/* * Copyright (c) 2016, lyao. [email protected] * * Part of the code from the open source community, * thanks stackOverflow & gitHub . * 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.hadlink.library.widget.pla; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Canvas; import android.graphics.Paint; import android.graphics.PixelFormat; import android.graphics.Rect; import android.graphics.drawable.ColorDrawable; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.util.SparseBooleanArray; import android.view.MotionEvent; import android.view.View; import android.view.ViewDebug; import android.view.ViewGroup; import android.view.accessibility.AccessibilityEvent; import android.widget.ListAdapter; import com.hadlink.library.R; import java.util.ArrayList; /* * Implementation Notes: * * Some terminology: * * index - index of the items that are currently visible * position - index of the items in the cursor */ /** * A view that shows items in a vertically scrolling list. The items * come from the {@link ListAdapter} associated with this view. * * <p>See the <a href="{@docRoot}resources/tutorials/views/hello-listview.html">List View * tutorial</a>.</p> * * @attr ref android.R.styleable#ListView_entries * @attr ref android.R.styleable#ListView_divider * @attr ref android.R.styleable#ListView_dividerHeight * @attr ref android.R.styleable#ListView_choiceMode * @attr ref android.R.styleable#ListView_headerDividersEnabled * @attr ref android.R.styleable#ListView_footerDividersEnabled */ public class PLAListView extends PLAAbsListView { //TODO Not Supproted Features //Entry from XML. //Choice Mode & Item Selection. //Filter //Handle Key Event & Arrow Scrolling.. //Can't find Footer & Header findBy methods... /** * Used to indicate a no preference for a position type. */ static final int NO_POSITION = -1; /** * When arrow scrolling, ListView will never scroll more than this factor * times the height of the list. */ private static final float MAX_SCROLL_FACTOR = 0.33f; /** * A class that represents a fixed view in a list, for example a header at the top * or a footer at the bottom. */ public class FixedViewInfo { /** The view to add to the list */ public View view; /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */ public Object data; /** <code>true</code> if the fixed view should be selectable in the list */ public boolean isSelectable; } private ArrayList<FixedViewInfo> mHeaderViewInfos = new ArrayList<FixedViewInfo>(); private ArrayList<FixedViewInfo> mFooterViewInfos = new ArrayList<FixedViewInfo>(); Drawable mDivider; int mDividerHeight; Drawable mOverScrollHeader; Drawable mOverScrollFooter; private boolean mIsCacheColorOpaque; private boolean mDividerIsOpaque; private boolean mClipDivider; private boolean mHeaderDividersEnabled; private boolean mFooterDividersEnabled; private boolean mAreAllItemsSelectable = true; private boolean mItemsCanFocus = false; // used for temporary calculations. private final Rect mTempRect = new Rect(); private Paint mDividerPaint; private Paint mContentPaint = new Paint(); public PLAListView(Context context) { this(context, null); } public PLAListView(Context context, AttributeSet attrs) { this(context, attrs, R.attr.listViewStyle); } public PLAListView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.ListView, defStyle, 0); // final Drawable d = a.getDrawable(android.R.drawable.divider_horizontal_bright); // if (d != null) { // // If a divider is specified use its intrinsic height for divider height // setDivider(d); // } final Drawable osHeader = a.getDrawable( R.styleable.ListView_overScrollHeader); if (osHeader != null) { setOverscrollHeader(osHeader); } final Drawable osFooter = a.getDrawable( R.styleable.ListView_overScrollFooter); if (osFooter != null) { setOverscrollFooter(osFooter); } // Use the height specified, zero being the default final int dividerHeight = a.getDimensionPixelSize( R.styleable.ListView_dividerHeight, 0); if (dividerHeight != 0) { setDividerHeight(dividerHeight); } mHeaderDividersEnabled = a.getBoolean(R.styleable.ListView_headerDividersEnabled, true); mFooterDividersEnabled = a.getBoolean(R.styleable.ListView_footerDividersEnabled, true); if (a.hasValue(R.styleable.ListView_plaContentBackground)) { int contentBackgroundColor = a.getColor(R.styleable.ListView_plaContentBackground, 0); mContentPaint = new Paint(); mContentPaint.setColor(contentBackgroundColor); } a.recycle(); } /** * @return The maximum amount a list view will scroll in response to * an arrow event. */ public int getMaxScrollAmount() { // return (int) (MAX_SCROLL_FACTOR * (mBottom - mTop)); return (int) (MAX_SCROLL_FACTOR * (getBottom() - getTop())); } /** * Make sure views are touching the top or bottom edge, as appropriate for * our gravity */ private void adjustViewsUpOrDown() { final int childCount = getChildCount(); int delta; if (childCount > 0) { //View child; if (!mStackFromBottom) { // Uh-oh -- we came up short. Slide all views up to make them // align with the top final int firstTop = getScrollChildTop(); //child = getChildAt(0); //delta = child.getTop() - mListPadding.top; delta = firstTop - mListPadding.top; if (mFirstPosition != 0) { // It's OK to have some space above the first item if it is // part of the vertical spacing delta -= mDividerHeight; } if (delta < 0) { // We only are looking to see if we are too low, not too high delta = 0; } } else { // we are too high, slide all views down to align with bottom //child = getChildAt(childCount - 1); //delta = child.getBottom() - (getHeight() - mListPadding.bottom); final int lastBottom = getScrollChildBottom(); delta = lastBottom - (getHeight() - mListPadding.bottom); if (mFirstPosition + childCount < mItemCount) { // It's OK to have some space below the last item if it is // part of the vertical spacing delta += mDividerHeight; } if (delta > 0) { delta = 0; } } if (delta != 0) { //offsetChildrenTopAndBottom(-delta); tryOffsetChildrenTopAndBottom(-delta); } } } /** * Add a fixed view to appear at the top of the list. If addHeaderView is * called more than once, the views will appear in the order they were * added. Views added using this call can take focus if they want. * <p> * NOTE: Call this before calling setAdapter. This is so ListView can wrap * the supplied cursor with one that will also account for header and footer * views. * * @param v The view to add. * @param data Data to associate with this view * @param isSelectable whether the item is selectable */ public void addHeaderView(View v, Object data, boolean isSelectable) { if (mAdapter != null) { throw new IllegalStateException( "Cannot add header view to list -- setAdapter has already been called."); } FixedViewInfo info = new FixedViewInfo(); info.view = v; info.data = data; info.isSelectable = isSelectable; mHeaderViewInfos.add(info); } /** * Add a fixed view to appear at the top of the list. If addHeaderView is * called more than once, the views will appear in the order they were * added. Views added using this call can take focus if they want. * <p> * NOTE: Call this before calling setAdapter. This is so ListView can wrap * the supplied cursor with one that will also account for header and footer * views. * * @param v The view to add. */ public void addHeaderView(View v) { addHeaderView(v, null, true); } @Override public int getHeaderViewsCount() { return mHeaderViewInfos.size(); } /** * check this view is fixed view(ex>Header & Footer) or not. * @param v * @return true if this is fixed view. */ public boolean isFixedView( View v ) { { //check header view. ArrayList<FixedViewInfo> where = mHeaderViewInfos; int len = where.size(); for (int i = 0; i < len; ++i) { FixedViewInfo info = where.get(i); if (info.view == v) { return true; } } } { //check footer view. ArrayList<FixedViewInfo> where = mFooterViewInfos; int len = where.size(); for (int i = 0; i < len; ++i) { FixedViewInfo info = where.get(i); if (info.view == v) { return true; } } } return false; } /** * Removes a previously-added header view. * * @param v The view to remove * @return true if the view was removed, false if the view was not a header * view */ public boolean removeHeaderView(View v) { if (mHeaderViewInfos.size() > 0) { boolean result = false; if (mAdapter != null && ((PLAHeaderViewListAdapter) mAdapter).removeHeader(v)) { mDataSetObserver.onChanged(); result = true; } removeFixedViewInfo(v, mHeaderViewInfos); return result; } return false; } private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) { int len = where.size(); for (int i = 0; i < len; ++i) { FixedViewInfo info = where.get(i); if (info.view == v) { where.remove(i); break; } } } /** * Add a fixed view to appear at the bottom of the list. If addFooterView is * called more than once, the views will appear in the order they were * added. Views added using this call can take focus if they want. * <p> * NOTE: Call this before calling setAdapter. This is so ListView can wrap * the supplied cursor with one that will also account for header and footer * views. * * @param v The view to add. * @param data Data to associate with this view * @param isSelectable true if the footer view can be selected */ public void addFooterView(View v, Object data, boolean isSelectable) { FixedViewInfo info = new FixedViewInfo(); info.view = v; info.data = data; info.isSelectable = isSelectable; mFooterViewInfos.add(info); // in the case of re-adding a footer view, or adding one later on, // we need to notify the observer if (mDataSetObserver != null) { mDataSetObserver.onChanged(); } } /** * Add a fixed view to appear at the bottom of the list. If addFooterView is called more * than once, the views will appear in the order they were added. Views added using * this call can take focus if they want. * <p>NOTE: Call this before calling setAdapter. This is so ListView can wrap the supplied * cursor with one that will also account for header and footer views. * * * @param v The view to add. */ public void addFooterView(View v) { addFooterView(v, null, true); } @Override public int getFooterViewsCount() { return mFooterViewInfos.size(); } /** * Removes a previously-added footer view. * * @param v The view to remove * @return * true if the view was removed, false if the view was not a footer view */ public boolean removeFooterView(View v) { if (mFooterViewInfos.size() > 0) { boolean result = false; if (mAdapter != null && ((PLAHeaderViewListAdapter) mAdapter).removeFooter(v)) { mDataSetObserver.onChanged(); result = true; } removeFixedViewInfo(v, mFooterViewInfos); return result; } return false; } /** * Returns the adapter currently in use in this ListView. The returned adapter * might not be the same adapter passed to {@link #setAdapter(ListAdapter)} but * might be a {@link android.widget.WrapperListAdapter}. * * @return The adapter currently used to display data in this ListView. * * @see #setAdapter(ListAdapter) */ @Override public ListAdapter getAdapter() { return mAdapter; } /** * Sets the data behind this ListView. * * The adapter passed to this method may be wrapped by a {@link android.widget.WrapperListAdapter}, * depending on the ListView features currently in use. For instance, adding * headers and/or footers will cause the adapter to be wrapped. * * @param adapter The ListAdapter which is responsible for maintaining the * data backing this list and for producing a view to represent an * item in that data set. * * @see #getAdapter() */ @Override public void setAdapter(ListAdapter adapter) { if (null != mAdapter) { mAdapter.unregisterDataSetObserver(mDataSetObserver); } resetList(); mRecycler.clear(); if (mHeaderViewInfos.size() > 0|| mFooterViewInfos.size() > 0) { mAdapter = new PLAHeaderViewListAdapter(mHeaderViewInfos, mFooterViewInfos, adapter); } else { mAdapter = adapter; } mOldSelectedPosition = INVALID_POSITION; mOldSelectedRowId = INVALID_ROW_ID; if (mAdapter != null) { mAreAllItemsSelectable = mAdapter.areAllItemsEnabled(); mOldItemCount = mItemCount; mItemCount = mAdapter.getCount(); mDataSetObserver = new AdapterDataSetObserver(); mAdapter.registerDataSetObserver(mDataSetObserver); mRecycler.setViewTypeCount(mAdapter.getViewTypeCount()); } else { mAreAllItemsSelectable = true; // Nothing selected } requestLayout(); } @Override public int getFirstVisiblePosition() { return Math.max( 0, mFirstPosition - getHeaderViewsCount()); } @Override public int getLastVisiblePosition() { return Math.min( mFirstPosition + getChildCount() - 1, mAdapter.getCount() - 1); } /** * The list is empty. Clear everything out. */ @Override void resetList() { // The parent's resetList() will remove all views from the layout so we need to // cleanup the state of our footers and headers clearRecycledState(mHeaderViewInfos); clearRecycledState(mFooterViewInfos); super.resetList(); mLayoutMode = LAYOUT_NORMAL; } private void clearRecycledState(ArrayList<FixedViewInfo> infos) { if (infos != null) { final int count = infos.size(); for (int i = 0; i < count; i++) { final View child = infos.get(i).view; final LayoutParams p = (LayoutParams) child.getLayoutParams(); if (p != null) { p.recycledHeaderFooter = false; } } } } /** * @return Whether the list needs to show the top fading edge */ private boolean showingTopFadingEdge() { // final int listTop = mScrollY + mListPadding.top; final int listTop = getScrollY() + mListPadding.top; return (mFirstPosition > 0) || (getChildAt(0).getTop() > listTop); } /** * @return Whether the list needs to show the bottom fading edge */ private boolean showingBottomFadingEdge() { final int childCount = getChildCount(); final int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); final int lastVisiblePosition = mFirstPosition + childCount - 1; // final int listBottom = mScrollY + getHeight() - mListPadding.bottom; final int listBottom = getScrollY() + getHeight() - mListPadding.bottom; return (lastVisiblePosition < mItemCount - 1) || (bottomOfBottomChild < listBottom); } @Override public boolean requestChildRectangleOnScreen(View child, Rect rect, boolean immediate) { int rectTopWithinChild = rect.top; // offset so rect is in coordinates of the this view rect.offset(child.getLeft(), child.getTop()); rect.offset(-child.getScrollX(), -child.getScrollY()); final int height = getHeight(); int listUnfadedTop = getScrollY(); int listUnfadedBottom = listUnfadedTop + height; final int fadingEdge = getVerticalFadingEdgeLength(); if (showingTopFadingEdge()) { // leave room for top fading edge as long as rect isn't at very top if (rectTopWithinChild > fadingEdge) { listUnfadedTop += fadingEdge; } } int childCount = getChildCount(); int bottomOfBottomChild = getChildAt(childCount - 1).getBottom(); if (showingBottomFadingEdge()) { // leave room for bottom fading edge as long as rect isn't at very bottom if (rect.bottom < (bottomOfBottomChild - fadingEdge)) { listUnfadedBottom -= fadingEdge; } } int scrollYDelta = 0; if (rect.bottom > listUnfadedBottom && rect.top > listUnfadedTop) { // need to MOVE DOWN to get it in view: move down just enough so // that the entire rectangle is in view (or at least the first // screen size chunk). if (rect.height() > height) { // just enough to get screen size chunk on scrollYDelta += (rect.top - listUnfadedTop); } else { // get entire rect at bottom of screen scrollYDelta += (rect.bottom - listUnfadedBottom); } // make sure we aren't scrolling beyond the end of our children int distanceToBottom = bottomOfBottomChild - listUnfadedBottom; scrollYDelta = Math.min(scrollYDelta, distanceToBottom); } else if (rect.top < listUnfadedTop && rect.bottom < listUnfadedBottom) { // need to MOVE UP to get it in view: move up just enough so that // entire rectangle is in view (or at least the first screen // size chunk of it). if (rect.height() > height) { // screen size chunk scrollYDelta -= (listUnfadedBottom - rect.bottom); } else { // entire rect at top scrollYDelta -= (listUnfadedTop - rect.top); } // make sure we aren't scrolling any further than the top our children int top = getChildAt(0).getTop(); int deltaToTop = top - listUnfadedTop; scrollYDelta = Math.max(scrollYDelta, deltaToTop); } final boolean scroll = scrollYDelta != 0; if (scroll) { scrollListItemsBy(-scrollYDelta); positionSelector(child); mSelectedTop = child.getTop(); invalidate(); } return scroll; } /** * override this method to manipulate the position of each item in list view. * return item left position. * @param pos * @return pos's item left position. */ protected int getItemLeft(int pos) { return mListPadding.left; } /** * override this method to manipulate the position of each item in list view. * return item's top position. (item will be added in down direction) * @param pos * @return value of pos's item top. */ protected int getItemTop(int pos) { //just return the last itme's bottom position.. int count = getChildCount(); return count > 0 ? getChildAt(count - 1).getBottom() + mDividerHeight : getListPaddingTop(); } /** * override this method to manipulate the position of each item in list view. * return item's bottom position. (item will be added in up direction) * @param pos * @return value of pos's item bottom. */ protected int getItemBottom(int pos) { int count = getChildCount(); return count > 0 ? getChildAt(0).getTop() - mDividerHeight : getHeight() - getListPaddingBottom(); } /** * {@inheritDoc} */ @Override protected void fillGap(boolean down) { final int count = getChildCount(); if (down) { fillDown(mFirstPosition + count, getFillChildBottom() + mDividerHeight); } else { fillUp(mFirstPosition - 1, getFillChildTop()); } onAdjustChildViews(down); } /** * Fills the list from pos down to the end of the list view. * * @param pos The first position to put in the list * * @param nextTop The location where the top of the item associated with pos * should be drawn * * @return The view that is currently selected, if it happens to be in the * range that we draw. */ private View fillDown(int pos, int nextTop) { int end = getBottom() - getTop() - mListPadding.bottom; while (nextTop < end && pos < mItemCount) { // is this the selected item? makeAndAddView(pos, getItemTop(pos), true, false); pos++; nextTop = getFillChildBottom() + mDividerHeight; } return null; } /** * Fills the list from pos up to the top of the list view. * * @param pos The first position to put in the list * * @param nextBottom The location where the bottom of the item associated * with pos should be drawn * * @return The view that is currently selected */ private View fillUp(int pos, int nextBottom) { int end = mListPadding.top; while (nextBottom > end && pos >= 0) { // is this the selected item? makeAndAddView(pos, getItemBottom(pos), false, false); // nextBottom = child.getTop() - mDividerHeight; pos--; nextBottom = getItemBottom(pos); } mFirstPosition = pos + 1; return null; } /** * Fills the list from top to bottom, starting with mFirstPosition * * @param nextTop The location where the top of the first item should be * drawn * * @return The view that is currently selected */ private View fillFromTop(int nextTop) { mFirstPosition = Math.min(mFirstPosition, -1); mFirstPosition = Math.min(mFirstPosition, mItemCount - 1); if (mFirstPosition < 0) { mFirstPosition = 0; } return fillDown(mFirstPosition, nextTop); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { // Sets up mListPadding super.onMeasure(widthMeasureSpec, heightMeasureSpec); int widthMode = View.MeasureSpec.getMode(widthMeasureSpec); int heightMode = View.MeasureSpec.getMode(heightMeasureSpec); int widthSize = View.MeasureSpec.getSize(widthMeasureSpec); int heightSize = View.MeasureSpec.getSize(heightMeasureSpec); int childWidth = 0; int childHeight = 0; mItemCount = mAdapter == null ? 0 : mAdapter.getCount(); if (mItemCount > 0 && (widthMode == View.MeasureSpec.UNSPECIFIED || heightMode == View.MeasureSpec.UNSPECIFIED)) { final View child = obtainView(0, mIsScrap); measureScrapChild(child, 0, widthMeasureSpec); childWidth = child.getMeasuredWidth(); childHeight = child.getMeasuredHeight(); if (recycleOnMeasure() && mRecycler.shouldRecycleViewType( ((LayoutParams) child.getLayoutParams()).viewType)) { mRecycler.addScrapView(child); } } if (widthMode == View.MeasureSpec.UNSPECIFIED) { widthSize = mListPadding.left + mListPadding.right + childWidth + getVerticalScrollbarWidth(); } if (heightMode == View.MeasureSpec.UNSPECIFIED) { heightSize = mListPadding.top + mListPadding.bottom + childHeight + getVerticalFadingEdgeLength() * 2; } if (heightMode == View.MeasureSpec.AT_MOST) { // TODO: after first layout we should maybe start at the first visible position, not 0 heightSize = measureHeightOfChildren(widthMeasureSpec, 0, NO_POSITION, heightSize, -1); } setMeasuredDimension(widthSize, heightSize); mWidthMeasureSpec = widthMeasureSpec; } private void measureScrapChild(View child, int position, int widthMeasureSpec) { LayoutParams p = (LayoutParams) child.getLayoutParams(); if (p == null) { p = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT, 0); child.setLayoutParams(p); } p.viewType = mAdapter.getItemViewType(position); p.forceAdd = true; int childWidthSpec = ViewGroup.getChildMeasureSpec(widthMeasureSpec, mListPadding.left + mListPadding.right, p.width); int lpHeight = p.height; int childHeightSpec; if (lpHeight > 0) { childHeightSpec = View.MeasureSpec.makeMeasureSpec(lpHeight, View.MeasureSpec.EXACTLY); } else { childHeightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED); } child.measure(childWidthSpec, childHeightSpec); } /** * @return True to recycle the views used to measure this ListView in * UNSPECIFIED/AT_MOST modes, false otherwise. * @hide */ @ViewDebug.ExportedProperty(category = "list") protected boolean recycleOnMeasure() { return true; } /** * Measures the height of the given range of children (inclusive) and * returns the height with this ListView's padding and divider heights * included. If maxHeight is provided, the measuring will stop when the * current height reaches maxHeight. * * @param widthMeasureSpec The width measure spec to be given to a child's * {@link View#measure(int, int)}. * @param startPosition The position of the first child to be shown. * @param endPosition The (inclusive) position of the last child to be * shown. Specify {@link #NO_POSITION} if the last child should be * the last available child from the adapter. * @param maxHeight The maximum height that will be returned (if all the * children don't fit in this value, this value will be * returned). * @param disallowPartialChildPosition In general, whether the returned * height should only contain entire children. This is more * powerful--it is the first inclusive position at which partial * children will not be allowed. Example: it looks nice to have * at least 3 completely visible children, and in portrait this * will most likely fit; but in landscape there could be times * when even 2 children can not be completely shown, so a value * of 2 (remember, inclusive) would be good (assuming * startPosition is 0). * @return The height of this ListView with the given children. */ final int measureHeightOfChildren(int widthMeasureSpec, int startPosition, int endPosition, final int maxHeight, int disallowPartialChildPosition) { final ListAdapter adapter = mAdapter; if (adapter == null) { return mListPadding.top + mListPadding.bottom; } // Include the padding of the list int returnedHeight = mListPadding.top + mListPadding.bottom; final int dividerHeight = ((mDividerHeight > 0) && mDivider != null) ? mDividerHeight : 0; // The previous height value that was less than maxHeight and contained // no partial children int prevHeightWithoutPartialChild = 0; int i; View child; // mItemCount - 1 since endPosition parameter is inclusive endPosition = (endPosition == NO_POSITION) ? adapter.getCount() - 1 : endPosition; final PLAAbsListView.RecycleBin recycleBin = mRecycler; final boolean recyle = recycleOnMeasure(); final boolean[] isScrap = mIsScrap; for (i = startPosition; i <= endPosition; ++i) { child = obtainView(i, isScrap); measureScrapChild(child, i, widthMeasureSpec); if (i > 0) { // Count the divider for all but one child returnedHeight += dividerHeight; } // Recycle the view before we possibly return from the method if (recyle && recycleBin.shouldRecycleViewType( ((LayoutParams) child.getLayoutParams()).viewType)) { recycleBin.addScrapView(child); } returnedHeight += child.getMeasuredHeight(); if (returnedHeight >= maxHeight) { // We went over, figure out which height to return. If returnedHeight > maxHeight, // then the i'th position did not fit completely. return (disallowPartialChildPosition >= 0) // Disallowing is enabled (> -1) && (i > disallowPartialChildPosition) // We've past the min pos && (prevHeightWithoutPartialChild > 0) // We have a prev height && (returnedHeight != maxHeight) // i'th child did not fit completely ? prevHeightWithoutPartialChild : maxHeight; } if ((disallowPartialChildPosition >= 0) && (i >= disallowPartialChildPosition)) { prevHeightWithoutPartialChild = returnedHeight; } } // At this point, we went through the range of children, and they each // completely fit, so return the returnedHeight return returnedHeight; } @Override int findMotionRow(int y) { int childCount = getChildCount(); if (childCount > 0) { if (!mStackFromBottom) { for (int i = 0; i < childCount; i++) { View v = getChildAt(i); if (y <= v.getBottom()) { return mFirstPosition + i; } } } else { for (int i = childCount - 1; i >= 0; i--) { View v = getChildAt(i); if (y >= v.getTop()) { return mFirstPosition + i; } } } } return INVALID_POSITION; } /** * Put a specific item at a specific location on the screen and then build * up and down from there. * * @param position The reference view to use as the starting point * @param top Pixel offset from the top of this view to the top of the * reference view. * * @return The selected view, or null if the selected view is outside the * visible area. */ private View fillSpecific(int position, int top) { View temp = makeAndAddView(position, top, true, false); // Possibly changed again in fillUp if we add rows above this one. mFirstPosition = position; final int dividerHeight = mDividerHeight; if (!mStackFromBottom) { fillUp(position - 1, getFillChildTop()); // This will correct for the top of the first view not touching the top of the list adjustViewsUpOrDown(); fillDown(position + 1, getFillChildBottom() + mDividerHeight); int childCount = getChildCount(); if (childCount > 0) { correctTooHigh(childCount); } } else { fillDown(position + 1, temp.getBottom() + dividerHeight); // This will correct for the bottom of the last view not touching the bottom of the list adjustViewsUpOrDown(); fillUp(position - 1, getFillChildTop()); int childCount = getChildCount(); if (childCount > 0) { correctTooLow(childCount); } } return null; } /** * Check if we have dragged the bottom of the list too high (we have pushed the * top element off the top of the screen when we did not need to). Correct by sliding * everything back down. * * @param childCount Number of children */ private void correctTooHigh(int childCount) { // First see if the last item is visible. If it is not, it is OK for the // top of the list to be pushed up. int lastPosition = mFirstPosition + childCount - 1; if (lastPosition == mItemCount - 1 && childCount > 0) { // Get the last child ... //final View lastChild = getChildAt(childCount - 1); // ... and its bottom edge //final int lastBottom = lastChild.getBottom(); final int lastBottom = getScrollChildBottom(); // This is bottom of our drawable area // final int end = (mBottom - mTop) - mListPadding.bottom; final int end = (getBottom() - getTop()) - mListPadding.bottom; // This is how far the bottom edge of the last view is from the bottom of the drawable area int bottomOffset = end - lastBottom; //View firstChild = getChildAt(0); //final int firstTop = firstChild.getTop(); final int firstTop = getScrollChildTop(); // Make sure we are 1) Too high, and 2) Either there are more rows above the // first row or the first row is scrolled off the top of the drawable area if (bottomOffset > 0 && (mFirstPosition > 0 || firstTop < mListPadding.top)) { if (mFirstPosition == 0) { // Don't pull the top too far down bottomOffset = Math.min(bottomOffset, mListPadding.top - firstTop); } // Move everything down // offsetChildrenTopAndBottom(bottomOffset); tryOffsetChildrenTopAndBottom(bottomOffset); if (mFirstPosition > 0) { // Fill the gap that was opened above mFirstPosition with more rows, if // possible int newFirstTop = getScrollChildTop(); fillUp(mFirstPosition - 1, getFillChildTop()); // Close up the remaining gap adjustViewsUpOrDown(); } } } } /** * Check if we have dragged the bottom of the list too low (we have pushed the * bottom element off the bottom of the screen when we did not need to). Correct by sliding * everything back up. * * @param childCount Number of children */ private void correctTooLow(int childCount) { // First see if the first item is visible. If it is not, it is OK for the // bottom of the list to be pushed down. if (mFirstPosition == 0 && childCount > 0) { // Get the first child and its top edge final int firstTop = getScrollChildTop(); // This is top of our drawable area final int start = mListPadding.top; // This is bottom of our drawable area final int end = (getBottom() - getTop()) - mListPadding.bottom; // This is how far the top edge of the first view is from the top of the drawable area int topOffset = firstTop - start; final int lastBottom = getScrollChildBottom(); int lastPosition = mFirstPosition + childCount - 1; // Make sure we are 1) Too low, and 2) Either there are more rows below the // last row or the last row is scrolled off the bottom of the drawable area if (topOffset > 0) { if (lastPosition < mItemCount - 1 || lastBottom > end) { if (lastPosition == mItemCount - 1) { // Don't pull the bottom too far up topOffset = Math.min(topOffset, lastBottom - end); } // Move everything up tryOffsetChildrenTopAndBottom(-topOffset); if (lastPosition < mItemCount - 1) { // Fill the gap that was opened below the last position with more rows, if // possible fillDown(lastPosition + 1, getFillChildBottom() + mDividerHeight); // Close up the remaining gap adjustViewsUpOrDown(); } } else if (lastPosition == mItemCount - 1) { adjustViewsUpOrDown(); } } } } @SuppressWarnings("deprecation") @Override protected void layoutChildren() { final boolean blockLayoutRequests = mBlockLayoutRequests; if (!blockLayoutRequests) { mBlockLayoutRequests = true; } else { return; } try { invalidate(); if (mAdapter == null) { resetList(); invokeOnItemScrollListener(); return; } int childrenTop = getFillChildBottom() + mDividerHeight; int childrenBottom = getFillChildTop(); int childCount = getChildCount(); int index = 0; View oldFirst = null; // Remember stuff we will need down below switch (mLayoutMode) { case LAYOUT_FORCE_TOP: case LAYOUT_FORCE_BOTTOM: case LAYOUT_SPECIFIC: case LAYOUT_SYNC: break; default: // Remember the previous first child oldFirst = getChildAt(0); } boolean dataChanged = mDataChanged; if (dataChanged) { handleDataChanged(); } // Handle the empty set by removing all views that are visible // and calling it a day if (mItemCount == 0) { resetList(); invokeOnItemScrollListener(); return; } else if (mItemCount != mAdapter.getCount()) { throw new IllegalStateException("The content of the adapter has changed but " + "ListView did not receive a notification. Make sure the content of " + "your adapter is not modified from a background thread, but only " + "from the UI thread. [in ListView(" + getId() + ", " + getClass() + ") with Adapter(" + mAdapter.getClass() + ")]"); } // Pull all children into the RecycleBin. // These views will be reused if possible final int firstPosition = mFirstPosition; final RecycleBin recycleBin = mRecycler; // reset the focus restoration // Don't put header or footer views into the Recycler. Those are // already cached in mHeaderViews; if (dataChanged) { for (int i = childCount - 1; i >= 0; i--) { recycleBin.addScrapView(getChildAt(i)); if (ViewDebug.TRACE_RECYCLER) { ViewDebug.trace(getChildAt(i), ViewDebug.RecyclerTraceType.MOVE_TO_SCRAP_HEAP, index, i); } } } else { recycleBin.fillActiveViews(childCount, firstPosition); } switch (mLayoutMode) { case LAYOUT_SYNC: onLayoutSync(mSyncPosition); // Clear out old views detachAllViewsFromParent(); if (mSpecificTops != null) { fillSynced(mSyncPosition, mSpecificTops); mSpecificTops = null; } else { fillSpecific(mSyncPosition, mSpecificTop); } onLayoutSyncFinished(mSyncPosition); break; case LAYOUT_FORCE_BOTTOM: detachAllViewsFromParent(); fillUp(mItemCount - 1, childrenBottom); adjustViewsUpOrDown(); break; case LAYOUT_FORCE_TOP: detachAllViewsFromParent(); mFirstPosition = 0; fillFromTop(childrenTop); adjustViewsUpOrDown(); break; case LAYOUT_SPECIFIC: detachAllViewsFromParent(); fillSpecific(reconcileSelectedPosition(), mSpecificTop); break; default: if (childCount == 0) { detachAllViewsFromParent(); if (!mStackFromBottom) { fillFromTop(childrenTop); } else { fillUp(mItemCount - 1, childrenBottom); } } else { if (mFirstPosition < mItemCount) { onLayoutSync(mFirstPosition); detachAllViewsFromParent(); fillSpecific(mFirstPosition, oldFirst == null ? childrenTop : oldFirst.getTop()); onLayoutSyncFinished(mFirstPosition); } else { onLayoutSync(0); detachAllViewsFromParent(); fillSpecific(0, childrenTop); onLayoutSyncFinished(0); } } break; } // Flush any cached views that did not get reused above recycleBin.scrapActiveViews(); if (mTouchMode > TOUCH_MODE_DOWN && mTouchMode < TOUCH_MODE_SCROLL) { View child = getChildAt(mMotionPosition - mFirstPosition); if (child != null) positionSelector(child); } else { mSelectedTop = 0; mSelectorRect.setEmpty(); } mLayoutMode = LAYOUT_NORMAL; mDataChanged = false; mNeedSync = false; if (mItemCount > 0) { checkSelectionChanged(); } invokeOnItemScrollListener(); } finally { if (!blockLayoutRequests) { mBlockLayoutRequests = false; } } } private void fillSynced(int position, int[] specificTops) { for (int i = 0; i < specificTops.length; i++) { makeAndAddView(position + i, specificTops[i], true, false); adjustViewsUpOrDown(); } mFirstPosition = position; } /** * Obtain the view and add it to our list of children. The view can be made * fresh, converted from an unused view, or used as is if it was in the * recycle bin. * * @param position Logical position in the list * @param childrenBottomOrTop Top or bottom edge of the view to add * @param flow If flow is true, align top edge to y. If false, align bottom * edge to y. * @param selected Is this position selected? * @return View that was added */ @SuppressWarnings("deprecation") private View makeAndAddView(int position, int childrenBottomOrTop, boolean flow, boolean selected) { View child; int childrenLeft; if (!mDataChanged) { // Try to use an exsiting view for this position child = mRecycler.getActiveView(position); if (child != null) { if (ViewDebug.TRACE_RECYCLER) { ViewDebug.trace(child, ViewDebug.RecyclerTraceType.RECYCLE_FROM_ACTIVE_HEAP, position, getChildCount()); } // Found it -- we're using an existing child // This just needs to be positioned childrenLeft = getItemLeft(position); setupChild(child, position, childrenBottomOrTop, flow, childrenLeft, selected, true); return child; } } //Notify new item is added to view. onItemAddedToList( position, flow ); childrenLeft = getItemLeft( position ); // Make a new view for this position, or convert an unused view if possible child = obtainView(position, mIsScrap); // This needs to be positioned and measured setupChild(child, position, childrenBottomOrTop, flow, childrenLeft, selected, mIsScrap[0]); return child; } /** * @param position position of newly adde ditem. * @param flow If flow is true, align top edge to y. If false, align bottom edge to y. */ protected void onItemAddedToList(int position, boolean flow) { } /** * Add a view as a child and make sure it is measured (if necessary) and * positioned properly. * * @param child The view to add * @param position The position of this child * @param y The y position relative to which this view will be positioned * @param flowDown If true, align top edge to y. If false, align bottom * edge to y. * @param childrenLeft Left edge where children should be positioned * @param selected Is this position selected? * @param recycled Has this view been pulled from the recycle bin? If so it * does not need to be remeasured. */ private void setupChild(View child, int position, int y, boolean flowDown, int childrenLeft, boolean selected, boolean recycled) { final boolean isSelected = selected && shouldShowSelector(); final boolean updateChildSelected = isSelected != child.isSelected(); final int mode = mTouchMode; final boolean isPressed = mode > TOUCH_MODE_DOWN && mode < TOUCH_MODE_SCROLL && mMotionPosition == position; final boolean updateChildPressed = isPressed != child.isPressed(); final boolean needToMeasure = !recycled || updateChildSelected || child.isLayoutRequested(); // Respect layout params that are already in the view. Otherwise make some up... // noinspection unchecked LayoutParams p = (LayoutParams) child.getLayoutParams(); if (p == null) { p = new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT, 0); } p.viewType = mAdapter.getItemViewType(position); p.scrappedFromPosition = position; if ((recycled && !p.forceAdd) || (p.recycledHeaderFooter && p.viewType == PLAAdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER)) { attachViewToParent(child, flowDown ? -1 : 0, p); } else { p.forceAdd = false; if (p.viewType == PLAAdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER) { p.recycledHeaderFooter = true; } addViewInLayout(child, flowDown ? -1 : 0, p, true); } if (updateChildSelected) { child.setSelected(isSelected); } if (updateChildPressed) { child.setPressed(isPressed); } if (needToMeasure) { int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, mListPadding.left + mListPadding.right, p.width); int lpHeight = p.height; int childHeightSpec; if (lpHeight > 0) { childHeightSpec = View.MeasureSpec.makeMeasureSpec(lpHeight, View.MeasureSpec.EXACTLY); } else { childHeightSpec = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED); } onMeasureChild( child, position, childWidthSpec, childHeightSpec ); //child.measure(childWidthSpec, childHeightSpec); } else { cleanupLayoutState(child); } final int w = child.getMeasuredWidth(); final int h = child.getMeasuredHeight(); final int childTop = flowDown ? y : y - h; if (needToMeasure) { final int childRight = childrenLeft + w; final int childBottom = childTop + h; //child.layout(childrenLeft, childTop, childRight, childBottom); onLayoutChild(child, position, childrenLeft, childTop, childRight, childBottom); } else { final int offsetLeft = childrenLeft - child.getLeft(); final int offsetTop = childTop - child.getTop(); onOffsetChild(child, position, offsetLeft, offsetTop); } if (mCachingStarted && !child.isDrawingCacheEnabled()) { child.setDrawingCacheEnabled(true); } } protected void onOffsetChild(View child, int position, int offsetLeft, int offsetTop) { child.offsetLeftAndRight(offsetLeft); child.offsetTopAndBottom(offsetTop); } protected void onLayoutChild(View child, int position, int l, int t, int r, int b) { child.layout(l, t, r, b); } /** * this method is called every time a new child is mesaure. * @param child * @param widthMeasureSpec * @param heightMeasureSpec */ protected void onMeasureChild(View child, int position, int widthMeasureSpec, int heightMeasureSpec) { child.measure(widthMeasureSpec, heightMeasureSpec); } /** * this method is called to adjust child view's up & down. * @param down */ protected void onAdjustChildViews( boolean down ) { if( down ) correctTooHigh(getChildCount()); else correctTooLow(getChildCount()); } @Override protected boolean canAnimate() { return super.canAnimate() && mItemCount > 0; } /** * Sets the currently selected item. If in touch mode, the item will not be selected * but it will still be positioned appropriately. If the specified selection position * is less than 0, then the item at position 0 will be selected. * * @param position Index (starting at 0) of the data item to be selected. */ @Override public void setSelection(int position) { } public void setSelectionFromTop(int position, int y) { mLayoutMode = LAYOUT_SPECIFIC; mSpecificTop = mListPadding.top + y; if (mNeedSync) { mSyncPosition = position; mSyncRowId = mAdapter.getItemId(position); } if (mPositionScroller != null) { mPositionScroller.stop(); } requestLayout(); } /** * Find a position that can be selected (i.e., is not a separator). * * @param position The starting position to look at. * @param lookDown Whether to look down for other positions. * @return The next selectable position starting at position and then searching either up or * down. Returns {@link #INVALID_POSITION} if nothing can be found. */ @Override int lookForSelectablePosition(int position, boolean lookDown) { final ListAdapter adapter = mAdapter; if (adapter == null || isInTouchMode()) { return INVALID_POSITION; } final int count = adapter.getCount(); if (!mAreAllItemsSelectable) { if (lookDown) { position = Math.max(0, position); while (position < count && !adapter.isEnabled(position)) { position++; } } else { position = Math.min(position, count - 1); while (position >= 0 && !adapter.isEnabled(position)) { position--; } } if (position < 0 || position >= count) { return INVALID_POSITION; } return position; } else { if (position < 0 || position >= count) { return INVALID_POSITION; } return position; } } @Override public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { boolean populated = super.dispatchPopulateAccessibilityEvent(event); // If the item count is less than 15 then subtract disabled items from the count and // position. Otherwise ignore disabled items. if (!populated) { int itemCount = 0; int currentItemIndex = getSelectedItemPosition(); ListAdapter adapter = getAdapter(); if (adapter != null) { final int count = adapter.getCount(); if (count < 15) { for (int i = 0; i < count; i++) { if (adapter.isEnabled(i)) { itemCount++; } else if (i <= currentItemIndex) { currentItemIndex--; } } } else { itemCount = count; } } event.setItemCount(itemCount); event.setCurrentItemIndex(currentItemIndex); } return populated; } /** * Go to the last or first item if possible (not worrying about panning across or navigating * within the internal focus of the currently selected item.) * * @param direction either {@link View#FOCUS_UP} or {@link View#FOCUS_DOWN} * * @return whether selection was moved */ public boolean fullScroll(int direction) { boolean moved = false; if (direction == FOCUS_UP) { int position = lookForSelectablePosition(0, true); if (position >= 0) { mLayoutMode = LAYOUT_FORCE_TOP; invokeOnItemScrollListener(); moved = true; } } else if (direction == FOCUS_DOWN) { int position = lookForSelectablePosition(mItemCount - 1, true); if (position >= 0) { mLayoutMode = LAYOUT_FORCE_BOTTOM; invokeOnItemScrollListener(); } moved = true; } if (moved && !awakenScrollBars()) { awakenScrollBars(); invalidate(); } return moved; } /** * Scroll the children by amount, adding a view at the end and removing * views that fall off as necessary. * * @param amount The amount (positive or negative) to scroll. */ private void scrollListItemsBy(int amount) { // offsetChildrenTopAndBottom(amount); tryOffsetChildrenTopAndBottom(amount); final int listBottom = getHeight() - mListPadding.bottom; final int listTop = mListPadding.top; final PLAAbsListView.RecycleBin recycleBin = mRecycler; if (amount < 0) { // shifted items up // may need to pan views into the bottom space View last = getLastChild(); int numChildren = getChildCount(); // View last = getChildAt(numChildren - 1); while (last.getBottom() < listBottom) { final int lastVisiblePosition = mFirstPosition + numChildren - 1; if (lastVisiblePosition < mItemCount - 1) { addViewBelow(last, lastVisiblePosition); last = getLastChild(); numChildren++; } else { break; } } // may have brought in the last child of the list that is skinnier // than the fading edge, thereby leaving space at the end. need // to shift back if (last.getBottom() < listBottom) { // offsetChildrenTopAndBottom(listBottom - last.getBottom()); tryOffsetChildrenTopAndBottom(listBottom - last.getBottom()); } // top views may be panned off screen View first = getChildAt(0); while (first.getBottom() < listTop) { LayoutParams layoutParams = (LayoutParams) first.getLayoutParams(); if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { detachViewFromParent(first); recycleBin.addScrapView(first); } else { removeViewInLayout(first); } first = getChildAt(0); mFirstPosition++; } } else { // shifted items down View first = getChildAt(0); // may need to pan views into top while ((first.getTop() > listTop) && (mFirstPosition > 0)) { first = addViewAbove(first, mFirstPosition); mFirstPosition--; } // may have brought the very first child of the list in too far and // need to shift it back if (first.getTop() > listTop) { // offsetChildrenTopAndBottom(listTop - first.getTop()); tryOffsetChildrenTopAndBottom(listTop - first.getTop()); } int lastIndex = getChildCount() - 1; View last = getChildAt(lastIndex); // bottom view may be panned off screen while (last.getTop() > listBottom) { LayoutParams layoutParams = (LayoutParams) last.getLayoutParams(); if (recycleBin.shouldRecycleViewType(layoutParams.viewType)) { detachViewFromParent(last); recycleBin.addScrapView(last); } else { removeViewInLayout(last); } last = getChildAt(--lastIndex); } } } protected View getLastChild() { int numChildren = getChildCount(); return getChildAt(numChildren - 1); } private View addViewAbove(View theView, int position) { int abovePosition = position - 1; View view = obtainView(abovePosition, mIsScrap); int edgeOfNewChild = theView.getTop() - mDividerHeight; setupChild(view, abovePosition, edgeOfNewChild, false, mListPadding.left, false, mIsScrap[0]); return view; } private View addViewBelow(View theView, int position) { int belowPosition = position + 1; View view = obtainView(belowPosition, mIsScrap); int edgeOfNewChild = theView.getBottom() + mDividerHeight; setupChild(view, belowPosition, edgeOfNewChild, true, mListPadding.left, false, mIsScrap[0]); return view; } /** * Indicates that the views created by the ListAdapter can contain focusable * items. * * @param itemsCanFocus true if items can get focus, false otherwise */ public void setItemsCanFocus(boolean itemsCanFocus) { mItemsCanFocus = itemsCanFocus; if (!itemsCanFocus) { setDescendantFocusability(ViewGroup.FOCUS_BLOCK_DESCENDANTS); } } /** * @return Whether the views created by the ListAdapter can contain focusable * items. */ public boolean getItemsCanFocus() { return mItemsCanFocus; } /** * @hide Pending API council approval. */ @Override public boolean isOpaque() { // return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque && // hasOpaqueScrollbars()) || super.isOpaque(); //we can ignore scrollbar... return (mCachingStarted && mIsCacheColorOpaque && mDividerIsOpaque) || super.isOpaque(); } @Override public void setCacheColorHint(int color) { final boolean opaque = (color >>> 24) == 0xFF; mIsCacheColorOpaque = opaque; if (opaque) { if (mDividerPaint == null) { mDividerPaint = new Paint(); } mDividerPaint.setColor(color); } super.setCacheColorHint(color); } void drawOverscrollHeader(Canvas canvas, Drawable drawable, Rect bounds) { final int height = drawable.getMinimumHeight(); canvas.save(); canvas.clipRect(bounds); final int span = bounds.bottom - bounds.top; if (span < height) { bounds.top = bounds.bottom - height; } drawable.setBounds(bounds); drawable.draw(canvas); canvas.restore(); } void drawOverscrollFooter(Canvas canvas, Drawable drawable, Rect bounds) { final int height = drawable.getMinimumHeight(); canvas.save(); canvas.clipRect(bounds); final int span = bounds.bottom - bounds.top; if (span < height) { bounds.bottom = bounds.top + height; } drawable.setBounds(bounds); drawable.draw(canvas); canvas.restore(); } @Override protected void dispatchDraw(Canvas canvas) { // Draw the dividers final int dividerHeight = mDividerHeight; final Drawable overscrollHeader = mOverScrollHeader; final Drawable overscrollFooter = mOverScrollFooter; final boolean drawOverscrollHeader = overscrollHeader != null; final boolean drawOverscrollFooter = overscrollFooter != null; final boolean drawDividers = dividerHeight > 0 && mDivider != null; drawContentBackground(canvas); if (drawDividers || drawOverscrollHeader || drawOverscrollFooter) { // Only modify the top and bottom in the loop, we set the left and right here final Rect bounds = mTempRect; // bounds.left = mPaddingLeft; // bounds.right = mRight - mLeft - mPaddingRight; bounds.left = getPaddingLeft(); bounds.right = getRight() - getLeft() - getPaddingRight(); final int count = getChildCount(); final int headerCount = mHeaderViewInfos.size(); final int itemCount = mItemCount; final int footerLimit = itemCount - mFooterViewInfos.size() - 1; final boolean headerDividers = mHeaderDividersEnabled; final boolean footerDividers = mFooterDividersEnabled; final int first = mFirstPosition; final boolean areAllItemsSelectable = mAreAllItemsSelectable; final ListAdapter adapter = mAdapter; // If the list is opaque *and* the background is not, we want to // fill a rect where the dividers would be for non-selectable items // If the list is opaque and the background is also opaque, we don't // need to draw anything since the background will do it for us final boolean fillForMissingDividers = drawDividers && isOpaque() && !super.isOpaque(); if (fillForMissingDividers && mDividerPaint == null && mIsCacheColorOpaque) { mDividerPaint = new Paint(); mDividerPaint.setColor(getCacheColorHint()); } final Paint paint = mDividerPaint; // final int listBottom = mBottom - mTop - mListPadding.bottom + mScrollY; final int listBottom = getBottom() - getTop() - mListPadding.bottom + getScrollY(); if (!mStackFromBottom) { int bottom = 0; // Draw top divider or header for overscroll // final int scrollY = mScrollY; final int scrollY = getScrollY(); if (count > 0 && scrollY < 0) { if (drawOverscrollHeader) { bounds.bottom = 0; bounds.top = scrollY; drawOverscrollHeader(canvas, overscrollHeader, bounds); } else if (drawDividers) { bounds.bottom = 0; bounds.top = -dividerHeight; drawDivider(canvas, bounds, -1); } } for (int i = 0; i < count; i++) { if ((headerDividers || first + i >= headerCount) && (footerDividers || first + i < footerLimit)) { View child = getChildAt(i); bottom = child.getBottom(); // Don't draw dividers next to items that are not enabled if (drawDividers && (bottom < listBottom && !(drawOverscrollFooter && i == count - 1))) { if ((areAllItemsSelectable || (adapter.isEnabled(first + i) && (i == count - 1 || adapter.isEnabled(first + i + 1))))) { bounds.top = bottom; bounds.bottom = bottom + dividerHeight; drawDivider(canvas, bounds, i); } else if (fillForMissingDividers) { bounds.top = bottom; bounds.bottom = bottom + dividerHeight; canvas.drawRect(bounds, paint); } } } } // final int overFooterBottom = mBottom + mScrollY; final int overFooterBottom = getBottom() + getScrollY(); if (drawOverscrollFooter && first + count == itemCount && overFooterBottom > bottom) { bounds.top = bottom; bounds.bottom = overFooterBottom; drawOverscrollFooter(canvas, overscrollFooter, bounds); } } else { int top; int listTop = mListPadding.top; // final int scrollY = mScrollY; final int scrollY = getScrollY(); if (count > 0 && drawOverscrollHeader) { bounds.top = scrollY; bounds.bottom = getChildAt(0).getTop(); drawOverscrollHeader(canvas, overscrollHeader, bounds); } final int start = drawOverscrollHeader ? 1 : 0; for (int i = start; i < count; i++) { if ((headerDividers || first + i >= headerCount) && (footerDividers || first + i < footerLimit)) { View child = getChildAt(i); top = child.getTop(); // Don't draw dividers next to items that are not enabled if (drawDividers && top > listTop) { if ((areAllItemsSelectable || (adapter.isEnabled(first + i) && (i == count - 1 || adapter.isEnabled(first + i + 1))))) { bounds.top = top - dividerHeight; bounds.bottom = top; // Give the method the child ABOVE the divider, so we // subtract one from our child // position. Give -1 when there is no child above the // divider. drawDivider(canvas, bounds, i - 1); } else if (fillForMissingDividers) { bounds.top = top - dividerHeight; bounds.bottom = top; canvas.drawRect(bounds, paint); } } } } if (count > 0 && scrollY > 0) { if (drawOverscrollFooter) { // final int absListBottom = mBottom; final int absListBottom = getBottom(); bounds.top = absListBottom; bounds.bottom = absListBottom + scrollY; drawOverscrollFooter(canvas, overscrollFooter, bounds); } else if (drawDividers) { bounds.top = listBottom; bounds.bottom = listBottom + dividerHeight; drawDivider(canvas, bounds, -1); } } } } // Draw the indicators (these should be drawn above the dividers) and children super.dispatchDraw(canvas); } private void drawContentBackground(Canvas canvas) { if (getHeaderViewsCount() > 0) { Rect rect = mTempRect; rect.left = getLeft(); rect.right = getRight(); View firstVisibleView = getChildAt(getFirstVisiblePosition()); if (isHeaderView(firstVisibleView)) { View lastHeader = mHeaderViewInfos.get(mHeaderViewInfos.size() - 1).view; rect.top = lastHeader.getBottom(); } else rect.top = 0; rect.bottom = getBottom(); canvas.drawRect(rect, mContentPaint); } } private boolean isHeaderView(View view) { for (FixedViewInfo info : mHeaderViewInfos) { if (info.view == view) return true; } return false; } /** * Draws a divider for the given child in the given bounds. * * @param canvas The canvas to draw to. * @param bounds The bounds of the divider. * @param childIndex The index of child (of the View) above the divider. * This will be -1 if there is no child above the divider to be * drawn. */ void drawDivider(Canvas canvas, Rect bounds, int childIndex) { // This widget draws the same divider for all children final Drawable divider = mDivider; final boolean clipDivider = mClipDivider; if (!clipDivider) { divider.setBounds(bounds); } else { canvas.save(); canvas.clipRect(bounds); } divider.draw(canvas); if (clipDivider) { canvas.restore(); } } /** * Returns the drawable that will be drawn between each item in the list. * * @return the current drawable drawn between list elements */ public Drawable getDivider() { return mDivider; } /** * Sets the drawable that will be drawn between each item in the list. If the drawable does * not have an intrinsic height, you should also call {@link #setDividerHeight(int)} * * @param divider The drawable to use. */ public void setDivider(Drawable divider) { if (divider != null) { mDividerHeight = divider.getIntrinsicHeight(); mClipDivider = divider instanceof ColorDrawable; } else { mDividerHeight = 0; mClipDivider = false; } mDivider = divider; mDividerIsOpaque = divider == null || divider.getOpacity() == PixelFormat.OPAQUE; requestLayoutIfNecessary(); } /** * @return Returns the height of the divider that will be drawn between each item in the list. */ public int getDividerHeight() { return mDividerHeight; } /** * Sets the height of the divider that will be drawn between each item in the list. Calling * this will override the intrinsic height as set by {@link #setDivider(Drawable)} * * @param height The new height of the divider in pixels. */ public void setDividerHeight(int height) { mDividerHeight = height; requestLayoutIfNecessary(); } /** * Enables or disables the drawing of the divider for header views. * * @param headerDividersEnabled True to draw the headers, false otherwise. * * @see #setFooterDividersEnabled(boolean) * @see #addHeaderView(View) */ public void setHeaderDividersEnabled(boolean headerDividersEnabled) { mHeaderDividersEnabled = headerDividersEnabled; invalidate(); } /** * Enables or disables the drawing of the divider for footer views. * * @param footerDividersEnabled True to draw the footers, false otherwise. * * @see #setHeaderDividersEnabled(boolean) * @see #addFooterView(View) */ public void setFooterDividersEnabled(boolean footerDividersEnabled) { mFooterDividersEnabled = footerDividersEnabled; invalidate(); } /** * Sets the drawable that will be drawn above all other list content. * This area can become visible when the user overscrolls the list. * * @param header The drawable to use */ public void setOverscrollHeader(Drawable header) { mOverScrollHeader = header; // if (mScrollY < 0) { // invalidate(); // } if (getScrollY() < 0) { invalidate(); } } /** * @return The drawable that will be drawn above all other list content */ public Drawable getOverscrollHeader() { return mOverScrollHeader; } /** * Sets the drawable that will be drawn below all other list content. * This area can become visible when the user overscrolls the list, * or when the list's content does not fully fill the container area. * * @param footer The drawable to use */ public void setOverscrollFooter(Drawable footer) { mOverScrollFooter = footer; invalidate(); } /** * @return The drawable that will be drawn below all other list content */ public Drawable getOverscrollFooter() { return mOverScrollFooter; } @Override protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); int closetChildIndex = -1; if (gainFocus && previouslyFocusedRect != null) { //previouslyFocusedRect.offset(mScrollX, mScrollY); previouslyFocusedRect.offset(getScrollX(), getScrollY()); final ListAdapter adapter = mAdapter; // Don't cache the result of getChildCount or mFirstPosition here, // it could change in layoutChildren. if (adapter.getCount() < getChildCount() + mFirstPosition) { mLayoutMode = LAYOUT_NORMAL; layoutChildren(); } // figure out which item should be selected based on previously // focused rect Rect otherRect = mTempRect; int minDistance = Integer.MAX_VALUE; final int childCount = getChildCount(); final int firstPosition = mFirstPosition; for (int i = 0; i < childCount; i++) { // only consider selectable views if (!adapter.isEnabled(firstPosition + i)) { continue; } View other = getChildAt(i); other.getDrawingRect(otherRect); offsetDescendantRectToMyCoords(other, otherRect); int distance = getDistance(previouslyFocusedRect, otherRect, direction); if (distance < minDistance) { minDistance = distance; closetChildIndex = i; } } } if (closetChildIndex >= 0) { setSelection(closetChildIndex + mFirstPosition); } else { requestLayout(); } } /* * (non-Javadoc) * * Children specified in XML are assumed to be header views. After we have * parsed them move them out of the children list and into mHeaderViews. */ @Override protected void onFinishInflate() { super.onFinishInflate(); int count = getChildCount(); if (count > 0) { for (int i = 0; i < count; ++i) { addHeaderView(getChildAt(i)); } removeAllViews(); } } @Override public boolean onTouchEvent(MotionEvent ev) { if (mItemsCanFocus && ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) { // Don't handle edge touches immediately -- they may actually belong to one of our // descendants. return false; } return super.onTouchEvent(ev); } @Override public boolean performItemClick(View view, int position, long id) { boolean handled = false; handled |= super.performItemClick(view, position, id); return handled; } /** * Sets the checked state of the specified position. The is only valid if * the choice mode has been set to {@link #CHOICE_MODE_SINGLE} or * {@link #CHOICE_MODE_MULTIPLE}. * * @param position The item whose checked state is to be checked * @param value The new checked state for the item */ public void setItemChecked(int position, boolean value) { } /** * Returns the checked state of the specified position. The result is only * valid if the choice mode has been set to {@link #CHOICE_MODE_SINGLE} * or {@link #CHOICE_MODE_MULTIPLE}. * * @param position The item whose checked state to return * @return The item's checked state or <code>false</code> if choice mode * is invalid * * @see #setChoiceMode(int) */ public boolean isItemChecked(int position) { return false; } /** * Returns the currently checked item. The result is only valid if the choice * mode has been set to {@link #CHOICE_MODE_SINGLE}. * * @return The position of the currently checked item or * {@link #INVALID_POSITION} if nothing is selected * * @see #setChoiceMode(int) */ public int getCheckedItemPosition() { return INVALID_POSITION; } /** * Returns the set of checked items in the list. The result is only valid if * the choice mode has not been set to {@link #CHOICE_MODE_NONE}. * * @return A SparseBooleanArray which will return true for each call to * get(int position) where position is a position in the list, * or <code>null</code> if the choice mode is set to * {@link #CHOICE_MODE_NONE}. */ public SparseBooleanArray getCheckedItemPositions() { return null; } /** * Returns the set of checked items ids. The result is only valid if the * choice mode has not been set to {@link #CHOICE_MODE_NONE}. * * @return A new array which contains the id of each checked item in the * list. * * @deprecated Use {@link #getCheckedItemIds()} instead. */ @Deprecated public long[] getCheckItemIds() { // Use new behavior that correctly handles stable ID mapping. if (mAdapter != null && mAdapter.hasStableIds()) { return getCheckedItemIds(); } return new long[0]; } /** * Returns the set of checked items ids. The result is only valid if the * choice mode has not been set to {@link #CHOICE_MODE_NONE} and the adapter * has stable IDs. ({@link ListAdapter#hasStableIds()} == {@code true}) * * @return A new array which contains the id of each checked item in the * list. */ public long[] getCheckedItemIds() { return new long[0]; } /** * Clear any choices previously set */ public void clearChoices() { } }//end of class