Andorid项目源码 实现 抽屉效果 案例

package com.android.demo.widget; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.util.Log; import android.view.GestureDetector; import android.view.MotionEvent; import android.view.View; import android.view.ViewGroup; import android.view.ViewParent; import android.view.GestureDetector.OnGestureListener; import android.view.animation.Animation; import android.view.animation.Interpolator; import android.view.animation.LinearInterpolator; import android.view.animation.TranslateAnimation; import android.view.animation.Animation.AnimationListener; import android.widget.FrameLayout; import android.widget.LinearLayout; import com.android.demo.R; public class Panel extends LinearLayout { private static final String TAG = "Panel"; /** * Callback invoked when the panel is opened/closed. */ public static interface OnPanelListener { /** * Invoked when the panel becomes fully closed. */ public void onPanelClosed(Panel panel); /** * Invoked when the panel becomes fully opened. */ public void onPanelOpened(Panel panel); } private boolean mIsShrinking; private int mPosition; private int mDuration; private boolean mLinearFlying; private int mHandleId; private int mContentId; private View mHandle; private View mContent; private Drawable mOpenedHandle; private Drawable mClosedHandle; private float mTrackX; private float mTrackY; private float mVelocity; private OnPanelListener panelListener; public static final int TOP = 0; public static final int BOTTOM = 1; public static final int LEFT = 2; public static final int RIGHT = 3; private enum State { ABOUT_TO_ANIMATE, ANIMATING, READY, TRACKING, FLYING, }; private State mState; private Interpolator mInterpolator; private GestureDetector mGestureDetector; private int mContentHeight; private int mContentWidth; private int mOrientation; private float mWeight; private PanelOnGestureListener mGestureListener; private boolean mBringToFront; public Panel(Context context, AttributeSet attrs) { super(context, attrs); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.Panel); mDuration = a.getInteger(R.styleable.Panel_animationDuration, 750); // duration defaults to 750 ms mPosition = a.getInteger(R.styleable.Panel_position, BOTTOM); // position defaults to BOTTOM mLinearFlying = a.getBoolean(R.styleable.Panel_linearFlying, false); // linearFlying defaults to false mWeight = a.getFraction(R.styleable.Panel_weight, 0, 1, 0.0f); // weight defaults to 0.0 if (mWeight < 0 || mWeight > 1) { mWeight = 0.0f; Log.w(TAG, a.getPositionDescription() + ": weight must be > 0 and <= 1"); } mOpenedHandle = a.getDrawable(R.styleable.Panel_openedHandle); mClosedHandle = a.getDrawable(R.styleable.Panel_closedHandle); RuntimeException e = null; mHandleId = a.getResourceId(R.styleable.Panel_handle, 0); if (mHandleId == 0) { e = new IllegalArgumentException(a.getPositionDescription() + ": The handle attribute is required and must refer to a valid child."); } mContentId = a.getResourceId(R.styleable.Panel_content, 0); if (mContentId == 0) { e = new IllegalArgumentException(a.getPositionDescription() + ": The content attribute is required and must refer to a valid child."); } a.recycle(); if (e != null) { throw e; } mOrientation = (mPosition == TOP || mPosition == BOTTOM)? VERTICAL : HORIZONTAL; setOrientation(mOrientation); mState = State.READY; mGestureListener = new PanelOnGestureListener(); mGestureDetector = new GestureDetector(mGestureListener); mGestureDetector.setIsLongpressEnabled(false); // i DON'T really know why i need this... setBaselineAligned(false); } /** * Sets the listener that receives a notification when the panel becomes open/close. * * @param onPanelListener The listener to be notified when the panel is opened/closed. */ public void setOnPanelListener(OnPanelListener onPanelListener) { panelListener = onPanelListener; } /** * Gets Panel's mHandle * * @return Panel's mHandle */ public View getHandle() { return mHandle; } /** * Gets Panel's mContent * * @return Panel's mContent */ public View getContent() { return mContent; } /** * Sets the acceleration curve for panel's animation. * * @param i The interpolator which defines the acceleration curve */ public void setInterpolator(Interpolator i) { mInterpolator = i; } /** * Set the opened state of Panel. * * @param open True if Panel is to be opened, false if Panel is to be closed. * @param animate True if use animation, false otherwise. * * @return True if operation was performed, false otherwise. * */ public boolean setOpen(boolean open, boolean animate) { if (mState == State.READY && isOpen() ^ open) { mIsShrinking = !open; if (animate) { mState = State.ABOUT_TO_ANIMATE; if (!mIsShrinking) { // this could make flicker so we test mState in dispatchDraw() // to see if is equal to ABOUT_TO_ANIMATE mContent.setVisibility(VISIBLE); } post(startAnimation); } else { mContent.setVisibility(open? VISIBLE : GONE); postProcess(); } return true; } return false; } /** * Returns the opened status for Panel. * * @return True if Panel is opened, false otherwise. */ public boolean isOpen() { return mContent.getVisibility() == VISIBLE; } @Override protected void onFinishInflate() { super.onFinishInflate(); mHandle = findViewById(mHandleId); if (mHandle == null) { String name = getResources().getResourceEntryName(mHandleId); throw new RuntimeException("Your Panel must have a child View whose id attribute is 'R.id." + name + "'"); } mHandle.setOnTouchListener(touchListener); mHandle.setOnClickListener(clickListener); mContent = findViewById(mContentId); if (mContent == null) { String name = getResources().getResourceEntryName(mHandleId); throw new RuntimeException("Your Panel must have a child View whose id attribute is 'R.id." + name + "'"); } // reposition children removeView(mHandle); removeView(mContent); if (mPosition == TOP || mPosition == LEFT) { addView(mContent); addView(mHandle); } else { addView(mHandle); addView(mContent); } if (mClosedHandle != null) { mHandle.setBackgroundDrawable(mClosedHandle); } mContent.setClickable(true); mContent.setVisibility(GONE); if (mWeight > 0) { ViewGroup.LayoutParams params = mContent.getLayoutParams(); if (mOrientation == VERTICAL) { params.height = ViewGroup.LayoutParams.FILL_PARENT; } else { params.width = ViewGroup.LayoutParams.FILL_PARENT; } mContent.setLayoutParams(params); } } @Override protected void onAttachedToWindow() { super.onAttachedToWindow(); ViewParent parent = getParent(); if (parent != null && parent instanceof FrameLayout) { mBringToFront = true; } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { if (mWeight > 0 && mContent.getVisibility() == VISIBLE) { View parent = (View) getParent(); if (parent != null) { if (mOrientation == VERTICAL) { heightMeasureSpec = MeasureSpec.makeMeasureSpec((int) (parent.getHeight() * mWeight), MeasureSpec.EXACTLY); } else { widthMeasureSpec = MeasureSpec.makeMeasureSpec((int) (parent.getWidth() * mWeight), MeasureSpec.EXACTLY); } } } super.onMeasure(widthMeasureSpec, heightMeasureSpec); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); mContentWi