Divide InputDispatcher into several files.

This CL does:
1) Isolate implementation details of InputDispatcher from outside and
only expose necessary header files;
2) Move implementation details into android::inputdispatcher namespace;
3) Make input dispatcher a static library for inputflinger to link
against;
4) Add InputDispatcherFactory.{h,cpp} to isolate implementation details
in InputDispatcher.h from InputManager.

Bug: 140139676
Test: Touches on touchscreen can be dispatched to right windows.
Change-Id: Ib61c16fd41f3f76f538a3de9b54f31ac304e03a5
diff --git a/services/inputflinger/dispatcher/include/InputDispatcherInterface.h b/services/inputflinger/dispatcher/include/InputDispatcherInterface.h
new file mode 100644
index 0000000..9329ca6
--- /dev/null
+++ b/services/inputflinger/dispatcher/include/InputDispatcherInterface.h
@@ -0,0 +1,158 @@
+/*
+ * Copyright (C) 2019 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.
+ */
+
+#ifndef _UI_INPUT_INPUTDISPATCHER_INPUTDISPATCHERINTERFACE_H
+#define _UI_INPUT_INPUTDISPATCHER_INPUTDISPATCHERINTERFACE_H
+
+#include <InputListener.h>
+#include <input/ISetInputWindowsListener.h>
+
+namespace android {
+
+class InputApplicationHandle;
+class InputChannel;
+class InputWindowHandle;
+
+/*
+ * Constants used to report the outcome of input event injection.
+ */
+enum {
+    /* (INTERNAL USE ONLY) Specifies that injection is pending and its outcome is unknown. */
+    INPUT_EVENT_INJECTION_PENDING = -1,
+
+    /* Injection succeeded. */
+    INPUT_EVENT_INJECTION_SUCCEEDED = 0,
+
+    /* Injection failed because the injector did not have permission to inject
+     * into the application with input focus. */
+    INPUT_EVENT_INJECTION_PERMISSION_DENIED = 1,
+
+    /* Injection failed because there were no available input targets. */
+    INPUT_EVENT_INJECTION_FAILED = 2,
+
+    /* Injection failed due to a timeout. */
+    INPUT_EVENT_INJECTION_TIMED_OUT = 3
+};
+
+/* Notifies the system about input events generated by the input reader.
+ * The dispatcher is expected to be mostly asynchronous. */
+class InputDispatcherInterface : public virtual RefBase, public InputListenerInterface {
+protected:
+    InputDispatcherInterface() {}
+    virtual ~InputDispatcherInterface() {}
+
+public:
+    /* Dumps the state of the input dispatcher.
+     *
+     * This method may be called on any thread (usually by the input manager). */
+    virtual void dump(std::string& dump) = 0;
+
+    /* Called by the heatbeat to ensures that the dispatcher has not deadlocked. */
+    virtual void monitor() = 0;
+
+    /* Runs a single iteration of the dispatch loop.
+     * Nominally processes one queued event, a timeout, or a response from an input consumer.
+     *
+     * This method should only be called on the input dispatcher thread.
+     */
+    virtual void dispatchOnce() = 0;
+
+    /* Injects an input event and optionally waits for sync.
+     * The synchronization mode determines whether the method blocks while waiting for
+     * input injection to proceed.
+     * Returns one of the INPUT_EVENT_INJECTION_XXX constants.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual int32_t injectInputEvent(const InputEvent* event, int32_t injectorPid,
+                                     int32_t injectorUid, int32_t syncMode, int32_t timeoutMillis,
+                                     uint32_t policyFlags) = 0;
+
+    /* Sets the list of input windows.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual void setInputWindows(
+            const std::vector<sp<InputWindowHandle> >& inputWindowHandles, int32_t displayId,
+            const sp<ISetInputWindowsListener>& setInputWindowsListener = nullptr) = 0;
+
+    /* Sets the focused application on the given display.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual void setFocusedApplication(
+            int32_t displayId, const sp<InputApplicationHandle>& inputApplicationHandle) = 0;
+
+    /* Sets the focused display.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual void setFocusedDisplay(int32_t displayId) = 0;
+
+    /* Sets the input dispatching mode.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual void setInputDispatchMode(bool enabled, bool frozen) = 0;
+
+    /* Sets whether input event filtering is enabled.
+     * When enabled, incoming input events are sent to the policy's filterInputEvent
+     * method instead of being dispatched.  The filter is expected to use
+     * injectInputEvent to inject the events it would like to have dispatched.
+     * It should include POLICY_FLAG_FILTERED in the policy flags during injection.
+     */
+    virtual void setInputFilterEnabled(bool enabled) = 0;
+
+    /* Transfers touch focus from one window to another window.
+     *
+     * Returns true on success.  False if the window did not actually have touch focus.
+     */
+    virtual bool transferTouchFocus(const sp<IBinder>& fromToken, const sp<IBinder>& toToken) = 0;
+
+    /* Registers input channels that may be used as targets for input events.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual status_t registerInputChannel(const sp<InputChannel>& inputChannel,
+                                          int32_t displayId) = 0;
+
+    /* Registers input channels to be used to monitor input events.
+     *
+     * Each monitor must target a specific display and will only receive input events sent to that
+     * display. If the monitor is a gesture monitor, it will only receive pointer events on the
+     * targeted display.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual status_t registerInputMonitor(const sp<InputChannel>& inputChannel, int32_t displayId,
+                                          bool gestureMonitor) = 0;
+
+    /* Unregister input channels that will no longer receive input events.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual status_t unregisterInputChannel(const sp<InputChannel>& inputChannel) = 0;
+
+    /* Allows an input monitor steal the current pointer stream away from normal input windows.
+     *
+     * This method may be called on any thread (usually by the input manager).
+     */
+    virtual status_t pilferPointers(const sp<IBinder>& token) = 0;
+};
+
+} // namespace android
+
+#endif // _UI_INPUT_INPUTDISPATCHER_INPUTDISPATCHERINTERFACE_H