Gallery平滑移动
看了些网上的方法弄了下平滑移动的效果，虽说最后是实现了，实现后发现也不是我想要的效果，对于我幸苦写过的代码先存放在这上面了
package com.layout;
import android.content.Context;
import android.graphics.Camera;
import android.graphics.Matrix;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.animation.Transformation;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.Scroller;
public class GalleryFlow extends Gallery{
private Camera mCamera = new Camera();
private int mMaxRotationAngle = 60;
private int mMaxZoom = -300;
private int mCoveflowCenter;
//test
private Scroller mScroller;
private int mTouchSlop;
private int mMinimumVelocitx;
private int mMaximumVelocitx;
private VelocityTracker mVelocityTracker;
private float mLastMotionX;
private boolean mIsInEdge = false;
private Context context;
public GalleryFlow(Context context) {
super(context);
this.context = context;
this.setStaticTransformationsEnabled(true);
}
public GalleryFlow(Context context, AttributeSet attrs) {
super(context, attrs);
this.setStaticTransformationsEnabled(true);
this.context = context;
init(context);
}
public void init(Context context) {
mScroller = new Scroller(context);
setFocusable(true);
setDescendantFocusability(FOCUS_AFTER_DESCENDANTS);
setWillNotDraw(false);
final ViewConfiguration configuration = ViewConfiguration.get(context);
mTouchSlop = configuration.getScaledTouchSlop();
mMinimumVelocitx = configuration.getScaledMinimumFlingVelocity();
mMaximumVelocitx = configuration.getScaledMaximumFlingVelocity();
}
public void fling(int velocityX) {
if (getChildCount() > 0) {
mScroller.fling(getScrollX(), getScrollY(), velocityX, 0, 0, 20, 0,
0);
final boolean movingDown = velocityX > 0;
awakenScrollBars(mScroller.getDuration());
invalidate();
}
}
private void obtainVelocityTracker(MotionEvent event) {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
}
private void releaseVelocityTracker() {
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
if (event.getAction() == MotionEvent.ACTION_DOWN
&& event.getEdgeFlags() != 0) {
return false;
}
obtainVelocityTracker(event);
final int action = event.getAction();
final float x = event.getX();
final float y = event.getY();
switch (action) {
case MotionEvent.ACTION_DOWN:
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
mLastMotionX = x;
break;
case MotionEvent.ACTION_MOVE:
final int deltaX = (int) (mLastMotionX - x);
mLastMotionX = x;
if (deltaX < 0) {
if (getScrollX() > 0) {
// scrollBy(0,deltaX);
scrollBy(deltaX,0);
}
}else if(deltaX > 0) {
int childTotalWidth = 0;
int width = 0;
if(getChildAt(0) != null){
width = getChildAt(0).getWidth();
}
for (int i = 0; i < getChildCount(); i++) {
childTotalWidth += this.getChildAt(i).getWidth();
}
mIsInEdge = getScrollX() <= childTotalWidth - 20;//width
if (mIsInEdge) {
// scrollBy(0, deltaX);
scrollBy(deltaX, 0);
}
}
break;
case MotionEvent.ACTION_UP:
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocitx);
int initialVelocity = (int) velocityTracker.getYVelocity();
if ((Math.abs(initialVelocity) > mMinimumVelocitx)
&& getChildCount() > 0) {
fling(-initialVelocity);
}
releaseVelocityTracker();
break;
}
return true;
}
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
int scrollX = getScrollX();
int scrollY = getScrollY();
int oldX = scrollX;
int oldY = scrollY;
int x = mScroller.getCurrX();
int y = mScroller.getCurrY();
scrollX = x ;
scrollX = scrollX + 10;
scrollY = y;
// scrollY = scrollY + 10;
scrollTo(scrollX, scrollY);
postInvalidate();
}
}
@Override
public int getChildCount() {
// TODO Auto-generated method stub
return super.getChildCount();
}
public int getMaxRotationAngle() {
return mMaxRotationAngle;
}
public void setMaxRotationAngle(int maxRotationAngle) {
mMaxRotationAngle = maxRotationAngle;
}
public int getMaxZoom() {
return mMaxZoom;
}
public void setMaxZoom(int maxZoom) {
mMaxZoom = maxZoom;
}
private int getCenterOfCoverflow() {
return (getWidth() - getPaddingLeft() - getPaddingRight()) / 2
+ getPaddingLeft();
}
private static int getCenterOfView(View view) {
System.out.println("view left :"+view.getLeft());
System.out.println("view width :"+view.getWidth());
return view.getLeft() + view.getWidth() / 2;
}
@Override
protected boolean getChildStaticTransformation(View child, Transformation t) {
/*/
final int childCenter = getCenterOfView(child);
final int childWidth = child.getWidth();
int rotationAngle = 0;
t.clear();
t.setTransformationType(Transformation.TYPE_MATRIX);
if (childCenter == mCoveflowCenter) {
transformImageBitmap((LinearLayout) child, t, 0);
} else {
rotationAngle = (int) (((float) (mCoveflowCenter - childCenter) / childWidth) * mMaxRotationAngle);
if (Math.abs(rotationAngle) > mMaxRotationAngle) {
rotationAngle = (rotationAngle < 0) ? -mMaxRotationAngle
: mMaxRotationAngle;
}
transformImageBitmap((LinearLayout) child, t, rotationAngle);
}
//*/
return true;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
mCoveflowCenter = getCenterOfCoverflow();
super.onSizeChanged(w, h, oldw, oldh);
}
private void transformImageBitmap(LinearLayout child, Transformation t,
int rotationAngle) {
mCamera.save();
final Matrix imageMatrix = t.getMatrix();
final int imageHeight = child.getLayoutParams().height;
final int imageWidth = child.getLayoutParams().width;
final int rotation = Math.abs(rotationAngle);
mCamera.translate(0.0f, 0.0f, 100.0f);
if (rotation < mMaxRotationAngle) {
float zoomAmount = (float) (mMaxZoom + (rotation * 1));//1.5
mCamera.translate(0.0f, 0.0f, 0);
}
mCamera.rotateY(rotationAngle);
mCamera.getMatrix(imageMatrix);
imageMatrix.preTranslate(-(imageWidth / 2), -(imageHeight / 2));
imageMatrix.postTranslate((imageWidth / 2), (imageHeight / 2));
mCamera.restore();
}
}
