MaterialProgressDrawable.java

/*
 * Copyright (C) 2014 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.scwang.smartrefresh.header.internal;

import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.Path;
import android.graphics.PixelFormat;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.Animatable;
import android.graphics.drawable.Drawable;
import android.support.annotation.ColorInt;
import android.support.annotation.IntDef;
import android.support.annotation.NonNull;
import android.support.v4.view.animation.FastOutSlowInInterpolator;
import android.util.DisplayMetrics;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.Interpolator;
import android.view.animation.LinearInterpolator;
import android.view.animation.Transformation;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.ArrayList;
import java.util.List;

/**
 * Fancy progress indicator for Material theme.
 */
@SuppressWarnings({"WeakerAccess"})
public class MaterialProgressDrawable extends Drawable implements Animatable {
    private static final Interpolator LINEAR_INTERPOLATOR = new LinearInterpolator();
    static final Interpolator MATERIAL_INTERPOLATOR = new FastOutSlowInInterpolator();

    private static final float FULL_ROTATION = 1080.0f;

    @Retention(RetentionPolicy.SOURCE)
    @IntDef({LARGE, DEFAULT})
    public @interface ProgressDrawableSize {}

    // Maps to ProgressBar.Large style
    public static final byte LARGE = 0;
    // Maps to ProgressBar default style
    public static final byte DEFAULT = 1;

    // Maps to ProgressBar default style
    private static final byte CIRCLE_DIAMETER = 40;
    private static final float CENTER_RADIUS = 8.75f; //should add up to 10 when + stroke_width
    private static final float STROKE_WIDTH = 2.5f;

    // Maps to ProgressBar.Large style
    private static final byte CIRCLE_DIAMETER_LARGE = 56;
    private static final float CENTER_RADIUS_LARGE = 12.5f;
    private static final float STROKE_WIDTH_LARGE = 3f;

    private static final int[] COLORS = new int[] {
        Color.BLACK
    };

    /**
     * The value in the linear interpolator for animating the drawable at which
     * the color transition should start
     */
    private static final float COLOR_START_DELAY_OFFSET = 0.75f;
    private static final float END_TRIM_START_DELAY_OFFSET = 0.5f;
    private static final float START_TRIM_DURATION_OFFSET = 0.5f;

    /** The duration of a single progress spin in milliseconds. */
    private static final int ANIMATION_DURATION = 1332;

    /** The number of points in the progress "star". */
    private static final byte NUM_POINTS = 5;
    /** The list of animators operating on this drawable. */
    private final List<Animation> mAnimators = new ArrayList<>();

    /** The indicator ring, used to manage animation state. */
    private final Ring mRing = new Ring();

    /** Canvas rotation in degrees. */
    private float mRotation;

    /** Layout info for the arrowhead in dp */
    private static final byte ARROW_WIDTH = 10;
    private static final byte ARROW_HEIGHT = 5;
    private static final float ARROW_OFFSET_ANGLE = 5;

    /** Layout info for the arrowhead for the large spinner in dp */
    private static final byte ARROW_WIDTH_LARGE = 12;
    private static final byte ARROW_HEIGHT_LARGE = 6;
    private static final float MAX_PROGRESS_ARC = .8f;

    private View mParent;
    private Animation mAnimation;
    float mRotationCount;
    private float mWidth;
    private float mHeight;
    boolean mFinishing;

    public MaterialProgressDrawable(View parent) {
        mParent = parent;
        setColorSchemeColors(COLORS);
        updateSizes(DEFAULT);
        setupAnimators();
    }

    private void setSizeParameters(int progressCircleWidth, int progressCircleHeight,
                                   float centerRadius, float strokeWidth, float arrowWidth, float arrowHeight) {
        final DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
        final float screenDensity = metrics.density;

        mWidth = progressCircleWidth * screenDensity;
        mHeight = progressCircleHeight * screenDensity;
        mRing.setColorIndex(0);
        mRing.mPaint.setStrokeWidth(strokeWidth * screenDensity);
        mRing.mStrokeWidth = strokeWidth * screenDensity;
        mRing.mRingCenterRadius = (centerRadius * screenDensity);
        mRing.mArrowWidth = (int) (arrowWidth * screenDensity);
        mRing.mArrowHeight = (int) (arrowHeight * screenDensity);
        mRing.setInsets((int) mWidth, (int) mHeight);
        final Drawable thisDrawable = this;
        thisDrawable.invalidateSelf();
    }

    /*
     * Set the overall size for the progress spinner. This updates the radius
     * and stroke width of the ring.
     */
    public void updateSizes(@ProgressDrawableSize int size) {
        if (size == LARGE) {
            setSizeParameters(CIRCLE_DIAMETER_LARGE, CIRCLE_DIAMETER_LARGE, CENTER_RADIUS_LARGE,
                    STROKE_WIDTH_LARGE, ARROW_WIDTH_LARGE, ARROW_HEIGHT_LARGE);
        } else {
            setSizeParameters(CIRCLE_DIAMETER, CIRCLE_DIAMETER, CENTER_RADIUS, STROKE_WIDTH,
                    ARROW_WIDTH, ARROW_HEIGHT);
        }
    }

    /*
     * @param show Set to true to display the arrowhead on the progress spinner.
     */
    public void showArrow(boolean show) {
        if (mRing.mShowArrow != show) {
            mRing.mShowArrow = show;
            final Drawable thisDrawable = this;
            thisDrawable.invalidateSelf();
        }
    }

    /*
     * @param scale Set the scale of the arrowhead for the spinner.
     */
    public void setArrowScale(float scale) {
        if (mRing.mArrowScale != scale) {
            mRing.mArrowScale = scale;
            final Drawable thisDrawable = this;
            thisDrawable.invalidateSelf();
        }
    }

    /*
     * Set the start and end trim for the progress spinner arc.
     *
     * @param startAngle start angle
     * @param endAngle end angle
     */
    public void setStartEndTrim(float startAngle, float endAngle) {
        mRing.mStartTrim = (startAngle);
        mRing.mEndTrim = (endAngle);
        final Drawable thisDrawable = this;
        thisDrawable.invalidateSelf();
    }

    /*
     * Set the amount of rotation to apply to the progress spinner.
     *
     * @param rotation Rotation is from [0..1]
     */
    public void setProgressRotation(float rotation) {
        mRing.mRotation = (rotation);
        final Drawable thisDrawable = this;
        thisDrawable.invalidateSelf();
    }

    /*
     * Update the background color of the circle image view.
     */
    public void setBackgroundColor(@ColorInt int color) {
        mRing.mBackgroundColor = (color);
    }

    /*
     * Set the colors used in the progress animation from color resources.
     * The first color will also be the color of the bar that grows in response
     * to a user swipe gesture.
     *
     * @param colors
     */
    public void setColorSchemeColors(@ColorInt int... colors) {
        mRing.mColors = (colors);
        mRing.setColorIndex(0);
    }

    @Override
    public int getIntrinsicHeight() {
        return (int) mHeight;
    }

    @Override
    public int getIntrinsicWidth() {
        return (int) mWidth;
    }

    @Override
    public void draw(@NonNull Canvas c) {
        final Drawable thisDrawable = this;
        final Rect bounds = thisDrawable.getBounds();
        final int saveCount = c.save();
        c.rotate(mRotation, bounds.exactCenterX(), bounds.exactCenterY());
        mRing.draw(c, bounds);
        c.restoreToCount(saveCount);
    }

    @Override
    public void setAlpha(int alpha) {
        mRing.mAlpha = (alpha);
    }

    public int getAlpha() {
        return mRing.mAlpha;
    }

    @Override
    public void setColorFilter(ColorFilter colorFilter) {
        mRing.mPaint.setColorFilter(colorFilter);
        final Drawable thisDrawable = this;
        thisDrawable.invalidateSelf();
    }

    void setRotation(float rotation) {
        mRotation = rotation;
        final Drawable thisDrawable = this;
        thisDrawable.invalidateSelf();
    }

    @Override
    public int getOpacity() {
        return PixelFormat.TRANSLUCENT;
    }

    @Override
    public boolean isRunning() {
        final List<Animation> animators = mAnimators;
        final int N = animators.size();
        for (int i = 0; i < N; i++) {
            final Animation animator = animators.get(i);
            if (animator.hasStarted() && !animator.hasEnded()) {
                return true;
            }
        }
        return false;
    }

    @Override
    public void start() {
        mAnimation.reset();
        mRing.storeOriginals();
        // Already showing some part of the ring
        if (mRing.mEndTrim != mRing.mStartTrim) {
            mFinishing = true;
            mAnimation.setDuration(ANIMATION_DURATION / 2);
            mParent.startAnimation(mAnimation);
        } else {
            mRing.setColorIndex(0);
            mRing.resetOriginals();
            mAnimation.setDuration(ANIMATION_DURATION);
            mParent.startAnimation(mAnimation);
        }
    }

    @Override
    public void stop() {
        mParent.clearAnimation();
        mRing.setColorIndex(0);
        mRing.resetOriginals();
        showArrow(false);
        setRotation(0);
    }

    float getMinProgressArc(Ring ring) {
        return (float) Math.toRadians(
                ring.mStrokeWidth / (2 * Math.PI * ring.mRingCenterRadius));
    }

    // Adapted from ArgbEvaluator.java
    @SuppressWarnings("RedundantCast")
    private int evaluateColorChange(float fraction, int startValue, int endValue) {
        int startA = (startValue >> 24) & 0xff;
        int startR = (startValue >> 16) & 0xff;
        int startG = (startValue >> 8) & 0xff;
        int startB = startValue & 0xff;

        int endA = (endValue >> 24) & 0xff;
        int endR = (endValue >> 16) & 0xff;
        int endG = (endValue >> 8) & 0xff;
        int endB = endValue & 0xff;

        return (int) ((startA + (int) (fraction * (endA - startA))) << 24)
                | (int) ((startR + (int) (fraction * (endR - startR))) << 16)
                | (int) ((startG + (int) (fraction * (endG - startG))) << 8)
                | (int) ((startB + (int) (fraction * (endB - startB))));
    }

    /*
     * Update the ring color if this is within the last 25% of the animation.
     * The new ring color will be a translation from the starting ring color to
     * the next color.
     */
    void updateRingColor(float interpolatedTime, Ring ring) {
        if (interpolatedTime > COLOR_START_DELAY_OFFSET) {
            // scale the interpolatedTime so that the full
            // transformation from 0 - 1 takes place in the
            // remaining time
            ring.mCurrentColor = (evaluateColorChange((interpolatedTime - COLOR_START_DELAY_OFFSET)
                    / (1.0f - COLOR_START_DELAY_OFFSET), ring.getStartingColor(),
                    ring.getNextColor()));
        }
    }

    void applyFinishTranslation(float interpolatedTime, Ring ring) {
        // shrink back down and complete a full rotation before
        // starting other circles
        // Rotation goes between [0..1].
        updateRingColor(interpolatedTime, ring);
        float targetRotation = (float) (Math.floor(ring.mStartingRotation / MAX_PROGRESS_ARC)
                + 1f);
        final float minProgressArc = getMinProgressArc(ring);
        final float startTrim = ring.mStartingStartTrim
                + (ring.mStartingEndTrim - minProgressArc - ring.mStartingStartTrim)
                * interpolatedTime;
        setStartEndTrim(startTrim, ring.mStartingEndTrim);
        final float rotation = ring.mStartingRotation
                + ((targetRotation - ring.mStartingRotation) * interpolatedTime);
        setProgressRotation(rotation);
    }

    private void setupAnimators() {
        final Ring ring = mRing;
        final Animation animation = new Animation() {
                @Override
            public void applyTransformation(float interpolatedTime, Transformation t) {
                if (mFinishing) {
                    applyFinishTranslation(interpolatedTime, ring);
                } else {
                    // The minProgressArc is calculated from 0 to create an
                    // angle that matches the stroke width.
                    final float minProgressArc = getMinProgressArc(ring);
                    final float startingEndTrim = ring.mStartingEndTrim;
                    final float startingTrim = ring.mStartingStartTrim;
                    final float startingRotation = ring.mStartingRotation;

                    updateRingColor(interpolatedTime, ring);

                    // Moving the start trim only occurs in the first 50% of a
                    // single ring animation
                    if (interpolatedTime <= START_TRIM_DURATION_OFFSET) {
                        // scale the interpolatedTime so that the full
                        // transformation from 0 - 1 takes place in the
                        // remaining time
                        final float scaledTime = (interpolatedTime)
                                / (1.0f - START_TRIM_DURATION_OFFSET);
                        ring.mStartTrim = (startingTrim
                                + ((MAX_PROGRESS_ARC - minProgressArc) * MATERIAL_INTERPOLATOR
                                        .getInterpolation(scaledTime)));
                    }

                    // Moving the end trim starts after 50% of a single ring
                    // animation completes
                    if (interpolatedTime > END_TRIM_START_DELAY_OFFSET) {
                        // scale the interpolatedTime so that the full
                        // transformation from 0 - 1 takes place in the
                        // remaining time
                        final float minArc = MAX_PROGRESS_ARC - minProgressArc;
                        float scaledTime = (interpolatedTime - START_TRIM_DURATION_OFFSET)
                                / (1.0f - START_TRIM_DURATION_OFFSET);
                        ring.mEndTrim = (startingEndTrim
                                + (minArc * MATERIAL_INTERPOLATOR.getInterpolation(scaledTime)));
                    }

                    setProgressRotation(startingRotation + (0.25f * interpolatedTime));

                    float groupRotation = ((FULL_ROTATION / NUM_POINTS) * interpolatedTime)
                            + (FULL_ROTATION * (mRotationCount / NUM_POINTS));
                    setRotation(groupRotation);
                }
            }
        };
        animation.setRepeatCount(Animation.INFINITE);
        animation.setRepeatMode(Animation.RESTART);
        animation.setInterpolator(LINEAR_INTERPOLATOR);
        animation.setAnimationListener(new Animation.AnimationListener() {

                @Override
            public void onAnimationStart(Animation animation) {
                mRotationCount = 0;
            }

                @Override
            public void onAnimationEnd(Animation animation) {
                // do nothing
            }

                @Override
            public void onAnimationRepeat(Animation animation) {
                ring.storeOriginals();
                ring.goToNextColor();
                ring.mStartTrim = (ring.mEndTrim);
                if (mFinishing) {
                    // finished closing the last ring from the swipe gesture; go
                    // into progress mode
                    mFinishing = false;
                    animation.setDuration(ANIMATION_DURATION);
                    showArrow(false);
                } else {
                    mRotationCount = (mRotationCount + 1) % (NUM_POINTS);
                }
            }
        });
        mAnimation = animation;
    }

    private class Ring {
        final RectF mTempBounds = new RectF();
        final Paint mPaint = new Paint();
        final Paint mArrowPaint = new Paint();

        float mStartTrim = 0.0f;
        float mEndTrim = 0.0f;
        float mRotation = 0.0f;
        float mStrokeWidth = 5.0f;
        float mStrokeInset = 2.5f;

        int[] mColors;
        // mColorIndex represents the offset into the available mColors that the
        // progress circle should currently display. As the progress circle is
        // animating, the mColorIndex moves by one to the next available color.
        int mColorIndex;
        float mStartingStartTrim;
        float mStartingEndTrim;
        float mStartingRotation;
        boolean mShowArrow;
        Path mArrow;
        float mArrowScale;
        double mRingCenterRadius;
        int mArrowWidth;
        int mArrowHeight;
        int mAlpha;
        final Paint mCirclePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        int mBackgroundColor;
        int mCurrentColor;

        Ring() {
            mPaint.setStrokeCap(Paint.Cap.SQUARE);
            mPaint.setAntiAlias(true);
            mPaint.setStyle(Style.STROKE);

            mArrowPaint.setStyle(Style.FILL);
            mArrowPaint.setAntiAlias(true);
        }

        /*
         * Draw the progress spinner
         */
        public void draw(Canvas c, Rect bounds) {
            final RectF arcBounds = mTempBounds;
            arcBounds.set(bounds);
            arcBounds.inset(mStrokeInset, mStrokeInset);

            final float startAngle = (mStartTrim + mRotation) * 360;
            final float endAngle = (mEndTrim + mRotation) * 360;
            float sweepAngle = endAngle - startAngle;

			if (mAlpha < 255) {
				mCirclePaint.setColor(mBackgroundColor);
				mCirclePaint.setAlpha(255 - mAlpha);
				c.drawCircle(bounds.exactCenterX(), bounds.exactCenterY(), (bounds.width() + 1f) / 2f,
							 mCirclePaint);
			}

            if (sweepAngle != 0) {
                mPaint.setColor(mCurrentColor);
                c.drawArc(arcBounds, startAngle, sweepAngle, false, mPaint);
            }

            drawTriangle(c, startAngle, sweepAngle, bounds);
        }

        private void drawTriangle(Canvas c, float startAngle, float sweepAngle, Rect bounds) {
            if (mShowArrow) {
                if (mArrow == null) {
                    mArrow = new Path();
                    mArrow.setFillType(Path.FillType.EVEN_ODD);
                } else {
                    mArrow.reset();
                }

                // Adjust the position of the triangle so that it is inset as
                // much as the arc, but also centered on the arc.
                float inset = (float) ((int) mStrokeInset / 2) * mArrowScale;
                float x = (float) (mRingCenterRadius * Math.cos(0) + bounds.exactCenterX());
                float y = (float) (mRingCenterRadius * Math.sin(0) + bounds.exactCenterY());

                // Update the path each time. This works around an issue in SKIA
                // where concatenating a rotation matrix to a scale matrix
                // ignored a starting negative rotation. This appears to have
                // been fixed as of API 21.
                mArrow.moveTo(0, 0);
                mArrow.lineTo(mArrowWidth * mArrowScale, 0);
                mArrow.lineTo((mArrowWidth * mArrowScale / 2), (mArrowHeight
                        * mArrowScale));
                mArrow.offset(x - inset, y);
                mArrow.close();
                // draw a triangle
                mArrowPaint.setColor(mCurrentColor);
                c.rotate(startAngle + sweepAngle - ARROW_OFFSET_ANGLE, bounds.exactCenterX(),
                        bounds.exactCenterY());
                c.drawPath(mArrow, mArrowPaint);
            }
        }

        /*
         * @param index Index into the color array of the color to display in
         *            the progress spinner.
         */
        public void setColorIndex(int index) {
            mColorIndex = index;
            mCurrentColor = mColors[mColorIndex];
        }

        /*
         * @return int describing the next color the progress spinner should use when drawing.
         */
        public int getNextColor() {
            return mColors[getNextColorIndex()];
        }

        private int getNextColorIndex() {
            return (mColorIndex + 1) % (mColors.length);
        }

        /*
         * Proceed to the next available ring color. This will automatically
         * wrap back to the beginning of colors.
         */
        public void goToNextColor() {
            setColorIndex(getNextColorIndex());
        }

        public int getStartingColor() {
            return mColors[mColorIndex];
        }

        public void setInsets(int width, int height) {
            final float minEdge = (float) Math.min(width, height);
            float insets;
            if (mRingCenterRadius <= 0 || minEdge < 0) {
                insets = (float) Math.ceil(mStrokeWidth / 2.0f);
            } else {
                insets = (float) (minEdge / 2.0f - mRingCenterRadius);
            }
            mStrokeInset = insets;
        }

        /*
         * If the start / end trim are offset to begin with, store them so that
         * animation starts from that offset.
         */
        public void storeOriginals() {
            mStartingStartTrim = mStartTrim;
            mStartingEndTrim = mEndTrim;
            mStartingRotation = mRotation;
        }

        /*
         * Reset the progress spinner to default rotation, start and end angles.
         */
        public void resetOriginals() {
            mStartingStartTrim = 0;
            mStartingEndTrim = 0;
            mStartingRotation = 0;
            mStartTrim = (0);
            mEndTrim = (0);
            mRotation = (0);
        }
    }
}