Subversion Repositories SmartDukaan

/*

 * Copyright (C) 2011 Patrik Akerfeldt

 * Copyright (C) 2011 Jake Wharton

 *

 * 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.viewpagerindicator;

import android.content.Context;

import android.content.res.Resources;

import android.content.res.TypedArray;

import android.graphics.Canvas;

import android.graphics.Paint;

import android.graphics.Paint.Style;

import android.graphics.drawable.Drawable;

import android.os.Parcel;

import android.os.Parcelable;

import android.support.v4.view.MotionEventCompat;

import android.support.v4.view.ViewConfigurationCompat;

import android.support.v4.view.ViewPager;

import android.util.AttributeSet;

import android.view.MotionEvent;

import android.view.View;

import android.view.ViewConfiguration;

import static android.graphics.Paint.ANTI_ALIAS_FLAG;

import static android.widget.LinearLayout.HORIZONTAL;

import static android.widget.LinearLayout.VERTICAL;

/**

 * Draws circles (one for each view). The current view position is filled and

 * others are only stroked.

 */

public class CirclePageIndicator extends View implements PageIndicator {

    private static final int INVALID_POINTER = -1;

    private float mRadius;

    private final Paint mPaintPageFill = new Paint(ANTI_ALIAS_FLAG);

    private final Paint mPaintStroke = new Paint(ANTI_ALIAS_FLAG);

    private final Paint mPaintFill = new Paint(ANTI_ALIAS_FLAG);

    private ViewPager mViewPager;

    private ViewPager.OnPageChangeListener mListener;

    private int mCurrentPage;

    private int mSnapPage;

    private float mPageOffset;

    private int mScrollState;

    private int mOrientation;

    private boolean mCentered;

    private boolean mSnap;

    private int mTouchSlop;

    private float mLastMotionX = -1;

    private int mActivePointerId = INVALID_POINTER;

    private boolean mIsDragging;

    public CirclePageIndicator(Context context) {

        this(context, null);

    }

    public CirclePageIndicator(Context context, AttributeSet attrs) {

        this(context, attrs, R.attr.vpiCirclePageIndicatorStyle);

    }

    public CirclePageIndicator(Context context, AttributeSet attrs, int defStyle) {

        super(context, attrs, defStyle);

        if (isInEditMode()) return;

        //Load defaults from resources

        final Resources res = getResources();

        final int defaultPageColor = res.getColor(R.color.default_circle_indicator_page_color);

        final int defaultFillColor = res.getColor(R.color.default_circle_indicator_fill_color);

        final int defaultOrientation = res.getInteger(R.integer.default_circle_indicator_orientation);

        final int defaultStrokeColor = res.getColor(R.color.default_circle_indicator_stroke_color);

        final float defaultStrokeWidth = res.getDimension(R.dimen.default_circle_indicator_stroke_width);

        final float defaultRadius = res.getDimension(R.dimen.default_circle_indicator_radius);

        final boolean defaultCentered = res.getBoolean(R.bool.default_circle_indicator_centered);

        final boolean defaultSnap = res.getBoolean(R.bool.default_circle_indicator_snap);

        //Retrieve styles attributes

        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CirclePageIndicator, defStyle, 0);

        mCentered = a.getBoolean(R.styleable.CirclePageIndicator_centered, defaultCentered);

        mOrientation = a.getInt(R.styleable.CirclePageIndicator_android_orientation, defaultOrientation);

        mPaintPageFill.setStyle(Style.FILL);

        mPaintPageFill.setColor(a.getColor(R.styleable.CirclePageIndicator_pageColor, defaultPageColor));

        mPaintStroke.setStyle(Style.STROKE);

        mPaintStroke.setColor(a.getColor(R.styleable.CirclePageIndicator_strokeColor, defaultStrokeColor));

        mPaintStroke.setStrokeWidth(a.getDimension(R.styleable.CirclePageIndicator_strokeWidth, defaultStrokeWidth));

        mPaintFill.setStyle(Style.FILL);

        mPaintFill.setColor(a.getColor(R.styleable.CirclePageIndicator_fillColor, defaultFillColor));

        mRadius = a.getDimension(R.styleable.CirclePageIndicator_radius, defaultRadius);

        mSnap = a.getBoolean(R.styleable.CirclePageIndicator_snap, defaultSnap);

        Drawable background = a.getDrawable(R.styleable.CirclePageIndicator_android_background);

        if (background != null) {

          setBackgroundDrawable(background);

        }

        a.recycle();

        final ViewConfiguration configuration = ViewConfiguration.get(context);

        mTouchSlop = ViewConfigurationCompat.getScaledPagingTouchSlop(configuration);

    }

    public void setCentered(boolean centered) {

        mCentered = centered;

        invalidate();

    }

    public boolean isCentered() {

        return mCentered;

    }

    public void setPageColor(int pageColor) {

        mPaintPageFill.setColor(pageColor);

        invalidate();

    }

    public int getPageColor() {

        return mPaintPageFill.getColor();

    }

    public void setFillColor(int fillColor) {

        mPaintFill.setColor(fillColor);

        invalidate();

    }

    public int getFillColor() {

        return mPaintFill.getColor();

    }

    public void setOrientation(int orientation) {

        switch (orientation) {

            case HORIZONTAL:

            case VERTICAL:

                mOrientation = orientation;

                requestLayout();

                break;

            default:

                throw new IllegalArgumentException("Orientation must be either HORIZONTAL or VERTICAL.");

        }

    }

    public int getOrientation() {

        return mOrientation;

    }

    public void setStrokeColor(int strokeColor) {

        mPaintStroke.setColor(strokeColor);

        invalidate();

    }

    public int getStrokeColor() {

        return mPaintStroke.getColor();

    }

    public void setStrokeWidth(float strokeWidth) {

        mPaintStroke.setStrokeWidth(strokeWidth);

        invalidate();

    }

    public float getStrokeWidth() {

        return mPaintStroke.getStrokeWidth();

    }

    public void setRadius(float radius) {

        mRadius = radius;

        invalidate();

    }

    public float getRadius() {

        return mRadius;

    }

    public void setSnap(boolean snap) {

        mSnap = snap;

        invalidate();

    }

    public boolean isSnap() {

        return mSnap;

    }

    @Override

    protected void onDraw(Canvas canvas) {

        super.onDraw(canvas);

        if (mViewPager == null) {

            return;

        }

        final int count = mViewPager.getAdapter().getCount();

        if (count == 0) {

            return;

        }

        if (mCurrentPage >= count) {

            setCurrentItem(count - 1);

            return;

        }

        int longSize;

        int longPaddingBefore;

        int longPaddingAfter;

        int shortPaddingBefore;

        if (mOrientation == HORIZONTAL) {

            longSize = getWidth();

            longPaddingBefore = getPaddingLeft();

            longPaddingAfter = getPaddingRight();

            shortPaddingBefore = getPaddingTop();

        } else {

            longSize = getHeight();

            longPaddingBefore = getPaddingTop();

            longPaddingAfter = getPaddingBottom();

            shortPaddingBefore = getPaddingLeft();

        }

        final float threeRadius = mRadius * 3;

        final float shortOffset = shortPaddingBefore + mRadius;

        float longOffset = longPaddingBefore + mRadius;

        if (mCentered) {

            longOffset += ((longSize - longPaddingBefore - longPaddingAfter) / 2.0f) - ((count * threeRadius) / 2.0f);

        }

        float dX;

        float dY;

        float pageFillRadius = mRadius;

        if (mPaintStroke.getStrokeWidth() > 0) {

            pageFillRadius -= mPaintStroke.getStrokeWidth() / 2.0f;

        }

        //Draw stroked circles

        for (int iLoop = 0; iLoop < count; iLoop++) {

            float drawLong = longOffset + (iLoop * threeRadius);

            if (mOrientation == HORIZONTAL) {

                dX = drawLong;

                dY = shortOffset;

            } else {

                dX = shortOffset;

                dY = drawLong;

            }

            // Only paint fill if not completely transparent

            if (mPaintPageFill.getAlpha() > 0) {

                canvas.drawCircle(dX, dY, pageFillRadius, mPaintPageFill);

            }

            // Only paint stroke if a stroke width was non-zero

            if (pageFillRadius != mRadius) {

                canvas.drawCircle(dX, dY, mRadius, mPaintStroke);

            }

        }

        //Draw the filled circle according to the current scroll

        float cx = (mSnap ? mSnapPage : mCurrentPage) * threeRadius;

        if (!mSnap) {

            cx += mPageOffset * threeRadius;

        }

        if (mOrientation == HORIZONTAL) {

            dX = longOffset + cx;

            dY = shortOffset;

        } else {

            dX = shortOffset;

            dY = longOffset + cx;

        }

        canvas.drawCircle(dX, dY, mRadius, mPaintFill);

    }

    public boolean onTouchEvent(android.view.MotionEvent ev) {

        if (super.onTouchEvent(ev)) {

            return true;

        }

        if ((mViewPager == null) || (mViewPager.getAdapter().getCount() == 0)) {

            return false;

        }

        final int action = ev.getAction() & MotionEventCompat.ACTION_MASK;

        switch (action) {

            case MotionEvent.ACTION_DOWN:

                mActivePointerId = MotionEventCompat.getPointerId(ev, 0);

                mLastMotionX = ev.getX();

                break;

            case MotionEvent.ACTION_MOVE: {

                final int activePointerIndex = MotionEventCompat.findPointerIndex(ev, mActivePointerId);

                final float x = MotionEventCompat.getX(ev, activePointerIndex);

                final float deltaX = x - mLastMotionX;

                if (!mIsDragging) {

                    if (Math.abs(deltaX) > mTouchSlop) {

                        mIsDragging = true;

                    }

                }

                if (mIsDragging) {

                    mLastMotionX = x;

                    if (mViewPager.isFakeDragging() || mViewPager.beginFakeDrag()) {

                        mViewPager.fakeDragBy(deltaX);

                    }

                }

                break;

            }

            case MotionEvent.ACTION_CANCEL:

            case MotionEvent.ACTION_UP:

                if (!mIsDragging) {

                    final int count = mViewPager.getAdapter().getCount();

                    final int width = getWidth();

                    final float halfWidth = width / 2f;

                    final float sixthWidth = width / 6f;

                    if ((mCurrentPage > 0) && (ev.getX() < halfWidth - sixthWidth)) {

                        if (action != MotionEvent.ACTION_CANCEL) {

                            mViewPager.setCurrentItem(mCurrentPage - 1);

                        }

                        return true;

                    } else if ((mCurrentPage < count - 1) && (ev.getX() > halfWidth + sixthWidth)) {

                        if (action != MotionEvent.ACTION_CANCEL) {

                            mViewPager.setCurrentItem(mCurrentPage + 1);

                        }

                        return true;

                    }

                }

                mIsDragging = false;

                mActivePointerId = INVALID_POINTER;

                if (mViewPager.isFakeDragging()) mViewPager.endFakeDrag();

                break;

            case MotionEventCompat.ACTION_POINTER_DOWN: {

                final int index = MotionEventCompat.getActionIndex(ev);

                mLastMotionX = MotionEventCompat.getX(ev, index);

                mActivePointerId = MotionEventCompat.getPointerId(ev, index);

                break;

            }

            case MotionEventCompat.ACTION_POINTER_UP:

                final int pointerIndex = MotionEventCompat.getActionIndex(ev);

                final int pointerId = MotionEventCompat.getPointerId(ev, pointerIndex);

                if (pointerId == mActivePointerId) {

                    final int newPointerIndex = pointerIndex == 0 ? 1 : 0;

                    mActivePointerId = MotionEventCompat.getPointerId(ev, newPointerIndex);

                }

                mLastMotionX = MotionEventCompat.getX(ev, MotionEventCompat.findPointerIndex(ev, mActivePointerId));

                break;

        }

        return true;

    }

    @Override

    public void setViewPager(ViewPager view) {

        if (mViewPager == view) {

            return;

        }

        if (mViewPager != null) {

            mViewPager.setOnPageChangeListener(null);

        }

        if (view.getAdapter() == null) {

            throw new IllegalStateException("ViewPager does not have adapter instance.");

        }

        mViewPager = view;

        mViewPager.setOnPageChangeListener(this);

        invalidate();

    }

    @Override

    public void setViewPager(ViewPager view, int initialPosition) {

        setViewPager(view);

        setCurrentItem(initialPosition);

    }

    @Override

    public void setCurrentItem(int item) {

        if (mViewPager == null) {

            throw new IllegalStateException("ViewPager has not been bound.");

        }

        mViewPager.setCurrentItem(item);

        mCurrentPage = item;

        invalidate();

    }

    @Override

    public void notifyDataSetChanged() {

        invalidate();

    }

    @Override

    public void onPageScrollStateChanged(int state) {

        mScrollState = state;

        if (mListener != null) {

            mListener.onPageScrollStateChanged(state);

        }

    }

    @Override

    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

        mCurrentPage = position;

        mPageOffset = positionOffset;

        invalidate();

        if (mListener != null) {

            mListener.onPageScrolled(position, positionOffset, positionOffsetPixels);

        }

    }

    @Override

    public void onPageSelected(int position) {

        if (mSnap || mScrollState == ViewPager.SCROLL_STATE_IDLE) {

            mCurrentPage = position;

            mSnapPage = position;

            invalidate();

        }

        if (mListener != null) {

            mListener.onPageSelected(position);

        }

    }

    @Override

    public void setOnPageChangeListener(ViewPager.OnPageChangeListener listener) {

        mListener = listener;

    }

    /*

     * (non-Javadoc)

     *

     * @see android.view.View#onMeasure(int, int)

     */

    @Override

    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {

        if (mOrientation == HORIZONTAL) {

            setMeasuredDimension(measureLong(widthMeasureSpec), measureShort(heightMeasureSpec));

        } else {

            setMeasuredDimension(measureShort(widthMeasureSpec), measureLong(heightMeasureSpec));

        }

    }

    /**

     * Determines the width of this view

     *

     * @param measureSpec

     *            A measureSpec packed into an int

     * @return The width of the view, honoring constraints from measureSpec

     */

    private int measureLong(int measureSpec) {

        int result;

        int specMode = MeasureSpec.getMode(measureSpec);

        int specSize = MeasureSpec.getSize(measureSpec);

        if ((specMode == MeasureSpec.EXACTLY) || (mViewPager == null)) {

            //We were told how big to be

            result = specSize;

        } else {

            //Calculate the width according the views count

            final int count = mViewPager.getAdapter().getCount();

            result = (int)(getPaddingLeft() + getPaddingRight()

                    + (count * 2 * mRadius) + (count - 1) * mRadius + 1);

            //Respect AT_MOST value if that was what is called for by measureSpec

            if (specMode == MeasureSpec.AT_MOST) {

                result = Math.min(result, specSize);

            }

        }

        return result;

    }

    /**

     * Determines the height of this view

     *

     * @param measureSpec

     *            A measureSpec packed into an int

     * @return The height of the view, honoring constraints from measureSpec

     */

    private int measureShort(int measureSpec) {

        int result;

        int specMode = MeasureSpec.getMode(measureSpec);

        int specSize = MeasureSpec.getSize(measureSpec);

        if (specMode == MeasureSpec.EXACTLY) {

            //We were told how big to be

            result = specSize;

        } else {

            //Measure the height

            result = (int)(2 * mRadius + getPaddingTop() + getPaddingBottom() + 1);

            //Respect AT_MOST value if that was what is called for by measureSpec

            if (specMode == MeasureSpec.AT_MOST) {

                result = Math.min(result, specSize);

            }

        }

        return result;

    }

    @Override

    public void onRestoreInstanceState(Parcelable state) {

        SavedState savedState = (SavedState)state;

        super.onRestoreInstanceState(savedState.getSuperState());

        mCurrentPage = savedState.currentPage;

        mSnapPage = savedState.currentPage;

        requestLayout();

    }

    @Override

    public Parcelable onSaveInstanceState() {

        Parcelable superState = super.onSaveInstanceState();

        SavedState savedState = new SavedState(superState);

        savedState.currentPage = mCurrentPage;

        return savedState;

    }

    static class SavedState extends BaseSavedState {

        int currentPage;

        public SavedState(Parcelable superState) {

            super(superState);

        }

        private SavedState(Parcel in) {

            super(in);

            currentPage = in.readInt();

        }

        @Override

        public void writeToParcel(Parcel dest, int flags) {

            super.writeToParcel(dest, flags);

            dest.writeInt(currentPage);

        }

        @SuppressWarnings("UnusedDeclaration")

        public static final Parcelable.Creator<SavedState> CREATOR = new Parcelable.Creator<SavedState>() {

            @Override

            public SavedState createFromParcel(Parcel in) {

                return new SavedState(in);

            }

            @Override

            public SavedState[] newArray(int size) {

                return new SavedState[size];

            }

        };

    }

}