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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_INPUT_MAPPER_H_
     18 #define ANDROID_INPUT_MAPPER_H_
     19 
     20 struct input_device_handle;
     21 
     22 namespace android {
     23 
     24 class InputDeviceNode;
     25 class InputReport;
     26 class InputReportDefinition;
     27 struct InputEvent;
     28 using InputDeviceHandle = struct input_device_handle;
     29 
     30 /**
     31  * An InputMapper processes raw evdev input events and combines them into
     32  * Android input HAL reports. A given InputMapper will focus on a particular
     33  * type of input, like key presses or touch events. A single InputDevice may
     34  * have multiple InputMappers, corresponding to the different types of inputs it
     35  * supports.
     36  */
     37 class InputMapper {
     38 public:
     39     InputMapper() = default;
     40     virtual ~InputMapper() {}
     41 
     42     /**
     43      * If the mapper supports input events from the InputDevice,
     44      * configureInputReport will populate the InputReportDefinition and return
     45      * true. If input is not supported, false is returned, and the InputDevice
     46      * may free or re-use the InputReportDefinition.
     47      */
     48     virtual bool configureInputReport(InputDeviceNode* devNode, InputReportDefinition* report) {
     49         return false;
     50     }
     51 
     52     /**
     53      * If the mapper supports output events from the InputDevice,
     54      * configureOutputReport will populate the InputReportDefinition and return
     55      * true. If output is not supported, false is returned, and the InputDevice
     56      * may free or re-use the InputReportDefinition.
     57      */
     58     virtual bool configureOutputReport(InputDeviceNode* devNode, InputReportDefinition* report) {
     59         return false;
     60     }
     61 
     62     // Set the InputDeviceHandle after registering the device with the host.
     63     virtual void setDeviceHandle(InputDeviceHandle* handle) { mDeviceHandle = handle; }
     64     // Process the InputEvent.
     65     virtual void process(const InputEvent& event) = 0;
     66 
     67 protected:
     68     virtual void setInputReportDefinition(InputReportDefinition* reportDef) final {
     69         mInputReportDef = reportDef;
     70     }
     71     virtual void setOutputReportDefinition(InputReportDefinition* reportDef) final {
     72         mOutputReportDef = reportDef;
     73     }
     74     virtual InputReportDefinition* getInputReportDefinition() final { return mInputReportDef; }
     75     virtual InputReportDefinition* getOutputReportDefinition() final { return mOutputReportDef; }
     76     virtual InputDeviceHandle* getDeviceHandle() final { return mDeviceHandle; }
     77     virtual InputReport* getInputReport() final;
     78 
     79 private:
     80     InputReportDefinition* mInputReportDef = nullptr;
     81     InputReportDefinition* mOutputReportDef = nullptr;
     82     InputDeviceHandle* mDeviceHandle = nullptr;
     83     InputReport* mReport = nullptr;
     84 };
     85 
     86 }  // namespace android
     87 
     88 #endif  // ANDROID_INPUT_MAPPER_H_
     89