initial import

Author: Paul Soucy

HorizontialListView.java

@@ -0,0 +1,358 @@
+/*
+ * HorizontalListView.java v1.5
+ *
+ * 
+ * The MIT License
+ * Copyright (c) 2011 Paul Soucy ([email protected])
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+package com.devsmart.android.ui;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+import android.content.Context;
+import android.database.DataSetObserver;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+import android.view.GestureDetector;
+import android.view.GestureDetector.OnGestureListener;
+import android.view.MotionEvent;
+import android.view.View;
+import android.widget.AdapterView;
+import android.widget.ListAdapter;
+import android.widget.Scroller;
+
+public class HorizontialListView extends AdapterView<ListAdapter> {
+
+	public boolean mAlwaysOverrideTouch = true;
+	protected ListAdapter mAdapter;
+	private int mLeftViewIndex = -1;
+	private int mRightViewIndex = 0;
+	protected int mCurrentX;
+	protected int mNextX;
+	private int mMaxX = Integer.MAX_VALUE;
+	private int mDisplayOffset = 0;
+	protected Scroller mScroller;
+	private GestureDetector mGesture;
+	private Queue<View> mRemovedViewQueue = new LinkedList<View>();
+	private OnItemSelectedListener mOnItemSelected;
+	private OnItemClickListener mOnItemClicked;
+	private boolean mDataChanged = false;
+	
+
+	public HorizontialListView(Context context, AttributeSet attrs) {
+		super(context, attrs);
+		initView();
+	}
+	
+	private synchronized void initView() {
+		mLeftViewIndex = -1;
+		mRightViewIndex = 0;
+		mDisplayOffset = 0;
+		mCurrentX = 0;
+		mNextX = 0;
+		mMaxX = Integer.MAX_VALUE;
+		mScroller = new Scroller(getContext());
+		mGesture = new GestureDetector(getContext(), mOnGesture);
+	}
+	
+	@Override
+	public void setOnItemSelectedListener(AdapterView.OnItemSelectedListener listener) {
+		mOnItemSelected = listener;
+	}
+	
+	@Override
+	public void setOnItemClickListener(AdapterView.OnItemClickListener listener){
+		mOnItemClicked = listener;
+	}
+	
+	private DataSetObserver mDataObserver = new DataSetObserver() {
+
+		@Override
+		public void onChanged() {
+			synchronized(HorizontialListView.this){
+				mDataChanged = true;
+			}
+			invalidate();
+			requestLayout();
+		}
+
+		@Override
+		public void onInvalidated() {
+			reset();
+			invalidate();
+			requestLayout();
+		}
+		
+	};
+
+	@Override
+	public ListAdapter getAdapter() {
+		return mAdapter;
+	}
+
+	@Override
+	public View getSelectedView() {
+		//TODO: implement
+		return null;
+	}
+
+	@Override
+	public void setAdapter(ListAdapter adapter) {
+		if(mAdapter != null) {
+			mAdapter.unregisterDataSetObserver(mDataObserver);
+		}
+		mAdapter = adapter;
+		mAdapter.registerDataSetObserver(mDataObserver);
+		reset();
+	}
+	
+	private synchronized void reset(){
+		initView();
+		removeAllViewsInLayout();
+        requestLayout();
+	}
+
+	@Override
+	public void setSelection(int position) {
+		//TODO: implement
+	}
+	
+	private void addAndMeasureChild(final View child, int viewPos) {
+		LayoutParams params = child.getLayoutParams();
+		if(params == null) {
+			params = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
+		}
+
+		addViewInLayout(child, viewPos, params, true);
+		child.measure(MeasureSpec.makeMeasureSpec(getWidth(), MeasureSpec.AT_MOST),
+				MeasureSpec.makeMeasureSpec(getHeight(), MeasureSpec.AT_MOST));
+	}
+
+	@Override
+	protected synchronized void onLayout(boolean changed, int left, int top, int right, int bottom) {
+		super.onLayout(changed, left, top, right, bottom);
+
+		if(mAdapter == null){
+			return;
+		}
+		
+		if(mDataChanged){
+			int oldCurrentX = mCurrentX;
+			initView();
+			removeAllViewsInLayout();
+			mNextX = oldCurrentX;
+			mDataChanged = false;
+		}
+
+		if(mScroller.computeScrollOffset()){
+			int scrollx = mScroller.getCurrX();
+			mNextX = scrollx;
+		}
+		
+		if(mNextX < 0){
+			mNextX = 0;
+			mScroller.forceFinished(true);
+		}
+		if(mNextX > mMaxX) {
+			mNextX = mMaxX;
+			mScroller.forceFinished(true);
+		}
+		
+		int dx = mCurrentX - mNextX;
+		
+		removeNonVisibleItems(dx);
+		fillList(dx);
+		positionItems(dx);
+		
+		mCurrentX = mNextX;
+		
+		if(!mScroller.isFinished()){
+			post(new Runnable(){
+				@Override
+				public void run() {
+					requestLayout();
+				}
+			});
+			
+		}
+	}
+	
+	private void fillList(final int dx) {
+		int edge = 0;
+		View child = getChildAt(getChildCount()-1);
+		if(child != null) {
+			edge = child.getRight();
+		}
+		fillListRight(edge, dx);
+		
+		edge = 0;
+		child = getChildAt(0);
+		if(child != null) {
+			edge = child.getLeft();
+		}
+		fillListLeft(edge, dx);
+		
+		
+	}
+	
+	private void fillListRight(int rightEdge, final int dx) {
+		while(rightEdge + dx < getWidth() && mRightViewIndex < mAdapter.getCount()) {
+			
+			View child = mAdapter.getView(mRightViewIndex, mRemovedViewQueue.poll(), this);
+			addAndMeasureChild(child, -1);
+			rightEdge += child.getMeasuredWidth();
+			
+			if(mRightViewIndex == mAdapter.getCount()-1){
+				mMaxX = mCurrentX + rightEdge - getWidth();
+			}
+			mRightViewIndex++;
+		}
+		
+	}
+	
+	private void fillListLeft(int leftEdge, final int dx) {
+		while(leftEdge + dx > 0 && mLeftViewIndex >= 0) {
+			View child = mAdapter.getView(mLeftViewIndex, mRemovedViewQueue.poll(), this);
+			addAndMeasureChild(child, 0);
+			leftEdge -= child.getMeasuredWidth();
+			mLeftViewIndex--;
+			mDisplayOffset -= child.getMeasuredWidth();
+		}
+	}
+	
+	private void removeNonVisibleItems(final int dx) {
+		View child = getChildAt(0);
+		while(child != null && child.getRight() + dx <= 0) {
+			mDisplayOffset += child.getMeasuredWidth();
+			mRemovedViewQueue.offer(child);
+			removeViewInLayout(child);
+			mLeftViewIndex++;
+			child = getChildAt(0);
+			
+		}
+		
+		child = getChildAt(getChildCount()-1);
+		while(child != null && child.getLeft() + dx >= getWidth()) {
+			mRemovedViewQueue.offer(child);
+			removeViewInLayout(child);
+			mRightViewIndex--;
+			child = getChildAt(getChildCount()-1);
+		}
+	}
+	
+	private void positionItems(final int dx) {
+		if(getChildCount() > 0){
+			mDisplayOffset += dx;
+			int left = mDisplayOffset;
+			for(int i=0;i<getChildCount();i++){
+				View child = getChildAt(i);
+				int childWidth = child.getMeasuredWidth();
+				child.layout(left, 0, left + childWidth, child.getMeasuredHeight());
+				left += childWidth;
+			}
+		}
+	}
+	
+	public synchronized void scrollTo(int x) {
+		mScroller.startScroll(mNextX, 0, x - mNextX, 0);
+		requestLayout();
+	}
+	
+	@Override
+	public boolean dispatchTouchEvent(MotionEvent ev) {
+		boolean handled = mGesture.onTouchEvent(ev);
+		return handled;
+	}
+	
+	protected boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
+				float velocityY) {
+		synchronized(HorizontialListView.this){
+			mScroller.fling(mNextX, 0, (int)-velocityX, 0, 0, mMaxX, 0, 0);
+		}
+		requestLayout();
+		
+		return true;
+	}
+	
+	protected boolean onDown(MotionEvent e) {
+		mScroller.forceFinished(true);
+		return true;
+	}
+	
+	private OnGestureListener mOnGesture = new GestureDetector.SimpleOnGestureListener() {
+
+		@Override
+		public boolean onDown(MotionEvent e) {
+			return HorizontialListView.this.onDown(e);
+		}
+
+		@Override
+		public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
+				float velocityY) {
+			return HorizontialListView.this.onFling(e1, e2, velocityX, velocityY);
+		}
+
+		@Override
+		public boolean onScroll(MotionEvent e1, MotionEvent e2,
+				float distanceX, float distanceY) {
+			
+			synchronized(HorizontialListView.this){
+				mNextX += (int)distanceX;
+			}
+			requestLayout();
+			
+			return true;
+		}
+
+		@Override
+		public boolean onSingleTapConfirmed(MotionEvent e) {
+			Rect viewRect = new Rect();
+			for(int i=0;i<getChildCount();i++){
+				View child = getChildAt(i);
+				int left = child.getLeft();
+				int right = child.getRight();
+				int top = child.getTop();
+				int bottom = child.getBottom();
+				viewRect.set(left, top, right, bottom);
+				if(viewRect.contains((int)e.getX(), (int)e.getY())){
+					if(mOnItemClicked != null){
+						mOnItemClicked.onItemClick(HorizontialListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId( mLeftViewIndex + 1 + i ));
+					}
+					if(mOnItemSelected != null){
+						mOnItemSelected.onItemSelected(HorizontialListView.this, child, mLeftViewIndex + 1 + i, mAdapter.getItemId( mLeftViewIndex + 1 + i ));
+					}
+					break;
+				}
+				
+			}
+			return true;
+		}
+		
+		
+		
+	};
+
+	
+
+}