blob: fed0884c3927c7931f6e79daccd2e181e3098e83 [file] [log] [blame]
/*
* Copyright (C) 2010 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.launcher2;
import com.android.launcher.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.view.ActionMode;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.view.animation.Interpolator;
import android.view.animation.Animation.AnimationListener;
import android.widget.Checkable;
import android.widget.Scroller;
import java.util.ArrayList;
import java.util.HashMap;
/**
* An abstraction of the original Workspace which supports browsing through a
* sequential list of "pages"
*/
public abstract class PagedView extends ViewGroup {
private static final String TAG = "PagedView";
protected static final int INVALID_PAGE = -1;
// the min drag distance for a fling to register, to prevent random page shifts
private static final int MIN_LENGTH_FOR_FLING = 25;
// The min drag distance to trigger a page shift (regardless of velocity)
private static final int MIN_LENGTH_FOR_MOVE = 200;
private static final int PAGE_SNAP_ANIMATION_DURATION = 550;
protected static final float NANOTIME_DIV = 1000000000.0f;
private static final float OVERSCROLL_DAMP_FACTOR = 0.08f;
private static final int MINIMUM_SNAP_VELOCITY = 2200;
private static final int MIN_FLING_VELOCITY = 250;
// the velocity at which a fling gesture will cause us to snap to the next page
protected int mSnapVelocity = 500;
protected float mSmoothingTime;
protected float mTouchX;
protected boolean mFirstLayout = true;
protected int mCurrentPage;
protected int mNextPage = INVALID_PAGE;
protected int mMaxScrollX;
protected Scroller mScroller;
private VelocityTracker mVelocityTracker;
private float mDownMotionX;
protected float mLastMotionX;
protected float mLastMotionY;
private int mLastScreenCenter = -1;
protected final static int TOUCH_STATE_REST = 0;
protected final static int TOUCH_STATE_SCROLLING = 1;
protected final static int TOUCH_STATE_PREV_PAGE = 2;
protected final static int TOUCH_STATE_NEXT_PAGE = 3;
protected final static float ALPHA_QUANTIZE_LEVEL = 0.0001f;
protected int mTouchState = TOUCH_STATE_REST;
protected OnLongClickListener mLongClickListener;
protected boolean mAllowLongPress = true;
protected int mTouchSlop;
private int mPagingTouchSlop;
private int mMaximumVelocity;
protected int mPageSpacing;
protected int mPageLayoutPaddingTop;
protected int mPageLayoutPaddingBottom;
protected int mPageLayoutPaddingLeft;
protected int mPageLayoutPaddingRight;
protected int mPageLayoutWidthGap;
protected int mPageLayoutHeightGap;
protected int mCellCountX;
protected int mCellCountY;
protected boolean mCenterPagesVertically;
protected boolean mAllowOverScroll = true;
protected int mUnboundedScrollX;
protected static final int INVALID_POINTER = -1;
protected int mActivePointerId = INVALID_POINTER;
private PageSwitchListener mPageSwitchListener;
private ArrayList<Boolean> mDirtyPageContent;
private boolean mDirtyPageAlpha;
// choice modes
protected static final int CHOICE_MODE_NONE = 0;
protected static final int CHOICE_MODE_SINGLE = 1;
// Multiple selection mode is not supported by all Launcher actions atm
protected static final int CHOICE_MODE_MULTIPLE = 2;
protected int mChoiceMode;
private ActionMode mActionMode;
protected PagedViewIconCache mPageViewIconCache;
// If true, syncPages and syncPageItems will be called to refresh pages
protected boolean mContentIsRefreshable = true;
// If true, modify alpha of neighboring pages as user scrolls left/right
protected boolean mFadeInAdjacentScreens = true;
// It true, use a different slop parameter (pagingTouchSlop = 2 * touchSlop) for deciding
// to switch to a new page
protected boolean mUsePagingTouchSlop = true;
// If true, the subclass should directly update mScrollX itself in its computeScroll method
// (SmoothPagedView does this)
protected boolean mDeferScrollUpdate = false;
protected boolean mIsPageMoving = false;
/**
* Simple cache mechanism for PagedViewIcon outlines.
*/
class PagedViewIconCache {
private final HashMap<Object, Bitmap> iconOutlineCache = new HashMap<Object, Bitmap>();
public void clear() {
iconOutlineCache.clear();
}
public void addOutline(Object key, Bitmap b) {
iconOutlineCache.put(key, b);
}
public void removeOutline(Object key) {
if (iconOutlineCache.containsKey(key)) {
iconOutlineCache.remove(key);
}
}
public Bitmap getOutline(Object key) {
return iconOutlineCache.get(key);
}
}
public interface PageSwitchListener {
void onPageSwitch(View newPage, int newPageIndex);
}
public PagedView(Context context) {
this(context, null);
}
public PagedView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public PagedView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mChoiceMode = CHOICE_MODE_NONE;
TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.PagedView, defStyle, 0);
mPageSpacing = a.getDimensionPixelSize(R.styleable.PagedView_pageSpacing, 0);
mPageLayoutPaddingTop = a.getDimensionPixelSize(
R.styleable.PagedView_pageLayoutPaddingTop, 10);
mPageLayoutPaddingBottom = a.getDimensionPixelSize(
R.styleable.PagedView_pageLayoutPaddingBottom, 10);
mPageLayoutPaddingLeft = a.getDimensionPixelSize(
R.styleable.PagedView_pageLayoutPaddingLeft, 10);
mPageLayoutPaddingRight = a.getDimensionPixelSize(
R.styleable.PagedView_pageLayoutPaddingRight, 10);
mPageLayoutWidthGap = a.getDimensionPixelSize(
R.styleable.PagedView_pageLayoutWidthGap, -1);
mPageLayoutHeightGap = a.getDimensionPixelSize(
R.styleable.PagedView_pageLayoutHeightGap, -1);
a.recycle();
setHapticFeedbackEnabled(false);
init();
}
/**
* Initializes various states for this workspace.
*/
protected void init() {
mDirtyPageContent = new ArrayList<Boolean>();
mDirtyPageContent.ensureCapacity(32);
mPageViewIconCache = new PagedViewIconCache();
mScroller = new Scroller(getContext(), new ScrollInterpolator());
mCurrentPage = 0;
mCenterPagesVertically = true;
final ViewConfiguration configuration = ViewConfiguration.get(getContext());
mTouchSlop = configuration.getScaledTouchSlop();
mPagingTouchSlop = configuration.getScaledPagingTouchSlop();
mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
}
public void setPageSwitchListener(PageSwitchListener pageSwitchListener) {
mPageSwitchListener = pageSwitchListener;
if (mPageSwitchListener != null) {
mPageSwitchListener.onPageSwitch(getPageAt(mCurrentPage), mCurrentPage);
}
}
/**
* Returns the index of the currently displayed page.
*
* @return The index of the currently displayed page.
*/
int getCurrentPage() {
return mCurrentPage;
}
int getPageCount() {
return getChildCount();
}
View getPageAt(int index) {
return getChildAt(index);
}
int getScrollWidth() {
return getWidth();
}
/**
* Updates the scroll of the current page immediately to its final scroll position. We use this
* in CustomizePagedView to allow tabs to share the same PagedView while resetting the scroll of
* the previous tab page.
*/
protected void updateCurrentPageScroll() {
int newX = getChildOffset(mCurrentPage) - getRelativeChildOffset(mCurrentPage);
scrollTo(newX, 0);
mScroller.setFinalX(newX);
}
/**
* Sets the current page.
*/
void setCurrentPage(int currentPage) {
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
if (getChildCount() == 0 || currentPage == mCurrentPage) {
return;
}
mCurrentPage = Math.max(0, Math.min(currentPage, getPageCount() - 1));
updateCurrentPageScroll();
invalidate();
notifyPageSwitchListener();
}
protected void notifyPageSwitchListener() {
if (mPageSwitchListener != null) {
mPageSwitchListener.onPageSwitch(getPageAt(mCurrentPage), mCurrentPage);
}
}
private void pageBeginMoving() {
mIsPageMoving = true;
onPageBeginMoving();
}
private void pageEndMoving() {
onPageEndMoving();
mIsPageMoving = false;
}
// a method that subclasses can override to add behavior
protected void onPageBeginMoving() {
}
// a method that subclasses can override to add behavior
protected void onPageEndMoving() {
}
/**
* Registers the specified listener on each page contained in this workspace.
*
* @param l The listener used to respond to long clicks.
*/
@Override
public void setOnLongClickListener(OnLongClickListener l) {
mLongClickListener = l;
final int count = getPageCount();
for (int i = 0; i < count; i++) {
getPageAt(i).setOnLongClickListener(l);
}
}
@Override
public void scrollBy(int x, int y) {
scrollTo(mUnboundedScrollX + x, mScrollY + y);
}
@Override
public void scrollTo(int x, int y) {
mUnboundedScrollX = x;
if (x < 0) {
super.scrollTo(0, y);
if (mAllowOverScroll) {
overScroll(x);
}
} else if (x > mMaxScrollX) {
super.scrollTo(mMaxScrollX, y);
if (mAllowOverScroll) {
overScroll(x - mMaxScrollX);
}
} else {
super.scrollTo(x, y);
}
mTouchX = x;
mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
}
// we moved this functionality to a helper function so SmoothPagedView can reuse it
protected boolean computeScrollHelper() {
if (mScroller.computeScrollOffset()) {
mDirtyPageAlpha = true;
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
invalidate();
return true;
} else if (mNextPage != INVALID_PAGE) {
mDirtyPageAlpha = true;
mCurrentPage = Math.max(0, Math.min(mNextPage, getPageCount() - 1));
mNextPage = INVALID_PAGE;
notifyPageSwitchListener();
// We don't want to trigger a page end moving unless the page has settled
// and the user has stopped scrolling
if (mTouchState == TOUCH_STATE_REST) {
pageEndMoving();
}
return true;
}
return false;
}
@Override
public void computeScroll() {
computeScrollHelper();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
if (widthMode != MeasureSpec.EXACTLY) {
throw new IllegalStateException("Workspace can only be used in EXACTLY mode.");
}
/* Allow the height to be set as WRAP_CONTENT. This allows the particular case
* of the All apps view on XLarge displays to not take up more space then it needs. Width
* is still not allowed to be set as WRAP_CONTENT since many parts of the code expect
* each page to have the same width.
*/
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
int maxChildHeight = 0;
final int verticalPadding = mPaddingTop + mPaddingBottom;
// The children are given the same width and height as the workspace
// unless they were set to WRAP_CONTENT
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
// disallowing padding in paged view (just pass 0)
final View child = getChildAt(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
int childWidthMode;
if (lp.width == LayoutParams.WRAP_CONTENT) {
childWidthMode = MeasureSpec.AT_MOST;
} else {
childWidthMode = MeasureSpec.EXACTLY;
}
int childHeightMode;
if (lp.height == LayoutParams.WRAP_CONTENT) {
childHeightMode = MeasureSpec.AT_MOST;
} else {
childHeightMode = MeasureSpec.EXACTLY;
}
final int childWidthMeasureSpec =
MeasureSpec.makeMeasureSpec(widthSize, childWidthMode);
final int childHeightMeasureSpec =
MeasureSpec.makeMeasureSpec(heightSize - verticalPadding, childHeightMode);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
maxChildHeight = Math.max(maxChildHeight, child.getMeasuredHeight());
}
if (heightMode == MeasureSpec.AT_MOST) {
heightSize = maxChildHeight + verticalPadding;
}
if (childCount > 0) {
mMaxScrollX = getChildOffset(childCount - 1) - getRelativeChildOffset(childCount - 1);
} else {
mMaxScrollX = 0;
}
setMeasuredDimension(widthSize, heightSize);
}
protected void moveToNewPageWithoutMovingCellLayouts(int newCurrentPage) {
int newX = getChildOffset(newCurrentPage) - getRelativeChildOffset(newCurrentPage);
int delta = newX - mScrollX;
final int screenCount = getChildCount();
for (int i = 0; i < screenCount; i++) {
CellLayout cl = (CellLayout) getChildAt(i);
cl.setX(cl.getX() + delta);
}
setCurrentPage(newCurrentPage);
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
if (mFirstLayout && mCurrentPage >= 0 && mCurrentPage < getChildCount()) {
setHorizontalScrollBarEnabled(false);
int newX = getChildOffset(mCurrentPage) - getRelativeChildOffset(mCurrentPage);
scrollTo(newX, 0);
mScroller.setFinalX(newX);
setHorizontalScrollBarEnabled(true);
mFirstLayout = false;
}
final int verticalPadding = mPaddingTop + mPaddingBottom;
final int childCount = getChildCount();
int childLeft = 0;
if (childCount > 0) {
childLeft = getRelativeChildOffset(0);
}
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != View.GONE) {
final int childWidth = child.getMeasuredWidth();
final int childHeight = child.getMeasuredHeight();
int childTop = mPaddingTop;
if (mCenterPagesVertically) {
childTop += ((getMeasuredHeight() - verticalPadding) - childHeight) / 2;
}
child.layout(childLeft, childTop,
childLeft + childWidth, childTop + childHeight);
childLeft += childWidth + mPageSpacing;
}
}
}
protected void updateAdjacentPagesAlpha() {
if (mFadeInAdjacentScreens) {
if (mDirtyPageAlpha || (mTouchState == TOUCH_STATE_SCROLLING) || !mScroller.isFinished()) {
int halfScreenSize = getMeasuredWidth() / 2;
int screenCenter = mScrollX + halfScreenSize;
final int childCount = getChildCount();
for (int i = 0; i < childCount; ++i) {
View layout = (View) getChildAt(i);
int childWidth = layout.getMeasuredWidth();
int halfChildWidth = (childWidth / 2);
int childCenter = getChildOffset(i) + halfChildWidth;
// On the first layout, we may not have a width nor a proper offset, so for now
// we should just assume full page width (and calculate the offset according to
// that).
if (childWidth <= 0) {
childWidth = getMeasuredWidth();
childCenter = (i * childWidth) + (childWidth / 2);
}
int d = halfChildWidth;
int distanceFromScreenCenter = childCenter - screenCenter;
if (distanceFromScreenCenter > 0) {
if (i > 0) {
d += getChildAt(i - 1).getMeasuredWidth() / 2;
}
} else {
if (i < childCount - 1) {
d += getChildAt(i + 1).getMeasuredWidth() / 2;
}
}
d += mPageSpacing;
// Preventing potential divide-by-zero
d = Math.max(1, d);
float dimAlpha = (float) (Math.abs(distanceFromScreenCenter)) / d;
dimAlpha = Math.max(0.0f, Math.min(1.0f, (dimAlpha * dimAlpha)));
float alpha = 1.0f - dimAlpha;
if (alpha < ALPHA_QUANTIZE_LEVEL) {
alpha = 0.0f;
} else if (alpha > 1.0f - ALPHA_QUANTIZE_LEVEL) {
alpha = 1.0f;
}
if (Float.compare(alpha, layout.getAlpha()) != 0) {
layout.setAlpha(alpha);
}
}
mDirtyPageAlpha = false;
}
}
}
protected void screenScrolled(int screenCenter) {
}
@Override
protected void dispatchDraw(Canvas canvas) {
int halfScreenSize = getMeasuredWidth() / 2;
int screenCenter = mScrollX + halfScreenSize;
if (screenCenter != mLastScreenCenter) {
screenScrolled(screenCenter);
updateAdjacentPagesAlpha();
mLastScreenCenter = screenCenter;
}
// Find out which screens are visible; as an optimization we only call draw on them
// As an optimization, this code assumes that all pages have the same width as the 0th
// page.
final int pageCount = getChildCount();
if (pageCount > 0) {
final int pageWidth = getChildAt(0).getMeasuredWidth();
final int screenWidth = getMeasuredWidth();
int x = getRelativeChildOffset(0) + pageWidth;
int leftScreen = 0;
int rightScreen = 0;
while (x <= mScrollX) {
leftScreen++;
x += pageWidth + mPageSpacing;
// replace above line with this if you don't assume all pages have same width as 0th
// page:
// x += getChildAt(leftScreen).getMeasuredWidth();
}
rightScreen = leftScreen;
while (x < mScrollX + screenWidth) {
rightScreen++;
x += pageWidth + mPageSpacing;
// replace above line with this if you don't assume all pages have same width as 0th
// page:
//if (rightScreen < pageCount) {
// x += getChildAt(rightScreen).getMeasuredWidth();
//}
}
rightScreen = Math.min(getChildCount() - 1, rightScreen);
final long drawingTime = getDrawingTime();
// Clip to the bounds
canvas.save();
canvas.clipRect(mScrollX, mScrollY, mScrollX + mRight - mLeft,
mScrollY + mBottom - mTop);
for (int i = leftScreen; i <= rightScreen; i++) {
drawChild(canvas, getChildAt(i), drawingTime);
}
canvas.restore();
}
}
@Override
public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
int page = indexOfChild(child);
if (page != mCurrentPage || !mScroller.isFinished()) {
snapToPage(page);
return true;
}
return false;
}
@Override
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
int focusablePage;
if (mNextPage != INVALID_PAGE) {
focusablePage = mNextPage;
} else {
focusablePage = mCurrentPage;
}
View v = getPageAt(focusablePage);
if (v != null) {
v.requestFocus(direction, previouslyFocusedRect);
}
return false;
}
@Override
public boolean dispatchUnhandledMove(View focused, int direction) {
if (direction == View.FOCUS_LEFT) {
if (getCurrentPage() > 0) {
snapToPage(getCurrentPage() - 1);
return true;
}
} else if (direction == View.FOCUS_RIGHT) {
if (getCurrentPage() < getPageCount() - 1) {
snapToPage(getCurrentPage() + 1);
return true;
}
}
return super.dispatchUnhandledMove(focused, direction);
}
@Override
public void addFocusables(ArrayList<View> views, int direction, int focusableMode) {
if (mCurrentPage >= 0 && mCurrentPage < getPageCount()) {
getPageAt(mCurrentPage).addFocusables(views, direction);
}
if (direction == View.FOCUS_LEFT) {
if (mCurrentPage > 0) {
getPageAt(mCurrentPage - 1).addFocusables(views, direction);
}
} else if (direction == View.FOCUS_RIGHT){
if (mCurrentPage < getPageCount() - 1) {
getPageAt(mCurrentPage + 1).addFocusables(views, direction);
}
}
}
/**
* If one of our descendant views decides that it could be focused now, only
* pass that along if it's on the current page.
*
* This happens when live folders requery, and if they're off page, they
* end up calling requestFocus, which pulls it on page.
*/
@Override
public void focusableViewAvailable(View focused) {
View current = getPageAt(mCurrentPage);
View v = focused;
while (true) {
if (v == current) {
super.focusableViewAvailable(focused);
return;
}
if (v == this) {
return;
}
ViewParent parent = v.getParent();
if (parent instanceof View) {
v = (View)v.getParent();
} else {
return;
}
}
}
/**
* {@inheritDoc}
*/
@Override
public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
if (disallowIntercept) {
// We need to make sure to cancel our long press if
// a scrollable widget takes over touch events
final View currentPage = getChildAt(mCurrentPage);
currentPage.cancelLongPress();
}
super.requestDisallowInterceptTouchEvent(disallowIntercept);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
/*
* This method JUST determines whether we want to intercept the motion.
* If we return true, onTouchEvent will be called and we do the actual
* scrolling there.
*/
// Skip touch handling if there are no pages to swipe
if (getChildCount() <= 0) return super.onInterceptTouchEvent(ev);
/*
* Shortcut the most recurring case: the user is in the dragging
* state and he is moving his finger. We want to intercept this
* motion.
*/
final int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE) &&
(mTouchState == TOUCH_STATE_SCROLLING)) {
return true;
}
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_MOVE: {
/*
* mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
* whether the user has moved far enough from his original down touch.
*/
if (mActivePointerId != INVALID_POINTER) {
determineScrollingStart(ev);
break;
}
// if mActivePointerId is INVALID_POINTER, then we must have missed an ACTION_DOWN
// event. in that case, treat the first occurence of a move event as a ACTION_DOWN
// i.e. fall through to the next case (don't break)
// (We sometimes miss ACTION_DOWN events in Workspace because it ignores all events
// while it's small- this was causing a crash before we checked for INVALID_POINTER)
}
case MotionEvent.ACTION_DOWN: {
final float x = ev.getX();
final float y = ev.getY();
// Remember location of down touch
mDownMotionX = x;
mLastMotionX = x;
mLastMotionY = y;
mActivePointerId = ev.getPointerId(0);
mAllowLongPress = true;
/*
* If being flinged and user touches the screen, initiate drag;
* otherwise don't. mScroller.isFinished should be false when
* being flinged.
*/
final int xDist = Math.abs(mScroller.getFinalX() - mScroller.getCurrX());
final boolean finishedScrolling = (mScroller.isFinished() || xDist < mTouchSlop);
if (finishedScrolling) {
mTouchState = TOUCH_STATE_REST;
mScroller.abortAnimation();
} else {
mTouchState = TOUCH_STATE_SCROLLING;
}
// check if this can be the beginning of a tap on the side of the pages
// to scroll the current page
if ((mTouchState != TOUCH_STATE_PREV_PAGE) && !handlePagingClicks() &&
(mTouchState != TOUCH_STATE_NEXT_PAGE)) {
if (getChildCount() > 0) {
int width = getMeasuredWidth();
int offset = getRelativeChildOffset(mCurrentPage);
if (x < offset - mPageSpacing) {
mTouchState = TOUCH_STATE_PREV_PAGE;
} else if (x > (width - offset + mPageSpacing)) {
mTouchState = TOUCH_STATE_NEXT_PAGE;
}
}
}
break;
}
case MotionEvent.ACTION_UP:
onWallpaperTap(ev);
case MotionEvent.ACTION_CANCEL:
mTouchState = TOUCH_STATE_REST;
mAllowLongPress = false;
mActivePointerId = INVALID_POINTER;
break;
case MotionEvent.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);
break;
}
/*
* The only time we want to intercept motion events is if we are in the
* drag mode.
*/
return mTouchState != TOUCH_STATE_REST;
}
protected void animateClickFeedback(View v, final Runnable r) {
// animate the view slightly to show click feedback running some logic after it is "pressed"
Animation anim = AnimationUtils.loadAnimation(getContext(),
R.anim.paged_view_click_feedback);
anim.setAnimationListener(new AnimationListener() {
@Override
public void onAnimationStart(Animation animation) {}
@Override
public void onAnimationRepeat(Animation animation) {
r.run();
}
@Override
public void onAnimationEnd(Animation animation) {}
});
v.startAnimation(anim);
}
/*
* Determines if we should change the touch state to start scrolling after the
* user moves their touch point too far.
*/
protected void determineScrollingStart(MotionEvent ev) {
/*
* Locally do absolute value. mLastMotionX is set to the y value
* of the down event.
*/
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final float y = ev.getY(pointerIndex);
final int xDiff = (int) Math.abs(x - mLastMotionX);
final int yDiff = (int) Math.abs(y - mLastMotionY);
final int touchSlop = mTouchSlop;
boolean xPaged = xDiff > mPagingTouchSlop;
boolean xMoved = xDiff > touchSlop;
boolean yMoved = yDiff > touchSlop;
if (xMoved || yMoved) {
if (mUsePagingTouchSlop ? xPaged : xMoved) {
// Scroll if the user moved far enough along the X axis
mTouchState = TOUCH_STATE_SCROLLING;
mLastMotionX = x;
mTouchX = mScrollX;
mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
pageBeginMoving();
}
// Either way, cancel any pending longpress
if (mAllowLongPress) {
mAllowLongPress = false;
// Try canceling the long press. It could also have been scheduled
// by a distant descendant, so use the mAllowLongPress flag to block
// everything
final View currentPage = getPageAt(mCurrentPage);
if (currentPage != null) {
currentPage.cancelLongPress();
}
}
}
}
protected boolean handlePagingClicks() {
return false;
}
// This curve determines how the effect of scrolling over the limits of the page dimishes
// as the user pulls further and further from the bounds
private float overScrollInfluenceCurve(float f) {
f -= 1.0f;
return f * f * f + 1.0f;
}
protected void overScroll(float amount) {
int screenSize = getMeasuredWidth();
float f = (amount / screenSize);
if (f == 0) return;
f = f / (Math.abs(f)) * (overScrollInfluenceCurve(Math.abs(f)));
int overScrollAmount = (int) Math.round(OVERSCROLL_DAMP_FACTOR * f * screenSize);
if (amount < 0) {
mScrollX = overScrollAmount;
} else {
mScrollX = mMaxScrollX + overScrollAmount;
}
invalidate();
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
// Skip touch handling if there are no pages to swipe
if (getChildCount() <= 0) return super.onTouchEvent(ev);
acquireVelocityTrackerAndAddMovement(ev);
final int action = ev.getAction();
switch (action & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
/*
* If being flinged and user touches, stop the fling. isFinished
* will be false if being flinged.
*/
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
// Remember where the motion event started
mDownMotionX = mLastMotionX = ev.getX();
mActivePointerId = ev.getPointerId(0);
if (mTouchState == TOUCH_STATE_SCROLLING) {
pageBeginMoving();
}
break;
case MotionEvent.ACTION_MOVE:
if (mTouchState == TOUCH_STATE_SCROLLING) {
// Scroll to follow the motion event
final int pointerIndex = ev.findPointerIndex(mActivePointerId);
final float x = ev.getX(pointerIndex);
final int deltaX = (int) (mLastMotionX - x);
mLastMotionX = x;
if (deltaX != 0) {
mTouchX += deltaX;
mSmoothingTime = System.nanoTime() / NANOTIME_DIV;
if (!mDeferScrollUpdate) {
scrollBy(deltaX, 0);
} else {
invalidate();
}
} else {
awakenScrollBars();
}
} else {
determineScrollingStart(ev);
}
break;
case MotionEvent.ACTION_UP:
if (mTouchState == TOUCH_STATE_SCROLLING) {
final int activePointerId = mActivePointerId;
final int pointerIndex = ev.findPointerIndex(activePointerId);
final float x = ev.getX(pointerIndex);
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
int velocityX = (int) velocityTracker.getXVelocity(activePointerId);
final int deltaX = (int) (x - mDownMotionX);
boolean isfling = Math.abs(deltaX) > MIN_LENGTH_FOR_FLING;
boolean isSignificantMove = Math.abs(deltaX) > MIN_LENGTH_FOR_MOVE;
final int snapVelocity = mSnapVelocity;
if ((isSignificantMove && deltaX > 0 ||
(isfling && velocityX > snapVelocity)) && mCurrentPage > 0) {
snapToPageWithVelocity(mCurrentPage - 1, velocityX);
} else if ((isSignificantMove && deltaX < 0 ||
(isfling && velocityX < -snapVelocity)) &&
mCurrentPage < getChildCount() - 1) {
snapToPageWithVelocity(mCurrentPage + 1, velocityX);
} else {
snapToDestination();
}
} else if (mTouchState == TOUCH_STATE_PREV_PAGE && !handlePagingClicks()) {
// at this point we have not moved beyond the touch slop
// (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
// we can just page
int nextPage = Math.max(0, mCurrentPage - 1);
if (nextPage != mCurrentPage) {
snapToPage(nextPage);
} else {
snapToDestination();
}
} else if (mTouchState == TOUCH_STATE_NEXT_PAGE && !handlePagingClicks()) {
// at this point we have not moved beyond the touch slop
// (otherwise mTouchState would be TOUCH_STATE_SCROLLING), so
// we can just page
int nextPage = Math.min(getChildCount() - 1, mCurrentPage + 1);
if (nextPage != mCurrentPage) {
snapToPage(nextPage);
} else {
snapToDestination();
}
} else {
onWallpaperTap(ev);
}
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
releaseVelocityTracker();
break;
case MotionEvent.ACTION_CANCEL:
if (mTouchState == TOUCH_STATE_SCROLLING) {
snapToDestination();
}
mTouchState = TOUCH_STATE_REST;
mActivePointerId = INVALID_POINTER;
releaseVelocityTracker();
break;
case MotionEvent.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);
break;
}
return true;
}
private void acquireVelocityTrackerAndAddMovement(MotionEvent ev) {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(ev);
}
private void releaseVelocityTracker() {
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
private void onSecondaryPointerUp(MotionEvent ev) {
final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >>
MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = ev.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
// TODO: Make this decision more intelligent.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastMotionX = mDownMotionX = ev.getX(newPointerIndex);
mLastMotionY = ev.getY(newPointerIndex);
mActivePointerId = ev.getPointerId(newPointerIndex);
if (mVelocityTracker != null) {
mVelocityTracker.clear();
}
}
if (mTouchState == TOUCH_STATE_REST) {
onWallpaperTap(ev);
}
}
protected void onWallpaperTap(MotionEvent ev) {
}
@Override
public void requestChildFocus(View child, View focused) {
super.requestChildFocus(child, focused);
int page = indexOfChild(child);
if (page >= 0 && !isInTouchMode()) {
snapToPage(page);
}
}
protected int getChildIndexForRelativeOffset(int relativeOffset) {
final int childCount = getChildCount();
int left;
int right;
for (int i = 0; i < childCount; ++i) {
left = getRelativeChildOffset(i);
right = (left + getChildAt(i).getMeasuredWidth());
if (left <= relativeOffset && relativeOffset <= right) {
return i;
}
}
return -1;
}
protected int getRelativeChildOffset(int index) {
return (getMeasuredWidth() - getChildAt(index).getMeasuredWidth()) / 2;
}
protected int getChildOffset(int index) {
if (getChildCount() == 0)
return 0;
int offset = getRelativeChildOffset(0);
for (int i = 0; i < index; ++i) {
offset += getChildAt(i).getMeasuredWidth() + mPageSpacing;
}
return offset;
}
int getPageNearestToCenterOfScreen() {
int minDistanceFromScreenCenter = getMeasuredWidth();
int minDistanceFromScreenCenterIndex = -1;
int screenCenter = mScrollX + (getMeasuredWidth() / 2);
final int childCount = getChildCount();
for (int i = 0; i < childCount; ++i) {
View layout = (View) getChildAt(i);
int childWidth = layout.getMeasuredWidth();
int halfChildWidth = (childWidth / 2);
int childCenter = getChildOffset(i) + halfChildWidth;
int distanceFromScreenCenter = Math.abs(childCenter - screenCenter);
if (distanceFromScreenCenter < minDistanceFromScreenCenter) {
minDistanceFromScreenCenter = distanceFromScreenCenter;
minDistanceFromScreenCenterIndex = i;
}
}
return minDistanceFromScreenCenterIndex;
}
protected void snapToDestination() {
snapToPage(getPageNearestToCenterOfScreen(), PAGE_SNAP_ANIMATION_DURATION);
}
private static class ScrollInterpolator implements Interpolator {
public ScrollInterpolator() {
}
public float getInterpolation(float t) {
t -= 1.0f;
return t*t*t*t*t + 1;
}
}
// We want the duration of the page snap animation to be influenced by the distance that
// the screen has to travel, however, we don't want this duration to be effected in a
// purely linear fashion. Instead, we use this method to moderate the effect that the distance
// of travel has on the overall snap duration.
float distanceInfluenceForSnapDuration(float f) {
f -= 0.5f; // center the values about 0.
f *= 0.3f * Math.PI / 2.0f;
return (float) Math.sin(f);
}
protected void snapToPageWithVelocity(int whichPage, int velocity) {
whichPage = Math.max(0, Math.min(whichPage, getChildCount() - 1));
int halfScreenSize = getMeasuredWidth() / 2;
final int newX = getChildOffset(whichPage) - getRelativeChildOffset(whichPage);
int delta = newX - mUnboundedScrollX;
int duration = 0;
if (Math.abs(velocity) < MIN_FLING_VELOCITY) {
// If the velocity is low enough, then treat this more as an automatic page advance
// as opposed to an apparent physical response to flinging
snapToPage(whichPage, PAGE_SNAP_ANIMATION_DURATION);
return;
}
// Here we compute a "distance" that will be used in the computation of the overall
// snap duration. This is a function of the actual distance that needs to be traveled;
// we keep this value close to half screen size in order to reduce the variance in snap
// duration as a function of the distance the page needs to travel.
float distanceRatio = 1.0f * Math.abs(delta) / 2 * halfScreenSize;
float distance = halfScreenSize + halfScreenSize *
distanceInfluenceForSnapDuration(distanceRatio);
velocity = Math.abs(velocity);
velocity = Math.max(MINIMUM_SNAP_VELOCITY, velocity);
// we want the page's snap velocity to approximately match the velocity at which the
// user flings, so we scale the duration by a value near to the derivative of the scroll
// interpolator at zero, ie. 5. We use 6 to make it a little slower.
duration = 6 * Math.round(1000 * Math.abs(distance / velocity));
snapToPage(whichPage, delta, duration);
}
protected void snapToPage(int whichPage) {
snapToPage(whichPage, PAGE_SNAP_ANIMATION_DURATION);
}
protected void snapToPage(int whichPage, int duration) {
whichPage = Math.max(0, Math.min(whichPage, getPageCount() - 1));
int newX = getChildOffset(whichPage) - getRelativeChildOffset(whichPage);
final int sX = mUnboundedScrollX;
final int delta = newX - sX;
snapToPage(whichPage, delta, duration);
}
protected void snapToPage(int whichPage, int delta, int duration) {
mNextPage = whichPage;
View focusedChild = getFocusedChild();
if (focusedChild != null && whichPage != mCurrentPage &&
focusedChild == getChildAt(mCurrentPage)) {
focusedChild.clearFocus();
}
pageBeginMoving();
awakenScrollBars(duration);
if (duration == 0) {
duration = Math.abs(delta);
}
if (!mScroller.isFinished()) mScroller.abortAnimation();
mScroller.startScroll(mUnboundedScrollX, 0, delta, 0, duration);
// only load some associated pages
loadAssociatedPages(mNextPage);
notifyPageSwitchListener();
invalidate();
}
@Override
protected Parcelable onSaveInstanceState() {
final SavedState state = new SavedState(super.onSaveInstanceState());
state.currentPage = mCurrentPage;
return state;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
SavedState savedState = (SavedState) state;
super.onRestoreInstanceState(savedState.getSuperState());
if (savedState.currentPage != -1) {
mCurrentPage = savedState.currentPage;
}
}
public void scrollLeft() {
if (mScroller.isFinished()) {
if (mCurrentPage > 0) snapToPage(mCurrentPage - 1);
} else {
if (mNextPage > 0) snapToPage(mNextPage - 1);
}
}
public void scrollRight() {
if (mScroller.isFinished()) {
if (mCurrentPage < getChildCount() -1) snapToPage(mCurrentPage + 1);
} else {
if (mNextPage < getChildCount() -1) snapToPage(mNextPage + 1);
}
}
public int getPageForView(View v) {
int result = -1;
if (v != null) {
ViewParent vp = v.getParent();
int count = getChildCount();
for (int i = 0; i < count; i++) {
if (vp == getChildAt(i)) {
return i;
}
}
}
return result;
}
/**
* @return True is long presses are still allowed for the current touch
*/
public boolean allowLongPress() {
return mAllowLongPress;
}
/**
* Set true to allow long-press events to be triggered, usually checked by
* {@link Launcher} to accept or block dpad-initiated long-presses.
*/
public void setAllowLongPress(boolean allowLongPress) {
mAllowLongPress = allowLongPress;
}
public static class SavedState extends BaseSavedState {
int currentPage = -1;
SavedState(Parcelable superState) {
super(superState);
}
private SavedState(Parcel in) {
super(in);
currentPage = in.readInt();
}
@Override
public void writeToParcel(Parcel out, int flags) {
super.writeToParcel(out, flags);
out.writeInt(currentPage);
}
public static final Parcelable.Creator<SavedState> CREATOR =
new Parcelable.Creator<SavedState>() {
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
public void loadAssociatedPages(int page) {
if (mContentIsRefreshable) {
final int count = getChildCount();
if (page < count) {
int lowerPageBound = getAssociatedLowerPageBound(page);
int upperPageBound = getAssociatedUpperPageBound(page);
for (int i = 0; i < count; ++i) {
final ViewGroup layout = (ViewGroup) getChildAt(i);
final int childCount = layout.getChildCount();
if (lowerPageBound <= i && i <= upperPageBound) {
if (mDirtyPageContent.get(i)) {
syncPageItems(i);
mDirtyPageContent.set(i, false);
}
} else {
if (childCount > 0) {
layout.removeAllViews();
}
mDirtyPageContent.set(i, true);
}
}
}
}
}
protected int getAssociatedLowerPageBound(int page) {
return Math.max(0, page - 1);
}
protected int getAssociatedUpperPageBound(int page) {
final int count = getChildCount();
return Math.min(page + 1, count - 1);
}
protected void startChoiceMode(int mode, ActionMode.Callback callback) {
if (isChoiceMode(CHOICE_MODE_NONE)) {
mChoiceMode = mode;
mActionMode = startActionMode(callback);
}
}
public void endChoiceMode() {
if (!isChoiceMode(CHOICE_MODE_NONE)) {
mChoiceMode = CHOICE_MODE_NONE;
resetCheckedGrandchildren();
if (mActionMode != null) mActionMode.finish();
mActionMode = null;
}
}
protected boolean isChoiceMode(int mode) {
return mChoiceMode == mode;
}
protected ArrayList<Checkable> getCheckedGrandchildren() {
ArrayList<Checkable> checked = new ArrayList<Checkable>();
final int childCount = getChildCount();
for (int i = 0; i < childCount; ++i) {
final ViewGroup layout = (ViewGroup) getChildAt(i);
final int grandChildCount = layout.getChildCount();
for (int j = 0; j < grandChildCount; ++j) {
final View v = layout.getChildAt(j);
if (v instanceof Checkable && ((Checkable) v).isChecked()) {
checked.add((Checkable) v);
}
}
}
return checked;
}
/**
* If in CHOICE_MODE_SINGLE and an item is checked, returns that item.
* Otherwise, returns null.
*/
protected Checkable getSingleCheckedGrandchild() {
if (mChoiceMode == CHOICE_MODE_SINGLE) {
final int childCount = getChildCount();
for (int i = 0; i < childCount; ++i) {
final ViewGroup layout = (ViewGroup) getChildAt(i);
final int grandChildCount = layout.getChildCount();
for (int j = 0; j < grandChildCount; ++j) {
final View v = layout.getChildAt(j);
if (v instanceof Checkable && ((Checkable) v).isChecked()) {
return (Checkable) v;
}
}
}
}
return null;
}
public Object getChosenItem() {
View checkedView = (View) getSingleCheckedGrandchild();
if (checkedView != null) {
return checkedView.getTag();
}
return null;
}
protected void resetCheckedGrandchildren() {
// loop through children, and set all of their children to _not_ be checked
final ArrayList<Checkable> checked = getCheckedGrandchildren();
for (int i = 0; i < checked.size(); ++i) {
final Checkable c = checked.get(i);
c.setChecked(false);
}
}
/**
* This method is called ONLY to synchronize the number of pages that the paged view has.
* To actually fill the pages with information, implement syncPageItems() below. It is
* guaranteed that syncPageItems() will be called for a particular page before it is shown,
* and therefore, individual page items do not need to be updated in this method.
*/
public abstract void syncPages();
/**
* This method is called to synchronize the items that are on a particular page. If views on
* the page can be reused, then they should be updated within this method.
*/
public abstract void syncPageItems(int page);
public void invalidatePageData() {
if (mContentIsRefreshable) {
// Update all the pages
syncPages();
// Mark each of the pages as dirty
final int count = getChildCount();
mDirtyPageContent.clear();
for (int i = 0; i < count; ++i) {
mDirtyPageContent.add(true);
}
// Load any pages that are necessary for the current window of views
loadAssociatedPages(mCurrentPage);
mDirtyPageAlpha = true;
updateAdjacentPagesAlpha();
requestLayout();
}
}
}