Add input filter mechanism for accessibility.
This patch adds a mechanism for capturing, filtering, transforming
and injecting input events at a very low level before the input
dispatcher attempts to deliver them to applications. At this time,
the mechanism is only intended to be used by the accessibility
system to implement built-in system-level accessibility affordances.
The accessibility input filter is currently just a stub.
It logs the input events receives and reinjects them unchanged,
except that it transforms KEYCODE_Q into KEYCODE_Z.
Currently, the accessibility input filter is installed whenever
accessibility is enabled. We'll probably want to change that
so it only enables the input filter when a screen reader is
installed and we want touch exploration.
Change-Id: I35764fdf75522b69d09ebd78c9766eb7593c1afe
diff --git a/services/jni/com_android_server_InputManager.cpp b/services/jni/com_android_server_InputManager.cpp
index 96cf4bd..ab2c125 100644
--- a/services/jni/com_android_server_InputManager.cpp
+++ b/services/jni/com_android_server_InputManager.cpp
@@ -56,6 +56,7 @@
jmethodID notifyLidSwitchChanged;
jmethodID notifyInputChannelBroken;
jmethodID notifyANR;
+ jmethodID filterInputEvent;
jmethodID interceptKeyBeforeQueueing;
jmethodID interceptMotionBeforeQueueingWhenScreenOff;
jmethodID interceptKeyBeforeDispatching;
@@ -174,6 +175,7 @@
virtual nsecs_t getKeyRepeatTimeout();
virtual nsecs_t getKeyRepeatDelay();
virtual int32_t getMaxEventsPerSecond();
+ virtual bool filterInputEvent(const InputEvent* inputEvent, uint32_t policyFlags);
virtual void interceptKeyBeforeQueueing(const KeyEvent* keyEvent, uint32_t& policyFlags);
virtual void interceptMotionBeforeQueueing(nsecs_t when, uint32_t& policyFlags);
virtual bool interceptKeyBeforeDispatching(const sp<InputWindowHandle>& inputWindowHandle,
@@ -638,6 +640,38 @@
return android_server_PowerManagerService_isScreenBright();
}
+bool NativeInputManager::filterInputEvent(const InputEvent* inputEvent, uint32_t policyFlags) {
+ jobject inputEventObj;
+
+ JNIEnv* env = jniEnv();
+ switch (inputEvent->getType()) {
+ case AINPUT_EVENT_TYPE_KEY:
+ inputEventObj = android_view_KeyEvent_fromNative(env,
+ static_cast<const KeyEvent*>(inputEvent));
+ break;
+ case AINPUT_EVENT_TYPE_MOTION:
+ inputEventObj = android_view_MotionEvent_obtainAsCopy(env,
+ static_cast<const MotionEvent*>(inputEvent));
+ break;
+ default:
+ return true; // dispatch the event normally
+ }
+
+ if (!inputEventObj) {
+ LOGE("Failed to obtain input event object for filterInputEvent.");
+ return true; // dispatch the event normally
+ }
+
+ // The callee is responsible for recycling the event.
+ jboolean pass = env->CallBooleanMethod(mCallbacksObj, gCallbacksClassInfo.filterInputEvent,
+ inputEventObj, policyFlags);
+ if (checkAndClearExceptionFromCallback(env, "filterInputEvent")) {
+ pass = true;
+ }
+ env->DeleteLocalRef(inputEventObj);
+ return pass;
+}
+
void NativeInputManager::interceptKeyBeforeQueueing(const KeyEvent* keyEvent,
uint32_t& policyFlags) {
// Policy:
@@ -1005,9 +1039,18 @@
}
}
+static void android_server_InputManager_nativeSetInputFilterEnabled(JNIEnv* env, jclass clazz,
+ jboolean enabled) {
+ if (checkInputManagerUnitialized(env)) {
+ return;
+ }
+
+ gNativeInputManager->getInputManager()->getDispatcher()->setInputFilterEnabled(enabled);
+}
+
static jint android_server_InputManager_nativeInjectInputEvent(JNIEnv* env, jclass clazz,
jobject inputEventObj, jint injectorPid, jint injectorUid,
- jint syncMode, jint timeoutMillis) {
+ jint syncMode, jint timeoutMillis, jint policyFlags) {
if (checkInputManagerUnitialized(env)) {
return INPUT_EVENT_INJECTION_FAILED;
}
@@ -1021,7 +1064,8 @@
}
return gNativeInputManager->getInputManager()->getDispatcher()->injectInputEvent(
- & keyEvent, injectorPid, injectorUid, syncMode, timeoutMillis);
+ & keyEvent, injectorPid, injectorUid, syncMode, timeoutMillis,
+ uint32_t(policyFlags));
} else if (env->IsInstanceOf(inputEventObj, gMotionEventClassInfo.clazz)) {
const MotionEvent* motionEvent = android_view_MotionEvent_getNativePtr(env, inputEventObj);
if (!motionEvent) {
@@ -1030,7 +1074,8 @@
}
return gNativeInputManager->getInputManager()->getDispatcher()->injectInputEvent(
- motionEvent, injectorPid, injectorUid, syncMode, timeoutMillis);
+ motionEvent, injectorPid, injectorUid, syncMode, timeoutMillis,
+ uint32_t(policyFlags));
} else {
jniThrowRuntimeException(env, "Invalid input event type.");
return INPUT_EVENT_INJECTION_FAILED;
@@ -1200,7 +1245,9 @@
(void*) android_server_InputManager_nativeRegisterInputChannel },
{ "nativeUnregisterInputChannel", "(Landroid/view/InputChannel;)V",
(void*) android_server_InputManager_nativeUnregisterInputChannel },
- { "nativeInjectInputEvent", "(Landroid/view/InputEvent;IIII)I",
+ { "nativeSetInputFilterEnabled", "(Z)V",
+ (void*) android_server_InputManager_nativeSetInputFilterEnabled },
+ { "nativeInjectInputEvent", "(Landroid/view/InputEvent;IIIII)I",
(void*) android_server_InputManager_nativeInjectInputEvent },
{ "nativeSetInputWindows", "([Lcom/android/server/wm/InputWindow;)V",
(void*) android_server_InputManager_nativeSetInputWindows },
@@ -1257,6 +1304,9 @@
"notifyANR",
"(Lcom/android/server/wm/InputApplicationHandle;Lcom/android/server/wm/InputWindowHandle;)J");
+ GET_METHOD_ID(gCallbacksClassInfo.filterInputEvent, clazz,
+ "filterInputEvent", "(Landroid/view/InputEvent;I)Z");
+
GET_METHOD_ID(gCallbacksClassInfo.interceptKeyBeforeQueueing, clazz,
"interceptKeyBeforeQueueing", "(Landroid/view/KeyEvent;IZ)I");