */

    public RotarySelector(Context context, AttributeSet attrs) {

        super(context, attrs);

        if (DBG) log("IncomingCallDialWidget constructor...");

        Resources r = getResources();

        mDensity = r.getDisplayMetrics().density;

        if (DBG) log("- Density: " + mDensity);

        // Density is 1.0 on HVGA (like Dream), and 1.5 on WVGA.

        // Usage: raw_pixel_value = (int) (dpi_value * mDensity + 0.5f)

        // Assets (all are BitmapDrawables).

        mBackground = r.getDrawable(R.drawable.jog_dial_bg_cropped);

        mDimple = r.getDrawable(R.drawable.jog_dial_dimple);

        mArrowLongLeft = r.getDrawable(R.drawable.jog_dial_arrow_long_left_green);

        mArrowLongRight = r.getDrawable(R.drawable.jog_dial_arrow_long_right_red);

        mArrowShortLeftAndRight = r.getDrawable(R.drawable.jog_dial_arrow_short_left_and_right);

        mInterpolator = new AccelerateInterpolator();

    }

    /**

     * 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.

     */

    public void setLeftHandleResource(int resId) {

        Drawable d = null;

        if (resId != 0) {

            d = getResources().getDrawable(resId);

        }

        setLeftHandleDrawable(d);

    }

    /**

     * Sets the left handle icon to a given Drawable.

     *

     * @param d the Drawable to use as the icon, or null to remove the icon.

     */

    public void setLeftHandleDrawable(Drawable d) {

        mLeftHandleIcon = d;

        invalidate();

    }

    /**

     * 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.

     */

    public void setRightHandleResource(int resId) {

        Drawable d = null;

        if (resId != 0) {

            d = getResources().getDrawable(resId);

        }

        setRightHandleDrawable(d);

    }

    /**

     * Sets the right handle icon to a given Drawable.

     *

     * @param d the Drawable to use as the icon, or null to remove the icon.

     */

    public void setRightHandleDrawable(Drawable d) {

        mRightHandleIcon = d;

        invalidate();

    }

    @Override

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        final int width = MeasureSpec.getSize(widthMeasureSpec);  // screen width

        final int arrowH = mArrowShortLeftAndRight.getIntrinsicHeight();

        final int backgroundH = mBackground.getIntrinsicHeight();

        // 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 arrowScrunch = (int) (ARROW_SCRUNCH_DIP * mDensity);

        setMeasuredDimension(width, backgroundH + arrowH - arrowScrunch);

    }

    @Override

    protected void onSizeChanged(int w, int h, int oldw, int oldh) {

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

        mLeftHandleX = (int) (EDGE_PADDING_DIP * mDensity) + mDimple.getIntrinsicWidth() / 2;

        mRightHandleX =

                getWidth() - (int) (EDGE_PADDING_DIP * mDensity) - mDimple.getIntrinsicWidth() / 2;

    }

//    private Paint mPaint = new Paint();

    @Override

    protected void onDraw(Canvas canvas) {

        super.onDraw(canvas);

        if (DBG) {

            log(String.format("onDraw: mAnimating=%s, mTouchDragOffset=%d, mGrabbedState=%d," +

                    "mFrozen=%s",

                    mAnimating, mTouchDragOffset, mGrabbedState, mFrozen));

        }

        final int height = getHeight();

        // update animating state before we draw anything

        if (mAnimating && !mFrozen) {

            long millisLeft = mAnimationEndTime - System.currentTimeMillis();

            if (DBG) log("millisleft for animating: " + millisLeft);

            if (millisLeft <= 0) {

                reset();

            } else {

                float interpolation = mInterpolator.getInterpolation(

                        (float) millisLeft / ANIMATION_DURATION_MILLIS);

                mTouchDragOffset = (int) (mAnimatingDelta * interpolation);

            }

        }

        // Background:

        final int backgroundW = mBackground.getIntrinsicWidth();

        final int backgroundH = mBackground.getIntrinsicHeight();

        final int backgroundY = height - backgroundH;

        if (DBG) log("- Background INTRINSIC: " + backgroundW + " x " + backgroundH);

        mBackground.setBounds(0, backgroundY,

                              backgroundW, backgroundY + backgroundH);

        if (DBG) log("  Background BOUNDS: " + mBackground.getBounds());

        mBackground.draw(canvas);

        // Arrows:

        // All arrow assets are the same size (they're the full width of

        // the screen) regardless of which arrows are actually visible.

        int arrowW = mArrowShortLeftAndRight.getIntrinsicWidth();

        int arrowH = mArrowShortLeftAndRight.getIntrinsicHeight();

        // Draw the correct arrow(s) depending on the current state:

        Drawable currentArrow;

        switch (mGrabbedState) {

            case NOTHING_GRABBED:

                currentArrow  = mArrowShortLeftAndRight;

                break;

            case LEFT_HANDLE_GRABBED:

                currentArrow = mArrowLongLeft;

                break;

            case RIGHT_HANDLE_GRABBED:

                currentArrow = mArrowLongRight;

                break;

            default:

                throw new IllegalStateException("invalid mGrabbedState: " + mGrabbedState);

        }

        currentArrow.setBounds(0, 0, arrowW, arrowH);

        currentArrow.draw(canvas);

        // debug: draw circle that should match the outer arc (good sanity check)

//        mPaint.setColor(Color.RED);

//        mPaint.setStyle(Paint.Style.STROKE);

//        float or = OUTER_ROTARY_RADIUS_DIP * mDensity;

//        canvas.drawCircle(getWidth() / 2, or + mBackground.getBounds().top, or, mPaint);

        final int outerRadius = (int) (mDensity * OUTER_ROTARY_RADIUS_DIP);

        final int innerRadius =

                (int) ((OUTER_ROTARY_RADIUS_DIP - ROTARY_STROKE_WIDTH_DIP) * mDensity);

        final int bgTop = mBackground.getBounds().top;

        {

            final int xOffset = mLeftHandleX + mTouchDragOffset;

            final int drawableY = getYOnArc(

                    mBackground,

                    innerRadius,

                    outerRadius,

                    xOffset);

            drawCentered(mDimple, canvas, xOffset, drawableY + bgTop);

            drawCentered(mLeftHandleIcon, canvas, xOffset, drawableY + bgTop);

        }

        if (DRAW_CENTER_DIMPLE) {

            final int xOffset = getWidth() / 2 + mTouchDragOffset;

            final int drawableY = getYOnArc(

                    mBackground,

                    innerRadius,

                    outerRadius,

                    xOffset);

            drawCentered(mDimple, canvas, xOffset, drawableY + bgTop);

        }

        {

            final int xOffset = mRightHandleX + mTouchDragOffset;

            final int drawableY = getYOnArc(

                    mBackground,

                    innerRadius,

                    outerRadius,

                    xOffset);

            drawCentered(mDimple, canvas, xOffset, drawableY + bgTop);

            drawCentered(mRightHandleIcon, canvas, xOffset, drawableY + bgTop);

        }

        if (mAnimating) invalidate();

    }

    /**

     * Assuming drawable 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 drawable The drawable.

     * @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.

     */

    private int getYOnArc(Drawable drawable, int innerRadius, int outerRadius, int x) {

        // the hypotenuse

        final int halfWidth = (outerRadius - innerRadius) / 2;

        final int middleRadius = innerRadius + halfWidth;

        // the bottom leg of the triangle

        final int triangleBottom = (drawable.getIntrinsicWidth() / 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;

    }

    /**

     * Handle touch screen events.

     *

     * @param event The motion event.

     * @return True if the event was handled, false otherwise.

     */

    @Override

    public boolean onTouchEvent(MotionEvent event) {

        if (mAnimating || mFrozen) {

            return true;

        }

        final int eventX = (int) event.getX();

        final int hitWindow = mDimple.getIntrinsicWidth();

        if (event.getAction() == MotionEvent.ACTION_DOWN) {

            if (DBG) log("touch-down");

            mTriggered = false;

            if (mGrabbedState != RotarySelector.NOTHING_GRABBED) {

                reset();

                invalidate();

            }

            if (eventX < mLeftHandleX + hitWindow) {

                mTouchDragOffset = eventX - mLeftHandleX;

                mGrabbedState = RotarySelector.LEFT_HANDLE_GRABBED;

                invalidate();

                vibrate(VIBRATE_SHORT);

            } else if (eventX > mRightHandleX - hitWindow) {

                mTouchDragOffset = eventX - mRightHandleX;

                mGrabbedState = RotarySelector.RIGHT_HANDLE_GRABBED;

                invalidate();

                vibrate(VIBRATE_SHORT);

            }

        } else if (event.getAction() == MotionEvent.ACTION_MOVE) {

            if (DBG) log("touch-move");

            if (mGrabbedState == RotarySelector.LEFT_HANDLE_GRABBED) {

                mTouchDragOffset = eventX - mLeftHandleX;

                invalidate();

                if (eventX >= mRightHandleX - EDGE_PADDING_DIP && !mTriggered) {

                    mTriggered = true;

                    mFrozen = dispatchTriggerEvent(OnDialTriggerListener.LEFT_HANDLE);

                }

            } else if (mGrabbedState == RotarySelector.RIGHT_HANDLE_GRABBED) {

                mTouchDragOffset = eventX - mRightHandleX;

                invalidate();

                if (eventX <= mLeftHandleX + EDGE_PADDING_DIP && !mTriggered) {

                    mTriggered = true;

                    mFrozen = dispatchTriggerEvent(OnDialTriggerListener.RIGHT_HANDLE);

                }

            }

        } else if ((event.getAction() == MotionEvent.ACTION_UP)) {

            if (DBG) log("touch-up");

            // handle animating back to start if they didn't trigger

            if (mGrabbedState == RotarySelector.LEFT_HANDLE_GRABBED

                    && Math.abs(eventX - mLeftHandleX) > 5) {

                mAnimating = true;

                mAnimationEndTime = System.currentTimeMillis() + ANIMATION_DURATION_MILLIS;

                mAnimatingDelta = eventX - mLeftHandleX;

            } else if (mGrabbedState == RotarySelector.RIGHT_HANDLE_GRABBED

                    && Math.abs(eventX - mRightHandleX) > 5) {

                mAnimating = true;

                mAnimationEndTime = System.currentTimeMillis() + ANIMATION_DURATION_MILLIS;

                mAnimatingDelta = eventX - mRightHandleX;

            }

            mTouchDragOffset = 0;

            mGrabbedState = RotarySelector.NOTHING_GRABBED;

            invalidate();

        } else if (event.getAction() == MotionEvent.ACTION_CANCEL) {

            if (DBG) log("touch-cancel");

            reset();

            invalidate();

        }

        return true;

    }

    private void reset() {

        mAnimating = false;

        mTouchDragOffset = 0;

        mGrabbedState = RotarySelector.NOTHING_GRABBED;

        mTriggered = false;

    }

    /**

     * Triggers haptic feedback.

     */

    private synchronized void vibrate(long duration) {

        if (mVibrator == null) {

            mVibrator = (android.os.Vibrator) getContext().getSystemService(Context.VIBRATOR_SERVICE);

        }

        mVibrator.vibrate(duration);

    }

    /**

     * Sets the bounds of the specified Drawable so that it's centered

     * on the point (x,y), then draws it onto the specified canvas.

     * TODO: is there already a utility method somewhere for this?

     */

    private static void drawCentered(Drawable d, Canvas c, int x, int y) {

        int w = d.getIntrinsicWidth();

        int h = d.getIntrinsicHeight();

        // if (DBG) log("--> drawCentered: " + x + " , " + y + "; intrinsic " + w + " x " + h);

        d.setBounds(x - (w / 2), y - (h / 2),

                    x + (w / 2), y + (h / 2));

        d.draw(c);

    }

    /**

     * 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

     */

    public void setOnDialTriggerListener(OnDialTriggerListener l) {

        mOnDialTriggerListener = l;

    }

    /**

     * Dispatches a trigger event to our listener.

     */

    private boolean dispatchTriggerEvent(int whichHandle) {

        vibrate(VIBRATE_LONG);

        if (mOnDialTriggerListener != null) {

            return mOnDialTriggerListener.onDialTrigger(this, whichHandle);

        }

        return false;

    }

    /**

     * Interface definition for a callback to be invoked when the dial

     * is "triggered" by rotating it one way or the other.

     */

    public interface OnDialTriggerListener {

        /**

         * The dial was triggered because the user grabbed the left handle,

         * and rotated the dial clockwise.

         */

        public static final int LEFT_HANDLE = 1;

        /**

         * The dial was triggered because the user grabbed the right handle,

         * and rotated the dial counterclockwise.

         */

        public static final int RIGHT_HANDLE = 2;

        /**

         * @hide

         * The center handle is currently unused.

         */

        public static final int CENTER_HANDLE = 3;

        /**

         * Called when the dial is triggered.

         *

         * @param v The view that was triggered

         * @param whichHandle  Which "dial handle" the user grabbed,

         *        either {@link #LEFT_HANDLE}, {@link #RIGHT_HANDLE}, or

         *        {@link #CENTER_HANDLE}.

         * @return Whether the widget should freeze (e.g when the action goes to another screen,

         *         you want the UI to stay put until the transition occurs).

         */

        boolean onDialTrigger(View v, int whichHandle);

    }

    // Debugging / testing code

    private void log(String msg) {

        Log.d(LOG_TAG, msg);

    }

}