Removing the SearchDropTarget bar as it no longer contains the QSB

> Renaming it to simply DropTargetBar
> Moving AppInfo to the top bar as well
> The workspace pages will extend to the top edge (minus some padding).
Since the QSB is no longer displayed on top of every page, there is
no reason to reserve the space.
> In spring-loaded mode, the workspace cell layout will scale enough
to make room for the drop target bar at the top

Change-Id: I2baf607310335dd576c9d9fcbb75ab708f47ac03

src/com/android/launcher3/DropTargetBar.java

@@ -0,0 +1,153 @@
+/*
+ * Copyright (C) 2011 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.animation.TimeInterpolator;
+import android.content.Context;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewDebug;
+import android.view.ViewPropertyAnimator;
+import android.view.accessibility.AccessibilityManager;
+import android.view.animation.AccelerateInterpolator;
+import android.widget.LinearLayout;
+
+import com.android.launcher3.dragndrop.DragController;
+
+/*
+ * The top bar containing various drop targets: Delete/App Info/Uninstall.
+ */
+public class DropTargetBar extends LinearLayout implements DragController.DragListener {
+
+    protected static final int DEFAULT_DRAG_FADE_DURATION = 175;
+    protected static final TimeInterpolator DEFAULT_INTERPOLATOR = new AccelerateInterpolator();
+
+    private final Runnable mFadeAnimationEndRunnable = new Runnable() {
+
+        @Override
+        public void run() {
+            AccessibilityManager am = (AccessibilityManager)
+                    getContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
+            boolean accessibilityEnabled = am.isEnabled();
+            AlphaUpdateListener.updateVisibility(DropTargetBar.this, accessibilityEnabled);
+        }
+    };
+
+    @ViewDebug.ExportedProperty(category = "launcher")
+    protected boolean mDeferOnDragEnd;
+
+    @ViewDebug.ExportedProperty(category = "launcher")
+    protected boolean mVisible = false;
+
+    private ViewPropertyAnimator mCurrentAnimation;
+
+    // Drop targets
+    private ButtonDropTarget mDeleteDropTarget;
+    private ButtonDropTarget mAppInfoDropTarget;
+    private ButtonDropTarget mUninstallDropTarget;
+
+    public DropTargetBar(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public DropTargetBar(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+
+        // Get the individual components
+        mDeleteDropTarget = (ButtonDropTarget) findViewById(R.id.delete_target_text);
+        mAppInfoDropTarget = (ButtonDropTarget) findViewById(R.id.info_target_text);
+        mUninstallDropTarget = (ButtonDropTarget) findViewById(R.id.uninstall_target_text);
+
+        mDeleteDropTarget.setDropTargetBar(this);
+        mAppInfoDropTarget.setDropTargetBar(this);
+        mUninstallDropTarget.setDropTargetBar(this);
+
+        // Initialize with hidden state
+        setAlpha(0f);
+    }
+
+    public void setup(DragController dragController) {
+        dragController.addDragListener(this);
+        dragController.setFlingToDeleteDropTarget(mDeleteDropTarget);
+
+        dragController.addDragListener(mDeleteDropTarget);
+        dragController.addDragListener(mAppInfoDropTarget);
+        dragController.addDragListener(mUninstallDropTarget);
+
+        dragController.addDropTarget(mDeleteDropTarget);
+        dragController.addDropTarget(mAppInfoDropTarget);
+        dragController.addDropTarget(mUninstallDropTarget);
+    }
+
+    private void animateToVisibility(boolean isVisible) {
+        if (mVisible != isVisible) {
+            mVisible = isVisible;
+
+            // Cancel any existing animation
+            if (mCurrentAnimation != null) {
+                mCurrentAnimation.cancel();
+                mCurrentAnimation = null;
+            }
+
+            float finalAlpha = mVisible ? 1 : 0;
+            if (Float.compare(getAlpha(), finalAlpha) != 0) {
+                setVisibility(View.VISIBLE);
+                mCurrentAnimation = animate().alpha(finalAlpha)
+                        .setInterpolator(DEFAULT_INTERPOLATOR)
+                        .setDuration(DEFAULT_DRAG_FADE_DURATION)
+                        .withEndAction(mFadeAnimationEndRunnable);
+            }
+
+        }
+    }
+
+    public void enableAccessibleDrag(boolean enable) {
+        mDeleteDropTarget.enableAccessibleDrag(enable);
+        mAppInfoDropTarget.enableAccessibleDrag(enable);
+        mUninstallDropTarget.enableAccessibleDrag(enable);
+    }
+
+    /*
+     * DragController.DragListener implementation
+     */
+    @Override
+    public void onDragStart(DragSource source, ItemInfo info, int dragAction) {
+        animateToVisibility(true);
+    }
+
+    /**
+     * This is called to defer hiding the delete drop target until the drop animation has completed,
+     * instead of hiding immediately when the drag has ended.
+     */
+    protected void deferOnDragEnd() {
+        mDeferOnDragEnd = true;
+    }
+
+    @Override
+    public void onDragEnd() {
+        if (!mDeferOnDragEnd) {
+            animateToVisibility(false);
+        } else {
+            mDeferOnDragEnd = false;
+        }
+    }
+}