Port AutoScroller to launcher3

Change-Id: Ic2b7b5faac4878f3b4645c291e36c5f7734c7f8b

1 files changed, 56 insertions, 0 deletions

diff --git a/src/com/android/launcher3/FolderAutoScrollHelper.java b/src/com/android/launcher3/FolderAutoScrollHelper.java
new file mode 100644
index 000000000..d7e677053
--- /dev/null
+++ b/src/com/android/launcher3/FolderAutoScrollHelper.java
@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2013 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.launcher3;
+
+import android.widget.ScrollView;
+
+/**
+ * An implementation of {@link AutoScrollHelper} that knows how to scroll
+ * through a {@link Folder}.
+ */
+public class FolderAutoScrollHelper extends AutoScrollHelper {
+    private static final float MAX_SCROLL_VELOCITY = 1500f;
+
+    private final ScrollView mTarget;
+
+    public FolderAutoScrollHelper(ScrollView target) {
+        super(target);
+
+        mTarget = target;
+
+        setActivationDelay(0);
+        setEdgeType(EDGE_TYPE_INSIDE);
+        setExclusive(true);
+        setMaximumVelocity(MAX_SCROLL_VELOCITY, MAX_SCROLL_VELOCITY);
+    }
+
+    @Override
+    public void scrollTargetBy(int deltaX, int deltaY) {
+        mTarget.scrollBy(deltaX, deltaY);
+    }
+
+    @Override
+    public boolean canTargetScrollHorizontally(int direction) {
+        // List do not scroll horizontally.
+        return false;
+    }
+
+    @Override
+    public boolean canTargetScrollVertically(int direction) {
+        return mTarget.canScrollVertically(direction);
+    }
+}
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