src/com/android/launcher2/PagedViewCellLayout.java - LeafOS-Project/android_packages_apps_Launcher3 - Gitiles

 /*
  * 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 android.content.Context;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Color;
 import android.graphics.Paint;
 import android.graphics.PorterDuff;
 import android.graphics.Rect;
 import android.util.AttributeSet;
 import android.util.Log;
 import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewDebug;
 import android.view.ViewGroup;

 /**
  * An abstraction of the original CellLayout which supports laying out items
  * which span multiple cells into a grid-like layout.  Also supports dimming
  * to give a preview of its contents.
  */
 public class PagedViewCellLayout extends ViewGroup {
     static final String TAG = "PagedViewCellLayout";

     private float mHolographicAlpha;

     private boolean mCenterContent;

     private int mCellCountX;
     private int mCellCountY;
     private int mCellWidth;
     private int mCellHeight;
     private int mWidthGap;
     private int mHeightGap;
     private static int sDefaultCellDimensions = 96;

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

     public PagedViewCellLayout(Context context, AttributeSet attrs) {
         this(context, attrs, 0);
     }

     public PagedViewCellLayout(Context context, AttributeSet attrs, int defStyle) {
         super(context, attrs, defStyle);

         setAlwaysDrawnWithCacheEnabled(false);

         // setup default cell parameters
         mCellWidth = mCellHeight = sDefaultCellDimensions;
         mCellCountX = LauncherModel.getCellCountX();
         mCellCountY = LauncherModel.getCellCountY();
         mHolographicAlpha = 0.0f;
         mWidthGap = mHeightGap = -1;
     }

     @Override
     protected boolean onSetAlpha(int alpha) {
         return true;
     }

     @Override
     public void setAlpha(float alpha) {
         mHolographicAlpha = 1.0f - alpha;
         setChildrenAlpha(alpha);
         super.setAlpha(alpha);
     }

     @Override
     public void cancelLongPress() {
         super.cancelLongPress();

         // Cancel long press for all children
         final int count = getChildCount();
         for (int i = 0; i < count; i++) {
             final View child = getChildAt(i);
             child.cancelLongPress();
         }
     }

     public boolean addViewToCellLayout(View child, int index, int childId,
             PagedViewCellLayout.LayoutParams params) {
         final PagedViewCellLayout.LayoutParams lp = params;

         // Generate an id for each view, this assumes we have at most 256x256 cells
         // per workspace screen
         if (lp.cellX >= 0 && lp.cellX <= (mCellCountX - 1) &&
                 lp.cellY >= 0 && (lp.cellY <= mCellCountY - 1)) {
             // If the horizontal or vertical span is set to -1, it is taken to
             // mean that it spans the extent of the CellLayout
             if (lp.cellHSpan < 0) lp.cellHSpan = mCellCountX;
             if (lp.cellVSpan < 0) lp.cellVSpan = mCellCountY;

             child.setId(childId);

             // We might be in the middle or end of shrinking/fading to a dimmed view
             // Make sure this view's alpha is set the same as all the rest of the views
             child.setAlpha(1.0f - mHolographicAlpha);

             addView(child, index, lp);
             return true;
         }
         return false;
     }

     @Override
     public void requestChildFocus(View child, View focused) {
         super.requestChildFocus(child, focused);
         if (child != null) {
             Rect r = new Rect();
             child.getDrawingRect(r);
             requestRectangleOnScreen(r);
         }
     }

     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         // TODO: currently ignoring padding

         int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
         int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);

         int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
         int heightSpecSize =  MeasureSpec.getSize(heightMeasureSpec);

         if (widthSpecMode == MeasureSpec.UNSPECIFIED || heightSpecMode == MeasureSpec.UNSPECIFIED) {
             throw new RuntimeException("CellLayout cannot have UNSPECIFIED dimensions");
         }

         final int cellWidth = mCellWidth;
         final int cellHeight = mCellHeight;

         int numWidthGaps = mCellCountX - 1;
         int numHeightGaps = mCellCountY - 1;

         int vSpaceLeft = heightSpecSize - mPaddingTop
                 - mPaddingBottom - (cellHeight * mCellCountY);
         int heightGap = vSpaceLeft / numHeightGaps;

         int hSpaceLeft = widthSpecSize - mPaddingLeft
                 - mPaddingRight - (cellWidth * mCellCountX);
         int widthGap = hSpaceLeft / numWidthGaps;

         // center it around the min gaps
         int minGap = Math.min(widthGap, heightGap);
         int paddingLeft = mPaddingLeft;
         int paddingTop = mPaddingTop;
         /*
         if (minGap < heightGap) {
             // vertical space has shrunken, so change padding accordingly
             paddingTop += ((heightGap - minGap) * (mCellCountY - 1)) / 2;
         } else if (minGap < widthGap) {
             // horizontal space has shrunken, so change padding accordingly
             paddingLeft += ((widthGap - minGap) * (mCellCountX - 1)) / 2;
         }
         */
         if (mWidthGap > -1 && mHeightGap > -1) {
             widthGap = mWidthGap;
             heightGap = mHeightGap;
         } else {
             widthGap = heightGap = minGap;
         }

         int newWidth = mPaddingLeft + mPaddingRight + (mCellCountX * cellWidth) +
             ((mCellCountX - 1) * widthGap);
         int newHeight = mPaddingTop + mPaddingBottom + (mCellCountY * cellHeight) +
             ((mCellCountY - 1) * heightGap);

         final int count = getChildCount();
         for (int i = 0; i < count; i++) {
             View child = getChildAt(i);
             PagedViewCellLayout.LayoutParams lp =
                 (PagedViewCellLayout.LayoutParams) child.getLayoutParams();
             lp.setup(cellWidth, cellHeight, widthGap, heightGap,
                     paddingLeft, paddingTop);

             int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(lp.width,
                     MeasureSpec.EXACTLY);
             int childheightMeasureSpec = MeasureSpec.makeMeasureSpec(lp.height,
                     MeasureSpec.EXACTLY);

             child.measure(childWidthMeasureSpec, childheightMeasureSpec);
         }

         setMeasuredDimension(newWidth, newHeight);
     }

     @Override
     protected void onLayout(boolean changed, int l, int t, int r, int b) {
         int count = getChildCount();

         int offsetX = 0;
         if (mCenterContent) {
             // determine the max width of all the rows and center accordingly
             int maxRowWidth = 0;
             for (int i = 0; i < count; i++) {
                 View child = getChildAt(i);
                 if (child.getVisibility() != GONE) {
                     PagedViewCellLayout.LayoutParams lp =
                         (PagedViewCellLayout.LayoutParams) child.getLayoutParams();
                     maxRowWidth = Math.max(maxRowWidth, lp.x + lp.width);
                 }
             }
             offsetX = (getMeasuredWidth() / 2) - (maxRowWidth / 2);
         }

         for (int i = 0; i < count; i++) {
             View child = getChildAt(i);
             if (child.getVisibility() != GONE) {
                 PagedViewCellLayout.LayoutParams lp =
                     (PagedViewCellLayout.LayoutParams) child.getLayoutParams();

                 int childLeft = offsetX + lp.x;
                 int childTop = lp.y;
                 child.layout(childLeft, childTop, childLeft + lp.width, childTop + lp.height);
             }
         }
     }

     @Override
     public boolean onTouchEvent(MotionEvent event) {
         return super.onTouchEvent(event) || true;
     }

     public void enableCenteredContent(boolean enabled) {
         mCenterContent = enabled;
     }

     @Override
     protected void setChildrenDrawingCacheEnabled(boolean enabled) {
         final int count = getChildCount();
         for (int i = 0; i < count; i++) {
             final View view = getChildAt(i);
             view.setDrawingCacheEnabled(enabled);
             // Update the drawing caches
             if (!view.isHardwareAccelerated()) {
                 view.buildDrawingCache(true);
             }
         }
     }

     public void setCellCount(int xCount, int yCount) {
         mCellCountX = xCount;
         mCellCountY = yCount;
         requestLayout();
     }

     public void setGap(int widthGap, int heightGap) {
         mWidthGap = widthGap;
         mHeightGap = heightGap;
     }

     public void setCellDimensions(int width, int height) {
         mCellWidth = width;
         mCellHeight = height;
         requestLayout();
     }

     public int getDefaultCellDimensions() {
         return sDefaultCellDimensions;
     }

     private void setChildrenAlpha(float alpha) {
         final int childCount = getChildCount();
         for (int i = 0; i < childCount; i++) {
             getChildAt(i).setAlpha(alpha);
         }
     }

     public int[] getCellCountForDimensions(int width, int height) {
         // Always assume we're working with the smallest span to make sure we
         // reserve enough space in both orientations
         int smallerSize = Math.min(mCellWidth, mCellHeight);

         // Always round up to next largest cell
         int spanX = (width + smallerSize) / smallerSize;
         int spanY = (height + smallerSize) / smallerSize;

         return new int[] { spanX, spanY };
     }

     /**
      * Start dragging the specified child
      *
      * @param child The child that is being dragged
      */
     void onDragChild(View child) {
         PagedViewCellLayout.LayoutParams lp = (PagedViewCellLayout.LayoutParams) child.getLayoutParams();
         lp.isDragging = true;
     }

     /**
      * Estimates the number of cells that the specified width would take up.
      */
     public int estimateCellHSpan(int width) {
         // TODO: we need to take widthGap into effect
         return (width + mCellWidth) / mCellWidth;
     }

     /**
      * Estimates the number of cells that the specified height would take up.
      */
     public int estimateCellVSpan(int height) {
         // TODO: we need to take heightGap into effect
         return (height + mCellHeight) / mCellHeight;
     }

     /**
      * Estimates the width that the number of vSpan cells will take up.
      */
     public int estimateCellWidth(int hSpan) {
         // TODO: we need to take widthGap into effect
         return hSpan * mCellWidth;
     }

     /**
      * Estimates the height that the number of vSpan cells will take up.
      */
     public int estimateCellHeight(int vSpan) {
         // TODO: we need to take heightGap into effect
         return vSpan * mCellHeight;
     }

     @Override
     public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
         return new PagedViewCellLayout.LayoutParams(getContext(), attrs);
     }

     @Override
     protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
         return p instanceof PagedViewCellLayout.LayoutParams;
     }

     @Override
     protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
         return new PagedViewCellLayout.LayoutParams(p);
     }

     public static class LayoutParams extends ViewGroup.MarginLayoutParams {
         /**
          * Horizontal location of the item in the grid.
          */
         @ViewDebug.ExportedProperty
         public int cellX;

         /**
          * Vertical location of the item in the grid.
          */
         @ViewDebug.ExportedProperty
         public int cellY;

         /**
          * Number of cells spanned horizontally by the item.
          */
         @ViewDebug.ExportedProperty
         public int cellHSpan;

         /**
          * Number of cells spanned vertically by the item.
          */
         @ViewDebug.ExportedProperty
         public int cellVSpan;

         /**
          * Is this item currently being dragged
          */
         public boolean isDragging;

         // a data object that you can bind to this layout params
         private Object mTag;

         // X coordinate of the view in the layout.
         @ViewDebug.ExportedProperty
         int x;
         // Y coordinate of the view in the layout.
         @ViewDebug.ExportedProperty
         int y;

         public LayoutParams() {
             super(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
             cellHSpan = 1;
             cellVSpan = 1;
         }

         public LayoutParams(Context c, AttributeSet attrs) {
             super(c, attrs);
             cellHSpan = 1;
             cellVSpan = 1;
         }

         public LayoutParams(ViewGroup.LayoutParams source) {
             super(source);
             cellHSpan = 1;
             cellVSpan = 1;
         }

         public LayoutParams(LayoutParams source) {
             super(source);
             this.cellX = source.cellX;
             this.cellY = source.cellY;
             this.cellHSpan = source.cellHSpan;
             this.cellVSpan = source.cellVSpan;
         }

         public LayoutParams(int cellX, int cellY, int cellHSpan, int cellVSpan) {
             super(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
             this.cellX = cellX;
             this.cellY = cellY;
             this.cellHSpan = cellHSpan;
             this.cellVSpan = cellVSpan;
         }

         public void setup(int cellWidth, int cellHeight, int widthGap, int heightGap,
                 int hStartPadding, int vStartPadding) {

             final int myCellHSpan = cellHSpan;
             final int myCellVSpan = cellVSpan;
             final int myCellX = cellX;
             final int myCellY = cellY;

             width = myCellHSpan * cellWidth + ((myCellHSpan - 1) * widthGap) -
                     leftMargin - rightMargin;
             height = myCellVSpan * cellHeight + ((myCellVSpan - 1) * heightGap) -
                     topMargin - bottomMargin;

             x = hStartPadding + myCellX * (cellWidth + widthGap) + leftMargin;
             y = vStartPadding + myCellY * (cellHeight + heightGap) + topMargin;
         }

         public Object getTag() {
             return mTag;
         }

         public void setTag(Object tag) {
             mTag = tag;
         }

         public String toString() {
             return "(" + this.cellX + ", " + this.cellY + ", " +
                 this.cellHSpan + ", " + this.cellVSpan + ")";
         }
     }
 }
	/*
	* 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 android.content.Context;
	import android.graphics.Bitmap;
	import android.graphics.Canvas;
	import android.graphics.Color;
	import android.graphics.Paint;
	import android.graphics.PorterDuff;
	import android.graphics.Rect;
	import android.util.AttributeSet;
	import android.util.Log;
	import android.view.MotionEvent;
	import android.view.View;
	import android.view.ViewDebug;
	import android.view.ViewGroup;

	/**
	* An abstraction of the original CellLayout which supports laying out items
	* which span multiple cells into a grid-like layout. Also supports dimming
	* to give a preview of its contents.
	*/
	public class PagedViewCellLayout extends ViewGroup {
	static final String TAG = "PagedViewCellLayout";

	private float mHolographicAlpha;

	private boolean mCenterContent;

	private int mCellCountX;
	private int mCellCountY;
	private int mCellWidth;
	private int mCellHeight;
	private int mWidthGap;
	private int mHeightGap;
	private static int sDefaultCellDimensions = 96;

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

	public PagedViewCellLayout(Context context, AttributeSet attrs) {
	this(context, attrs, 0);
	}

	public PagedViewCellLayout(Context context, AttributeSet attrs, int defStyle) {
	super(context, attrs, defStyle);

	setAlwaysDrawnWithCacheEnabled(false);

	// setup default cell parameters
	mCellWidth = mCellHeight = sDefaultCellDimensions;
	mCellCountX = LauncherModel.getCellCountX();
	mCellCountY = LauncherModel.getCellCountY();
	mHolographicAlpha = 0.0f;
	mWidthGap = mHeightGap = -1;
	}

	@Override
	protected boolean onSetAlpha(int alpha) {
	return true;
	}

	@Override
	public void setAlpha(float alpha) {
	mHolographicAlpha = 1.0f - alpha;
	setChildrenAlpha(alpha);
	super.setAlpha(alpha);
	}

	@Override
	public void cancelLongPress() {
	super.cancelLongPress();

	// Cancel long press for all children
	final int count = getChildCount();
	for (int i = 0; i < count; i++) {
	final View child = getChildAt(i);
	child.cancelLongPress();
	}
	}

	public boolean addViewToCellLayout(View child, int index, int childId,
	PagedViewCellLayout.LayoutParams params) {
	final PagedViewCellLayout.LayoutParams lp = params;

	// Generate an id for each view, this assumes we have at most 256x256 cells
	// per workspace screen
	if (lp.cellX >= 0 && lp.cellX <= (mCellCountX - 1) &&
	lp.cellY >= 0 && (lp.cellY <= mCellCountY - 1)) {
	// If the horizontal or vertical span is set to -1, it is taken to
	// mean that it spans the extent of the CellLayout
	if (lp.cellHSpan < 0) lp.cellHSpan = mCellCountX;
	if (lp.cellVSpan < 0) lp.cellVSpan = mCellCountY;

	child.setId(childId);

	// We might be in the middle or end of shrinking/fading to a dimmed view
	// Make sure this view's alpha is set the same as all the rest of the views
	child.setAlpha(1.0f - mHolographicAlpha);

	addView(child, index, lp);
	return true;
	}
	return false;
	}

	@Override
	public void requestChildFocus(View child, View focused) {
	super.requestChildFocus(child, focused);
	if (child != null) {
	Rect r = new Rect();
	child.getDrawingRect(r);
	requestRectangleOnScreen(r);
	}
	}

	@Override
	protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	// TODO: currently ignoring padding

	int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
	int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);

	int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
	int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);

	if (widthSpecMode == MeasureSpec.UNSPECIFIED \|\| heightSpecMode == MeasureSpec.UNSPECIFIED) {
	throw new RuntimeException("CellLayout cannot have UNSPECIFIED dimensions");
	}

	final int cellWidth = mCellWidth;
	final int cellHeight = mCellHeight;

	int numWidthGaps = mCellCountX - 1;
	int numHeightGaps = mCellCountY - 1;

	int vSpaceLeft = heightSpecSize - mPaddingTop
	- mPaddingBottom - (cellHeight * mCellCountY);
	int heightGap = vSpaceLeft / numHeightGaps;

	int hSpaceLeft = widthSpecSize - mPaddingLeft
	- mPaddingRight - (cellWidth * mCellCountX);
	int widthGap = hSpaceLeft / numWidthGaps;

	// center it around the min gaps
	int minGap = Math.min(widthGap, heightGap);
	int paddingLeft = mPaddingLeft;
	int paddingTop = mPaddingTop;
	/*
	if (minGap < heightGap) {
	// vertical space has shrunken, so change padding accordingly
	paddingTop += ((heightGap - minGap) * (mCellCountY - 1)) / 2;
	} else if (minGap < widthGap) {
	// horizontal space has shrunken, so change padding accordingly
	paddingLeft += ((widthGap - minGap) * (mCellCountX - 1)) / 2;
	}
	*/
	if (mWidthGap > -1 && mHeightGap > -1) {
	widthGap = mWidthGap;
	heightGap = mHeightGap;
	} else {
	widthGap = heightGap = minGap;
	}

	int newWidth = mPaddingLeft + mPaddingRight + (mCellCountX * cellWidth) +
	((mCellCountX - 1) * widthGap);
	int newHeight = mPaddingTop + mPaddingBottom + (mCellCountY * cellHeight) +
	((mCellCountY - 1) * heightGap);

	final int count = getChildCount();
	for (int i = 0; i < count; i++) {
	View child = getChildAt(i);
	PagedViewCellLayout.LayoutParams lp =
	(PagedViewCellLayout.LayoutParams) child.getLayoutParams();
	lp.setup(cellWidth, cellHeight, widthGap, heightGap,
	paddingLeft, paddingTop);

	int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(lp.width,
	MeasureSpec.EXACTLY);
	int childheightMeasureSpec = MeasureSpec.makeMeasureSpec(lp.height,
	MeasureSpec.EXACTLY);

	child.measure(childWidthMeasureSpec, childheightMeasureSpec);
	}

	setMeasuredDimension(newWidth, newHeight);
	}

	@Override
	protected void onLayout(boolean changed, int l, int t, int r, int b) {
	int count = getChildCount();

	int offsetX = 0;
	if (mCenterContent) {
	// determine the max width of all the rows and center accordingly
	int maxRowWidth = 0;
	for (int i = 0; i < count; i++) {
	View child = getChildAt(i);
	if (child.getVisibility() != GONE) {
	PagedViewCellLayout.LayoutParams lp =
	(PagedViewCellLayout.LayoutParams) child.getLayoutParams();
	maxRowWidth = Math.max(maxRowWidth, lp.x + lp.width);
	}
	}
	offsetX = (getMeasuredWidth() / 2) - (maxRowWidth / 2);
	}

	for (int i = 0; i < count; i++) {
	View child = getChildAt(i);
	if (child.getVisibility() != GONE) {
	PagedViewCellLayout.LayoutParams lp =
	(PagedViewCellLayout.LayoutParams) child.getLayoutParams();

	int childLeft = offsetX + lp.x;
	int childTop = lp.y;
	child.layout(childLeft, childTop, childLeft + lp.width, childTop + lp.height);
	}
	}
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
	return super.onTouchEvent(event) \|\| true;
	}

	public void enableCenteredContent(boolean enabled) {
	mCenterContent = enabled;
	}

	@Override
	protected void setChildrenDrawingCacheEnabled(boolean enabled) {
	final int count = getChildCount();
	for (int i = 0; i < count; i++) {
	final View view = getChildAt(i);
	view.setDrawingCacheEnabled(enabled);
	// Update the drawing caches
	if (!view.isHardwareAccelerated()) {
	view.buildDrawingCache(true);
	}
	}
	}

	public void setCellCount(int xCount, int yCount) {
	mCellCountX = xCount;
	mCellCountY = yCount;
	requestLayout();
	}

	public void setGap(int widthGap, int heightGap) {
	mWidthGap = widthGap;
	mHeightGap = heightGap;
	}

	public void setCellDimensions(int width, int height) {
	mCellWidth = width;
	mCellHeight = height;
	requestLayout();
	}

	public int getDefaultCellDimensions() {
	return sDefaultCellDimensions;
	}

	private void setChildrenAlpha(float alpha) {
	final int childCount = getChildCount();
	for (int i = 0; i < childCount; i++) {
	getChildAt(i).setAlpha(alpha);
	}
	}

	public int[] getCellCountForDimensions(int width, int height) {
	// Always assume we're working with the smallest span to make sure we
	// reserve enough space in both orientations
	int smallerSize = Math.min(mCellWidth, mCellHeight);

	// Always round up to next largest cell
	int spanX = (width + smallerSize) / smallerSize;
	int spanY = (height + smallerSize) / smallerSize;

	return new int[] { spanX, spanY };
	}

	/**
	* Start dragging the specified child
	*
	* @param child The child that is being dragged
	*/
	void onDragChild(View child) {
	PagedViewCellLayout.LayoutParams lp = (PagedViewCellLayout.LayoutParams) child.getLayoutParams();
	lp.isDragging = true;
	}

	/**
	* Estimates the number of cells that the specified width would take up.
	*/
	public int estimateCellHSpan(int width) {
	// TODO: we need to take widthGap into effect
	return (width + mCellWidth) / mCellWidth;
	}

	/**
	* Estimates the number of cells that the specified height would take up.
	*/
	public int estimateCellVSpan(int height) {
	// TODO: we need to take heightGap into effect
	return (height + mCellHeight) / mCellHeight;
	}

	/**
	* Estimates the width that the number of vSpan cells will take up.
	*/
	public int estimateCellWidth(int hSpan) {
	// TODO: we need to take widthGap into effect
	return hSpan * mCellWidth;
	}

	/**
	* Estimates the height that the number of vSpan cells will take up.
	*/
	public int estimateCellHeight(int vSpan) {
	// TODO: we need to take heightGap into effect
	return vSpan * mCellHeight;
	}

	@Override
	public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
	return new PagedViewCellLayout.LayoutParams(getContext(), attrs);
	}

	@Override
	protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
	return p instanceof PagedViewCellLayout.LayoutParams;
	}

	@Override
	protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
	return new PagedViewCellLayout.LayoutParams(p);
	}

	public static class LayoutParams extends ViewGroup.MarginLayoutParams {
	/**
	* Horizontal location of the item in the grid.
	*/
	@ViewDebug.ExportedProperty
	public int cellX;

	/**
	* Vertical location of the item in the grid.
	*/
	@ViewDebug.ExportedProperty
	public int cellY;

	/**
	* Number of cells spanned horizontally by the item.
	*/
	@ViewDebug.ExportedProperty
	public int cellHSpan;

	/**
	* Number of cells spanned vertically by the item.
	*/
	@ViewDebug.ExportedProperty
	public int cellVSpan;

	/**
	* Is this item currently being dragged
	*/
	public boolean isDragging;

	// a data object that you can bind to this layout params
	private Object mTag;

	// X coordinate of the view in the layout.
	@ViewDebug.ExportedProperty
	int x;
	// Y coordinate of the view in the layout.
	@ViewDebug.ExportedProperty
	int y;

	public LayoutParams() {
	super(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
	cellHSpan = 1;
	cellVSpan = 1;
	}

	public LayoutParams(Context c, AttributeSet attrs) {
	super(c, attrs);
	cellHSpan = 1;
	cellVSpan = 1;
	}

	public LayoutParams(ViewGroup.LayoutParams source) {
	super(source);
	cellHSpan = 1;
	cellVSpan = 1;
	}

	public LayoutParams(LayoutParams source) {
	super(source);
	this.cellX = source.cellX;
	this.cellY = source.cellY;
	this.cellHSpan = source.cellHSpan;
	this.cellVSpan = source.cellVSpan;
	}

	public LayoutParams(int cellX, int cellY, int cellHSpan, int cellVSpan) {
	super(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
	this.cellX = cellX;
	this.cellY = cellY;
	this.cellHSpan = cellHSpan;
	this.cellVSpan = cellVSpan;
	}

	public void setup(int cellWidth, int cellHeight, int widthGap, int heightGap,
	int hStartPadding, int vStartPadding) {

	final int myCellHSpan = cellHSpan;
	final int myCellVSpan = cellVSpan;
	final int myCellX = cellX;
	final int myCellY = cellY;

	width = myCellHSpan * cellWidth + ((myCellHSpan - 1) * widthGap) -
	leftMargin - rightMargin;
	height = myCellVSpan * cellHeight + ((myCellVSpan - 1) * heightGap) -
	topMargin - bottomMargin;

	x = hStartPadding + myCellX * (cellWidth + widthGap) + leftMargin;
	y = vStartPadding + myCellY * (cellHeight + heightGap) + topMargin;
	}

	public Object getTag() {
	return mTag;
	}

	public void setTag(Object tag) {
	mTag = tag;
	}

	public String toString() {
	return "(" + this.cellX + ", " + this.cellY + ", " +
	this.cellHSpan + ", " + this.cellVSpan + ")";
	}
	}
	}