Long-press on an app to reveal its shortcuts.

- Add ShortcutsContainerListener to icons on workspace, folders, and
  all apps. This handles long-press and forwards following touches to
  the DeepShortcutsContainer that is created.
- Drag over shortcut before lifting finger to launch it.
- Shortcuts are rendered in pill-shaped DeepShortcutViews,
  which are inside DeepShortcutContainer on DragLayer.
- The shortcut container orients above or below the icon, and left or
  right-aligns with it. Biases for above + left-align.
- Long press a DeepShortcutPill to drag and pin it to the workspace.

Bug: 28980830
Change-Id: I08658d13ae51fe53064644e8d8f7b42f150fdd7d

src/com/android/launcher3/folder/FolderPagedView.java

@@ -46,6 +46,8 @@ import com.android.launcher3.Workspace.ItemOperator;
 import com.android.launcher3.dragndrop.DragController;
 import com.android.launcher3.pageindicators.PageIndicator;
 import com.android.launcher3.keyboard.ViewGroupFocusHelper;
+import com.android.launcher3.shortcuts.DeepShortcutManager;
+import com.android.launcher3.shortcuts.ShortcutsContainerListener;
 import com.android.launcher3.util.Thunk;
 
 import java.util.ArrayList;
@@ -234,6 +236,10 @@ public class FolderPagedView extends PagedView {
         textView.applyFromShortcutInfo(item, mIconCache);
         textView.setOnClickListener(mFolder);
         textView.setOnLongClickListener(mFolder);
+        if (DeepShortcutManager.supportsShortcuts(item)) {
+            // TODO: only add this listener if the item has shortcuts associated with it.
+            textView.setOnTouchListener(new ShortcutsContainerListener(textView));
+        }
         textView.setOnFocusChangeListener(mFocusIndicatorHelper);
         textView.setOnKeyListener(mKeyListener);