packages/SystemUI/src/com/android/systemui/recent/RecentsVerticalScrollView.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2011 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.systemui.recent;

 import com.android.systemui.recent.RecentsPanelView.ActivityDescriptionAdapter;

 import android.animation.Animator;
 import android.animation.Animator.AnimatorListener;
 import android.animation.LayoutTransition;
 import android.animation.ObjectAnimator;
 import android.animation.ValueAnimator;
 import android.animation.ValueAnimator.AnimatorUpdateListener;
 import android.content.Context;
 import android.database.DataSetObserver;
 import android.graphics.RectF;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.LayoutInflater;
 import android.view.MotionEvent;
 import android.view.VelocityTracker;
 import android.view.View;
 import android.view.animation.DecelerateInterpolator;
 import android.view.animation.LinearInterpolator;
 import android.widget.LinearLayout;
 import android.widget.ScrollView;

 import com.android.systemui.R;

 public class RecentsVerticalScrollView extends ScrollView
         implements View.OnClickListener, View.OnTouchListener {
     private static final float FADE_CONSTANT = 0.5f;
     private static final int SNAP_BACK_DURATION = 250;
     private static final int ESCAPE_VELOCITY = 100; // speed of item required to "curate" it
     private static final String TAG = RecentsPanelView.TAG;
     private static final float THRESHHOLD = 50;
     private static final boolean DEBUG_INVALIDATE = false;
     private LinearLayout mLinearLayout;
     private ActivityDescriptionAdapter mAdapter;
     private RecentsCallback mCallback;
     protected int mLastScrollPosition;
     private View mCurrentView;
     private float mLastX;
     private boolean mDragging;
     private VelocityTracker mVelocityTracker;

     public RecentsVerticalScrollView(Context context) {
         this(context, null);
     }

     public RecentsVerticalScrollView(Context context, AttributeSet attrs) {
         super(context, attrs, 0);
     }

     private int scrollPositionOfMostRecent() {
         return mLinearLayout.getHeight() - getHeight();
     }

     public void update() {
         mLinearLayout.removeAllViews();
         for (int i = 0; i < mAdapter.getCount(); i++) {
             View view = mAdapter.getView(i, null, mLinearLayout);
             view.setClickable(true);
             view.setOnClickListener(this);
             view.setOnTouchListener(this);
             mLinearLayout.addView(view);
         }
         // Scroll to end after layout.
         post(new Runnable() {
             public void run() {
                 mLastScrollPosition = scrollPositionOfMostRecent();
                 scrollTo(0, mLastScrollPosition);
             }
         });
     }

     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
         if (mVelocityTracker == null) {
             mVelocityTracker = VelocityTracker.obtain();
         }
         mVelocityTracker.addMovement(ev);
         switch (ev.getAction()) {
             case MotionEvent.ACTION_DOWN:
                 mDragging = false;
                 mLastX = ev.getX();
                 break;

             case MotionEvent.ACTION_MOVE:
                 float delta = ev.getX() - mLastX;
                 Log.v(TAG, "ACTION_MOVE : " + delta);
                 if (Math.abs(delta) > THRESHHOLD) {
                     mDragging = true;
                 }
                 break;

             case MotionEvent.ACTION_UP:
                 mDragging = false;
                 break;
         }
         return mDragging ? true : super.onInterceptTouchEvent(ev);
     }

     private float getAlphaForOffset(View view, float thumbWidth) {
         final float fadeWidth = FADE_CONSTANT * thumbWidth;
         float result = 1.0f;
         if (view.getX() >= thumbWidth) {
             result = 1.0f - (view.getX() - thumbWidth) / fadeWidth;
         } else if (view.getX() < 0.0f) {
             result = 1.0f + (thumbWidth + view.getX()) / fadeWidth;
         }
         Log.v(TAG, "FADE AMOUNT: " + result);
         return result;
     }

     @Override
     public boolean onTouchEvent(MotionEvent ev) {
         if (!mDragging) {
             return super.onTouchEvent(ev);
         }

         mVelocityTracker.addMovement(ev);

         final View animView = mCurrentView;
         // TODO: Cache thumbnail
         final View thumb = animView.findViewById(R.id.app_thumbnail);
         switch (ev.getAction()) {
             case MotionEvent.ACTION_MOVE:
                 if (animView != null) {
                     final float delta = ev.getX() - mLastX;
                     animView.setX(animView.getX() + delta);
                     animView.setAlpha(getAlphaForOffset(animView, thumb.getWidth()));
                     invalidateGlobalRegion(animView);
                 }
                 mLastX = ev.getX();
                 break;

             case MotionEvent.ACTION_UP:
                 final ObjectAnimator anim;
                 if (animView != null) {
                     final VelocityTracker velocityTracker = mVelocityTracker;
                     velocityTracker.computeCurrentVelocity(1000, 10000);
                     final float velocityX = velocityTracker.getXVelocity();
                     final float velocityY = velocityTracker.getYVelocity();
                     final float curX = animView.getX();
                     final float newX = (velocityX >= 0.0f ? 1 : -1) * animView.getWidth();

                     if (Math.abs(velocityX) > Math.abs(velocityY)
                             && Math.abs(velocityX) > ESCAPE_VELOCITY
                             && (velocityX > 0.0f) == (animView.getX() >= 0)) {
                         final long duration =
                             (long) (Math.abs(newX-curX) * 1000.0f / Math.abs(velocityX));
                         anim = ObjectAnimator.ofFloat(animView, "x", curX, newX);
                         anim.setInterpolator(new LinearInterpolator());
                         final int swipeDirection = animView.getX() >= 0.0f ?
                                 RecentsCallback.SWIPE_RIGHT : RecentsCallback.SWIPE_LEFT;
                         anim.addListener(new AnimatorListener() {
                             public void onAnimationStart(Animator animation) {
                             }
                             public void onAnimationRepeat(Animator animation) {
                             }
                             public void onAnimationEnd(Animator animation) {
                                 mLinearLayout.removeView(mCurrentView);
                                 mCallback.handleSwipe(animView, swipeDirection);
                             }
                             public void onAnimationCancel(Animator animation) {
                                 mLinearLayout.removeView(mCurrentView);
                                 mCallback.handleSwipe(animView, swipeDirection);
                             }
                         });
                         anim.setDuration(duration);
                     } else { // Animate back to position
                         final long duration = Math.abs(velocityX) > 0.0f ?
                                 (long) (Math.abs(newX-curX) * 1000.0f / Math.abs(velocityX))
                                 : SNAP_BACK_DURATION;
                         anim = ObjectAnimator.ofFloat(animView, "x", animView.getX(), 0.0f);
                         anim.setInterpolator(new DecelerateInterpolator(4.0f));
                         anim.setDuration(duration);
                     }

                     anim.addUpdateListener(new AnimatorUpdateListener() {
                         public void onAnimationUpdate(ValueAnimator animation) {
                             animView.setAlpha(getAlphaForOffset(animView, thumb.getWidth()));
                             invalidateGlobalRegion(animView);
                         }
                     });
                     anim.start();
                 }

                 mVelocityTracker.recycle();
                 mVelocityTracker = null;
                 break;
         }
         return true;
     }

     void invalidateGlobalRegion(View view) {
         RectF childBounds
                 = new RectF(view.getLeft(), view.getTop(), view.getRight(), view.getBottom());
         childBounds.offset(view.getX(), view.getY());
         if (DEBUG_INVALIDATE) Log.v(TAG, "-------------");
         while (view.getParent() != null && view.getParent() instanceof View) {
             view = (View) view.getParent();
             view.getMatrix().mapRect(childBounds);
             view.invalidate((int) Math.floor(childBounds.left),
                     (int) Math.floor(childBounds.top),
                     (int) Math.ceil(childBounds.right),
                     (int) Math.ceil(childBounds.bottom));
             if (DEBUG_INVALIDATE) {
                 Log.v(TAG, "INVALIDATE(" + (int) Math.floor(childBounds.left)
                         + "," + (int) Math.floor(childBounds.top)
                         + "," + (int) Math.ceil(childBounds.right)
                         + "," + (int) Math.ceil(childBounds.bottom));
             }
         }
     }

     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();
         LayoutInflater inflater = (LayoutInflater)
                 mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

         setScrollbarFadingEnabled(true);

         mLinearLayout = (LinearLayout) findViewById(R.id.recents_linear_layout);

         final int leftPadding = mContext.getResources()
             .getDimensionPixelOffset(R.dimen.status_bar_recents_thumbnail_left_margin);
         setOverScrollEffectPadding(leftPadding, 0);
     }

     private void setOverScrollEffectPadding(int leftPadding, int i) {
         // TODO Add to (Vertical)ScrollView
     }

     @Override
     protected void onSizeChanged(int w, int h, int oldw, int oldh) {
         super.onSizeChanged(w, h, oldw, oldh);
         // Keep track of the last visible item in the list so we can restore it
         // to the bottom when the orientation changes.
         mLastScrollPosition = scrollPositionOfMostRecent();

         // This has to happen post-layout, so run it "in the future"
         post(new Runnable() {
             public void run() {
                 scrollTo(0, mLastScrollPosition);
             }
         });
     }

     @Override
     protected void onVisibilityChanged(View changedView, int visibility) {
         super.onVisibilityChanged(changedView, visibility);
         // scroll to bottom after reloading
         if (visibility == View.VISIBLE && changedView == this) {
             post(new Runnable() {
                 public void run() {
                     update();
                 }
             });
         }
     }

     public void setAdapter(ActivityDescriptionAdapter adapter) {
         mAdapter = adapter;
         mAdapter.registerDataSetObserver(new DataSetObserver() {
             public void onChanged() {
                 update();
             }

             public void onInvalidated() {
                 update();
             }
         });
     }

     @Override
     public void setLayoutTransition(LayoutTransition transition) {
         // The layout transition applies to our embedded LinearLayout
         mLinearLayout.setLayoutTransition(transition);
     }

     public void onClick(View view) {
         mCallback.handleOnClick(view);
     }

     public void setCallback(RecentsCallback callback) {
         mCallback = callback;
     }

     public boolean onTouch(View v, MotionEvent event) {
         mCurrentView = v;
         return false;
     }
 }
	/*
	* Copyright (C) 2011 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.systemui.recent;

	import com.android.systemui.recent.RecentsPanelView.ActivityDescriptionAdapter;

	import android.animation.Animator;
	import android.animation.Animator.AnimatorListener;
	import android.animation.LayoutTransition;
	import android.animation.ObjectAnimator;
	import android.animation.ValueAnimator;
	import android.animation.ValueAnimator.AnimatorUpdateListener;
	import android.content.Context;
	import android.database.DataSetObserver;
	import android.graphics.RectF;
	import android.util.AttributeSet;
	import android.util.Log;
	import android.view.LayoutInflater;
	import android.view.MotionEvent;
	import android.view.VelocityTracker;
	import android.view.View;
	import android.view.animation.DecelerateInterpolator;
	import android.view.animation.LinearInterpolator;
	import android.widget.LinearLayout;
	import android.widget.ScrollView;

	import com.android.systemui.R;

	public class RecentsVerticalScrollView extends ScrollView
	implements View.OnClickListener, View.OnTouchListener {
	private static final float FADE_CONSTANT = 0.5f;
	private static final int SNAP_BACK_DURATION = 250;
	private static final int ESCAPE_VELOCITY = 100; // speed of item required to "curate" it
	private static final String TAG = RecentsPanelView.TAG;
	private static final float THRESHHOLD = 50;
	private static final boolean DEBUG_INVALIDATE = false;
	private LinearLayout mLinearLayout;
	private ActivityDescriptionAdapter mAdapter;
	private RecentsCallback mCallback;
	protected int mLastScrollPosition;
	private View mCurrentView;
	private float mLastX;
	private boolean mDragging;
	private VelocityTracker mVelocityTracker;

	public RecentsVerticalScrollView(Context context) {
	this(context, null);
	}

	public RecentsVerticalScrollView(Context context, AttributeSet attrs) {
	super(context, attrs, 0);
	}

	private int scrollPositionOfMostRecent() {
	return mLinearLayout.getHeight() - getHeight();
	}

	public void update() {
	mLinearLayout.removeAllViews();
	for (int i = 0; i < mAdapter.getCount(); i++) {
	View view = mAdapter.getView(i, null, mLinearLayout);
	view.setClickable(true);
	view.setOnClickListener(this);
	view.setOnTouchListener(this);
	mLinearLayout.addView(view);
	}
	// Scroll to end after layout.
	post(new Runnable() {
	public void run() {
	mLastScrollPosition = scrollPositionOfMostRecent();
	scrollTo(0, mLastScrollPosition);
	}
	});
	}

	@Override
	public boolean onInterceptTouchEvent(MotionEvent ev) {
	if (mVelocityTracker == null) {
	mVelocityTracker = VelocityTracker.obtain();
	}
	mVelocityTracker.addMovement(ev);
	switch (ev.getAction()) {
	case MotionEvent.ACTION_DOWN:
	mDragging = false;
	mLastX = ev.getX();
	break;

	case MotionEvent.ACTION_MOVE:
	float delta = ev.getX() - mLastX;
	Log.v(TAG, "ACTION_MOVE : " + delta);
	if (Math.abs(delta) > THRESHHOLD) {
	mDragging = true;
	}
	break;

	case MotionEvent.ACTION_UP:
	mDragging = false;
	break;
	}
	return mDragging ? true : super.onInterceptTouchEvent(ev);
	}

	private float getAlphaForOffset(View view, float thumbWidth) {
	final float fadeWidth = FADE_CONSTANT * thumbWidth;
	float result = 1.0f;
	if (view.getX() >= thumbWidth) {
	result = 1.0f - (view.getX() - thumbWidth) / fadeWidth;
	} else if (view.getX() < 0.0f) {
	result = 1.0f + (thumbWidth + view.getX()) / fadeWidth;
	}
	Log.v(TAG, "FADE AMOUNT: " + result);
	return result;
	}

	@Override
	public boolean onTouchEvent(MotionEvent ev) {
	if (!mDragging) {
	return super.onTouchEvent(ev);
	}

	mVelocityTracker.addMovement(ev);

	final View animView = mCurrentView;
	// TODO: Cache thumbnail
	final View thumb = animView.findViewById(R.id.app_thumbnail);
	switch (ev.getAction()) {
	case MotionEvent.ACTION_MOVE:
	if (animView != null) {
	final float delta = ev.getX() - mLastX;
	animView.setX(animView.getX() + delta);
	animView.setAlpha(getAlphaForOffset(animView, thumb.getWidth()));
	invalidateGlobalRegion(animView);
	}
	mLastX = ev.getX();
	break;

	case MotionEvent.ACTION_UP:
	final ObjectAnimator anim;
	if (animView != null) {
	final VelocityTracker velocityTracker = mVelocityTracker;
	velocityTracker.computeCurrentVelocity(1000, 10000);
	final float velocityX = velocityTracker.getXVelocity();
	final float velocityY = velocityTracker.getYVelocity();
	final float curX = animView.getX();
	final float newX = (velocityX >= 0.0f ? 1 : -1) * animView.getWidth();

	if (Math.abs(velocityX) > Math.abs(velocityY)
	&& Math.abs(velocityX) > ESCAPE_VELOCITY
	&& (velocityX > 0.0f) == (animView.getX() >= 0)) {
	final long duration =
	(long) (Math.abs(newX-curX) * 1000.0f / Math.abs(velocityX));
	anim = ObjectAnimator.ofFloat(animView, "x", curX, newX);
	anim.setInterpolator(new LinearInterpolator());
	final int swipeDirection = animView.getX() >= 0.0f ?
	RecentsCallback.SWIPE_RIGHT : RecentsCallback.SWIPE_LEFT;
	anim.addListener(new AnimatorListener() {
	public void onAnimationStart(Animator animation) {
	}
	public void onAnimationRepeat(Animator animation) {
	}
	public void onAnimationEnd(Animator animation) {
	mLinearLayout.removeView(mCurrentView);
	mCallback.handleSwipe(animView, swipeDirection);
	}
	public void onAnimationCancel(Animator animation) {
	mLinearLayout.removeView(mCurrentView);
	mCallback.handleSwipe(animView, swipeDirection);
	}
	});
	anim.setDuration(duration);
	} else { // Animate back to position
	final long duration = Math.abs(velocityX) > 0.0f ?
	(long) (Math.abs(newX-curX) * 1000.0f / Math.abs(velocityX))
	: SNAP_BACK_DURATION;
	anim = ObjectAnimator.ofFloat(animView, "x", animView.getX(), 0.0f);
	anim.setInterpolator(new DecelerateInterpolator(4.0f));
	anim.setDuration(duration);
	}

	anim.addUpdateListener(new AnimatorUpdateListener() {
	public void onAnimationUpdate(ValueAnimator animation) {
	animView.setAlpha(getAlphaForOffset(animView, thumb.getWidth()));
	invalidateGlobalRegion(animView);
	}
	});
	anim.start();
	}

	mVelocityTracker.recycle();
	mVelocityTracker = null;
	break;
	}
	return true;
	}

	void invalidateGlobalRegion(View view) {
	RectF childBounds
	= new RectF(view.getLeft(), view.getTop(), view.getRight(), view.getBottom());
	childBounds.offset(view.getX(), view.getY());
	if (DEBUG_INVALIDATE) Log.v(TAG, "-------------");
	while (view.getParent() != null && view.getParent() instanceof View) {
	view = (View) view.getParent();
	view.getMatrix().mapRect(childBounds);
	view.invalidate((int) Math.floor(childBounds.left),
	(int) Math.floor(childBounds.top),
	(int) Math.ceil(childBounds.right),
	(int) Math.ceil(childBounds.bottom));
	if (DEBUG_INVALIDATE) {
	Log.v(TAG, "INVALIDATE(" + (int) Math.floor(childBounds.left)
	+ "," + (int) Math.floor(childBounds.top)
	+ "," + (int) Math.ceil(childBounds.right)
	+ "," + (int) Math.ceil(childBounds.bottom));
	}
	}
	}

	@Override
	protected void onFinishInflate() {
	super.onFinishInflate();
	LayoutInflater inflater = (LayoutInflater)
	mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

	setScrollbarFadingEnabled(true);

	mLinearLayout = (LinearLayout) findViewById(R.id.recents_linear_layout);

	final int leftPadding = mContext.getResources()
	.getDimensionPixelOffset(R.dimen.status_bar_recents_thumbnail_left_margin);
	setOverScrollEffectPadding(leftPadding, 0);
	}

	private void setOverScrollEffectPadding(int leftPadding, int i) {
	// TODO Add to (Vertical)ScrollView
	}

	@Override
	protected void onSizeChanged(int w, int h, int oldw, int oldh) {
	super.onSizeChanged(w, h, oldw, oldh);
	// Keep track of the last visible item in the list so we can restore it
	// to the bottom when the orientation changes.
	mLastScrollPosition = scrollPositionOfMostRecent();

	// This has to happen post-layout, so run it "in the future"
	post(new Runnable() {
	public void run() {
	scrollTo(0, mLastScrollPosition);
	}
	});
	}

	@Override
	protected void onVisibilityChanged(View changedView, int visibility) {
	super.onVisibilityChanged(changedView, visibility);
	// scroll to bottom after reloading
	if (visibility == View.VISIBLE && changedView == this) {
	post(new Runnable() {
	public void run() {
	update();
	}
	});
	}
	}

	public void setAdapter(ActivityDescriptionAdapter adapter) {
	mAdapter = adapter;
	mAdapter.registerDataSetObserver(new DataSetObserver() {
	public void onChanged() {
	update();
	}

	public void onInvalidated() {
	update();
	}
	});
	}

	@Override
	public void setLayoutTransition(LayoutTransition transition) {
	// The layout transition applies to our embedded LinearLayout
	mLinearLayout.setLayoutTransition(transition);
	}

	public void onClick(View view) {
	mCallback.handleOnClick(view);
	}

	public void setCallback(RecentsCallback callback) {
	mCallback = callback;
	}

	public boolean onTouch(View v, MotionEvent event) {
	mCurrentView = v;
	return false;
	}
	}