Refactoring CellLayout into three classes

- splitting the rendering of children from the CellLayout to enhance performance, gives ~4 fps boost while scrolling on pages full of icons, and no change on pages full of widgets
- this will allow us to add hardware layer support trivially, which will increase performance while scrolling ~6-10 fps
- separated logic for caching celllayouts to bitmaps into a separate class

Change-Id: Ib6abeb19126e1504997b43c2f44af2a2fb3cd39f

1 files changed, 170 insertions, 0 deletions

diff --git a/src/com/android/launcher2/CellLayoutChildren.java b/src/com/android/launcher2/CellLayoutChildren.java
new file mode 100644
index 000000000..09ab26688
--- /dev/null
+++ b/src/com/android/launcher2/CellLayoutChildren.java
@@ -0,0 +1,170 @@
+/*
+ * Copyright (C) 2008 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.app.WallpaperManager;
+import android.content.Context;
+import android.graphics.Canvas;
+import android.graphics.Rect;
+import android.view.View;
+
+public class CellLayoutChildren extends CachedViewGroup {
+    static final String TAG = "CellLayoutChildren";
+
+    // These are temporary variables to prevent having to allocate a new object just to
+    // return an (x, y) value from helper functions. Do NOT use them to maintain other state.
+    private final int[] mTmpCellXY = new int[2];
+
+    private final WallpaperManager mWallpaperManager;
+
+    private int mCellWidth;
+    private int mCellHeight;
+
+    private int mLeftPadding;
+    private int mTopPadding;
+
+    private int mWidthGap;
+    private int mHeightGap;
+
+    public CellLayoutChildren(Context context) {
+        super(context);
+        mWallpaperManager = WallpaperManager.getInstance(context);
+    }
+
+    public void setCellDimensions(int cellWidth, int cellHeight,
+            int leftPadding, int topPadding, int widthGap, int heightGap ) {
+        mCellWidth = cellWidth;
+        mCellHeight = cellHeight;
+        mLeftPadding = leftPadding;
+        mTopPadding = topPadding;
+        mWidthGap = widthGap;
+        mHeightGap = heightGap;
+    }
+
+    public View getChildAt(int x, int y) {
+        final int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            View child = getChildAt(i);
+            CellLayout.LayoutParams lp = (CellLayout.LayoutParams) child.getLayoutParams();
+
+            if ((lp.cellX <= x) && (x < lp.cellX + lp.cellHSpan) &&
+                    (lp.cellY <= y) && (y < lp.cellY + lp.cellHSpan)) {
+                return child;
+            }
+        }
+        return null;
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        final int cellWidth = mCellWidth;
+        final int cellHeight = mCellHeight;
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            View child = getChildAt(i);
+            CellLayout.LayoutParams lp = (CellLayout.LayoutParams) child.getLayoutParams();
+
+            lp.setup(cellWidth, cellHeight, mWidthGap, mHeightGap,
+                    mLeftPadding, mTopPadding);
+
+            int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(lp.width, MeasureSpec.EXACTLY);
+            int childheightMeasureSpec = MeasureSpec.makeMeasureSpec(lp.height,
+                    MeasureSpec.EXACTLY);
+
+            child.measure(childWidthMeasureSpec, childheightMeasureSpec);
+        }
+        int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);
+        int heightSpecSize =  MeasureSpec.getSize(heightMeasureSpec);
+        setMeasuredDimension(widthSpecSize, heightSpecSize);
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        super.onLayout(changed, l, t, r, b);
+        int count = getChildCount();
+        for (int i = 0; i < count; i++) {
+            final View child = getChildAt(i);
+            if (child.getVisibility() != GONE) {
+                CellLayout.LayoutParams lp = (CellLayout.LayoutParams) child.getLayoutParams();
+
+                int childLeft = lp.x;
+                int childTop = lp.y;
+                child.layout(childLeft, childTop, childLeft + lp.width, childTop + lp.height);
+
+                if (lp.dropped) {
+                    lp.dropped = false;
+
+                    final int[] cellXY = mTmpCellXY;
+                    getLocationOnScreen(cellXY);
+                    mWallpaperManager.sendWallpaperCommand(getWindowToken(),
+                            WallpaperManager.COMMAND_DROP,
+                            cellXY[0] + childLeft + lp.width / 2,
+                            cellXY[1] + childTop + lp.height / 2, 0, null);
+
+                    if (lp.animateDrop) {
+                        lp.animateDrop = false;
+
+                        // This call does not result in a requestLayout(), but at one point did.
+                        // We need to be cautious about any method calls within the layout pass
+                        // to insure we don't leave the view tree in a bad state.
+                        ((Workspace) mParent.getParent()).animateViewIntoPosition(child);
+                    }
+                }
+            }
+        }
+    }
+
+    @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
+    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();
+        }
+    }
+
+    @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);
+            }
+        }
+    }
+
+    @Override
+    protected void setChildrenDrawnWithCacheEnabled(boolean enabled) {
+        super.setChildrenDrawnWithCacheEnabled(enabled);
+    }
+}
\ No newline at end of file