commit e54cb8574f9c44256c88c192ec28256fbd0b3006
author Siarhei Vishniakou <svv@google.com> Tue Mar 21 17:48:16 2017 -0700
committer Siarhei Vishniakou <svv@google.com> Wed May 03 16:04:01 2017 -0700
tree 369896d837c05fd3fc4c5834e63d16fca3ebcbef
parent 50c3195e94d99c8515595a8f3926d2bd2b5cb8cc

Adding feature: input device disable/enable

This functionality will only be available for signed system
services. A disable call will cause a file descriptor to the input
device driver to be closed, which in turn may cause the input
device to switch into a low-power mode. An enable call will
reopen the input device.

Bug: 30143923
Test: CTS test - android.view.cts.InputDeviceEnabledTest
Native test - WhenEnabledChanges_SendsDeviceResetNotification,
WhenDeviceCreated_EnabledIsTrue. Also developed a custom apk
with signature permission that calls disable/enable on a
touchscreen device. Verified that touchscreen stops working
when disable is called and starts working again when
enable is called. Verified that the file
handle to the driver is closed and reopened. Verified that
the notification onInputDeviceChanged is received in the
app.

Change-Id: I99a7866cebff873dc1848e11a39045ed2eaec07c

services/inputflinger/InputReader.cpp

diff --git a/services/inputflinger/InputReader.cpp b/services/inputflinger/InputReader.cpp
index 2705e13..8af9038 100644
--- a/services/inputflinger/InputReader.cpp
+++ b/services/inputflinger/InputReader.cpp
@@ -788,6 +788,18 @@
     }
 }
 
+bool InputReader::isInputDeviceEnabled(int32_t deviceId) {
+    AutoMutex _l(mLock);
+
+    ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
+    if (deviceIndex >= 0) {
+        InputDevice* device = mDevices.valueAt(deviceIndex);
+        return device->isEnabled();
+    }
+    ALOGW("Ignoring invalid device id %" PRId32 ".", deviceId);
+    return false;
+}
+
 void InputReader::dump(String8& dump) {
     AutoMutex _l(mLock);
 
@@ -961,6 +973,26 @@
     mMappers.clear();
 }
 
+bool InputDevice::isEnabled() {
+    return getEventHub()->isDeviceEnabled(mId);
+}
+
+void InputDevice::setEnabled(bool enabled, nsecs_t when) {
+    if (isEnabled() == enabled) {
+        return;
+    }
+
+    if (enabled) {
+        getEventHub()->enableDevice(mId);
+        reset(when);
+    } else {
+        reset(when);
+        getEventHub()->disableDevice(mId);
+    }
+    // Must change generation to flag this device as changed
+    bumpGeneration();
+}
+
 void InputDevice::dump(String8& dump) {
     InputDeviceInfo deviceInfo;
     getDeviceInfo(& deviceInfo);
@@ -1032,6 +1064,12 @@
             }
         }
 
+        if (!changes || (changes & InputReaderConfiguration::CHANGE_ENABLED_STATE)) {
+            ssize_t index = config->disabledDevices.indexOf(mId);
+            bool enabled = index < 0;
+            setEnabled(enabled, when);
+        }
+
         size_t numMappers = mMappers.size();
         for (size_t i = 0; i < numMappers; i++) {
             InputMapper* mapper = mMappers[i];