Updating drop button targets

> Splitting DeleteDropTarget into delete and uninstall
> Showing UninstallDropTarget for app shortcuts on workspace
> Showing InfoDropTarget only when developer options is enabled

Change-Id: I4396571d2199d1581bb9c733aef88ab9b0ebd79d

src/com/android/launcher3/UninstallDropTarget.java

@@ -0,0 +1,122 @@
+package com.android.launcher3;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.os.Build;
+import android.os.Bundle;
+import android.os.UserManager;
+import android.util.AttributeSet;
+import android.util.Pair;
+
+import com.android.launcher3.R;
+import com.android.launcher3.compat.UserHandleCompat;
+import com.android.launcher3.util.Thunk;
+
+public class UninstallDropTarget extends ButtonDropTarget {
+
+    public UninstallDropTarget(Context context, AttributeSet attrs) {
+        this(context, attrs, 0);
+    }
+
+    public UninstallDropTarget(Context context, AttributeSet attrs, int defStyle) {
+        super(context, attrs, defStyle);
+    }
+
+    @Override
+    protected void onFinishInflate() {
+        super.onFinishInflate();
+        // Get the hover color
+        mHoverColor = getResources().getColor(R.color.delete_target_hover_tint);
+
+        setDrawable(R.drawable.uninstall_target_selector);
+    }
+
+    @Override
+    protected boolean supportsDrop(DragSource source, Object info) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2) {
+            UserManager userManager = (UserManager)
+                    getContext().getSystemService(Context.USER_SERVICE);
+            Bundle restrictions = userManager.getUserRestrictions();
+            if (restrictions.getBoolean(UserManager.DISALLOW_APPS_CONTROL, false)
+                    || restrictions.getBoolean(UserManager.DISALLOW_UNINSTALL_APPS, false)) {
+                return false;
+            }
+        }
+
+        Pair<ComponentName, Integer> componentInfo = getAppInfoFlags(info);
+        return componentInfo != null && (componentInfo.second & AppInfo.DOWNLOADED_FLAG) != 0;
+    }
+
+    /**
+     * @return the component name and flags if {@param info} is an AppInfo or an app shortcut.
+     */
+    private static Pair<ComponentName, Integer> getAppInfoFlags(Object item) {
+        if (item instanceof AppInfo) {
+            AppInfo info = (AppInfo) item;
+            return Pair.create(info.componentName, info.flags);
+        } else if (item instanceof ShortcutInfo) {
+            ShortcutInfo info = (ShortcutInfo) item;
+            ComponentName component = info.getTargetComponent();
+            if (info.itemType == LauncherSettings.BaseLauncherColumns.ITEM_TYPE_APPLICATION
+                    && component != null) {
+                return Pair.create(component, info.flags);
+            }
+        }
+        return null;
+    }
+
+    @Override
+    public void onDrop(DragObject d) {
+        // Differ item deletion
+        if (d.dragSource instanceof UninstallSource) {
+            ((UninstallSource) d.dragSource).deferCompleteDropAfterUninstallActivity();
+        }
+        super.onDrop(d);
+    }
+
+    @Override
+    void completeDrop(final DragObject d) {
+        final Pair<ComponentName, Integer> componentInfo = getAppInfoFlags(d.dragInfo);
+        final UserHandleCompat user = ((ItemInfo) d.dragInfo).user;
+        if (mLauncher.startApplicationUninstallActivity(
+                componentInfo.first, componentInfo.second, user)) {
+
+            final Runnable checkIfUninstallWasSuccess = new Runnable() {
+                @Override
+                public void run() {
+                    String packageName = componentInfo.first.getPackageName();
+                    boolean uninstallSuccessful = !AllAppsList.packageHasActivities(
+                            getContext(), packageName, user);
+                    sendUninstallResult(d.dragSource, uninstallSuccessful);
+                }
+            };
+            mLauncher.addOnResumeCallback(checkIfUninstallWasSuccess);
+        } else {
+            sendUninstallResult(d.dragSource, false);
+        }
+    }
+
+    @Thunk void sendUninstallResult(DragSource target, boolean result) {
+        if (target instanceof UninstallSource) {
+            ((UninstallSource) target).onUninstallActivityReturned(result);
+        }
+    }
+
+    /**
+     * Interface defining an object that can provide uninstallable drag objects.
+     */
+    public static interface UninstallSource {
+
+        /**
+         * A pending uninstall operation was complete.
+         * @param result true if uninstall was successful, false otherwise.
+         */
+        void onUninstallActivityReturned(boolean result);
+
+        /**
+         * Indicates that an uninstall request are made and the actual result may come
+         * after some time.
+         */
+        void deferCompleteDropAfterUninstallActivity();
+    }
+}