Adding paging for the widget/shortcut/folder customization area and fixing bugs.

Adding pages for customization drawer with initial implementation of proposed flow
layout for widgets.  Fixes for keeping all apps, and widgets in sync with Launcher
Model, optimizations for reloading all apps pages when invalidating.  Adding some
animations for tab transitions and feedback when long pressing to add certain items.

Change-Id: I8d51749f3a91c964bed35681f3a9192200b0d93e

src/com/android/launcher2/PagedViewCellLayout.java

@@ -55,6 +55,8 @@ public class PagedViewCellLayout extends ViewGroup {
     private final Rect mLayoutRect = new Rect();
     private final Rect mDimmedBitmapRect = new Rect();
 
+    private boolean mCenterContent;
+
     private int mCellCountX;
     private int mCellCountY;
     private int mCellWidth;
@@ -236,13 +238,28 @@ public class PagedViewCellLayout extends ViewGroup {
     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 = lp.x;
+                int childLeft = offsetX + lp.x;
                 int childTop = lp.y;
                 child.layout(childLeft, childTop, childLeft + lp.width, childTop + lp.height);
             }
@@ -261,6 +278,10 @@ public class PagedViewCellLayout extends ViewGroup {
         return super.onTouchEvent(event) || true;
     }
 
+    public void enableCenteredContent(boolean enabled) {
+        mCenterContent = enabled;
+    }
+
     @Override
     protected void setChildrenDrawingCacheEnabled(boolean enabled) {
         final int count = getChildCount();
@@ -327,12 +348,32 @@ public class PagedViewCellLayout extends ViewGroup {
         }
     }
 
+    public void clearDimmedBitmap() {
+        setDimmedBitmapAlpha(0.0f);
+        if (mDimmedBitmap != null) {
+            mDimmedBitmap.recycle();
+            mDimmedBitmap = null;
+        }
+    }
+
     private void setChildrenAlpha(float alpha) {
         for (int i = 0; i < getChildCount(); 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
      *
@@ -343,6 +384,39 @@ public class PagedViewCellLayout extends ViewGroup {
         lp.isDragging = true;
     }
 
+    public int estimateCellHSpan(int width) {
+        return (width + mCellWidth) / mCellWidth;
+    }
+    public int estimateCellVSpan(int height) {
+        return (height + mCellHeight) / mCellHeight;
+    }
+    public int[] estimateCellDimensions(int approxWidth, int approxHeight, 
+            int cellHSpan, int cellVSpan) {
+        // NOTE: we are disabling this until we find a good way to approximate this without fully
+        // measuring
+        /*
+        // we may want to use this before any measuring/layout happens, so we pass in an approximate
+        // size for the layout
+        int numWidthGaps = mCellCountX - 1;
+        int numHeightGaps = mCellCountY - 1;
+        int hSpaceLeft = approxWidth - mPaddingLeft
+            - mPaddingRight - (mCellWidth * mCellCountX);
+        int vSpaceLeft = approxHeight - mPaddingTop
+            - mPaddingBottom - (mCellHeight * mCellCountY);
+        int widthGap = hSpaceLeft / numWidthGaps;
+        int heightGap = vSpaceLeft / numHeightGaps;
+        int minGap = Math.min(widthGap, heightGap);
+        return new int[] {
+            (cellHSpan * mCellWidth) + ((cellHSpan - 1) * minGap),
+            (cellVSpan * mCellHeight) + ((cellVSpan - 1) * minGap)
+        };
+        */
+        return new int[] {
+            (cellHSpan * mCellWidth),
+            (cellVSpan * mCellHeight)
+        };
+    }
+
     @Override
     public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
         return new PagedViewCellLayout.LayoutParams(getContext(), attrs);
@@ -388,6 +462,9 @@ public class PagedViewCellLayout extends ViewGroup {
          */
         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;
@@ -395,6 +472,12 @@ public class PagedViewCellLayout extends ViewGroup {
         @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;
@@ -440,8 +523,17 @@ public class PagedViewCellLayout extends ViewGroup {
             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 + ")";
+            return "(" + this.cellX + ", " + this.cellY + ", " +
+                this.cellHSpan + ", " + this.cellVSpan + ")";
         }
     }
 }