commit 9415d87eda0cf28b8df1eccde39b0ca1646be3b9
author Adam Cohen <adamcohen@google.com> Mon Sep 13 14:49:43 2010 -0700
committer Adam Cohen <adamcohen@google.com> Tue Sep 28 16:56:10 2010 -0700
tree 90af24bc558676ae26831eec04ca0cb392104aa0
parent 163c9c0236b7824673d4ead9dbf664bf38ec047e

-Added 3D effect to home screen scrolling
-Added background outline fade in / out
-Modified the feel of scrolling: now using quintic
 interpolator and modified the influence of
 scroll velocity

Change-Id: Ifddcab5223ac20be7d9f800ccf09442d9b4db781

src/com/android/launcher2/PagedView.java

diff --git a/src/com/android/launcher2/PagedView.java b/src/com/android/launcher2/PagedView.java
index 5aec48e..4e47acb 100644
--- a/src/com/android/launcher2/PagedView.java
+++ b/src/com/android/launcher2/PagedView.java
@@ -78,6 +78,7 @@
     protected final static int TOUCH_STATE_SCROLLING = 1;
     protected final static int TOUCH_STATE_PREV_PAGE = 2;
     protected final static int TOUCH_STATE_NEXT_PAGE = 3;
+    protected final static float ALPHA_QUANTIZE_LEVEL = 0.01f;
 
     protected int mTouchState = TOUCH_STATE_REST;
 
@@ -367,7 +368,6 @@
             if (mDirtyPageAlpha || (mTouchState == TOUCH_STATE_SCROLLING) || !mScroller.isFinished()) {
                 int halfScreenSize = getMeasuredWidth() / 2;
                 int screenCenter = mScrollX + halfScreenSize;
-
                 final int childCount = getChildCount();
                 for (int i = 0; i < childCount; ++i) {
                     View layout = (View) getChildAt(i);
@@ -391,6 +391,12 @@
                     dimAlpha = Math.max(0.0f, Math.min(1.0f, (dimAlpha * dimAlpha)));
                     float alpha = 1.0f - dimAlpha;
 
+                    if (alpha < ALPHA_QUANTIZE_LEVEL) {
+                        alpha = 0.0f;
+                    } else if (alpha > 1.0f - ALPHA_QUANTIZE_LEVEL) {
+                        alpha = 1.0f;
+                    }
+
                     if (Float.compare(alpha, layout.getAlpha()) != 0) {
                         layout.setAlpha(alpha);
                     }
@@ -400,10 +406,16 @@
         }
     }
 
+    protected void screenScrolled(int screenCenter) {
+    }
+
     @Override
     protected void dispatchDraw(Canvas canvas) {
         updateAdjacentPagesAlpha();
 
+        int halfScreenSize = getMeasuredWidth() / 2;
+        int screenCenter = mScrollX + halfScreenSize;
+        screenScrolled(screenCenter);
         // Find out which screens are visible; as an optimization we only call draw on them
         // As an optimization, this code assumes that all pages have the same width as the 0th
         // page.