Android横向ListView.doc

Android横向ListView在日常开发中经常会发现横向的ListView。下面讨论实现方案。 1.动态的添加布局。RelativeLayout view = (RelativeLayout) LayoutInflater.from(this) .inflate(R.layout.demo, null);ListView.addView(view);2.通过继承AdapterView（ListAdapter）自定义类实现 部分关键代码如下： 类名：HorizontalListView（这个类不是我实现的，我只是拿来用）布局代码代码粘贴如下：package com.homelink.newlink.view;import android.annotation.SuppressLint;import android.annotation.TargetApi;import android.content.Context;import android.content.res.TypedArray;import android.database.DataSetObserver;import android.graphics.Canvas;import android.graphics.Rect;import android.graphics.drawable.Drawable;import android.os.Build;import android.os.Bundle;import android.os.Parcelable;import android.support.v4.view.ViewCompat;import android.support.v4.widget.EdgeEffectCompat;import android.util.AttributeSet;import android.view.GestureDetector;import android.view.HapticFeedbackConstants;import android.view.MotionEvent;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.ListAdapter;import android.widget.ListView;import android.widget.ScrollView;import android.widget.Scroller;import com.homelink.newlink.R;import mon.utils.device.DensityUtil;import java.util.ArrayList;import java.util.LinkedList;import java.util.List;import java.util.Queue;/* * Created by jou on 2017/1/4. */public class HorizontalListView extends AdapterView /* * Defines where to insert items into the ViewGroup, as defined in code ViewGroup * #addViewInLayout(View, int, LayoutParams, boolean) */ private static final int INSERT_AT_END_OF_LIST = -1; private static final int INSERT_AT_START_OF_LIST = 0; /* The velocity to use for overscroll absorption */ private static final float FLING_DEFAULT_ABSORB_VELOCITY = 30f; /* The friction amount to use for the fling tracker */ private static final float FLING_FRICTION = 0.009f; /* * Used for tracking the state data necessary to restore the HorizontalListView to its previous * state after a rotation occurs */ private static final String BUNDLE_ID_CURRENT_X = BUNDLE_ID_CURRENT_X; /* * The bundle id of the parents state. Used to restore the parents state after a rotation * occurs */ private static final String BUNDLE_ID_PARENT_STATE = BUNDLE_ID_PARENT_STATE; /* Tracks ongoing flings */ protected Scroller mFlingTracker = new Scroller(getContext(); /* Gesture listener to receive callbacks when gestures are detected */ private final GestureListener mGestureListener = new GestureListener(); /* Used for detecting gestures within this view so they can be handled */ private GestureDetector mGestureDetector; /* This tracks the starting layout position of the leftmost view */ private int mDisplayOffset; /* Holds a reference to the adapter bound to this view */ protected ListAdapter mAdapter; /* Holds a cache of recycled views to be reused as needed */ private ListQueue mRemovedViewsCache = new ArrayListQueue(); /* Flag used to mark when the adapters data has changed, so the view can be relaid out */ private boolean mDataChanged = false; /* Temporary rectangle to be used for measurements */ private Rect mRect = new Rect(); /* Tracks the currently touched view, used to delegate touches to the view being touched */ private View mViewBeingTouched = null; /* The width of the divider that will be used between list items */ private int mDividerWidth = 0; /* The drawable that will be used as the list divider */ private Drawable mDivider = null; /* The x position of the currently rendered view */ protected int mCurrentX; /* The x position of the next to be rendered view */ protected int mNextX; /* Used to hold the scroll position to restore to post rotate */ private Integer mRestoreX = null; /* * Tracks the maximum possible X position, stays at max value until last item is laid out and it * can be determined */ private int mMaxX = Integer.MAX_VALUE; /* The adapter index of the leftmost view currently visible */ private int mLeftViewAdapterIndex; /* The adapter index of the rightmost view currently visible */ private int mRightViewAdapterIndex; /* This tracks the currently selected accessibility item */ private int mCurrentlySelectedAdapterIndex; /* * Callback interface to notify listener that the user has scrolled this view to the point that * it is low on data. */ private RunningOutOfDataListener mRunningOutOfDataListener = null; /* * This tracks the user value set of how many items from the end will be considered running out * of data. */ private int mRunningOutOfDataThreshold = 0; /* * Tracks if we have told the listener that we are running low on data. We only want to tell * them once. */ private boolean mHasNotifiedRunningLowOnData = false; /* * Callback interface to be invoked when the scroll state has changed. */ private OnScrollStateChangedListener mOnScrollStateChangedListener = null; /* * Represents the current scroll state of this view. Needed so we can detect when the state * changes so scroll listener can be notified. */ private OnScrollStateChangedListener.ScrollState mCurrentScrollState = OnScrollStateChangedListener.ScrollState.SCROLL_STATE_IDLE; /* * Tracks the state of the left edge glow. */ private EdgeEffectCompat mEdgeGlowLeft; /* * Tracks the state of the right edge glow. */ private EdgeEffectCompat mEdgeGlowRight; /* The height measure spec for this view, used to help size children views */ private int mHeightMeasureSpec; /* Used to track if a view touch should be blocked because it stopped a fling */ private boolean mBlockTouchAction = false; /* * Used to track if the parent vertically scrollable view has been told to * DisallowInterceptTouchEvent */ private boolean mIsParentVerticiallyScrollableViewDisallowingInterceptTouchEvent = false; /* * The listener that receives notifications when this view is clicked. */ private OnClickListener mOnClickListener; /* * Recode the position of press and loose */ private MotionEvent mPressEvent; private MotionEvent mLooseEvent; /* * MaoDian mode */ private boolean mIsAnchorEnable; /* * Filing mode */ private boolean mIsFilingEnable = true; public HorizontalListView(Context context, AttributeSet attrs) super(context, attrs); mEdgeGlowLeft = new EdgeEffectCompat(context); mEdgeGlowRight = new EdgeEffectCompat(context); mGestureDetector = new GestureDetector(context, mGestureListener); bindGestureDetector(); initView(); retrieveXmlConfiguration(context, attrs); setWillNotDraw(false); / If the OS version is high enough then set the friction on the fling tracker */ if (Build.VERSION.SDK_INT = Build.VERSION_CODES.HONEYCOMB) HoneycombPlus.setFriction(mFlingTracker, FLING_FRICTION); /* Registers the gesture detector to receive gesture notifications for this view */ private void bindGestureDetector() / Generic touch listener that can be applied to any view that needs to process gestures final OnTouchListener gestureListenerHandler = new OnTouchListener() Override public boolean onTouch(final View v, final MotionEvent event) / Delegate the touch event to our gesture detector return mGestureDetector.onTouchEvent(event); ; setOnTouchListener(gestureListenerHandler); /* * When this HorizontalListView is embedded within a vertical scrolling view it is important to * disable the parent view from interacting with * any touch events while the user is scrolling within this HorizontalListView. This will start * at this view and go up the view tree looking * for a vertical scrolling view. If one is found it will enable or disable parent touch * interception. * * param disallowIntercept If true the parent will be prevented from intercepting child touch * events */ private void requestParentListViewToNotInterceptTouchEvents(Boolean disallowIntercept) / Prevent calling this more than once needlessly if (mIsParentVerticiallyScrollableViewDisallowingInterceptTouchEvent != disallowIntercept) View view = this; while (view.getParent() instanceof View) / If the parent is a ListView or ScrollView then disallow intercepting of touch events if (view.getParent() instanceof ListView | view.getParent() instanceof ScrollView) view.getParent().requestDisallowInterceptTouchEvent(disallowIntercept); mIsParentVerticiallyScrollableViewDisallowingInterceptTouchEvent = disallowIntercept; return; view = (View) view.getParent(); /* * Parse the XML configuration for this widget * * param context Context used for extracting attributes * param attrs The Attribute Set containing the ColumnView attributes */ private void retrieveXmlConfiguration(Context context, AttributeSet attrs) if (attrs != null) TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.HorizontalListView); / Get the provided drawable from the XML final Drawable d = a.getDrawable(R.styleable.HorizontalListView_android_divider); if (d != null) / If a drawable is provided to use as the divider then use its intrinsic width for the divider width setDivider(d); / If a width is explicitly specified then use that width final int dividerWidth = a.getDimensionPixelSize(R.styleable.HorizontalListView_dividerWidth, 0); if (dividerWidth != 0) setDividerWidth(dividerWidth); a.recycle(); Override public Parcelable onSaveInstanceState() Bundle bundle = new Bundle(); / Add the parent state to the bundle bundle.putParcelable(BUNDLE_ID_PARENT_STATE, super.onSaveInstanceState(); / Add our state to the bundle bundle.putInt(BUNDLE_ID_CURRENT_X, mCurrentX); return bundle; Override public void onRestoreInstanceState(Parcelable state) if (state instanceof Bundle) Bundle bundle = (Bundle) state; / Restore our state from the bundle mRestoreX = Integer.valueOf(bundle.getInt(BUNDLE_ID_CURRENT_X); / Restore out parents state from the bundle super.onRestoreInstanceState(bundle.getParcelable(BUNDLE_ID_PARENT_STATE); /* * Sets the drawable that will be drawn between each item in the list. If the drawable does * not have an intrinsic width, you should also call link #setDividerWidth(int) * * param divider The drawable to use. */ public void setDivider(Drawable divider) mDivider = divider; if (divider != null) setDividerWidth(divider.getIntrinsicWidth(); else setDividerWidth(0); /* * Sets the width of the divider that will be drawn between each item in the list. Calling * this will override the intrinsic width as set by link #setDivider(android.graphics.drawable.Drawable) * * param width The width of the divider in pixels. */ public void setDividerWidth(int width) mDividerWidth = width; / Force the view to rerender itself requestLayout(); invalidate(); private void initView() mLeftViewAdapterIndex = -1; mRightViewAdapterIndex = -1; mDisplayOffset = 0; mCurrentX = 0; mNextX = 0; mMaxX = Integer.MAX_VALUE; setCurrentScrollState(OnScrollStateChangedListener.ScrollState.SCROLL_STATE_IDLE); /* * Will re-initialize the HorizontalListView to remove all child views rendered and reset to * initial configuration. */ private void reset() initView(); removeAllViewsInLayout(); requestLayout(); /* DataSetObserver used to capture adapter data change events */ private DataSetObserver mAdapterDataObserver = new DataSetObserver() Override public void onChanged() mDataChanged = true; / Clear so we can notify again as we run out of data mHasNotifiedRunningLowOnData = false; unpressTouchedChild(); / Invalidate and request layout to force this view to completely redraw itself invalidate(); requestLayout(); Override public void onInvalidated() / Clear so we can notify again as we run out of data mHasNotifiedRunningLowOnData = false; unpressTouchedChild(); reset(); / Invalidate and request layout to force this view to completely redraw itself invalidate(); requestLayout(); ; Override public void setSelection(int position) mCurrentlySelectedAdapterIndex = position; Override public View getSelectedView() return getChild(mCurrentlySelectedAdapterIndex); Override public void setAdapter(ListAdapter adapter) if (mAdapter != null) mAdapter.unregisterDataSetObserver(mAdapterDataObserver); if (adapter != null) / Clear so we can notify again as we run out of data mHasNotifiedRunningLowOnData = false; mAdapter = adapter; mAdapter.registerDataSetObserver(mAdapterDataObserver); initializeRecycledViewCache(mAdapter.getViewTypeCount(); reset(); Override public ListAdapter getAdapter() return mAdapter; /* * Will create and initialize a cache for the given number of different types of views. * * param viewTypeCount - The total number of different views supported */ private void initializeRecycledViewCache(int viewTypeCount) / The cache is created such that the response from mAdapter.getItemViewType is the array index to the correct cache for that item. mRemovedViewsCache.clear(); for (int i = 0; i viewTypeCount; i+) mRemovedViewsCache.add(new LinkedList(); /* * Returns a recycled view from the cache that can be reused, or null if one is not available. */ private View getRecycledView(int adapterIndex) int itemViewType = mAdapter.getItemViewType(adapterIndex); if (isItemViewTypeValid(itemViewType) return mRemovedViewsCache.get(itemViewType).poll(); return null; /* * Adds the provided view to a recycled views cache. */ private void recycleView(int adapterIndex, View view) / There is one Queue of views for each different type of view. / Just add the view to the pile of other views of the same type. / The order they are added and removed does not matter. int itemViewType = mAdapter.getItemViewType(adapterIndex); if (isItemViewTypeValid(itemViewType) mRemovedViewsCache.get(itemViewType).offer(view); private boolean isItemViewTypeValid(int itemViewType) return itemViewType 0) childWidthSpec = MeasureSpec.makeMeasureSpec(childLayoutParams.width, MeasureSpec.EXACTLY); else childWidthSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); child.measure(childWidthSpec, childHeightSpec); /* Gets a childs layout parameters, defaults if not available. */ private LayoutParams getLayoutParams(View child) LayoutParams layoutParams = child.getLayoutParams(); if (layoutParams = null) / Since this is a horizontal list view default to matching the parents height, and wrapping the width layoutParams = new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT); return layoutParams; SuppressLint(WrongCall) Override protected void onLayout(boolean changed, int left, int top, int right, int bottom) super.onLayout(changed, left, top, right, bottom); if (mAdapter = null) return; / Force the OS to redraw this view invalidate(); / If the data changed then reset everything and render from scratch at the same offset as