android 抽屉类slidingdrawer源码解析及运行调试
最近有个项目需要用到一个抽屉效果,android提供了一个封装好的view,但是有局限行,只能在右侧和底部展开,而且最主要的官方提出
This class was deprecated in API level 17.
This class is not supported anymore. It is recommended you base your own implementation on the source code for the Android Open Source Project if you must use it in your application.
由于本人比较懒.不想去研究源码.于是找到了drawerLayout,但是简单的研究过以后发现了一个致命问题..这个view居然没有handle,无奈啊.只能回来继续研究源码了,但是把弄出来了以后.发现不能运行.各种问题啊..
先是无法找到一些文件,再是发现一些参数没有声明.毫无头绪..经过2天的资料查找和代码推测,终于将问题都解决了,可以在本地运行成功..
下面将源码中发现的问题,和解决后的代码列出来.希望可以对需要研究源码的朋友有些帮助.注释有点简单.如果有疑问可以联系我.我会尽力帮助大家解答,我也是个新手,希望可以通过交流相互学习.
(注:代码中的一些注释是参考网上的一些资料,并不是全部由本人注释.)
先说一下为找到的文件.
将源码导入项目后发现构造方法中找不到
R.styleable.SlidingDrawer
public SlidingDrawer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SlidingDrawer, defStyle, 0);
int orientation = a.getInt(R.styleable.SlidingDrawer_orientation, ORIENTATION_VERTICAL);
mVertical = orientation == ORIENTATION_VERTICAL;
mBottomOffset = (int) a.getDimension(R.styleable.SlidingDrawer_bottomOffset, 0.0f);
mTopOffset = (int) a.getDimension(R.styleable.SlidingDrawer_topOffset, 0.0f);
mAllowSingleTap = a.getBoolean(R.styleable.SlidingDrawer_allowSingleTap, true);
mAnimateOnClick = a.getBoolean(R.styleable.SlidingDrawer_animateOnClick, true);
//以下省略...
}
解决办法:创建/res/values/attrs.xml,写入如下代码
<?xml version="1.0" encoding="utf-8"?>
<resources>
<attr name="orientation">
<!-- Defines an horizontal widget. -->
<enum name="horizontal" value="0" />
<!-- Defines a vertical widget. -->
<enum name="vertical" value="1" />
</attr>
<declare-styleable name="SlidingDrawer">
<!-- Orientation of the SlidingDrawer. -->
<attr name="orientation" />
<!-- Identifier for the child that represents the drawer's handle. -->
<attr name="handle" format="reference" />
<!-- Identifier for the child that represents the drawer's content. -->
<attr name="content" format="reference" />
<!-- Extra offset for the handle at the bottom of the SlidingDrawer. -->
<attr name="bottomOffset" format="dimension" />
<!-- Extra offset for the handle at the top of the SlidingDrawer. -->
<attr name="topOffset" format="dimension" />
<!-- Indicates whether the drawer can be opened/closed by a single tap
on the handle. (If false, the user must drag or fling, or click
using the trackball, to open/close the drawer.) Default is true. -->
<attr name="allowSingleTap" format="boolean" />
<!-- Indicates whether the drawer should be opened/closed with an animation
when the user clicks the handle. Default is true. -->
<attr name="animateOnClick" format="boolean" />
</declare-styleable>
</resources>
找不文件的问题解决了,这时候发现有4个属性(mTop,mBottom mRight ,mLeft)没有声明.不知道从哪里来的也不知道干什么的,经过上下文查找和测试.推测这个这个应该是slidingdrawer的属性,修改后发现一切Ok.
解决办法,只要将其都修改为getBottom() ,getTop(),getRight() ,getLeft()就行了..
好了下面将源码奉上.
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.os.Handler;
import android.os.Message;
import android.os.SystemClock;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.SoundEffectConstants;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
public class SlidingDrawer extends ViewGroup {
private final String logTag="SlidingDrawer";
public static final int ORIENTATION_HORIZONTAL = 0;//右侧展开
public static final int ORIENTATION_VERTICAL = 1;//底部展开
private static final int TAP_THRESHOLD = 6;//敲击临界点
private static final float MAXIMUM_TAP_VELOCITY = 100.0f;//最大敲击速度
private static final float MAXIMUM_MINOR_VELOCITY = 150.0f;//最大次速度
private static final float MAXIMUM_MAJOR_VELOCITY = 200.0f;//最大主速度
private static final float MAXIMUM_ACCELERATION = 2000.0f;//最大加速度
private static final int VELOCITY_UNITS = 1000;//最小速度（速度单元）
private static final int MSG_ANIMATE = 1000;//消息动画
private static final int ANIMATION_FRAME_DURATION = 1000 / 60;//动画框架持续时间
private static final int EXPANDED_FULL_OPEN = -10001;//展开
private static final int COLLAPSED_FULL_CLOSED = -10002;//关闭
private final int mHandleId;//手柄的id.
private final int mContentId;//内容的id.
private View mHandle;//手柄.
private View mContent;//内容view.
private final Rect mFrame = new Rect();//唯一框架矩形引用
private final Rect mInvalidate = new Rect();//唯一无效矩形引用
private boolean mTracking;//是否正在跟踪
private boolean mLocked;//是否已被锁上
private VelocityTracker mVelocityTracker;
private boolean mVertical;//是否垂直
private boolean mExpanded;//是否已经被展开
private int mBottomOffset;//底部偏移量
private int mTopOffset;//顶部偏移量
private int mHandleHeight;//把手高度
private int mHandleWidth;//把手宽度
//三个抽屉状态监听器
private OnDrawerOpenListener mOnDrawerOpenListener;//打开时
private OnDrawerCloseListener mOnDrawerCloseListener;//关闭时
private OnDrawerScrollListener mOnDrawerScrollListener;//滚动时
private final Handler mHandler = new SlidingHandler();
private float mAnimatedAcceleration;
private float mAnimatedVelocity;
private float mAnimationPosition;
private long mAnimationLastTime;
private long mCurrentAnimationTime;
private int mTouchDelta;
private boolean mAnimating;
private boolean mAllowSingleTap;
private boolean mAnimateOnClick;
private final int mTapThreshold;
private final int mMaximumTapVelocity;
private final int mMaximumMinorVelocity;
private final int mMaximumMajorVelocity;
private final int mMaximumAcceleration;
private final int mVelocityUnits;
/**
* Callback invoked when the drawer is opened.
*/
public static interface OnDrawerOpenListener {
/**
* Invoked when the drawer becomes fully open.
*/
public void onDrawerOpened();
}
/**
* Callback invoked when the drawer is closed.
*/
public static interface OnDrawerCloseListener {
/**
* Invoked when the drawer becomes fully closed.
*/
public void onDrawerClosed();
}
/**
* Callback invoked when the drawer is scrolled.
*/
public static interface OnDrawerScrollListener {
/**
* Invoked when the user starts dragging/flinging the drawer's handle.
*/
public void onScrollStarted();
/**
* Invoked when the user stops dragging/flinging the drawer's handle.
*/
public void onScrollEnded();
}
/**
* Creates a new SlidingDrawer from a specified set of attributes defined in XML.
*
* @param context The application's environment.
* @param attrs The attributes defined in XML.
*/
public SlidingDrawer(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
/**
* Creates a new SlidingDrawer from a specified set of attributes defined in XML.
*
* @param context The application's environment.
* @param attrs The attributes defined in XML.
* @param defStyle The style to apply to this widget.
*/
public SlidingDrawer(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SlidingDrawer, defStyle, 0);
int orientation = a.getInt(R.styleable.SlidingDrawer_orientation, ORIENTATION_VERTICAL);
mVertical = orientation == ORIENTATION_VERTICAL;
mBottomOffset = (int) a.getDimension(R.styleable.SlidingDrawer_bottomOffset, 0.0f);
mTopOffset = (int) a.getDimension(R.styleable.SlidingDrawer_topOffset, 0.0f);
mAllowSingleTap = a.getBoolean(R.styleable.SlidingDrawer_allowSingleTap, true);
mAnimateOnClick = a.getBoolean(R.styleable.SlidingDrawer_animateOnClick, true);
Log.d(logTag, "contentId "+ R.id.lin_content);
int contentId = a.getResourceId(R.styleable.SlidingDrawer_content, 0);
if (contentId == 0) {
throw new IllegalArgumentException("The content attribute is required and must refer "
+ "to a valid child.");
}
int handleId = a.getResourceId(R.styleable.SlidingDrawer_handle, 0);
if (handleId == 0) {
throw new IllegalArgumentException("The handle attribute is required and must refer "
+ "to a valid child.");
}
if (handleId == contentId) {
throw new IllegalArgumentException("The content and handle attributes must refer "
+ "to different children.");
}
mHandleId = handleId;
mContentId = contentId;
final float density = getResources().getDisplayMetrics().density;
mTapThreshold = (int) (TAP_THRESHOLD * density + 0.5f);
mMaximumTapVelocity = (int) (MAXIMUM_TAP_VELOCITY * density + 0.5f);
mMaximumMinorVelocity = (int) (MAXIMUM_MINOR_VELOCITY * density + 0.5f);
mMaximumMajorVelocity = (int) (MAXIMUM_MAJOR_VELOCITY * density + 0.5f);
mMaximumAcceleration = (int) (MAXIMUM_ACCELERATION * density + 0.5f);
mVelocityUnits = (int) (VELOCITY_UNITS * density + 0.5f);
a.recycle();
setAlwaysDrawnWithCacheEnabled(false);
}
@Override
protected void onFinishInflate() {
mHandle = findViewById(mHandleId);
if (mHandle == null) {
throw new IllegalArgumentException("The handle attribute is must refer to an"
+ " existing child.");
}
mHandle.setOnClickListener(new DrawerToggler());
mContent = findViewById(mContentId);
if (mContent == null) {
throw new IllegalArgumentException("The content attribute is must refer to an"
+ " existing child.");
}
mContent.setVisibility(View.GONE);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);
if (widthSpecMode == MeasureSpec.UNSPECIFIED || heightSpecMode == MeasureSpec.UNSPECIFIED) {
throw new RuntimeException("SlidingDrawer cannot have UNSPECIFIED dimensions");
}
final View handle = mHandle;
measureChild(handle, widthMeasureSpec, heightMeasureSpec);
if (mVertical) {
int height = heightSpecSize - handle.getMeasuredHeight() - mTopOffset;
mContent.measure(MeasureSpec.makeMeasureSpec(widthSpecSize, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
} else {
int width = widthSpecSize - handle.getMeasuredWidth() - mTopOffset;
mContent.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(heightSpecSize, MeasureSpec.EXACTLY));
}
setMeasuredDimension(widthSpecSize, heightSpecSize);
}
@Override
protected void dispatchDraw(Canvas canvas) {
final long drawingTime = getDrawingTime();
final View handle = mHandle;
final boolean isVertical = mVertical;
drawChild(canvas, handle, drawingTime);
if (mTracking || mAnimating) {
final Bitmap cache = mContent.getDrawingCache();
if (cache != null) {
if (isVertical) {
canvas.drawBitmap(cache, 0, handle.getBottom(), null);
} else {
canvas.drawBitmap(cache, handle.getRight(), 0, null);
}
} else {
canvas.save();
canvas.translate(isVertical ? 0 : handle.getLeft() - mTopOffset,
isVertical ? handle.getTop() - mTopOffset : 0);
drawChild(canvas, mContent, drawingTime);
canvas.restore();
}
} else if (mExpanded) {
drawChild(canvas, mContent, drawingTime);
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (mTracking) {
return;
}
final int width = r - l;
final int height = b - t;
final View handle = mHandle;
int childWidth = handle.getMeasuredWidth();
int childHeight = handle.getMeasuredHeight();
int childLeft;
int childTop;
final View content = mContent;
if (mVertical) {
childLeft = (width - childWidth) / 2;
childTop = mExpanded ? mTopOffset : height - childHeight + mBottomOffset;
content.layout(0, mTopOffset + childHeight, content.getMeasuredWidth(),
mTopOffset + childHeight + content.getMeasuredHeight());
} else {
childLeft = mExpanded ? mTopOffset : width - childWidth + mBottomOffset;
childTop = (height - childHeight) / 2;
content.layout(mTopOffset + childWidth, 0,
mTopOffset + childWidth + content.getMeasuredWidth(),
content.getMeasuredHeight());
}
handle.layout(childLeft, childTop, childLeft + childWidth, childTop + childHeight);
mHandleHeight = handle.getHeight();
mHandleWidth = handle.getWidth();
}
@Override
public boolean onInterceptTouchEvent(MotionEvent event) {
if (mLocked) {
return false;
}
final int action = event.getAction();
float x = event.getX();
float y = event.getY();
final Rect frame = mFrame;
final View handle = mHandle;
handle.getHitRect(frame);
if (!mTracking && !frame.contains((int) x, (int) y)) {
return false;
}
if (action == MotionEvent.ACTION_DOWN) {
mTracking = true;
handle.setPressed(true);
// Must be called before prepareTracking()
prepareContent();
// Must be called after prepareContent()
if (mOnDrawerScrollListener != null) {
mOnDrawerScrollListener.onScrollStarted();
}
if (mVertical) {
final int top = mHandle.getTop();
mTouchDelta = (int) y - top;
prepareTracking(top);
} else {
final int left = mHandle.getLeft();
mTouchDelta = (int) x - left;
prepareTracking(left);
}
mVelocityTracker.addMovement(event);
}
return true;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (mLocked) {
return true;
}
if (mTracking) {
mVelocityTracker.addMovement(event);
final int action = event.getAction();
switch (action) {
case MotionEvent.ACTION_MOVE:
moveHandle((int) (mVertical ? event.getY() : event.getX()) - mTouchDelta);
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL: {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(mVelocityUnits);
float yVelocity = velocityTracker.getYVelocity();
float xVelocity = velocityTracker.getXVelocity();
boolean negative;
final boolean vertical = mVertical;
if (vertical) {
negative = yVelocity < 0;
if (xVelocity < 0) {
xVelocity = -xVelocity;
}
if (xVelocity > mMaximumMinorVelocity) {
xVelocity = mMaximumMinorVelocity;
}
} else {
negative = xVelocity < 0;
if (yVelocity < 0) {
yVelocity = -yVelocity;
}
if (yVelocity > mMaximumMinorVelocity) {
yVelocity = mMaximumMinorVelocity;
}
}
float velocity = (float) Math.hypot(xVelocity, yVelocity);
if (negative) {
velocity = -velocity;
}
final int top = mHandle.getTop();
final int left = mHandle.getLeft();
if (Math.abs(velocity) < mMaximumTapVelocity) {
if (vertical ? (mExpanded && top < mTapThreshold + mTopOffset) ||
(!mExpanded && top > mBottomOffset + getBottom() - getTop() -
mHandleHeight - mTapThreshold) :
(mExpanded && left < mTapThreshold + mTopOffset) ||
(!mExpanded && left > mBottomOffset + getRight() - getLeft() -
mHandleWidth - mTapThreshold)) {
if (mAllowSingleTap) {
playSoundEffect(SoundEffectConstants.CLICK);
if (mExpanded) {
animateClose(vertical ? top : left);
} else {
animateOpen(vertical ? top : left);
}
} else {
performFling(vertical ? top : left, velocity, false);
}
} else {
performFling(vertical ? top : left, velocity, false);
}
} else {
performFling(vertical ? top : left, velocity, false);
}
}
break;
}
}
return mTracking || mAnimating || super.onTouchEvent(event);
}
private void animateClose(int position) {
prepareTracking(position);
performFling(position, mMaximumAcceleration, true);
}
/**
* 展开动画.
* @param position
*/
private void animateOpen(int position) {
prepareTracking(position);
performFling(position, -mMaximumAcceleration, true);
}
private void performFling(int position, float velocity, boolean always) {
mAnimationPosition = position;
mAnimatedVelocity = velocity;
if (mExpanded) {
if (always || (velocity > mMaximumMajorVelocity ||
(position > mTopOffset + (mVertical ? mHandleHeight : mHandleWidth) &&
velocity > -mMaximumMajorVelocity))) {
// We are expanded, but they didn't move sufficiently to cause
// us to retract. Animate back to the expanded position.
mAnimatedAcceleration = mMaximumAcceleration;
if (velocity < 0) {
mAnimatedVelocity = 0;
}
} else {
// We are expanded and are now going to animate away.
mAnimatedAcceleration = -mMaximumAcceleration;
if (velocity > 0) {
mAnimatedVelocity = 0;
}
}
} else {
if (!always && (velocity > mMaximumMajorVelocity ||
(position > (mVertical ? getHeight() : getWidth()) / 2 &&
velocity > -mMaximumMajorVelocity))) {
// We are collapsed, and they moved enough to allow us to expand.
mAnimatedAcceleration = mMaximumAcceleration;
if (velocity < 0) {
mAnimatedVelocity = 0;
}
} else {
// We are collapsed, but they didn't move sufficiently to cause
// us to retract. Animate back to the collapsed position.
mAnimatedAcceleration = -mMaximumAcceleration;
if (velocity > 0) {
mAnimatedVelocity = 0;
}
}
}
long now = SystemClock.uptimeMillis();
mAnimationLastTime = now;
mCurrentAnimationTime = now + ANIMATION_FRAME_DURATION;
mAnimating = true;
mHandler.removeMessages(MSG_ANIMATE);
mHandler.sendMessageAtTime(mHandler.obtainMessage(MSG_ANIMATE), mCurrentAnimationTime);
stopTracking();
}
private void prepareTracking(int position) {
mTracking = true;
mVelocityTracker = VelocityTracker.obtain();
boolean opening = !mExpanded;
if (opening) {
mAnimatedAcceleration = mMaximumAcceleration;
mAnimatedVelocity = mMaximumMajorVelocity;
mAnimationPosition = mBottomOffset +
(mVertical ? getHeight() - mHandleHeight : getWidth() - mHandleWidth);
moveHandle((int) mAnimationPosition);
mAnimating = true;
mHandler.removeMessages(MSG_ANIMATE);
long now = SystemClock.uptimeMillis();
mAnimationLastTime = now;
mCurrentAnimationTime = now + ANIMATION_FRAME_DURATION;
mAnimating = true;
} else {
if (mAnimating) {
mAnimating = false;
mHandler.removeMessages(MSG_ANIMATE);
}
moveHandle(position);
}
}
/**
* 手柄移动.
* @param position
*/
private void moveHandle(int position) {
final View handle = mHandle;
if (mVertical) {//底部展开
if (position == EXPANDED_FULL_OPEN) {
handle.offsetTopAndBottom(mTopOffset - handle.getTop());
invalidate();
} else if (position == COLLAPSED_FULL_CLOSED) {
handle.offsetTopAndBottom(mBottomOffset + getBottom() - getTop() -
mHandleHeight - handle.getTop());
invalidate();
} else {
final int top = handle.getTop();
int deltaY = position - top;
if (position < mTopOffset) {
deltaY = mTopOffset - top;
} else if (deltaY > mBottomOffset + getBottom() - getTop() - mHandleHeight - top) {
deltaY = mBottomOffset + getBottom() - getTop() - mHandleHeight - top;
}
handle.offsetTopAndBottom(deltaY);
final Rect frame = mFrame;
final Rect region = mInvalidate;
handle.getHitRect(frame);
region.set(frame);
region.union(frame.left, frame.top - deltaY, frame.right, frame.bottom - deltaY);
region.union(0, frame.bottom - deltaY, getWidth(),
frame.bottom - deltaY + mContent.getHeight());
invalidate(region);
}
} else {//右侧展开.
if (position == EXPANDED_FULL_OPEN) {
handle.offsetLeftAndRight(mTopOffset - handle.getLeft());
invalidate();
} else if (position == COLLAPSED_FULL_CLOSED) {
handle.offsetLeftAndRight(mBottomOffset + getRight() - getLeft() -
mHandleWidth - handle.getLeft());
invalidate();
} else {
final int left = handle.getLeft();
int deltaX = position - left;
if (position < mTopOffset) {
deltaX = mTopOffset - left;
} else if (deltaX > mBottomOffset + getRight() - getLeft() - mHandleWidth - left) {
deltaX = mBottomOffset + getRight() - getLeft() - mHandleWidth - left;
}
handle.offsetLeftAndRight(deltaX);
final Rect frame = mFrame;
final Rect region = mInvalidate;
handle.getHitRect(frame);
region.set(frame);
region.union(frame.left - deltaX, frame.top, frame.right - deltaX, frame.bottom);
region.union(frame.right - deltaX, 0,
frame.right - deltaX + mContent.getWidth(), getHeight());
invalidate(region);
}
}
}
/**
* 准备内容view.
*/
private void prepareContent() {
if (mAnimating) {
return;
}
// Something changed in the content, we need to honor the layout request
// before creating the cached bitmap
final View content = mContent;
if (content.isLayoutRequested()) {
if (mVertical) {
final int childHeight = mHandleHeight;
int height = getBottom() - getTop() - childHeight - mTopOffset;
content.measure(MeasureSpec.makeMeasureSpec(getRight() - getLeft(), MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY));
content.layout(0, mTopOffset + childHeight, content.getMeasuredWidth(),
mTopOffset + childHeight + content.getMeasuredHeight());
} else {
final int childWidth = mHandle.getWidth();
int width = getRight() - getLeft() - childWidth - mTopOffset;
content.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY),
MeasureSpec.makeMeasureSpec( getBottom() - getTop(), MeasureSpec.EXACTLY));
content.layout(childWidth + mTopOffset, 0,
mTopOffset + childWidth + content.getMeasuredWidth(),
content.getMeasuredHeight());
}
}
// Try only once... we should really loop but it's not a big deal
// if the draw was cancelled, it will only be temporary anyway
content.getViewTreeObserver().dispatchOnPreDraw();
if (!content.isHardwareAccelerated()) content.buildDrawingCache();
content.setVisibility(View.GONE);
}
private void stopTracking() {
mHandle.setPressed(false);
mTracking = false;
if (mOnDrawerScrollListener != null) {
mOnDrawerScrollListener.onScrollEnded();
}
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
private void doAnimation() {
if (mAnimating) {
incrementAnimation();
if (mAnimationPosition >= mBottomOffset + (mVertical ? getHeight() : getWidth()) - 1) {
mAnimating = false;
closeDrawer();
} else if (mAnimationPosition < mTopOffset) {
mAnimating = false;
openDrawer();
} else {
moveHandle((int) mAnimationPosition);
mCurrentAnimationTime += ANIMATION_FRAME_DURATION;
mHandler.sendMessageAtTime(mHandler.obtainMessage(MSG_ANIMATE),
mCurrentAnimationTime);
}
}
}
private void incrementAnimation() {
long now = SystemClock.uptimeMillis();
float t = (now - mAnimationLastTime) / 1000.0f; // ms -> s
final float position = mAnimationPosition;
final float v = mAnimatedVelocity; // px/s
final float a = mAnimatedAcceleration; // px/s/s
mAnimationPosition = position + (v * t) + (0.5f * a * t * t); // px
mAnimatedVelocity = v + (a * t); // px/s
mAnimationLastTime = now; // ms
}
/**
* Toggles the drawer open and close. Takes effect immediately.
*
* @see #open()
* @see #close()
* @see #animateClose()
* @see #animateOpen()
* @see #animateToggle()
*/
public void toggle() {
if (!mExpanded) {
openDrawer();
} else {
closeDrawer();
}
invalidate();
requestLayout();
}
/**
* Toggles the drawer open and close with an animation.
*
* @see #open()
* @see #close()
* @see #animateClose()
* @see #animateOpen()
* @see #toggle()
*/
public void animateToggle() {
if (!mExpanded) {
animateOpen();
} else {
animateClose();
}
}
/**
* Opens the drawer immediately.
*
* @see #toggle()
* @see #close()
* @see #animateOpen()
*/
public void open() {
openDrawer();
invalidate();
requestLayout();
//发送一个事件.
sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
}
/**
* Closes the drawer immediately.
*
* @see #toggle()
* @see #open()
* @see #animateClose()
*/
public void close() {
closeDrawer();
invalidate();
requestLayout();
}
/**
* Closes the drawer with an animation.
*
* @see #close()
* @see #open()
* @see #animateOpen()
* @see #animateToggle()
* @see #toggle()
*/
public void animateClose() {
prepareContent();
final OnDrawerScrollListener scrollListener = mOnDrawerScrollListener;
if (scrollListener != null) {
scrollListener.onScrollStarted();
}
animateClose(mVertical ? mHandle.getTop() : mHandle.getLeft());
if (scrollListener != null) {
scrollListener.onScrollEnded();
}
}
/**
* Opens the drawer with an animation.
*
* @see #close()
* @see #open()
* @see #animateClose()
* @see #animateToggle()
* @see #toggle()
*/
public void animateOpen() {
prepareContent();
final OnDrawerScrollListener scrollListener = mOnDrawerScrollListener;
if (scrollListener != null) {
scrollListener.onScrollStarted();
}
animateOpen(mVertical ? mHandle.getTop() : mHandle.getLeft());
sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
if (scrollListener != null) {
scrollListener.onScrollEnded();
}
}
private void closeDrawer() {
moveHandle(COLLAPSED_FULL_CLOSED);
mContent.setVisibility(View.GONE);
mContent.destroyDrawingCache();
if (!mExpanded) {
return;
}
mExpanded = false;
if (mOnDrawerCloseListener != null) {
mOnDrawerCloseListener.onDrawerClosed();
}
}
private void openDrawer() {
moveHandle(EXPANDED_FULL_OPEN);
mContent.setVisibility(View.VISIBLE);
if (mExpanded) {
return;
}
mExpanded = true;
if (mOnDrawerOpenListener != null) {
mOnDrawerOpenListener.onDrawerOpened();
}
}
/**
* Sets the listener that receives a notification when the drawer becomes open.
*
* @param onDrawerOpenListener The listener to be notified when the drawer is opened.
*/
public void setOnDrawerOpenListener(OnDrawerOpenListener onDrawerOpenListener) {
mOnDrawerOpenListener = onDrawerOpenListener;
}
/**
* Sets the listener that receives a notification when the drawer becomes close.
*
* @param onDrawerCloseListener The listener to be notified when the drawer is closed.
*/
public void setOnDrawerCloseListener(OnDrawerCloseListener onDrawerCloseListener) {
mOnDrawerCloseListener = onDrawerCloseListener;
}
/**
* Sets the listener that receives a notification when the drawer starts or ends
* a scroll. A fling is considered as a scroll. A fling will also trigger a
* drawer opened or drawer closed event.
*
* @param onDrawerScrollListener The listener to be notified when scrolling
* starts or stops.
*/
public void setOnDrawerScrollListener(OnDrawerScrollListener onDrawerScrollListener) {
mOnDrawerScrollListener = onDrawerScrollListener;
}
/**
* Returns the handle of the drawer.
*
* @return The View reprenseting the handle of the drawer, identified by
* the "handle" id in XML.
*/
public View getHandle() {
return mHandle;
}
/**
* Returns the content of the drawer.
*
* @return The View reprenseting the content of the drawer, identified by
* the "content" id in XML.
*/
public View getContent() {
return mContent;
}
/**
* Unlocks the SlidingDrawer so that touch events are processed.
*
* @see #lock()
*/
public void unlock() {
mLocked = false;
}
/**
* Locks the SlidingDrawer so that touch events are ignores.
*
* @see #unlock()
*/
public void lock() {
mLocked = true;
}
/**
* Indicates whether the drawer is currently fully opened.
*
* @return True if the drawer is opened, false otherwise.
*/
public boolean isOpened() {
return mExpanded;
}
/**
* Indicates whether the drawer is scrolling or flinging.
*
* @return True if the drawer is scroller or flinging, false otherwise.
*/
public boolean isMoving() {
return mTracking || mAnimating;
}
private class DrawerToggler implements OnClickListener {
public void onClick(View v) {
if (mLocked) {
return;
}
// mAllowSingleTap isn't relevant here; you're *always*
// allowed to open/close the drawer by clicking with the
// trackball.
if (mAnimateOnClick) {
animateToggle();
} else {
toggle();
}
}
}
private class SlidingHandler extends Handler {
public void handleMessage(Message m) {
switch (m.what) {
case MSG_ANIMATE:
doAnimation();
break;
}
}
}
}
第一次编写.有点乱.还望见谅.我打算将slidingdrawer修改可以从上下左右都可以展出的view.有需要的朋友可以关注我的博客,近期将会整理出来.