Android重写Gallery

重写的Gallery,Gallery滑动的时候下面的点跟着动package com.ray.ui.view; import java.util.ArrayList; import android.app.Activity; import android.content.Context; import android.util.Log; import android.view.GestureDetector; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.View; 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; import android.widget.FrameLayout.LayoutParams; import com.jxtoon.flight.R; // 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 MyGallery 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 Activity mContext; private Adapter mAdapter; private FlingGalleryView[] mViews; private FlingGalleryAnimation mAnimation; private GestureDetector mGestureDetector; //An interpolator defines the rate of change of animation. This allows the basic animation effects (alpha, scale, translate, rotate) to be accelerated, decelerated, repeated, etc. private Interpolator mDecelerateInterpolater; private ArrayList indicatorView; //Gallery构造方法public MyGallery(Activity context) { super(context); //增加选择指示灯indicatorView = new ArrayList(); indicatorView.add(context.findViewById(R.id.switcher1)); indicatorView.add(context.findViewById(R.id.switcher2)); indicatorView.add(context.findViewById(R.id.switcher3)); indicatorView.add(context.findViewById(R.id.switcher4)); indicatorView.add(context.findViewById(R.id.switcher5)); indicatorView.get(0).setSelected(true);//初始化选择第一个mContext = context; //指定只能有三个缓存View mViews = new FlingGalleryView[3]; mViews[0] = new FlingGalleryView(0, this); mViews[1] = new FlingGalleryView(1, this); mViews[2] = new FlingGalleryView(2, this); //切换View动画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; } /** *是否Circular *设置gallery的循环情况* @param isGalleryCircular */ 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, mCurrentViewNumber); mViews[1].setOffset(0, mCurrentViewNumber); mViews[2].setOffset(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, mCurrentViewNumber); mViews[1].setOffset(0, mCurrentViewNumber); mViews[2].setOffset(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); } @Override public boolean onTouchEvent(MotionEvent event) { boolean consumed = mGestureDetector.onTouchEvent(event); if (event.getAction() == MotionEvent.ACTION_UP) { if (mIsTouched || mIsDragging) { processScrollSnap(); processGesture(); } } return consumed; } 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(mCurrentViewNumber); reloadPosition = getNextPosition(mCurrentPosition); } } if (newViewNumber != mCurrentViewNumber) { mCurrentViewNumber = newViewNumber; // Reload outgoing view from adapter in new position mViews[reloadViewNumber].recycleView(reloadPosition); } // Ensure input focus on the current view mViews[mCurrentViewNumber].requestFocus(); // Run the slide animations for view transitions mAnimation.prepareAnimation(mCurrentViewNumber); this.startAnimation(mAnimation); // Reset fling state mFlingDirection = 0; } void processScrollSnap() { // Snap to next view if scrolled passed snap position float rollEdgeWidth = mGalleryWidth * mSnapBorderRatio; int rollOffset = mGalleryWidth - (int) rollEdgeWidth; int currentOffset = mViews[mCurrentViewNumber].getCurrentOffset(); if (currentOffset = rollOffset) { // Snap to next view mFlingDirection = -1; } } //Gallery滑动类private class FlingGalleryView { private int mViewNumber; private FrameLayout mParentLayout; private FrameLayout mInvalidLayout = null; private LinearLayout mInternalLayout = null; private View mExternalView = null; private int positionOfAdapter;//当前View的位置public FlingGalleryView(int viewNumber, FrameLayout parentLayout) { mViewNumber = viewNumber; mParentLayout = parentLayout; // Invalid layout is used when outside gallery mInvalidLayout = new FrameLayout(mContext); mInvalidLayout.setLayoutParams(new LinearLayout.LayoutParams( LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); // Internal layout is permanent for duration mInternalLayout = new LinearLayout(mContext); mInternalLayout.setLayoutParams(new LinearLayout.LayoutParams( LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); mParentLayout.addView(mInternalLayout); } public void recycleView(int newPosition) { if (mExternalView != null) { mInternalLayout.removeView(mExternalView); } if (mAdapter != null) { if (newPosition >= getFirstPosition() && newPosition 1.0f) ? 1.0f : interpolatedTime; int offset = mInitialOffset + (int) (mTargetDistance * interpolatedTime); for (int viewNumber = 0; viewNumber < 3; viewNumber++) { // Only need to animate the visible views as the other view will // always be off-screen if ((mTargetDistance > 0 && viewNumber != getNextViewNumber(mRelativeViewNumber)) || (mTargetDistance < 0 && viewNumber != getPrevViewNumber(mRelativeViewNumber))) { mViews[viewNumber] .setOffset(offset, 0, mRelativeViewNumber); } } } @Override public boolean getTransformation(long currentTime, Transformation outTransformation) { if (super.getTransformation(currentTime, outTransformation) == false) { // Perform final adjustment to offsets to cleanup animation mViews[0].setOffset(mTargetOffset, 0, mRelativeViewNumber); mViews[1].setOffset(mTargetOffset, 0, mRelativeViewNumber); mViews[2].setOffset(mTargetOffset, 0, mRelativeViewNumber); // Reached the animation target mIsAnimationInProgres = false; return false; } // Cancel if the screen touched if (mIsTouched || mIsDragging) { // Note that this point we still consider ourselves to be // animating // because we have not yet reached the target offset; its just // that the // user has temporarily interrupted the animation with a touch // gesture return false; } return true; } } private class FlingGestureDetector extends GestureDetector.SimpleOnGestureListener { @Override public boolean onDown(MotionEvent e) { // Stop animation mIsTouched = true; // Reset fling state mFlingDirection = 0; return true; } @Override public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { if (e2.getAction() == MotionEvent.ACTION_MOVE) { if (mIsDragging == false) { // Stop animation mIsTouched = true; // Reconfigure scroll mIsDragging = true; mFlingDirection = 0; mScrollTimestamp = System.currentTimeMillis(); mCurrentOffset = mViews[mCurrentViewNumber] .getCurrentOffset(); } float maxVelocity = mGalleryWidth / (mAnimationDuration / 1000.0f); long timestampDelta = System.currentTimeMillis() - mScrollTimestamp; float maxScrollDelta = maxVelocity * (timestampDelta / 1000.0f); float currentScrollDelta = e1.getX() - e2.getX(); if (currentScrollDelta < maxScrollDelta * -1) currentScrollDelta = maxScrollDelta * -1; if (currentScrollDelta > maxScrollDelta) currentScrollDelta = maxScrollDelta; int scrollOffset = Math.round(mCurrentOffset + currentScrollDelta); // We can't scroll more than the width of our own frame layout if (scrollOffset >= mGalleryWidth) scrollOffset = mGalleryWidth; if (scrollOffset swipe_threshold_veloicty) { movePrevious(); } if (e1.getX() - e2.getX() > swipe_min_distance && Math.abs(velocityX) > swipe_threshold_veloicty) { moveNext(); } } return false; } @Override public void onLongPress(MotionEvent e) { // Finalise scrolling mFlingDirection = 0; processGesture(); } @Override public void onShowPress(MotionEvent e) { } @Override public boolean onSingleTapUp(MotionEvent e) { // Reset fling state mFlingDirection = 0; return false; } } }