Android拖动效果图

转载至：http://iaiai.iteye.com/blog/1580587

先来看效果图:

就两个文件，新建一个项目把下面两个文件放进去，设置好启动activity就行了

FlingGallery.java

Java代码

package com.iaiai.fg;
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
/**
*
*
* Title: FlingGallery.java
*
*
* E-Mail: 176291935@qq.com
*
*
* QQ: 176291935
*
*
* Http: iaiai.iteye.com
*
*
* Create time: 2012-7-7 上午10:18:53
*
*
* @author 丸子
* @version 0.0.1
*/
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(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 * -1) {
// Snap to previous view
mFlingDirection = 1;
}
if (currentOffset >= rollOffset) {
// Snap to next view
mFlingDirection = -1;
}
}
private class FlingGalleryView {
private int mViewNumber;
private FrameLayout mParentLayout;
private FrameLayout mInvalidLayout = null;
private LinearLayout mInternalLayout = null;
private View mExternalView = null;
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.MATCH_PARENT, LayoutParams.MATCH_PARENT));
// Internal layout is permanent for duration
mInternalLayout = new LinearLayout(mContext);
mInternalLayout.setLayoutParams(new LinearLayout.LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
mParentLayout.addView(mInternalLayout);
}
public void recycleView(int newPosition) {
if (mExternalView != null) {
mInternalLayout.removeView(mExternalView);
}
if (mAdapter != null) {
if (newPosition >= getFirstPosition()
&& newPosition <= getLastPosition()) {
mExternalView = mAdapter.getView(newPosition,
mExternalView, mInternalLayout);
} else {
mExternalView = mInvalidLayout;
}
}
if (mExternalView != null) {
mInternalLayout.addView(mExternalView,
new LinearLayout.LayoutParams(
LayoutParams.MATCH_PARENT,
LayoutParams.MATCH_PARENT));
}
}
public void setOffset(int xOffset, int yOffset, int relativeViewNumber) {
// Scroll the target view relative to its own position relative to
// currently displayed view
mInternalLayout.scrollTo(
getViewOffset(mViewNumber, relativeViewNumber) + xOffset,
yOffset);
}
public int getCurrentOffset() {
// Return the current scroll position
return mInternalLayout.getScrollX();
}
public void requestFocus() {
mInternalLayout.requestFocus();
}
}
private class FlingGalleryAnimation extends Animation {
private boolean mIsAnimationInProgres;
private int mRelativeViewNumber;
private int mInitialOffset;
private int mTargetOffset;
private int mTargetDistance;
public FlingGalleryAnimation() {
mIsAnimationInProgres = false;
mRelativeViewNumber = 0;
mInitialOffset = 0;
mTargetOffset = 0;
mTargetDistance = 0;
}
public void prepareAnimation(int relativeViewNumber) {
// If we are animating relative to a new view
if (mRelativeViewNumber != relativeViewNumber) {
if (mIsAnimationInProgres == true) {
// We only have three views so if requested again to animate
// in same direction we must snap
int newDirection = (relativeViewNumber == getPrevViewNumber(mRelativeViewNumber)) ? 1
: -1;
int animDirection = (mTargetDistance < 0) ? 1 : -1;
// If animation in same direction
if (animDirection == newDirection) {
// Ran out of time to animate so snap to the target
// offset
mViews[0].setOffset(mTargetOffset, 0,
mRelativeViewNumber);
mViews[1].setOffset(mTargetOffset, 0,
mRelativeViewNumber);
mViews[2].setOffset(mTargetOffset, 0,
mRelativeViewNumber);
}
}
// Set relative view number for animation
mRelativeViewNumber = relativeViewNumber;
}
// Note: In this implementation the targetOffset will always be zero
// as we are centering the view; but we include the calculations of
// targetOffset and targetDistance for use in future implementations
mInitialOffset = mViews[mRelativeViewNumber].getCurrentOffset();
mTargetOffset = getViewOffset(mRelativeViewNumber,
mRelativeViewNumber);
mTargetDistance = mTargetOffset - mInitialOffset;
// Configure base animation properties
this.setDuration(mAnimationDuration);
this.setInterpolator(mDecelerateInterpolater);
// Start/continued animation
mIsAnimationInProgres = true;
}
@Override
protected void applyTransformation(float interpolatedTime,
Transformation transformation) {
// Ensure interpolatedTime does not over-shoot then calculate new
// offset
interpolatedTime = (interpolatedTime > 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 at 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 <= mGalleryWidth * -1)
scrollOffset = mGalleryWidth * -1;
mViews[0].setOffset(scrollOffset, 0, mCurrentViewNumber);
mViews[1].setOffset(scrollOffset, 0, mCurrentViewNumber);
mViews[2].setOffset(scrollOffset, 0, mCurrentViewNumber);
}
return false;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
float velocityY) {
if (Math.abs(e1.getY() - e2.getY()) <= swipe_max_off_path) {
if (e2.getX() - e1.getX() > swipe_min_distance
&& Math.abs(velocityX) > 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;
}
}
}

package com.iaiai.fg;

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 
/**
 * 
 * <p>
 * Title: FlingGallery.java
 * </p>
 * <p>
 * E-Mail: 176291935@qq.com
 * </p>
 * <p>
 * QQ: 176291935
 * </p>
 * <p>
 * Http: iaiai.iteye.com
 * </p>
 * <p>
 * Create time: 2012-7-7 上午10:18:53
 * </p>
 * 
 * @author 丸子
 * @version 0.0.1
 */
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(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 * -1) {
			// Snap to previous view
			mFlingDirection = 1;
		}

		if (currentOffset >= rollOffset) {
			// Snap to next view
			mFlingDirection = -1;
		}
	}

	private class FlingGalleryView {
		private int mViewNumber;
		private FrameLayout mParentLayout;
		private FrameLayout mInvalidLayout = null;
		private LinearLayout mInternalLayout = null;
		private View mExternalView = null;

		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.MATCH_PARENT, LayoutParams.MATCH_PARENT));

			// Internal layout is permanent for duration
			mInternalLayout = new LinearLayout(mContext);
			mInternalLayout.setLayoutParams(new LinearLayout.LayoutParams(
					LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT));
			mParentLayout.addView(mInternalLayout);
		}

		public void recycleView(int newPosition) {
			if (mExternalView != null) {
				mInternalLayout.removeView(mExternalView);
			}

			if (mAdapter != null) {
				if (newPosition >= getFirstPosition()
						&& newPosition <= getLastPosition()) {
					mExternalView = mAdapter.getView(newPosition,
							mExternalView, mInternalLayout);
				} else {
					mExternalView = mInvalidLayout;
				}
			}

			if (mExternalView != null) {
				mInternalLayout.addView(mExternalView,
						new LinearLayout.LayoutParams(
								LayoutParams.MATCH_PARENT,
								LayoutParams.MATCH_PARENT));
			}
		}

		public void setOffset(int xOffset, int yOffset, int relativeViewNumber) {
			// Scroll the target view relative to its own position relative to
			// currently displayed view
			mInternalLayout.scrollTo(
					getViewOffset(mViewNumber, relativeViewNumber) + xOffset,
					yOffset);
		}

		public int getCurrentOffset() {
			// Return the current scroll position
			return mInternalLayout.getScrollX();
		}

		public void requestFocus() {
			mInternalLayout.requestFocus();
		}
	}

	private class FlingGalleryAnimation extends Animation {
		private boolean mIsAnimationInProgres;
		private int mRelativeViewNumber;
		private int mInitialOffset;
		private int mTargetOffset;
		private int mTargetDistance;

		public FlingGalleryAnimation() {
			mIsAnimationInProgres = false;
			mRelativeViewNumber = 0;
			mInitialOffset = 0;
			mTargetOffset = 0;
			mTargetDistance = 0;
		}

		public void prepareAnimation(int relativeViewNumber) {
			// If we are animating relative to a new view
			if (mRelativeViewNumber != relativeViewNumber) {
				if (mIsAnimationInProgres == true) {
					// We only have three views so if requested again to animate
					// in same direction we must snap
					int newDirection = (relativeViewNumber == getPrevViewNumber(mRelativeViewNumber)) ? 1
							: -1;

					int animDirection = (mTargetDistance < 0) ? 1 : -1;
					// If animation in same direction
					if (animDirection == newDirection) {
						// Ran out of time to animate so snap to the target
						// offset
						mViews[0].setOffset(mTargetOffset, 0,
								mRelativeViewNumber);
						mViews[1].setOffset(mTargetOffset, 0,
								mRelativeViewNumber);
						mViews[2].setOffset(mTargetOffset, 0,
								mRelativeViewNumber);
					}
				}

				// Set relative view number for animation
				mRelativeViewNumber = relativeViewNumber;
			}
			// Note: In this implementation the targetOffset will always be zero
			// as we are centering the view; but we include the calculations of
			// targetOffset and targetDistance for use in future implementations
			mInitialOffset = mViews[mRelativeViewNumber].getCurrentOffset();
			mTargetOffset = getViewOffset(mRelativeViewNumber,
					mRelativeViewNumber);
			mTargetDistance = mTargetOffset - mInitialOffset;
			// Configure base animation properties
			this.setDuration(mAnimationDuration);
			this.setInterpolator(mDecelerateInterpolater);

			// Start/continued animation
			mIsAnimationInProgres = true;
		}

		@Override
		protected void applyTransformation(float interpolatedTime,
				Transformation transformation) {
			// Ensure interpolatedTime does not over-shoot then calculate new
			// offset
			interpolatedTime = (interpolatedTime > 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 at 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 <= mGalleryWidth * -1)
					scrollOffset = mGalleryWidth * -1;
				mViews[0].setOffset(scrollOffset, 0, mCurrentViewNumber);
				mViews[1].setOffset(scrollOffset, 0, mCurrentViewNumber);
				mViews[2].setOffset(scrollOffset, 0, mCurrentViewNumber);
			}

			return false;
		}

		@Override
		public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
				float velocityY) {
			if (Math.abs(e1.getY() - e2.getY()) <= swipe_max_off_path) {
				if (e2.getX() - e1.getX() > swipe_min_distance
						&& Math.abs(velocityX) > 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;
		}
	}
}

MainActivity.java

Java代码

package com.iaiai.fg;
import android.app.Activity;
import android.os.Bundle;
import android.content.Context;
import android.graphics.Color;
import android.util.Log;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TableLayout;
import android.widget.TextView;
/**
*
*
* Title: MainActivity.java
*
*
* E-Mail: 176291935@qq.com
*
*
* QQ: 176291935
*
*
* Http: iaiai.iteye.com
*
*
* Create time: 2012-7-7 上午10:18:53
*
*
* @author 丸子
* @version 0.0.1
*/
public class MainActivity extends Activity {
private final int color_red = Color.argb(100, 200, 0, 0);
private final int color_green = Color.argb(100, 0, 200, 0);
private final int color_blue = Color.argb(100, 0, 0, 200);
private final int color_yellow = Color.argb(100, 200, 200, 0);
private final int color_purple = Color.argb(100, 200, 0, 200);
private final String[] mLabelArray = { "View1", "View2", "View3", "View4",
"View5" };
private final int[] mColorArray = { color_red, color_green, color_blue,
color_yellow, color_purple };
private FlingGallery mGallery;
private CheckBox mCheckBox;
// Note: The following handler is critical to correct function of
// the FlingGallery class. This enables the FlingGallery class to
// detect when the motion event has ended by finger being lifted
@Override
public boolean onTouchEvent(MotionEvent event) {
return mGallery.onGalleryTouchEvent(event);
}
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGallery = new FlingGallery(this);
mGallery.setPaddingWidth(5);
mGallery.setAdapter(new ArrayAdapter<String>(getApplicationContext(),
android.R.layout.simple_list_item_1, mLabelArray) {
@Override
public View getView(int position, View convertView, ViewGroup parent) {
Log.d("111", "count=" + position);
// if (convertView != null && convertView instanceof
// GalleryViewItem)
// {
// GalleryViewItem galleryView = (GalleryViewItem) convertView;
//
// galleryView.mEdit1.setText("");
// galleryView.mText1.setText(mLabelArray[position]);
// galleryView.mText1.setBackgroundColor(mColorArray[position]);
// galleryView.mText2.setText(mLabelArray[position]);
// galleryView.mText2.setBackgroundColor(mColorArray[position]);
//
// Log.d("111", "count="+position);
//
// return galleryView;
//
// }
return new GalleryViewItem(getApplicationContext(), position);
}
});
LinearLayout layout = new LinearLayout(getApplicationContext());
layout.setOrientation(LinearLayout.VERTICAL);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT);
layoutParams.setMargins(10, 10, 10, 10);
layoutParams.weight = 1.0f;
layout.addView(mGallery, layoutParams);
mCheckBox = new CheckBox(getApplicationContext());
mCheckBox.setText("Gallery is Circular");
mCheckBox.setText("Gallery is Circular");
mCheckBox.setPadding(50, 10, 0, 10);
mCheckBox.setTextSize(30);
mCheckBox.setChecked(true);
mCheckBox.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
mGallery.setIsGalleryCircular(mCheckBox.isChecked());
}
});
layout.addView(mCheckBox, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
setContentView(layout);
}
private class GalleryViewItem extends TableLayout {
private EditText mEdit1;
private TextView mText1;
private TextView mText2;
private Button mButton1;
private Button mButton2;
public GalleryViewItem(Context context, int position) {
super(context);
this.setOrientation(LinearLayout.VERTICAL);
this.setLayoutParams(new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT));
mEdit1 = new EditText(context);
this.addView(mEdit1, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
mText1 = new TextView(context);
mText1.setText(mLabelArray[position]);
mText1.setTextSize(30);
mText1.setGravity(Gravity.LEFT);
mText1.setBackgroundColor(mColorArray[position]);
this.addView(mText1, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
mButton1 = new Button(context);
mButton1.setText("<<");
mButton1.setGravity(Gravity.LEFT);
mButton1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
mGallery.movePrevious();
}
});
this.addView(mButton1, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
mButton2 = new Button(context);
mButton2.setText(">>");
mButton2.setGravity(Gravity.RIGHT);
mButton2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
mGallery.moveNext();
}
});
this.addView(mButton2, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT));
mText2 = new TextView(context);
mText2.setText(mLabelArray[position]);
mText2.setTextSize(30);
mText2.setGravity(Gravity.RIGHT);
mText2.setBackgroundColor(mColorArray[position]);
this.addView(mText2, new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.MATCH_PARENT,
LinearLayout.LayoutParams.MATCH_PARENT, 1));
}
}
}

posted @ 2012-12-25 10:25 圣诞树下的猫阅读(110) 评论(0) 收藏举报

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