android 仿UC源代码

package com.droidful.flinggallery; import android.content.Context; import android.view.GestureDetector; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.View; import android.view.animation.Animation; import android.view.animation.AnimationUtils; import android.view.animation.Interpolator; import android.view.animation.Transformation; import android.widget.Adapter; import android.widget.FrameLayout; import android.widget.LinearLayout; // TODO: // 1. In order to improve performance Cache screen bitmap and use for animation // 2. Establish superfluous memory allocations and delay or replace with reused objects // Probably need to make sure we are not allocating objects (strings, etc.) in loops public class FlingGallery extends FrameLayout { // Constants private final int swipe_min_distance = 120; private final int swipe_max_off_path = 250; private final int swipe_threshold_veloicty = 400; // Properties private int mViewPaddingWidth = 0; private int mAnimationDuration = 250; private float mSnapBorderRatio = 0.5f; private boolean mIsGalleryCircular = true; // Members private int mGalleryWidth = 0; private boolean mIsTouched = false; private boolean mIsDragging = false; private float mCurrentOffset = 0.0f; private long mScrollTimestamp = 0; private int mFlingDirection = 0; private int mCurrentPosition = 0; private int mCurrentViewNumber = 0; private Context mContext; private Adapter mAdapter; private FlingGalleryView[] mViews; private FlingGalleryAnimation mAnimation; private GestureDetector mGestureDetector; private Interpolator mDecelerateInterpolater; public FlingGallery(Context context) { super(context); mContext = context; mAdapter = null; mViews = new FlingGalleryView[3]; mViews[0] = new FlingGalleryView(0, this); mViews[1] = new FlingGalleryView(1, this); mViews[2] = new FlingGalleryView(2, this); mAnimation = new FlingGalleryAnimation(); mGestureDetector = new GestureDetector(new FlingGestureDetector()); mDecelerateInterpolater = AnimationUtils.loadInterpolator(mContext, android.R.anim.decelerate_interpolator); } public void setPaddingWidth(int viewPaddingWidth) { mViewPaddingWidth = viewPaddingWidth; } public void setAnimationDuration(int animationDuration) { mAnimationDuration = animationDuration; } public void setSnapBorderRatio(float snapBorderRatio) { mSnapBorderRatio = snapBorderRatio; } public void setIsGalleryCircular(boolean isGalleryCircular) { if (mIsGalleryCircular != isGalleryCircular) { mIsGalleryCircular = isGalleryCircular; if (mCurrentPosition == getFirstPosition()) { // We need to reload the view immediately to the left to change it to circular view or blank mViews[getPrevViewNumber(mCurrentViewNumber)].recycleView(getPrevPosition(mCurrentPosition)); } if (mCurrentPosition == getLastPosition()) { // We need to reload the view immediately to the right to change it to circular view or blank mViews[getNextViewNumber(mCurrentViewNumber)].recycleView(getNextPosition(mCurrentPosition)); } } } public int getGalleryCount() { return (mAdapter == null) ? 0 : mAdapter.getCount(); } public int getFirstPosition() { return 0; } public int getLastPosition() { return (getGalleryCount() == 0) ? 0 : getGalleryCount() - 1; } private int getPrevPosition(int relativePosition) { int prevPosition = relativePosition - 1; if (prevPosition < getFirstPosition()) { prevPosition = getFirstPosition() - 1; if (mIsGalleryCircular == true) { prevPosition = getLastPosition(); } } return prevPosition; } private int getNextPosition(int relativePosition) { int nextPosition = relativePosition + 1; if (nextPosition > getLastPosition()) { nextPosition = getLastPosition() + 1; if (mIsGalleryCircular == true) { nextPosition = getFirstPosition(); } } return nextPosition; } private int getPrevViewNumber(int relativeViewNumber) { return (relativeViewNumber == 0) ? 2 : relativeViewNumber - 1; } private int getNextViewNumber(int relativeViewNumber) { return (relativeViewNumber == 2) ? 0 : relativeViewNumber + 1; } @Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) { super.onLayout(changed, left, top, right, bottom); // Calculate our view width mGalleryWidth = right - left; if (changed == true) { // Position views at correct starting offsets mViews[0].setOffset(0, 0, mCurrentViewNumber); mViews[1].setOffset(0, 0, mCurrentViewNumber); mViews[2].setOffset(0, 0, mCurrentViewNumber); } } public void setAdapter(Adapter adapter) { mAdapter = adapter; mCurrentPosition = 0; mCurrentViewNumber = 0; // Load the initial views from adapter mViews[0].recycleView(mCurrentPosition); mViews[1].recycleView(getNextPosition(mCurrentPosition)); mViews[2].recycleView(getPrevPosition(mCurrentPosition)); // Position views at correct starting offsets mViews[0].setOffset(0, 0, mCurrentViewNumber); mViews[1].setOffset(0, 0, mCurrentViewNumber); mViews[2].setOffset(0, 0, mCurrentViewNumber); } private int getViewOffset(int viewNumber, int relativeViewNumber) { // Determine width including configured padding width int offsetWidth = mGalleryWidth + mViewPaddingWidth; // Position the previous view one measured width to left if (viewNumber == getPrevViewNumber(relativeViewNumber)) { return offsetWidth; } // Position the next view one measured width to the right if (viewNumber == getNextViewNumber(relativeViewNumber)) { return offsetWidth * -1; } return 0; } void movePrevious() { // Slide to previous view mFlingDirection = 1; processGesture(); } void moveNext() { // Slide to next view mFlingDirection = -1; processGesture(); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { switch (keyCode) { case KeyEvent.KEYCODE_DPAD_LEFT: movePrevious(); return true; case KeyEvent.KEYCODE_DPAD_RIGHT: moveNext(); return true; case KeyEvent.KEYCODE_DPAD_CENTER: case KeyEvent.KEYCODE_ENTER: } return super.onKeyDown(keyCode, event); } public boolean onGalleryTouchEvent(MotionEvent event) { boolean consumed = mGestureDetector.onTouchEvent(event); if (event.getAction() == MotionEvent.ACTION_UP) { if (mIsTouched || mIsDragging) { processScrollSnap(); processGesture(); } } return consumed; } void processGesture() { int newViewNumber = mCurrentViewNumber; int reloadViewNumber = 0; int reloadPosition = 0; mIsTouched = false; mIsDragging = false; if (mFlingDirection > 0) { if (mCurrentPosition > getFirstPosition() || mIsGalleryCircular == true) { // Determine previous view and outgoing view to recycle newViewNumber = getPrevViewNumber(mCurrentViewNumber); mCurrentPosition = getPrevPosition(mCurrentPosition); reloadViewNumber = getNextViewNumber(mCurrentViewNumber); reloadPosition = getPrevPosition(mCurrentPosition); } } if (mFlingDirection < 0) { if (mCurrentPosition < getLastPosition() || mIsGalleryCircular == true) { // Determine the next view and outgoing view to recycle newViewNumber = getNextViewNumber(mCurrentViewNumber); mCurrentPosition = getNextPosition(mCurrentPosition); reloadViewNumber = getPrevViewNumber(mCurrentViewNumbe