Iterate on data usage chart UI.

Switched to inflating chart views from XML, using attributes for
configuration.  Start using drawable assets for chart components
instead of manually painting.  Include hand-cut assets, and animate
between states when touched to invoke.

Clamp sweeps to valid chart ranges and prepare for sweep labels.

Bug: 4768483, 4598460
Change-Id: Ic660c35bec826eb5e3f6a1dde3cc04d8c437ef2b
diff --git a/res/drawable/data_sweep_left.xml b/res/drawable/data_sweep_left.xml
new file mode 100644
index 0000000..739a74e
--- /dev/null
+++ b/res/drawable/data_sweep_left.xml
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- 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.
+-->
+
+<selector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:exitFadeDuration="@android:integer/config_mediumAnimTime">
+
+    <item android:state_activated="true" android:drawable="@drawable/data_sweep_left_activated" />
+    <item android:state_activated="false" android:drawable="@drawable/data_sweep_left_default" />
+</selector>